Development of Nano-scale Precipitation Strengthened Hot-rolled 590MPa Grade Wheel Steel
超细粉体的团聚机理和表征及消除
收稿日期：２００７－０７－０６，修回日期：２００７－－０９－１０。 基金项目：国家自然科学基金项目．编号：２０５６６０１：内蒙古自治区自然 科学基金项目．编号：２００６０７０１０２０１。 第一作者简介：王觅堂（１９８２一），男，硕士研究生。电话：１３７３９９２３９６９。 Ｅ－ｍａｉｌ：ｂｔｗｍｔ＠１２６．ｃｏｍ。
ＡＡ＝：订１Ｔ２ｃａ＝２１：Ｔｐ而－二２．』２！， 旦 堕了 堡
－４（４盯￡ｏ）
式中。ｈ为颗粒间距；Ｒ为球形颗粒半径；Ｃ为色散作
用能系数；ｐ为密度（个数密度／ｍ，；或质量密度， ｋｇ／ｍ３）；Ｏｔｏ为原子极化率Ｃ２１１１２·Ｊ－ｌ；丘为普朗克常数， ６．６２６ｘ１０＂３４Ｊ·Ｓ；矽为电子的旋转频率，对于原子Ｖ－－－－
Ｗａｎｇ Ｍｉｔａｎｇ，Ｌｉ Ｍｅｉ，Ｌｉｕ Ｚｈａｏｇａｎｇ，Ｈｕ Ｙａｎｈｏｎｇ
（Ｓｃｈｏｏｌ ｏｆＭａｔｅｒｉａｌ ａｎｄ Ｍｅｔａｌｌｕｒｇｙ。Ｉｎｎｅｒ Ｍｏｎｇｏｌｉａ Ｕｎｉｖｅｒｓｉｔｙ ｏｆ Ｓｃｉｅｎｃｅ ａｎｄ Ｔｅｃｈｎｏｌｏｇｙ，Ｂａｏｔｏｕ ０１４０１０。Ｃｈｉｎａ）
Ａｂｅ－ａｃｔ：Ｗｈｅｎ ｔｈｅ ｐａｒｔｉｃｌｅ ｓｌ孺ｏｆｐｏｗｄｅｒ ｄＣＣＴＣＳｂ＇匏ｔｏ ｎａｎｏｓｃａｌｅ．１ｔ ｈａｓ ｍａｎｙ ｎｏｖｅｌ ｐｒｏｐｅｒｔｉｅｓ ａｎｄ ｔｈｅｒｅｆｏｒｅ ｈａｓ ｎｕｍｅｌ＇Ｏｔｉ￥ａｐｐｌｉｃａｔｉｏｎ．Ｈｏｗｅｖｅｒ， ｔｈｅ ａｇｇｌｏｍｅｒａｔｉｏｎ ｉｓ ｃａｌｌｓｅｇｔ ｅａｓｉｌｙ ｉｎ ｔｈｅ ｐｒｏｃｅｓｓ ｏｆｐｒｅｐａｒａｔｉｏｎ ａｎｄ ａｐｐｌｉ－ ｃａｔｉｏｎ ｂｅｃａｕｓｅ ｏｆｉｔｓ ｈｉｇｈｅｒ ｓｕｒｆａｃｅ ｅｎｅｒｇｙ．Ｔｈｅ ｍｅｃｈａｎｉｓｍ ａｎｄｃｈａｒａｏ－ ｔｅｌ＂ｉｚａｔｉｏｎ ａｎｄ ｃｏｌｍｔｅｒｍｅａｓｎｌ－髓ｏｆ ｔｈｅ ａｇｇｌｏｍｅｒａｔｉｏｎ ｏｆ ｕｌｔｒａ－ｆｉｎｅ ｐａｒｄ－
纳米生物学英文单词
纳米生物学英文单词nanometer 纳米nanoparticle 纳米粒子nanomateria 纳米材料lnanobiology 纳米生物学nanotechnology 纳米技术nanocapsule 纳米胶囊nanocapsulation 纳米胶囊化nanocolloidal 纳米溶胶nanosphere 纳米球AFM atomic force microscope 原子力显微镜STM scanning tunneling microscope 扫描扫显微镜nanolabel 纳米标记nano-drug 纳米药物nano-medicine 纳米医药nano-carrier 纳米载体controlled-releaseing system 控制释放系统micro emulsion微乳biodegradable可降解的liposome 脂质体lipid vehicle 脂质小泡magnetic nano particle 磁性纳米微粒solid lipid nanoparticle 固体脂质纳米粒emulsification-evaporation technique 乳化蒸发法high pressure homogenization technique 高压均质法nano-precipitation 纳米沉淀envelop包封disperse 分散drug delivery system 药物递送系统drug incorparation 药物掺入nanostructure 纳米结构nanocrystal 纳米晶体nanosized 纳米尺寸diffusion 扩散diameter 直径polydispersity 多分散性surfactant 表面活性剂self-microemulsion drug delivery system自乳化药物递送系统micelle 胶束molecular cluster 分子簇amphilic 亲脂性的catanionic surfactant 阳离子表面活性剂anionic surfactant 阴离子表面活性剂amphoteric surfactant 两性表面活性剂amphipathic 两亲性disperse system 分散系统aggregate 凝聚reticuloendothelial system 网状内皮系统macrophage 巨噬细胞polylactic acid 聚乳酸poly(lectide-co-glycolide 乳酸、羟基乙酸共聚物poly(D, L-lactide-co-glycolide D，L-乳酸、羟基乙酸共聚物latex 乳液microencapsulattion 微囊包裹chitosan 壳聚糖poly ethylene glycol 聚乙二醇polyethyleneeinine 聚乙二氨oligonucleotide 寡核苷酸colloid 溶胶conjugate 偶连sustained release 持续释放long circulation 长循环gene delivery 基因递送drug-loaded 载药的spray-drying 喷雾干燥phagocytic 吞噬性uptake 吸收gene transfer 基因转导entry 进入lipid fusion 脂质融合cationic liposome 阳离子脂质体non-viral gene transfer system 非病毒基因递送系统polycation liposome 多聚阳离子脂质体glycosylated 糖基化modified 修饰targeting 靶向immunoliposome 免疫脂质体gelator 明胶organogel 有机凝胶cross-link 交联reverse aerogel 反相气凝胶sol-gel 溶胶-凝胶法gelatin 明胶magnetic microsphere 磁性微球magnetic nanoparticle 磁性纳米粒magnetic capsule 磁性微囊magnetic nanosphere 磁性毫微球magnetic liposome 磁性脂质体magnetic emulsion 磁性乳液magnetic starch microsphere 磁性淀粉微球magnetic albumin nanosphere磁性白蛋白毫微球biocompatibility 生物相溶性immunomagnetic microsphere免疫磁性微球immunomagnetic bead 免疫磁性微球superparamagnetic iron oxide 超顺磁性铁氧化物ferrocolloid 铁溶胶bioseperation 生物分离vector 载体graft 偶联bioavailability 生物利用度complexelectrochemical biosensor 电化学生物传感器optical biosenser 光学生物传感器thermal biosensor 热生物传感器piezoelectric biosensor 压电生物传感器intelligent microreactor 智能微反应器reversed micelle 反相胶束nano bioprobe 生物探针biochip 生物芯片microfluidic chip 微流芯片gene chip 基因芯片。
纳米混悬剂（Nanosuspension）
纳米混悬剂（Nano suspension）Nanosuspension research progressAuthor: Wangyu source of scientific information: Literature hits: 531 update time: 2007-4-3[keyword]: nanosuspension, sirolimus, aprepitant, insulinReuters health:At present, more than 40% of the drugs in development of the problem of poor water solubility, which makes the potential varieties not listed or can not give full play to effect. It is difficult to solve the solution problem of low bioavailability of drugs is very urgent. The commonly used solvent solubilization, cyclodextrin and emulsion technology has some limitations, such as the co solvent of organic solvents in toxicity, and drug release; the inclusion of the size of the drug molecules with special requirements; requires high drug solubility emulsion in oil phase.Suspension mixed Muller in 1994 in the research and development of nano (nanosuspensions) can better solve the above problem. The stabilizing effect of the surfactant, the drug particles dispersed in water by grinding or crystallizing technology to form a stable dispersion of nano colloidal. Whether the drug is difficult to dissolve in water or insoluble drugs in water and insoluble in oil, can be prepared by this method to obtain the corresponding nanosuspension. As an intermediate form, nanosuspension can further prepare for oral administration, injection or other dosage forms, so as to improve the absorptionand bioavailability of drugs. And nanosuspension can improve the content of drug formulations, especially suitable for large dose, insoluble drug oral and injection. In addition, the prescription is not included in the carrier and co solvent injection toxicity is very low.Preparation characteristicsColloidal drug nanoparticle suspension is the "pure" dispersion system. Different from the matrix type nano system in the traditional sense, nanosuspension without carrier material, it is through the stabilizing effect of the surfactant, the drug particles of nano scale dispersion system formed in water.Because of the characteristics of nanosuspension, which reflects the unique advantages in various administration (Table 1): such as simple prescription and preparation, is conducive to the rapid screening of active compounds to reduce the cost and improve the drug dissolution and bioavailability, without additional ingredients caused by irritating and toxic effect and low dose volume etc..Table 1 Characteristics of drug nanosuspensions-- -- --Drug dosage form characteristics-- -- --Oral administration of small size increase the drug absorption rate and absorption rate, improve the bioavailabilityMucosal adhesion increased high drug content, prolong the retention time of the gastrointestinal tract, reduce the absorption of individual differencesTo avoid the first pass metabolism, and can be targeted to the treatment of lymphatic system diseasesNo carrier injection or co solvent to reduce the toxicity, reduce the volume of Administration (especially muscle, subcutaneous and intradermal injection)The high drug content of monocyte phagocytosis, reduce toxicity, increase effectivenessBy Twain -80 to apolipoprotein E deposition on the nanoparticles,.The brain endothelial cell receptors promote brain uptakeInhalation of small particle size on alveolar macrophage targeted drug delivery, increased respiratory drug absorption, reduce systemic absorption-- -- --PreparationNanosuspension preparation mainly has two aspects, namely theprescription and technology. The prescription is mainly the choice of type and amount of surfactant, in order to improve the long-term stability of the product; process optimization by adjusting the production process such as pressure and cycle number and other parameters of the high pressure homogenizer, the ideal particle size distribution.Screening of surfactantsIn order to prepare stable nano suspension, avoid agglomeration of nanoparticles and increase of surfactant must be screened properly. The general choice of ionic and nonionic surfactants, nonionic surfactant nanoparticles can be generated between the electrostatic repulsion; non ionic polymer is the steric repulsion between particles. Research shows that the long-term stability of combination of two types of surfactants can make better preparations.Preparing nanosuspension by direct homogenization method, the long-term stability of the type and amount of surfactant affects only the product, does not affect the product size. MUller was prepared by direct homogeneous buparvaquone nanosuspension, adding poloxamer formulation (poloxamer) and polyvinyl alcohol (PVA) 188, 3 months after the drug particle size did not change significantly. But when the drug content is up to 10%, 6 months after the drug has re dispersible difficult problem; prescription such as adding hydrogel or freeze drying products, the product can maintain stability in years.The trace precipitation or emulsifying preparation ofnanosuspension, surfactant type and dosage can affect the formation of crystals, choose different surfactants and their ratio can be obtained with different particle size distribution of the products. Kocbek by emulsification preparation of ibuprofen nanosuspension, prescription containing 0.25% Twain -80 product size of 158.1nm containing 0.5, twelve sodium dodecyl sulfate (SDS) when the particle size is 263.2nm, poloxamer188, PVA as the stabilizer or combination of several kinds of surfactant, the particle sizes of products are the difference.The preparation processPreparation method of nano suspension mainly milling method and ultrasonic method and high pressure homogenization method. The first two kinds of preparation methods are grinding medium or metal residue, and high pressure homogenization method for metal residue, and is easy for industrialized production.Direct homogenization method (direct homogenization)Direct homogenization method is cavitation and cavitation effect caused by high pressure homogenization, micronized drug particles will be further crushed for nano scale particles, while reducing drug particle size polydispersity (PI). To avoid the addition of organic solvent by direct homogenization method,Suitable for both insoluble drugs in water insoluble in oil, and the reproducibility of the process better. Research shows that the particle size is determined by the drug itself hardness,high pressure homogenization pressure and cycle number. By