读书报告

Choose the paper's reason:
To study some knowledge about NMR Correlation with my research
BACKGROUND
Controlled release of drugs is becoming one of the more dynamic fields of pharmaceutical research. It shows numerous advantages including fewer side effects and better patient compliance. Hydrogels are 3-dimensional complex systems composed of tangled polymer network structures and incorporated water. NMR spectroscopy is a powerful technique for detailed studies of the structure, mobility, and hydration properties of various polymeric systems
1 1 1 = − = ∆( ) T1 T1 f T1
5τC 2τC 1 ( )INTRA•η =η •C(τC + ) + 2 2 2 2 T2b 3(1+ 4ωL τC ) 3(1+ 4ωL τC )
1 1 1 = − = ∆( ) T2 T2 f T2
mb mb η= = m tot 100 − m pol
S Z (τ ) = A − B • exp( − τ / T1 )
S Z (τ ) = C • exp( − τ / T 2 )
η 1 = Ti T ib
1 − η + T if
η
=
N
b
N b + N
f
η
=
K V
• S
τC 4τ C 1 2 ( ) INTRA •η = η • • C( + ) 2 2 2 2 T1b 3 1 + ωL τ C 1 + 4ωL τ C
PAPER'S PURPOSE:
The aim of this work was to study the effect of the type of substituent of the cellulose ethers and the molecular mass on the state and dynamics of water in the respective hydrogels to specify the quantity of adsorbed water on the polymers or, to calculate the average number of water molecules bound to a PRU.
spin-spin relaxation time :自旋 自旋弛豫时间，高能态的 自旋-自旋弛豫时间 自旋 自旋弛豫时间， 自旋核与同类的低能态核之间能量的转移时间。 自旋核与同类的低能态核之间能量的转移时间。 HPC:Hydroxypropylcellulose-羟丙基纤维 羟丙基纤维 HPMC:hydroxypropyl methyl cellulose --羟丙基甲基纤维 羟丙基甲基纤维 素 HEC:羟乙基纤维素 羟乙基纤维素
Nouns explanation
• 在磁共振成象技术中，由停止发射无线 在磁共振成象技术中， 电波至原子核恢复原来平衡状态的间隔 时间，称弛豫时间。弛豫时间有纵向、 时间，称弛豫时间。弛豫时间有纵向、 横向两种。前者称自旋—晶格弛豫时间 晶格弛豫时间， 横向两种。前者称自旋 晶格弛豫时间， 后者称自旋—自旋弛豫时间 自旋弛豫时间。 后者称自旋 自旋弛豫时间。 • spin-lattice relaxation time :也称纵向弛 也称纵向弛 豫时间， 豫时间，是处于高能态的核自旋体系与 周围的环境之间的能量交换过程， 周围的环境之间的能量交换过程，达到 热平衡状态所需的时间，用半衰期T 热平衡状态所需的时间，用半衰期 1表 示。
Investigation of the State and Dynamics of Water in Hydrogels of Cellulose Ethers by 1H NMR Spectroscopy
--AAPS PharmSciTech 2002
林业工程 2011102012013
• Saša Baumgartner1, Gojmir Lahajnar2, Ana Sepe2, and Julijana Kristl1 • 1University of Ljubljana, Faculty of Pharmacy,Aškerčeva 7, SI-1000 Ljubljana, Slovenia • 2Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia • Submitted: September 13, 2002; Accepted: December 28, 2002
ResultCLUSION
• The rate 1/T1 has been observed to be more sensitive than rate 1/T2 to the polymer substution and insensitive to the polymer molecular mass. • A procedure for calculating average numbers of water molecules bound per PRU was developed.