adjusting the pressure and cycle number of homogenizer can get proper particle size distribution of the product. With the increase of circulating pressure, the particle size is reduced, finally can reach a constant value, that is the optimal particle size; dispersion decreases with the increase of cycle number. But reduce the size increase of high pressure homogenization pressure and drug particle and no linear relationship, because the process of high pressure homogenization is the destruction of the drug particles is not perfect crystal, the smaller the particle size, drug crystal more perfect, crushing energy required is higher. The study showed that 1500bar pressure drugs can be crushed to smaller crystals, and the pressure is increased to 4000bar, and did not get finer crystals.Trace precipitation (microprecipitation)Trace precipitation is the first drug is dissolved in an organic solvent miscible with water, then the liquid is added to water, controlling the crystallization conditions to form nanoparticles. The initial crystallization of the crystallization involves the establishment and subsequent nuclear particle growth phase. The preparation of stable nano suspension to high nucleation rate but low growth rate and supersaturation and mechanical stirring speed rate is determined both in temperature and drug. So the trace organic solvent precipitation method to screening and appropriate proportion, and choose the appropriate crystallization temperature and stirring speed.The trace of precipitation is the drug from the dissolved stateinto the suspended state, so the mechanical consumption than the direct homogenization method, suitable for the poor stability of drugs. But due to the use of organic solvents in the preparation process, may lead to organic solvent residues, and may cause drug size change in removing organic solvent.Emulsification method (lipid emulsions)Emulsification method is the first drug prepared O/W nano emulsion, and then control the drug in the droplet precipitated in the prepared nanosuspensions. The drug is dissolved in an organic solvent and insoluble in water (such as ethyl acetate, three acetic acid esters of glycerol and chloroform); then the medicine liquid is added to an aqueous solution containing a surfactant, using high shear mixing to form colostrum, and then use the high pressure homogenizer will further homogenization for nano colostrum milk, finally nanoemulsion added to a large number of water, the organic solvent phase to aqueous phase diffusion, and the precipitation of drug nanoparticles. At the same time the drug precipitation combined with high pressure homogenizer can get better particle size distribution. This method is developed by using paclitaxel albumin nanosuspensions (Abraxane) has been listed in the United states.Physicochemical evaluationWhen the solid particle size less than 1 ~ 2 m, the solubility of particles by the influence of particle size, the solubility of small particles, and the solubility of small particles, which leads to small particles and large particles graduallydissolve gradually become larger, the phenomenon known as Ostwald ripening phenomenon (Ostwald ripening). In order to prevent the occurrence of this phenomenon, must select proper prescription to increase the physical stability of nanosuspension, while optimizing the preparation process to ensure that the final product has a narrow particle size distribution.In addition, in order to study the drug release performance of nano suspension agent, also need the crystal type, the drug release rate were investigated.The particle size and polydispersityResearch shows that in addition to the surfactant, the particle size distribution is an important factor affecting the stability of nanosuspension, therefore in the process of R & D nanosuspension, decided the success of prescription must first examine the grain size and its distribution, and the accelerated test, the influence of temperature and mechanical force on the particle size and distribution effect.According to the different characteristics of nanosuspension, various technique can be used to measure the particle size and polydispersity. Proton correlation spectroscopy (PCs) can detect 3nm ~ 3 m in the range of particles, is commonly used detection particle size and polydispersity (PI < 0.3 has better stability) instrument; laser diffraction (LD) fast detection speed, can detect larger particles or aggregation of nanoparticles (detection range is 0.02 ~ 2000 m), of which 99% of the data on particle sensitive, has important significancein injection detection. In addition, in the preparation of injectable nano suspension, can also use the Kurt particle counting method.Nonionic surfactant and Zeta potentialThe nanosuspension, repulsion between particles is also conducive to long-term stability of the colloidal dispersion. If a single use of ionic surfactants, then achieve the lowest Zeta potential for the stability of about + 30mV; but the combined use of ionic and nonionic surfactant, even if the Zeta potential is lower than the critical value, but also has good physical stability, because the nonionic surfactant with particle steric repulsion effect enough, the Zeta + 20mV can reach as long as the potential.Study on the preparation of crystal form and appearanceIf the drug exists polymorphs, so different crystal types will affect the rate of drug release and drug efficacy. At present, usually by differential scanning calorimetry and X-ray diffraction determination of crystalline state of the drug, can also be observed by nano suspension form.In the preparation of nanosuspensions can according to need to add appropriate suppression of grain, the control of the core drugs in the amorphous state. The general is adding a water soluble substance such as Miglyol is very low, it combined with drugs in reducing the interfacial tension of drug particles, while the formation of dense interface on the surface of the drug, reduce the internal diffusion of drug molecules to theaqueous phase, thereby inhibiting the Ostwald ripening phenomenon, the particle internal stability of amorphous.The solubility and dissolution rateRegardless of the route of administration, the nano suspension solid nanoparticle agent must dissolve into molecules form before they can play a role in treatment, the dissolution rate of drug molecules and the formation rate depends on the nano particles. In the dissolution medium, combined with dialysis and dissolution determination method can be used to determine the dissolution rate of mixed suspension of different nano. According to the Ostwald- Freundlich equation andNoyes-Whitney equation, improve the dissolution rate of the drug can increase the solubility of nanoparticles, so as to further improve the drug absorption and diffusion in the gastrointestinal tract. The determination method of dialysis and traditional saturated solubility (the drug solution under the condition of constant temperature stirring or shaking until the dissolution equilibrium with),The saturation solubility of nanoparticles in nano suspension can be measured. In addition, depending on the size of the drug, ultrafiltration or direct filtration can be used to determine the solubility of the drug.Application exampleIt often takes decades for a pharmaceutical technology to be transformed into an actual product, and a nano suspension is available in just a few years. The first nano crystal patentis at the beginning of 90s by Nanosysterms company (now Elan) application: by 2000 the first nanosuspension products of sirolimus (Rapamune) successfully listed, it is oral tablets, each containing 1mg or 2mg sirolimus, clinical results show its bioavailability than oral solution high 21%; then the first intravenous nanosuspensions by albumin bound paclitaxel nanoparticles injection suspension (Abraxane) is successful, it gets rid of the addition of surfactants Cremophor-EL, to avoid pre drug allergy treatment, improve the compliance of patients. At present, there are many other kinds of nano suspension in clinical research (Table 2).Table 2 formulations of solid particle suspensions listed and developed- - - - - - - - - - - - - - - - - - - --Drug name (trade name) certification research and development company- - - - - - - - - - - - - - - - - - - --Sirolimus (Rapamune) inhibits immune Elan NanosystemsArai Tan (Emend Elan Nanosystems) antiemeticPaclitaxel (Abraxane), metastatic breast cancer, American Life Sciences (AmericanBioscience)Cytokine inhibitors localized enteritis, Elan, NanosystemsDiagnostic agent, contrast medium, Elan, NanosystemsThymectacin anticancer Elan NanosystemsBai Xiaoan (Busulfan) anticancer SkyePharmaBudesonide (Budesonide), asthma, Elan, NanosystemsSilver eczema, atopic dermatitis, NUCRYSTCalcium phosphate herpes mucosal vaccine adjuvant BioSanteInsulin, diabetes mellitus, BioSanteNot publicly resistant to infection with Baxter NANOEDGENot publicly anti-cancer Baxter NANOEDGE- - - - - - - - - - - - - - - - - - - --Advances in drug delivery routes by collaborative pharmaceutical companies- - - - - - - - - - - - - - - - - - - --Wyeth (Wyeth) oral has been listedMerck (Merck) oral has been listedAmerican pharmaceutical partners (American venous phase III Pharmaceutical Partners)Cytokine PharmaSciences phase II clinical oralPhotogen I / II clinical veinNewBiotics./Ilex Oncology I / II clinical veinIntrathecal Supergen phase I clinicalSheffield Pharmaceuticals phase I clinical lungNo local phase I clinicalNo oral phase I clinicalNo oral phase I clinicalStudy on undisclosed pre clinical oral veinStudy on undisclosed pre clinical oral vein-- -- ---epilogueNanosuspension is a generally applicable to insoluble drug formulations, it was originally designed to improve drug bioavailability of insoluble through process and simpleprescription, while avoiding the side effects on patients with a large number of additional components. In recent years, researchers pay more attention to the surface modification agent nanosuspension, can change the objects within the drug pharmacokinetics; in addition, nano suspension of agent technology in peptide and protein drugs in the field is also highly anticipated. I believe, nanosuspension will have a more splendid future.。
纳米颗粒F-SiO2对地层原油中沥青质沉淀抑制效果
大庆石油地质与开发Petroleum Geology ＆ Oilfield Development in Daqing2023 年 12 月第 42 卷第 6 期Dec. ，2023Vol. 42 No. 6DOI ：10.19597/J.ISSN.1000-3754.202208052纳米颗粒F⁃SiO 2对地层原油中沥青质沉淀抑制效果张旭1 张瑞1 马若楠2 吴晓旭1 李希娟1 广怡初1（1.中国石油玉门油田公司老君庙采油厂，甘肃 酒泉735000；2.中国石油玉门油田公司科技信息与对外合作处，甘肃 酒泉735000）摘要： 为明确纳米颗粒对原油中沥青质沉淀的抑制效果及吸附沥青质机理，采用X 射线衍射、傅里叶变换红外光谱、场发射扫描电子显微镜和低温氮气吸附实验方法，开展了沥青质起始沉淀点测定实验和沥青质溶解线及沉淀线测定实验，研究了改性F‑SiO 2纳米颗粒作用下的沥青质起始沉淀点、吸附量及亚稳定区宽度的变化。
结果表明：纳米颗粒对轻质油中沥青质的吸附以单层为主，最大吸附量为0.8 g/g ，而对重质油中沥青质的吸附以多层和大颗粒沥青质聚集体（10~50 μm ）为主，最大吸附量可达8.6 g/g ；F‑SiO 2纳米颗粒增大了沥青质的亚稳定区，推迟了沥青质自发成核的形成时间，延迟了沥青质起始沉淀点，抑制了沥青质沉淀；F‑SiO 2纳米颗粒作用下的重质油沥青质的燃烧残余物质量分数为11.6%，优于轻质油沥青质（52.8 %），证明F‑SiO 2纳米颗粒对重质油中沥青质的吸附及抑制效果好于轻质油。
研究成果为预防沥青质沉淀、缓解沉积伤害提供了理论依据。
关键词：纳米颗粒；沥青质；沉淀；吸附；亚稳定区中图分类号：TE348 文献标识码：A 文章编号：1000-3754（2023）06-0091-08Inhibition effect of F⁃SiO 2 nanoparticles on asphalteneprecipitation in strata oilZHANG Xu 1，ZHANG Rui 1，MA Ruonan 2，WU Xiaoxu 1，LI Xijuan 1，GUANG Yichu 1（ojunmiao Oil Production Company of PetroChina Yumen Oilfield Company ，Jiuquan 735000，China ；2.Science and Technology Information and Foreign Cooperation Division of PetroChina Yumen OilfieldCompany ，Jiuquan 735000，China ）Abstract ：In order to clarify the inhibition effect of nanoparticles on asphaltene precipitation in oil and the mecha‑nism of asphaltene adsorption ， measurement experiment of asphaltene initial precipitation point and measurement experiment of asphaltene dissolution line and precipitation line are carried out by X -ray diffraction （XRD ）， Fourier transform infrared spectroscopy （FTIR ）， field emission scanning electron microscopy （FESEM ） and low -tempera‑ture nitrogen adsorption. Variation of asphaltene initial precipitation point ， adsorption amount and metastable zone width effected by modified SiO 2 nanoparticles are studied. The results show that asphaltene adsorption of nanoparti‑cles in light oil is mainly in single -layer ， with maximum adsorption of 0.8 g/g ， while asphaltene adsorption in heavy oil mainly presents multi -layered and large -particle asphaltene aggregates （10~50 μm ）， with maximum adsorption of 8.6 g/g. F -SiO 2 nanoparticles enlarge asphaltene metastable zone and delay formation time of spontaneous nucle‑ation of asphaltene ， as well as initial precipitation point of asphaltene and inhibit asphaltene precipitation. Mass fraction of asphaltene combustion residue in heavy oil effected by F -SiO 2 nanoparticles is 11.6%， which is betterthan that of asphaltene in light oil （52.8%） and proves F -SiO 2 nanoparticles ’ better adsorption and inhibition on as‑phaltene in heavy oil than in light oil. The research provides theoretical evidence for preventing asphaltene precipi‑收稿日期：2022-08-23 改回日期：2023-02-25基金项目：国家重点研发计划“CO 2驱油技术及地质封存安全监测”（2018YFB0605500）。
纳米制剂
纳米粒子（Nanoparticle）：
Also called ultrafine particles, 1 ~ 100 nm particles or tiny structures in atomic clusters and macroscopic objects at the junction of the transition region.
Moreover, the choice of stabilizer are also closely related to formulations.
2.The physical stability of nano-drug
Stability of Nano-drug ：physical, che
1 nm = ? m
Atom Molecular
Nanoparticle
Macroscopic objects
0.1-1.0 nm
1-100 nm
>1 mm
Properties of Nanoparticles：
surface effect small size effect quantum effect superior performance
物理化学 的角度
sedimentation aggregation crystal growth crystalline state change
2.1 Sedimentation
Nano-drug generally have three kinds of precipitation: agglomeration, loose aggregates and open floc.
粒子稳定的乳液和高内相乳液的研究
中国科学技术大学硕士学位论文粒子稳定的乳液和高内相乳液的研究姓名：李停停申请学位级别：硕士专业：高分子化学与物理指导教师：刘华蓉2011-05 摘要摘要随着纳米技术的发展，纳米粒子在油-水界面的吸附行为及其稳定的乳液越来越受到人们的关注，但目前人们对于此类乳液的研究还不是很完善。
本论文中，我们首先合成了一种新型的两亲性聚合物粒子，将其用于稳定乳液的研究；然后合成了一种AOA 改性的磁性纳米粒子，并将其用于高内相乳液的研究中。
具体的工作内容概括如下：1. 通过反相微乳液法合成了聚（甲基丙烯酸十八酯-co-丙烯酰胺-co-丙烯，酸）这种粒子内部亲水、外部疏水，通过调节油溶性单体和水溶性单体的比例，可以很方便地改善粒子的润湿性。
将上述聚合物粒子用于稳定苯乙烯的正相乳液体系，聚合之后我们得到了尺寸分布较均匀的亚微米级聚苯乙烯微球。
通过研究我们发现，在乳液的制备过程中，刚开始乳化时会形成Pickering 乳液；但是随着时间的延长，大的液滴逐渐消失，聚合物粒子有可能被溶胀、脱落，成为种子球，即发生Pickering 乳液向种子乳液的转变；这是与无机粒子稳定乳液的不同之处。
2. 通过共沉淀法制备磁性纳米粒子，并用12-丙烯酰氧基-9-十八烯酸（AOA）对其进行表面改性，将改性的磁性粒子用于St-DVB 高内相乳液（HIPE）的制备和聚合中。
由于AOA 结构中含有活性双键，经AOA 修饰后的磁性粒子（MPs）可以参与聚合，进一步提高了乳液稳定性和界面结合力；而且，磁性粒子的添加对聚合物多孔材料起到一定的增强作用。
我们研究了MPs 浓度和内水相含量对高内相乳液稳定性和多孔材料结构的影响。
结果表明，当粒子浓度达到20时，材料的杨氏模量达到最大值（69.7 MPa），压缩强度也提高到5.29 MPa。
同时，材料的孔洞尺寸也随粒子浓度的增大而逐渐降低并且尺寸大小趋向均匀。
然而，增加内水相含量会导致材料的机械性能下降，密度降低，孔洞尺寸增加，但是有利于多孔贯通结构的形成。
纳米二氧化锰的制备及其电容性能研究
二氧化锰是一种晶格结构比较复杂的氧化物，目前己知的多种二氧化锰中， 大多数是混合晶型，其氧化程度和水含量都是可变的。所以常用ＭｎＯ。来表示其 分子式，其中ｘ为含氧量，其数值总是小于２Ｅ１１。通常，二氧化锰在其化学组成 上还含有低价锰离子和ＯＨ’，而且有的还含有Ｋ＋、Ｎａ＋、Ｂａ２＋、Ｒｂ＋、Ｌｉ十、Ｎ池＋等 金属离子。晶格常有缺陷，包括隧道和空穴。 １．１．１二氧化锰的结构和分类
水热合成中，ＫＭｎ０４和ＭｎＳ０４在较低摩尔比下反应后主要得到隧道结构的 ａ－Ｍｎ０２；较高摩尔比时产物主要为层状结构的６．Ｍｎ０２，后者的其层状结构更有 利于矿或Ｎａ＋的嵌入和脱嵌，因此其电容性能较好。ＫＭｎ０４和ＭｎＳ０４在起始摩尔 比为１：１时，１２０℃水热反应６ｈ后，制得直径约２０～３０ｎｍ，长ｌｇｍ左右的均匀 ｅｔ－Ｍｎ０２纳米棒。ＫＭｎ０４和ＭｎＳ０４的摩尔比为３：’ｌ，１２０℃水热反应２ｈ时，所得 样品为纳米尺度的花状薄片，它属于层状结构的６．Ｍｎ０２。样品结晶性较差，平 均粒径约为８．３ｎｍ，在Ｏ．５ ｍｏｌ·Ｌ～Ｎａ２Ｓ０４溶液中，．０．２～１．０Ｖ（ｖｓ．ＳＣＥ）电位范围内， 以７０ｍＡ·ｇＪ恒流充放电测得其比容量为２５９．１９ Ｆ．９１。
ＸＲＤ，ＴＥＭ，ＢＥＴ，ｃｙｃｌｉｃ ｖｏｌｔａｍｍｅｔｒｙ（ＣＶ）ａｎｄ ｃｈｒｏｎｏｐｏｔｅｎｔｉｏｍｔｒｙ ｗｅｒｅ ｕｓｅｄ ｔｏ ｓｔｕｄｙ ｔｈｅ ｐｈｙｓｉｃａｌ ａｎｄ ｃｈｅｍｉｃａｌ ｐｒｏｐｅｒｔｉｅｓ ａｎｄ ｅｌｅｃｔｒｏｃｈｅｍｉｃａｌ ｐｅｒｆｏｒｍａｎｃｅｓ ｏｆ ｔｈｅ
ａｄｊｕｓｔｅｄ ｔＯ ６．ｆｏｌｌｏｗｅｄ ｂｙ ａｎｎｅａｌｉｎｇ ｔｈｅ ｄｒｙ—ｇｅｌ ａｔ ３００℃．Ａｎｄ ｔｈｅ ａｓ－ｐｒｅｐａｒｅｄ ＭｎＯｘ ｗａｓ ａｃｉｄｉｆｉｅｄ ｂｙ Ｈ２Ｓ０４，ｆｉｎａｌｌｙ Ｍｎ０２ ｎａｎｏ—ｆｉｂｅｒｓ ｗｉｔｈ ｓｌｉｇｈｔｌｙ ａｇｇｒｅｇａｔｅ ｗｅｒｅ
沉淀法制备氧化锌粉体_郑兴芳
沉淀法制备氧化锌粉体郑兴芳，郭成花，郑建国（临沂大学化学化工学院，山东临沂276005）摘要：以碳酸钠和硫酸锌为原料，采用沉淀法制备前驱体碱式碳酸锌，前驱体经过热分解得到氧化锌粉体。
采用热重分析（TG-DTG-DTA）、X射线衍射（XRD）、红外光谱（IR）和扫描电镜（SEM）等方法对前驱体和产品氧化锌进行表征。
结果表明：制备的前驱体为碱式碳酸锌Zn4（OH）6CO3；以水、乙二醇为溶剂及聚乙二醇（PEG）为分散剂，均可制备出较为纯净的氧化锌；乙二醇为溶剂和PEG为分散剂，改善了氧化锌的形貌和分散性，避免了氧化锌团聚。
关键词：氧化锌；制备；沉淀法中图分类号：TQ132.4文献标识码：A文章编号：1006-4990（2012）03-0019-03Preparation of zinc oxide powder by precipitation methodZheng Xingfang，Guo Chenghua，Zheng Jianguo（School of Chemistry and Chemical Engineering，Linyi University，Linyi276005，China）Abstract：The precursor，basic zinc carbonate was obtained by precipitation method with ZnSO4and Na2CO3as raw materials. Then ZnO powders were prepared after pyrolysis of precursor.Precursor and ZnO powders were characterized and analyzed by TG-DTG-DTA，XRD，IR，and SEM respectively.Results showed that the precursor was Zn4（OH）6CO3；pure ZnO can be both prepared by water and ethylene glycol as solvents and by PEG as dispersant；and the morphology and dispersibility of ZnO could be improved and agglomeration could be avoided with ethylene glycol as solvent and PEG as dispersant.Key words：zinc oxide；preparation；precipitation method纳米氧化锌由于其粒子尺寸小、比表面积大、具有明显的表面与界面效应等特点，在化学、光学、生物和电学等方面表现出许多独特的优异的物理和化学性能，被广泛应用于变阻器、气体敏感材料、电材料以及光材料等重要领域。
纳米材料专业英语词汇
纳米尺度nanoscale纳米基元nano-unit纳米结构单元nanostructure unit纳米材料nanomaterial纳米技术nanotechnology纳米结构体系nanostructure system纳米组装体系nanostructure assembling syst em纳米器件nanodevice碳纳米管carbon nanotubes原子团簇atom cluster单分散颗粒[系] monodispersed particle纳米颗粒nanoparticle团粒aggregate纳米粉体nano-powder纳米纤维nano-fibre纳米薄膜nano-film纳米块体nano-bulk纳米孔nano-pore纳米晶体材料nanocrystalline material纳米非晶材料amorphous nanomaterial纳米准晶材料quasi-crystal nanomaterial金属纳米材料metallic nanomaterial无机非金属纳米材料inorganic non-metallic na nomaterial高分子纳米材料polymer nanomaterial纳米复合材料nanocomposites结构纳米材料structured nanomaterial功能纳米材料functional nanomaterial生物医用纳米材料biomedical nanomaterial 小尺寸效应small-size effect表面效应surface effect量子尺寸效应quantum size effect宏观量子隧道效应macroscopic quantum tun neling effect惰性气体沉积法inert gas deposition物理粉碎法physics grinding高能球磨法high energy ball mill溅射法sputtering物理粉碎法physics grinding爆炸法explosion喷雾法spraying冷冻干燥法freeze drying化学气相沉积法chemical vapor deposition沉淀法precipitation水热合成法hydrothermal synthesis溶胶-凝胶法sol－gel辐射化学合成法radiation chemical synthesis 快速凝固法rapidly quenching强烈塑性变形法severe(intense) plastic deform ationh非晶晶化法amorphous solid crystallizatio n溅射法sputtering非晶晶化法crystallization of amorphous soli d原位复合法in-situ composite插层复合法intercalation hybrids微乳液法micro emulsion模板合成法template synthesis自组装法self-assembly石墨电弧放电法graphite arc discharge快速凝固法rapidly quenching表面处理surface treatment表面修饰surface decoration稳定化处理passivating treatmentX射线衍射法X-ray diffractometry扫描探针显微镜scanning probe microscopy 扫描隧道显微镜scanning tunneling microscop y,扫描近场光学显微镜scanning near-field optica l microscopy,原子力显微镜atomic force microscopy扫描电容显微镜scanning capacitance microsc opy磁力显微镜magnetic force microscopy扫描热显微镜scanning thermal microscopy X射线衍射法X-ray diffractometryX射线衍射线宽化法X-ray diffractometry line b roadeningX射线小角度散射法small angle X-ray scatteri ng透射电子显微镜法transmission electron micro scopy ,TEM透射电镜法TEM method扫描电子显微镜法scanning electron microsco py , SEM扫描电镜法SEM method拉曼光谱法raman spectrometry红外吸收光谱法infrared absorption spectrosc opy穆斯堡尔谱法mossbauer spectrometry光子相关谱法photon correlation spectroscop yBET法BET压汞仪法mercury porosimetry纳米压痕仪nano impress扫描探针显微法scanning probe microscopy, 扫描隧道电子显微法scanning tunneling electr on microscopy,STM扫描近场光学显微法scanning near-field optica l microscopy，SNOM原子力显微法atomic force microscopy，AFM 扫描电容显微法scanning capacitance micros copy, SCM扫描热显微法scanning thermal microscopy, STHM场离子显微法field ion microscopy, FIM磁力显微法magnetic force microscopy, MFM 激光干涉仪laser interferometer激光衍射/散射法laser diffraction and scatterin g离心沉降法centrifugal sedimentation。
选择性合成碱式碳酸钴三维结构及其热转化产物尖晶石结构的四氧化三钴三维超结构
Selective Synthesis of Cobalt Hydroxide Carbonate 3DArchitectures and Their Thermal Conversion to CobaltSpinel 3D SuperstructuresBenxia Li, Yi Xie, Changzheng Wu, Zhengquan Li, Jin ZhangNano-materials and Nano-chemistry, Hefei National Laboratory for Physical Sciences at Microscale, University of Science & Technology of China, Hefei, Anhui 230026, P. R. China Email: yxielab@AbstractHighly uniform 3D sisal-like, dandelion-like and rose-like architectures of cobalt hydroxide carbonate with orthorhombic or monoclinic phase were synthesized through a facile selected-control hydrothermal process at 100 °C, 140 °C and 180 °C, respectively. In addition, cobalt spinel Co3O4 superstructures with broom-like, dandelion-like and rose-like morphologies were obtained by thermal conversion of the corresponding precursor of 3D architectures based on the thermal analysis results, and TEM images show that all Co3O4 superstructures were assembled by nanoparticles. The optical absorption properties of the Co3O4 superstructures were investigated and the results indicate that the superstructures are semiconducting with transitions corresponding to 775nm and 530 nm in the UV-visible spectroscopy.Keywords:cobalt hydroxide carbonate; 3D architectures; superstructures; cobalt spinel.1 IntroductionIt is generally believed that special morphologies and crystallographic forms are responsible for their properties, and thus, controlling the anisotropic inorganic materials at the mesoscopic level has attracted intensive interest presently and become a studying focus in chemical synthetic fields. Recently, the ordered patterned aggregation of nanoparticles are promising candidates in several fields of research and application, therefore, the building and patterning of inorganic nanoparticles into 2D and 3D organized structures by manipulation of individual units is a potential route to utilizing their chemical, optical, catalytic, magnetic and electronic properties.[1,2] Much effort has been made in the fabrication of patterns of well-arranged nanostructures, especially the arrangement of one-dimensional nanostructures because of their interesting physical properties and potential applications in many areas.[3] The oriented growth of nanostructures is difficult in a certain extent because it usually requires additional templates to act as a support, such as porous alumina and polymer additives to control the direct growth.[4,5] However, the introduction of templates and substrates introduces heterogeneous impurities and complicates the synthesis process, which may restrict the wide development of researches and applications. Thus it is very significant to develop facile, mild, easily-controlled methods to synthesize novel patterns through self-assembly of nanoparticles.Co3O4 has been extensively investigated for the last two decades in view of their application as gas sensors, catalysts, magnetic materials, electrochromic devices, and high-temperature solar selective absorbers.[6-10] In recent years, remarkable process has been made in the synthesis of cobalt spinel Co3O4 with different morphologies and by various methods including microemulsion method, reduction/oxidation route, homogeneous precipitation, and metal organic chemical vapor deposition (MOCVD).[11-15] However, there has been no reports about the synthesis of 3D Co3O4 nanostructures.Synthesis of novel nanostructures from suitable precursors is an available and convenient method in the synthesis of nanomaterials, which can help control morphology of the nanostructures through treating the as-obtained precursor with desired morphologies.[16] In the case of Co3O4, it is well known that H2O and CO2 are released from cobalt hydroxide carbonates at elevated temperature, and thus cobalt hydroxide carbonates are more desirable precursors for the cobalt spinel because there are no toxic byproducts during their pyrogenation process.[17] Thus, it is possible to fabricate Co3O4 nanostructures with novel morphologies through as-obtained cobalt hydroxide carbonates precursors.In this work, we successfully synthesized three novel kinds of cobalt hydroxide carbonate 3D architectures through a facile selected-control hydrothermal process via the direct reaction between only cobalt salt (CoCl2·6H2O) and urea under different temperatures (100o C, 140o C and 180o C). The corresponding cobalt spinel Co3O4 3D superstructures were obtained by thermal conversion and oxidization of the 3D architectures cobalt hydroxide carbonate, and the obtained Co3O4 3D superstructures inherit the morphologies of their precursors to some extent. There are some significative features in this work: First, this is the first report of 3D sisal-like, dandelion-like and rose-like architectures of cobalt hydroxide carbonate with orthorhombic or monoclinic phase, and the synthesis process is simple andeasy-manipulated. Then, this is also the first report of 3D Co3O4 superstructures with broom-like, dandelion-like and rose-like morphologies which are further assembled by uniform nanoparticles as observed from their microstructures.2 Experimental2.1 Methods of SynthesisSynthesis of cobalt hydroxide carbonate 3D architectures with different morphologies. All chemical reagents were of analytical grade and used as received without purification. In a typical procedure, 1 mmol CoCl2·6H2O and 3 mmol urea were added to distilled water (12 mL) under stirring to form homogeneous transparent solution. The solution then was transferred into a stainless steel autoclave with a Teflon liner of 15 mL capacity, and heated in an oven at 100°C (140°C or 180°C) for 10 h. After the autoclave was air-cooled to room temperature, the resulting pink product was filtered, washed with distilled water and absolute ethanol for several times, then dried under vacuum at 60°C for 4h.Thermal Conversion to Co3O4 3D superstructures. The samples of cobalt hydroxide carbonate were further heat-treated in static air. The temperatures of pyrogenation were set above those at which the stable weight was obtained in TGA measurements (see Figure 2). In a typical procedure, 1 mmol as-obtained cobalt hydroxide carbonate sample (obtained at 100o C, 140o C or 180o C respectively) was put into a corundum crucible with capacity of 40 mL which was heated to 500o C for 5 hours at a heating rate of 5°C/min, and then cooled to room temperature. The black powder was collected for the following characterization.2.2 CharacterizationThe samples were characterized by X-ray powder diffraction (XRD) with a Japan Rigaku D/max rA X-ray diffractometer equipped with graphite monochromatized high-intensity Cu-Ka radiation (λ = 1.54178 Å). The accelerating voltage was set at 50 kV, with 100 mA flux at a scanning rate of 0.06 °/s. The morphologies and sizes of the products were observed by scanning electron microscopy (SEM) and field emission scanning electron microscopy (FE-SEM), respectively. The field emission scanning electron microscopy (FE-SEM) images were taken on a JEOL JSM-6700FSEM. The transmission electron microscopy (TEM) images and electronic diffraction (ED) patterns were taken on a Hitachi Model H-800 instrument with a tungsten filament, using an accelerating voltage of 200 kV. Thermal gravimetric analysis (TGA) of the as-synthesized samples was carried out on a Shimadzu TA-50 thermal analyzer at a heating rate of 10 K min-1 from room temperature to 700°C in air. X-ray photoelectron spectrum (XPS) was collected on an ESCALab MKII X-ray photoelectron spectrometer, using nonmonochromatized Mg Ka X-ray as the excitation source and C 1s (284.6 eV) as the reference line. Optical absorption spectrum was recorded on a Shimadzu UV-2401PC UV-vis recording spectrophotometer.3. Results and discussion3.1 Phases and morphologies of the cobalt hydroxide carbonate 3D architectures.X-ray power diffraction (XRD) pattern. Morphologies of the three products are determined by scanning electron microscopy (SEM) and field emission scanning electron microscopy (FE-SEM). The systems at different temperatures produce different morphologies: sisal-like obtained at 100oC, dandelion-likeFigure 1. The morphologies of as-obtained cobalt hydroxide carbonates: FESEM images (A-B) of the sisal-like architectures obtained at 100o C; TEM images (C) of two typical nanorods in the sisal-like architectures, inset SAED from a single nanorod;SEM and FESEM images (D-E) of the dandelion-like architectures obtained at 140o C;TEM images (F) of several typical nanorods in the dandelion-like architectures, inset SAED from a single nanorod; SEM images (G-H) of the rose-like architectures obtained at 180o C.obtained at 140o C and rose-like obtained at 180o C, as shown in Figure 1. XRD patterns of the samples shown in Figure 2 identify the phases. All the peaks in sisal-like and dandelion-like products prepared at 100°C and 140°C can both be perfectly indexed to the orthorhombic cobalt basic carbonate phase with constants of a =8.914 Å, b =10.294 Å, c =4.458 Å, which are consistent with the reported values of the orthorhombic Co(OH)x(CO3)0.5⋅0.11H2O (JCPDS card, No.48-0083). All the peaks in the rose-like product prepared at 180°C can be perfectly indexed to the monoclinic cobalt hydroxide carbonate phase with constants of a =9.268 Å, b =12.162 Å, c =3.347 Å, which are very close to the reported values (JCPDS card, No. 29-1416, Co 2(OH)2CO 3 ).Morphologies of cobalt hydroxide carbonate nanostructures. The FE-SEM image of the product obtained at 100o C (Figure 1A) shows that sample consists of uniform 3D sisal-like architectures with average diameter of 15 μm. From the magnified FESEM image of a single sisal (Figure 1B), one can find that this sisal-like architecture is formed by many needle-like nanorods growing radially from the core; and these nanorods were about 200-500 nm wide and 5-8 μm long. The TEM (Figure 1C) shows two typical nanorods growing from the core and inserted SAED pattern of a single nanorod shown in Figure 1C indicates that these nanorods are single crystals with the growth direction along [010].Under the raised temperature of 140°C, 3D dandelion-like architectures (Figure 1D-F) were obtained. Figure 1D depicts that the product is composed of dandelion-like spheres with diameter of 5-8 μm. More details about the structure of a dandelion-like sphere can be observed from Figure 1E, which indicates that10203040506070AB C(023)(450)(412)(142)(060)(340)(050)(231)(301)(040)(221)(300)(220)(020)(100)(052)(451)(351)(170)(520)(510)(350)(160)(430)(250)(150)(330)(240)(031)(040)(140)(130)(120)(020)I n t e n s i t y (a .u .)2θ (degree)Figure 2. The XRD patterns of the as-obtained cobalt hydroxide carbonate. (A) sisal-like architectures obtained at 100o C; (B) dandelion-like architectures obtained at 140o C; (C) rose-like architectures obtained at 180o C.the 3D architectures were aggregated by well-arranged nanorods with uniform diameters about 100 nm and length up to 4 μm, growing from a core. Compared with the sisal-like architectures, the nanorods without sharp ends in the dandelion-like architectures were congregated more compactly into a sphere from the core. The TEM image (Figure 1F) shows several typical nanorods growing from a core and inserted SAED demonstrates the single-crystal nature of the nanorods with the growth direction of [010].At the elevated temperature of 180°C, the phase and morphology of the product obtained were quite different from the other two samples obtained at lower temperatures. The panoramic morphology of this sample (Figure 1G) indicates many rose-like assemblies with sizes ranging between 60 and 80 μm formed by many petal-like flakes. Figure 1H shows a typical magnified SEM image of the rose-like architectures and the petal-like flakes with different sizes congregate layer by layer from a core to form a rose-like architecture.Thermal Analysis for the cobalt hydroxide carbonate 3D architectures. The TGA and DrTGA study on the sisal-like and dandelion-like cobalt hydroxide carbonate architectures indicate that under air atmosphere, the sisal-like and dandelion-like cobalt hydroxide carbonate architectures have very similar thermal behaviors. Typically, one TGA and DrTGA curve is shown in Figure 3A, which shows a obvious weight loss peak at the temperature range of 200-300°C and a little peak at 310-360°C. The weight losses corresponding to the two steps in TGA are about 21.17% and 2.97%, respectively. The first weight loss ascribes to a simultaneous removal of structural water and carbon dioxide by dehydroxylation and decomposition of carbonate groups, and the second may be due to the continuing decomposition of some residual carbonate groups. Whereas in DrTGA curve of the rose-like cobalt hydroxide carbonate architectures (Figure 3B), there is a well-defined peak at 260-357°C, which may be due to a simultaneous removal of hydroxyl and carbonate anions, and the total weight loss is about 22.32%. According to the thermal analysis datum, the rose-like monoclinic cobalt hydroxide carbonate architectures decompose at higher temperature, indicating that the monoclinic cobalt hydroxide carbonate is thermally more stable than its orthorhombic polymorph, which is consistent with the fact that the monoclinic rose-like cobalt hydroxide carbonate architectures formed under higher temperature.1002003004005006007007580859095100105A DrTGA%TGAw e i g h t l o s s (a r b . u n i t )Temp(oC)1002003004005006007007580859095100105DrTGATGA %w e i g h t l o s s (a r b . u n i t )Temp(oC)B3.2 Phases and morphologies of the thermal conversion products of Co3O4.X-ray power diffraction (XRD) pattern. XRD patterns of the pyrolysis products from three precursors of cobalt hydroxide carbonate are shown in Figure 4, from which one can clearly see that three pyrolysis products show identical phase. All the reflection peaks can be indexed to pure cubic phase of Co 3O 4 spinel with lattice parameter a=8.075 Å, which are very close to the reported value (a = 8.083 Å) (JCPDS: 42-1467). No other peaks for impurities were detected.Figure 3. TGA and DrTGA curves of the as-obtained cobalt hydroxide carbonates (A) sisal-like or dandelion-like architectures obtained at 100o C; (B) rose-like architectures obtained at 180o C.Figure 4. XRD patterns of thermal conversion products Co 3O 4: (A) obtained from the pyrolysis of the sisal-like architectures, (B) obtained from the pyrolysis of the dandelion-like architectures, (C) obtained from the pyrolysis of the rose-like architectures.XPS measurement. Further evidence for purity and composition of the samples is obtained by XPS measurements. Figure 5 shows the typical Co 2p and O 1s core spectrum. The two core lever peaks at 780.5 and 795.7 eV in Figure 5A correspond to Co 2p3/2 and Co 2p1/2, respectively, characteristic of the Co 3O 4 phase. [18] The O 1s core spectrum (figure 5B) shows three peaks at 530.4 and 531.8 and 533.2 eV, respectively, which can be attributed to absorbed gaseous oxygen ( 530.4 eV) and O 2- combined with Co 2+ (531.8 eV) ,Co 3+(533.2 eV) .770780790800810Co 2p 1/2Co 2p 3/2AR e l a t i v e t e n s i t y (c p s )Binding energy (eV)526528530532534536538540BO 1sR e l a t i v e i n t e n s i t y (c p s )Binding energy (eV)Morphologies of Co 3O 4 nanostructures. Morphologies of the three pyrolysis products Co 3O 4 are shown in Figure 6A-I. Figure 6A-C belong to the as-obtained Co 3O 4 from pyrolysis of the sisal-like cobalt hydroxide carbonate architectures at 500°C. The morphology (Figure 6A) of the final product depicts that most of them are broom-like superstructures with average length of 10 μm and width of 5 μm, and these broom-like superstructures consist of many nanorods with different lengths radiating from the center. Further details shown in Figure 6B reveal that the nanorods look like bead-like chains formed by lots of nanoparticles interconnected with each other along a definite direction. The TEM image of a single Co 3O 4 nanorod shown in Figure 6C demonstrates that the nanorod, with 250 nm wide in the middle and 2.5 μm long, are flat and has a sharp end, which is consistent with that of its precursor observed in Figure 1C, but it is interesting that the nanorods split into several nanorods with smaller width. The insert of Figure 6C shows a magnified TEM image of a nanorod formed with uniform nanoparticles, which indicates these nanoparticles were orderly arranged into a line, and the observed average size of the particles is about 100-150 nm. This nanostructure was investigated by the electron diffraction (ED) patterns (insert b in Figure 6C) in which the electron diffraction spots separate clearly, which indicates these nanoparticles are well crystallized and self-assembled along a desired pattern.Figure 5. High-resolution XPS core spectrum: (A) Co 2p in the oxide sample; (B) O 1s.Figure 6D-F show the FESEM image of the dandelion-like Co 3O 4 superstructures obtained from pyrolysis of the dandelion-like cobalt hydroxide carbonate architectures at 500°C. The typical panoramic morphology of some assemblies shown in Figure 6D indicates that all the 3D dandelion-like structures with diameter of 6-10 μm are assembled by well-aligned nanorods, which is similar to its corresponding precursor. But the magnified FESEM image of a part of the dandelion-like Co 3O 4 superstructures (Figure 6E) shows that the nanorods look like bead-like chains assembled by many nanoparticles. Figure 6F shows a TEM image of a nanorod formed by uniform nanoparticles with sizes of about 100 nm which were orderly arranged into a line. And the SAED pattern (insert in Figure 6F) consistent with insert b in Figure 6F indicates these uniform nanoparticles are self-assembled along a desired pattern.Figure 6G-I show the representative FESEM images of the product obtained by pyrolysis of the rose-like cobalt hydroxide carbonate architectures at 500o C. The image with low magnification (Figure 6G) reveals that the as-prepared product consists of a large scale of highly uniform rose-like superstructures with average size of 60 μm, which perfectly inherit the morphologies of their precursors. However, from anFigure 6. FESEM images （A, B ） of broom-like Co 3O 4superstructures obtained from the pyrolysis of the sisal-like cobalt hydroxide carbonate architectures; TEM image （C ）of a nanorod formed with nanoparticles, inserted SAED and a amplified part of the nanorod. FESEM images (D, E) of the dandelion-like Co 3O 4superstructures obtained from the pyrolysis of the dandelion-like cobalt hydroxide carbonateimage with high magnification (Figure 6H), it is found that these flakes in fact are assembled with many uniform nanoparticles distributing on two-dimension plane, which is different from their precursors of rose-like cobalt hydroxide carbonate architectures. The TEM image (Figure 6I) of a flake further confirms that the flake consists of many particles with average size about 80 nm, and the inserted SAED pattern taken on the flake exhibits diffuse polycrystalline ring patterns, which may attribute to the relatively small size of the nanoparticles and their two-dimension dispersion. The result of SAED also further confirms that these flakes are constructed from crystalline Co 3O 4 nanoparticles. 3.3 Possible formation mechanismFormation mechanism of the precursors: cobalt hydroxide carbonates architectures. In previous reports, the synthesis of the metal hydroxide carbonates usually involves precipitation of metal salts with an alkaline carbonate in the appropriate pH range of 7 to 9, [19] while these reactions are too rapid to control the crystal growth. Urea, (NH 2)2CO is a nonionic, nontoxic, cheap, stable, crystalline, and water soluble compound. It decompose to release NH 3 and CO 2 at about 70 o C, then NH 3 and CO 2 hydrolyzed to produce the precipitators OH - and CO 32- which slowly deposit metal ion, and thus homogeneous precipitation of metal salt by urea hydrolysis can overcome the faults brought by directly adding precipitator into solution.The formation of cobalt hydroxide carbonate involved a hydrolysis-precipitation process, in which urea afforded simultaneously hydrolysis-precipitation to bivalent Co 2+ ions. The main reactions in the system can be expressed as follows.232222CO NH O H NCONH H +→+ (1) −−+→+H CO O H CO 22322 (2)−++→+OH NH O H NH 423 (3)The formation of orthorhombic cobalt hydroxide carbonate phase can formulate as:Co2+ + xOH - + 0.5CO 32- + 0.11H 2O Co(OH)x (CO 3)0.5⋅0.11H 2O (4)At the elevated temperature of 180°C, the reaction can be expressed as follow:2Co 2+ + 2OH - + CO 32-Co 2(OH)2CO 3 (5)The formation of the 3D architectures relates to the experimental parameters as well as thermodynamics and kinetics control on the reaction between metal salts and urea, which are well-known factors influencing the crystal growth. The kinetics is modulated by adjusting the temperature and the concentration of reagents, which control the hydrolysis rate and ratio, thus controlling the nucleation and growth processes. At higher temperature, the thermally more stable product, monoclinic Co 2(OH)2CO 3, was obtained through the reaction expressed in Equation (5).As these cobalt hydroxide carbonate 3D assemblies formed spontaneously and neither templates nor surfactants were used to control the process of crystallization in our experiment, a possible formationprocess was supposed. At first, many nuclei initially formed in the homogeneous solution at the beginning of the reaction. Then, as the concentration of the reactants became lower, these nuclei preferentially grew along the [010] direction to form 1D nanorods if the chemical environment constantly feed resource for cobalt basic carbonate. Therefore, the 3D architectures could form by these nanorods grow epitaxially along with the [010] direction from the nuclei formed initially, for which the TEM images (Figure 3C, 3G) provided direct evidences that these nanorods grew from a common core.The morphologies of cobalt hydroxide carbonate 3D nanostructures obtained at different temperatures have elucidated that reaction temperature also plays a crucial role in the growth process of cobalt hydroxide carbonate 3D assemblies. As the reaction temperature was elevated from 140°C to 180°C, the morphologies of cobalt hydroxide carbonate 3D nanostructures have changed greatly in their structures and sizes. Kinetics theory gave us implication that temperature influences greatly on the rate of hydrolysis, nucleation as well as on the growth processes. From the thermodynamic and crystal-symmetry arguments, the monoclinic Co2(OH)2CO3 is thermally more stable, and thus increasing the temperature to 180°C in this approach obtained the 3D rose-like architectures of monoclinic cobalt hydroxide carbonate. In addition, the XRD pattern of the rose-like cobalt hydroxide carbonate architectures shows that the diffraction intensity of the (020) plane are stronger than the reported values, which indicates that the crystal shape anisotropy and the growing orientation of the rose-like cobalt hydroxide carbonate were in the (020) plane perpendicular to the second symmetrical axis of the monoclinic crystal to form 2D flakes. These flakes epitaxially grow from a core and thus aggregate into a rose-like structure.Formation mechanism of Co3O4 superstructures. Upon the pyrolysis of the obtained cobalt hydroxide carbonate samples at 500°C in air, corresponding Co3O4 superstructures were obtained. As indicated from FESEM images (Figure 6), it is observed that the 3D superstructures of Co3O4 approximately maintain the morphology of their corresponding precursors. Seen from the detailed structures, these Co3O4 3D superstructures were built by many uniform nanoparticles which were interconnected along the original directions of the cobalt hydroxide carbonate nanostructures. In addition, one can find that the sisal-like cobalt hydroxide carbonate architectures changed into broom-like superstructures after heat-treated at 500°C for 5h, which is possibly because that the core of the sisal-like architectures is relatively small, and thus when heated at 500°C the sisal-like architectures split into nanorod-bundles. In the other two structures, the nanorods or flakes combine more compactly and the main shapes keep unaltered after heat-treated. Furthermore, in the XRD patterns of Co3O4 superstructures, the intensities of all the reflection peaks are identical with that of the reported values, which are characteristic of the nanoparticles in the Co3O4 superstructures.As indicated in TGA/DrTGA results (Figure 2), the precursor cobalt hydroxide carbonate decomposed to release H2O and CO2 when they were heated above 200°C (or 263°C) in air. The elimination of hydroxyl and carbonate groups from the precursors has great influence on the crystallinity of Co3O4, and the formation of new crystalline phase caused the disruption of the original rod-like or flake-like morphology and led to the architectures formed with nanoparticle array. In the other hand, H2O and CO2 were released in-situ from the precursors of cobalt hydroxide carbonate during the process of the precursors decomposing,and thus the produced Co 3O 4 nanoparticles remain the relative positions along the patterns of their corresponding precursors. This may be the primary reason for the phenomena that these Co 3O 4 nanoparticles have a predominant assembling along 1D direction (or 2D plane) instead of monodisperse nanoparticles.3.4 The optical properties of as-obtained Co 3O 4 products.The optical absorption property of Co 3O 4 products was investigated with room-temperature (RT) by UV-visible spectroscopy (Figure 7), when ethanol is used as a reference. The Co 3O 4 is a p-type semiconductor [21] and its optical band gap can be obtained from the spectra elaboration. The UV-Vis spectra of the three samples are similar except some tiny difference which may contribute to their different sizes and morphologies. The UV-Vis spectroscopy result shows that there are two absorption bands at about 530 nm and 775 nm, respectively. It should be attributed to the valence-to-conduction-band transition in Co 3O 4, and the results are in agreement with the Co 3O 4 band structure.[14b, 21]4. Conclusion and Future worksIn conclusion, we successfully synthesized 3D architectures of cobalt hydroxide carbonate through a facile selected-control hydrothermal process via the direct reaction between only cobalt salt (CoCl 2·6H 2O)Figure 7. UV-visible spectroscopy of Co 3O 4superstructures: (A) obtained from the pyrolysis of the sisal-like precursor, (B) obtained from the pyrolysis of the dandelion-like precursor, (C) obtained from the pyrolysis of the rose-like precursor. 400500600700800C B A 775 nm530 nm I n t e n s i t y wavelength (nm)and urea under different temperatures (100°C, 140°C and 180°C), in which the cobalt hydroxide carbonate 3D nanostructures with orthorhombic or monoclinic phase and morphologies of sisal-like, dandelion-like and rose-like can be selectively prepared, respectively. The thermal stability of these nanostructures was studied and compared with thermal analysis data. In addition, cobalt spinel Co3O4 superstructures with broom-like, dandelion-like and rose-like morphologies were correspondingly obtained by pyrolysis of the 3D architectures of cobalt hydroxide carbonate precursors. Possible mechanism was proposed to elucidate the formation of cobalt hydroxide carbonate architectures and their pyrolysis product of the Co3O4 superstructures. The optical absorption properties of the Co3O4 nanoparticles were investigated and the results indicate that the nanoparticles are semiconducting with transitions corresponding to 775 nm and 530 nm in the UV-visible spectroscopy. These novel Co3O4 nanostructures, which own the highly specific area on the surface of the particles, may bring some novel and unexpected properties, for example, molecular sieves and catalysts, especially for the electrochromic devices, and so on.AcknowledgementsThis work was supported by Specialized Research Fund for the Doctoral Program of Higher Education, the National Natural Science Foundation of China, Chinese Ministry of Education and Chinese Academy of Sciences.References[1] a) L. L. Beecroft, C. K. Ober, Chem. Mater.1997,9, 1302; b) C. B. Murray, C. R. Kagan, M. G.Bawendi, Science1995, 270, 1335.[2] O. Vidoni, K. Philippot, C. Amiens, B. Chaudret, O. Balmes, J. O. Malm, J. O. Bovin, F. Senocq, M.Casanove, Angew. Chem. Int. Ed., 1999, 38, 3736.[3] a) A. M. Morales, C. M.Lieber, Science1998, 279, 208 ; b) W. Q. Han, S. S. Fan, Q. Q. Li, Y. D. Hu,Science1997, 277, 1287; c) C. Feldman,; H. O. Jungk, Angew. Chem.2001, 13, 372; d) H. Yu, P. C.Gibbons, K.F. Kelton, W. E. Bubro, J. Am. Chem. Soc.2001, 123, 359.[4] a) H. Cao, Z. Xu, H. Sang, D. Sheng, C. Tie, AdV. Mater.2001, 13, 121; b) C. Liu, J. A. Zapien, Y. Yao,X. Meng, C. S. Lee, S. Fan, Y. Lifshitz, S. T. Lee, Adv. Mater.2003, 15, 838.[5] C. Wu , Y. Xie, J. Phys. Chem. B2003, 107, 13583.[6] a) M. Andok, T. Kobayashi, S. Iijima, M. Haruta, J. Mater. Chem.1997, 7, 1779; b) H. Yamaura, J.。
不同材料表面构筑水凝胶涂层的通用策略
不同材料表面构筑水凝胶涂层的通用策略1.利用化学交联和物理交联的方法，可以在不同材料表面构筑水凝胶涂层。
Using methods of chemical crosslinking and physical crosslinking, water gel coatings can be constructed on the surfaces of different materials.2.水凝胶涂层可以提高材料的稳定性和耐久性。
Water gel coatings can improve the stability and durability of materials.3.通过在材料表面构筑水凝胶涂层，可以实现材料的抗污染和防腐蚀功能。
By constructing water gel coatings on the surface of materials, the functions of anti-pollution and anti-corrosion of materials can be achieved.4.超疏水表面结构可以用于构筑水凝胶涂层，提高材料的防水性能。
Superhydrophobic surface structure can be used to construct water gel coatings to improve the waterproof performance of materials.5.聚合物材料在表面构筑水凝胶涂层可以提高其抗撕裂性能。
Constructing water gel coatings on the surface of polymer materials can improve their tear resistance performance.6.金属材料的耐蚀性能可以通过构筑水凝胶涂层得到显著提升。
The corrosion resistance of metal materials can be significantly improved by constructing water gel coatings.7.纳米材料表面构筑水凝胶涂层可以增强其光电性能和化学稳定性。
PVC发泡术语中英对照
PVC发泡术语中英对照1) foamed polyvinyl chloride发泡PVC例句>>2) PVC foamingPVC发泡1.A wood-like PVC foaming material was made by the process of coloring and clouding.阐述了应用色拉、云纹工艺制作的仿木纹PVC发泡材料的物理特性、生产配料工艺、制作的模具类型以及试验与应用等方面的内容。
更多例句>>3) PVC foamed sheetPVC发泡片1.This paper studied the formula of EVA hot melt adhesive used for PVC foamed sheet and PP artificial paper, and designed the adhesive technology, discussed the effect of the amount of EVA resin, the adhesive temperature, the amount of VAc in EVA and MI on the Peel strength.研制了PP人造纸与PVC发泡片材粘合用EVA热熔胶并对其粘合工艺进行了设计。
4) PVC crusting and foamingPVC结皮发泡5) PVC low foamed boardPVC低发泡板材1.The article introduces the product performance, raw and auxiliary materials, production process and equipment of PVC low foamed board as well as the importance of substituting wood with plastics.本文介绍PVC低发泡板材的产品性能、原辅材料、生产工艺设备及以塑代木的重要性。
纳米级机器人英语作文
纳米级机器人英语作文Nano-scale robots, also known as nanobots, are tiny machines that can perform specific tasks at the molecularor cellular level. These incredibly small robots have the potential to revolutionize fields such as medicine, manufacturing, and environmental remediation.Imagine a world where nanobots could be injected into the human body to target and destroy cancer cells with unprecedented precision. These tiny machines could also be used to deliver drugs directly to diseased tissues, minimizing side effects and improving treatment outcomes.In the realm of manufacturing, nanobots could be employed to assemble products at the atomic level, leadingto the development of materials with extraordinary strength, flexibility, and conductivity. This could open up new possibilities for the creation of advanced electronics, aerospace components, and medical devices.Furthermore, nanobots have the potential to play a crucial role in environmental cleanup efforts. These miniature robots could be designed to break down pollutants and contaminants at the molecular level, offering a promising solution to some of the most pressing environmental challenges facing our planet.The development of nanobots raises important ethical and safety considerations. As with any emerging technology, there are concerns about potential misuse and unintended consequences. It will be essential to establish robust regulations and safeguards to ensure that nanobots are used responsibly and ethically.In conclusion, the emergence of nanobots represents a significant leap forward in the field of robotics and nanotechnology. While there are still many challenges to overcome, the potential applications of these tiny machines are truly staggering. With careful research and responsible implementation, nanobots could bring about transformative changes in medicine, manufacturing, and environmental protection.。
神奇的纳米盒子作文450字
神奇的纳米盒子作文450字英文回答：Nanotechnology, the science of manipulating matter at the atomic and molecular scale, has the potential to revolutionize many aspects of our lives, including the way we store and share information. One promising application of nanotechnology is the development of nano-containers, or nano-boxes, which could be used to safely and efficiently store and deliver drugs, vaccines, and other sensitive materials.Nano-boxes can be made from a variety of materials, including polymers, metals, and ceramics. They aretypically designed to be small enough to circulate through the bloodstream without being filtered out by the kidneys. This allows them to reach target cells or tissues more efficiently. Nano-boxes can also be engineered to release their contents in a controlled manner, which can improve drug delivery and reduce side effects.One of the most promising applications of nano-boxes is in the field of cancer treatment. Cancer cells are often characterized by their rapid growth and uncontrolled division. Nano-boxes could be used to deliver drugsdirectly to cancer cells, where they could kill the cells or prevent them from dividing. This targeted approach could improve the effectiveness of cancer treatment and reduce the risk of side effects.Nano-boxes could also be used to deliver vaccines more effectively. Vaccines are typically given as injections, which can be painful and inconvenient. Nano-boxes could be used to deliver vaccines orally or through the skin, which would be less invasive and more convenient. This could lead to increased vaccination rates and better protection against infectious diseases.The development of nano-boxes is still in its early stages, but the potential applications are vast. As research continues, nano-boxes could become an important tool for improving drug delivery, vaccine development, andother biomedical applications.中文回答：纳米技术是操控原子和分子尺度物质的科学，它有可能革新我们生活的许多方面，包括储存和共享信息的方式。
规模化制备高纯度牛奶外泌体工艺方法的建立及其分子与细胞生物学活性鉴定
第47卷第3期2021年5月吉林大学学报（医学版）Journal of Jilin University（Medicine Edition）Vol.47No.3May2021DOI：10.13481/j.1671⁃587X.20210331规模化制备高纯度牛奶外泌体工艺方法的建立及其分子与细胞生物学活性鉴定杨晶1,2,徐铭枝2,张东伟2,董亚楠2,王伊2,宋海峰1,2（1.安徽医科大学特殊环境组学教研室，安徽合肥230000；2.中国人民解放军军事科学院军事医学研究院生命组学研究所特殊环境组学研究室蛋白质药物国家工程研究中心，北京102206）［摘要］目的目的：建立一种规模化的牛奶外泌体纯化工艺，用于实验室制备和工业规模生产，并评价牛奶外泌体的分子与细胞生物学活性。
方法方法：取市售多种全脂或脱脂牛奶，以外泌体提取金标准——超速离心法（UC）作为对照，采用多种化学前处理方法去除乳蛋白，切向流超滤技术（TFF）进一步去除残留的乳蛋白，并实现牛奶样品的初纯与浓缩，多模式色谱法（BE-SEC）精纯牛奶外泌体，采用纳米流式细胞术（NanoFCM）检测牛奶外泌体的粒径、颗粒浓度和纯度，透射电子显微镜（TEM）观察牛奶外泌体的形态表现，高效液相色谱（HPLC）验证牛奶外泌体的尺寸和纯度，Western blotting法检测牛奶外泌体特异性蛋白的表达，，基因本体（GO）富集分析差异表达微小RNA （miRNA）的候选靶基因，DAVID Bioinformatics Resources6.8和KOBAS软件检测京都基因和基因组百科（KEGG）通路中目标候选基因的统计富集度，CytoFlex流式细胞术检测细胞对牛奶外泌体的摄取情况，流式细胞术检测牛奶外泌体作用后Caco-2细胞凋亡率。
结果结果：工艺研究，磷酸钠沉淀法在操作便利性、方法稳定性和产品质量方便均优于其他预处理方法。
TFF法可进一步去除残留乳蛋白并可实现液体浓缩目的，有效衔接至下游BE-SEC精纯方法。
纳米衣物作文英语
纳米衣物作文英语In recent years, the field of nanotechnology has been making significant strides, and one of the areas where it has shown great promise is in the development of nano-textiles. These advanced materials are not only revolutionizing the textile industry but also offering new possibilities for various applications, from sportswear to medical garments.Innovation in FabricsNano-textiles are fabrics that have been engineered at the nanoscale, which is the scale of atoms and molecules. This level of precision allows for the creation of materials with enhanced properties such as increased strength, flexibility, and resistance to environmental factors like water and bacteria. The nano-scale manipulation of fibers results in fabrics that are lighter, stronger, and more durable than traditional textiles.Benefits for ConsumersFor consumers, the benefits of nano-textiles are manifold. They offer improved comfort and performance, particularly in sportswear where athletes can benefit from the lightweight and breathable nature of nano-fabrics. Additionally, nano-textiles can be designed to have self-cleaning properties, reducing the need for frequent washing and maintenance.Environmental ImpactThe environmental impact of nano-textiles is a topic of ongoing research. While they can reduce the need for water and detergent in washing, there are concerns about the potential release of nanoparticles into the environment. Scientists are working to understand and mitigate any negative effects, ensuring that the development of nano-textiles is sustainable and eco-friendly.Medical ApplicationsIn the medical field, nano-textiles are being used to create bandages and dressings with antibacterial properties, reducing the risk of infection. They can also be engineered to release medication slowly over time, providing a new method for drug delivery.Future ProspectsThe future of nano-textiles looks bright, with ongoing research and development leading to new applications and improvements in existing ones. As technology advances, we can expect to see nano-textiles becoming more commonplace in everyday clothing, offering consumers a range of benefits from enhanced comfort to improved health and safety.ConclusionNano-textiles represent a significant leap forward in the textile industry, offering a glimpse into a future whereclothing is not just a form of protection and expression but also a tool for health, performance, and sustainability. As research continues, the potential of nano-textiles to transform our lives in various ways is becoming increasingly apparent.。
nanotechnology-based-drug-delivery纳米药物递送
20/03/2008
Dept. of Pharmaceutics
10
PRIORITY AREAS
DNA Vaccines for parasitic, bacterial and viral diseases
Oral and pulmonary routes for systemic delivery of proteins and peptides
Such compounds have two or more different
cations (positively charged elements) in their
chemical formula. An example of a complex
compound is calcium titanate (CaTiO3).
20/03/2008
Dept. of Pharmaceutics
6
Drug Delivery Technology Important to Pharma Industry
Delivery systems increase commercial opportunity by distinguishing a drug from competitive threats posed by “me too” drugs and
Nanotechnology Based Drug Delivery
Dr. Basavaraj K. Nanjwade M.Pharm., Ph.D Associate Professor
Department of Pharmaceutics JN Medical College KLE University Belgaum-590010
Micro- and Nano-scale Engineering
Micro- and Nano-scale Engineering Micro- and nano-scale engineering is an incredibly exciting and rapidly evolving field that holds immense potential for revolutionizing various industries, from electronics and medicine to materials science and energy. At the micro- and nano-scale, materials and devices behave differently than at the macro-scale, leading to unique properties and behaviors that can be harnessed for novel applications. However, despite the promise of this field, there are alsosignificant challenges and limitations that must be addressed in order to fully realize its potential. One of the most significant challenges in micro- and nano-scale engineering is the fabrication of structures and devices with precisecontrol over their dimensions and properties. At these small scales, traditional manufacturing techniques are often inadequate, and new methods must be developedto enable the precise manipulation of materials. For example, lithography techniques, such as electron beam lithography and nanoimprint lithography, have been developed to create patterns with nanoscale resolution, but these techniques are often time-consuming and expensive. Additionally, the development of reliable and scalable processes for the mass production of nanostructured materials and devices remains a significant challenge. Another major challenge in micro- and nano-scale engineering is the characterization and manipulation of materials and devices at such small scales. Traditional measurement techniques, such as optical microscopy and scanning electron microscopy, have limitations when it comes to resolving features at the nanoscale. New characterization techniques, such as atomic force microscopy and transmission electron microscopy, have been developed to address these limitations, but they often require specialized expertise and equipment. Furthermore, the manipulation of materials and devices at the nanoscale often requires the development of new tools and techniques, such as nanomanipulators and nanorobots, which are still in the early stages of development. In addition to the technical challenges, there are also ethical and societal considerations that must be taken into account in micro- and nano-scale engineering. For example, the development of nanomaterials and nanodevices raises concerns about their potential impact on human health and the environment. It is crucial to thoroughly understand the potential risks associated with thesematerials and devices and to develop appropriate safety protocols and regulations to mitigate these risks. Furthermore, the societal implications of micro- and nano-scale engineering, such as its impact on employment and income inequality, must also be carefully considered and addressed. Despite these challenges, the potential applications of micro- and nano-scale engineering are incredibly diverse and impactful. In the field of electronics, the development of nanoscale transistors and memory devices has the potential to enable faster and more energy-efficient computers and smartphones. In the field of medicine, nanoscale drug delivery systems and diagnostic devices hold the promise of more targeted and effective treatments for a wide range of diseases. In materials science, the development of nanomaterials with unique mechanical, electrical, and optical properties could lead to the creation of stronger, lighter, and more functional materials. In the energy sector, nanoscale engineering could enable the development of more efficient solar cells, batteries, and fuel cells. In conclusion, micro- and nano-scale engineering is a field with immense potentialfor driving technological innovation and addressing some of the most pressing challenges facing society today. However, realizing this potential will require addressing a wide range of technical, ethical, and societal challenges. By developing new fabrication and characterization techniques, addressing ethical and safety considerations, and exploring the diverse range of potential applications, we can work towards unlocking the full potential of micro- and nano-scale engineering.。
三氧化二铝在陶瓷领域上的发展
纳米三氧化二铝在陶瓷领域上的发展纳米三氧化二铝在陶瓷领域上的发展摘要：为了探索纳米三氧化二铝在陶瓷领域上的应用。
查阅大量的期刊和文献，得出了纳米三氧化二铝在陶瓷领域发挥了巨大的作用，具有非常大的发展前景。
纳米三氧化二铝，陶瓷粉粒径分布均匀，电阻率高，具有良好的绝缘性能，广泛用于塑料，橡胶，陶瓷，涂料等绝缘性能要求高的领域。
主要综述了纳米三氧化二铝的主要制备方法，包括：化学沉淀法、无压烧结法、溶胶一凝胶法。
同时，也介绍了纳米三氧化二铝的特殊结构性能，在陶瓷领域发挥的作用，其性能包括：Al203／TiC纳米陶瓷刀具材料的抗热震性能、纳米Ni-Al2O3金属陶瓷粉末热压致密化、Al2O3系纳米陶瓷抗拉强度、Al2O3系纳米陶瓷韧性。
通过以上资料的查询，得出纳米三氧化二铝在陶瓷领域具有非常好的发展前景的结论。
关键字:纳米；三氧化二铝；陶瓷；应用Abstract: in order to explore the nano 3 oxidation 2 aluminium in ceramic field application. Access to a lot of periodicals and literature, it is concluded that the nano 3 oxidation 2 aluminium in ceramic field played a huge role, has the very big prospects for development. Nano 3 oxidation 2 aluminium, ceramic powder with uniform paricle size distribution, resistance rate is high, has the good insulation performance, is widely used in plastic, rubber, ceramics, paint the insulation performance of the high demand on the field. The paper mainly describes the main preparation methods of nanometer 3 oxidation 2 aluminium, including chemical precipitation, pressureless sintering process, sol a gel method. At the same time, also introduces the nano 3 oxidation 2 aluminium special structure performance, in ceramic field play a role, its performance include: Al203 / TiC nanostructured ceramic cutting tool material thermal shock performance, nano Ni - Al2O3 metal ceramic powder extrusion densification, Al2O3 system nanostructured ceramic tensile strength, Al2O3 system nanostructured ceramic toughness. Through the above information query, it is concluded that nano 3 oxidation 2 aluminium in ceramic field has very good prospects for development of the conclusion.Key words: nano; 3 oxidation 2 aluminium; Ceramic; application陶瓷是人类最早使用的材料之一，在人类发展史上起着重要的作用。
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Materials Science Forum Vol. 762
153
2 Material and Methods 2.1 Material. Table 1 shows the chemical compositions of the experimental steel and welding wire. By design, the experimental steel must have low carbon content and also microalloying elements Nb, V and Ti were added. Table 1 Chemical composition of the experimental steel (wt. %)
C 0.085 Si 0.17 Mn 1.45 P 0.007 S 0.0015 Al 0.04 Nb V Nb+V+Ti<0.12 Ti N 0.004
2.2 Methods. The hot rolling experiments were completed on the Φ450 two-high, reversing hot-rolling mill, and the thickness of strip was 8.0mm. The finishing rolling start temperature was 950oC, and the finish rolling temperature was controlled at 810±20oC. Different coiling temperatures of 650oC, 600oC, 540oC and 430oC were tried. Metallographic specimens were polished and etched with 4% nital before examination in a LEICA-DMIRM light microscope (OM) and an FEI Quanta 600 scanning electron microscope (SEM). Examination of thin foils was carried out in a FEI Tecnai G2 F20 transmission electron microscope (TEM). Tensile test was performed in a WDW-300 tensile testing machine. Low temperature impact toughness tests were conducted in an INSTRON 9250 drop hammer impact testing machine with “V”-type notched specimen (55×10×5mm). Hole expansion test was based on the standard GB/T 15825.4-2008, conducted in a BCS universal metal sheet forming machine. The sample was 100×100×2.5mm plate with Ф16.5 mm hole prefabricated in the middle. 3 Results and Discussion 3.1 Effect of coiling temperature on microstructure. Fig. 1 shows the optical microstructure and secondary electron images of the experimental steels under different coiling temperatures (CT). PF, P and B are the abbreviations of polygonal ferrite, pearlite and bainite, respectively. When the coiling temperature was between 400 to 650oC, the microstructural constituents of experimental steel were PF with boundary precipitation of fine carbides and a certain amount of P or B or both. Table 2 shows the volume fraction of the different phases under different coiling temperatures. With the decreasing of the coiling temperature, the volume fractions of PF and P were gradually decreasing and the volume fraction of B was increasing.
Materials Science Forum Vol. 762 (2013) pp 152-157 Online available since 2013/Jul/01 at © (2013) Trans Tech Publications, Switzerland doi:10.4028//MSF.762.152
All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of TTP, . (ID: 210.28.76.197-02/07/13,13:15:06)
Development of Nano-scale Precipitation Strengthened Hot-rolled 590MPa Grade Wheel Steel Xiaonan Wang1,a, Linxiu Du2,b and Hongshuang Di2,c
Shagang School of Iron and Steel, Soochow University, Suzhou, Jiangsu 215021, P.R. China 2 The State Key Laboratory of Rolling and Automation of Northeastern University, Shenyang, Liaoning 110819, P R. China
a 1
wxn@, bdulx@, cdhshuang@
Keywords: microalloy steel, precipitation strengthening, microstructure and properties
Abstract: In order to promote the production of lightweight automobiles and enhance the strength grade of the automobile wheel steel, a nano-scale precipitation strengthened hot-rolled 590MPa grade wheel steel was developed to replace the Q235 steel, which was originally use for the wheel. The new wheel steel type was based on a C-Mn steel composition, microalloyed with Nb, V and Ti, thus making full use of the strengthening from both grain refinement as well as nano-scale precipitation. The microstructure of the wheel steel was composed of fine-grained ferrite and pearlite and carbides distributed along the ferrite grain boundaries. The yield and tensile strengths of the strip were about 550 MPa and 620 MPa, respectively. The value of hole expansion rate was 90%. The strip has shown high low temperature impact toughness and cold formability. The strengthening mechanisms of the strip were mainly governed by grain refinement and nano-scale precipitation (Nb,V,Ti)C, and the amount of the contribution from precipitation strengthening alone was about 215 MPa. The finishing rolling start temperature was about 950oC and the finish rolling temperature was between 790~830oC. Coiling temperature of 650oC gave the best combination of mechanical properties. 1 Introduction Energy conservation is a key research topic in the development of the automobile industry. Manufacturing of lightweight automobiles is one of the effective measures to solve this problem. A study confirmed that if the body weight can be made 10% lighter, the fuel consumption can be reduced by 6-8% [1, 2]. The wheel steel of domestic heavy-duty truck is Q235 steel, the chemical compositions (wt. %): 0.15C - 0.4Mn - 0.2Si - 0.02P - 0.02S. The microstructure of Q235 steel is relatively coarse ferrite and pearlite, the average grain size of ferrite is about 14~16µm, and the yield strength of Q235 steel is about 260MPa, so that the wheel is thicker and heavy to meet the property requirements. Therefore, in recent years, the development of high strength wheel steel is being widely conducted. For the tensile strength 590MPa grade wheel steel, the microstructure of steel is usually a mixture of ferrite with pearlite and/or bainite or martensite. While the soft phase ferrite could impart good formability and elongation, the hard phase of pearlite or bainite or martensite ensures high tensile strength in wheel steel [3-5]. Therefore, the volume fraction, shape and hardness of phases are the main factors affecting the mechanical properties of wheel steel [6,7]. In this paper, the effects of microstructure on strength, plasticity, impact toughness and stretch flangeability were studied, and the process parameters of hot-rolled 590MPa grade wheel steel were determined.