pH和UV刺激响应表面材料_从超疏水到超亲水

17-P-006

pH和UV刺激响应表面材料：从超疏水到超亲水

蒋玉贵，万鹏博，王治强，张希*

清华大学化学系，有机光电子与分子工程教育部重点实验室，北京100084

E-mail: xi@

刺激响应材料是指一类具有在外界刺激下可调控其物理化学性质的材料，将这类刺激响应材料引入到自组装单层膜体系中，就可实现利用外界刺激来调控表面结构和性质。以前报道的pH刺激响应表面，基本上都是在低pH值条件下为超疏水表面，在高pH值条件下为超亲水表面。为了制备一种新型的pH刺激响应表面，即在高pH值条件下为超疏水表面，在低pH值条件下为超亲水表面，我们设计合成了一种具有刺激响应性的末端为孔雀绿基团的烷基硫醇衍生物。一方面，孔雀绿是一种刺激响应材料，在没有外界pH或者UV刺激条件下，孔雀绿基团是疏水的；而在外界pH或者UV刺激条件下，孔雀绿基团变为相应的带正电荷的亲水基团。另一方面，硫醇衍生物中的巯基可以化学吸附于镀金表面形成自组装单层膜。研究表明修饰上述单层膜的粗糙金表面，对pH=13的水滴，呈现约146.8º的接触角，而对pH=1的水滴，呈现约0º的接触角，同时这种从接近超疏水表面到超亲水表面的转变可以循环多次。另外，上述表面的浸润性质，还可以通过UV光照时间进行调控，即从光照前的接近超疏水表面到光照后的超亲水表面。

关键词：pH和UV刺激响应材料；自组装单层膜；超疏水-超亲水转变。

参考文献：

[1] Y. Jiang, P. Wan, M. Smet, Z. Wang, X. Zhang, Adv. Mater. 2008, adma.200702366.

[2] Y. Jiang, Y. Wang, N. Ma, Z. Wang, M. Smet, X. Zhang, Langmuir2007, 23, 4029.

[3] Y. Jiang, Z. Wang, H. Xu, H. Chen, X. Zhang, M. Smet, W. Dehaen, Y. Hirano, Y. Ozaki, Langmuir

2006, 22, 3715.

[4] Y. Jiang, Z. Wang, X. Yu, F. Shi, H. Xu, X. Zhang, M. Smet, W. Dehaen, Langmuir2005, 21, 1986.

pH and UV-responsive surface material：from superhydrophobicity

to superhydrophilicity

Yugui Jiang，Pengbo Wan，Zhiqiang Wang，Xi Zhang* Key Lab of Organic Optoelectronics and Molecular Engineering，Department of

Chemistry，Tsinghua University，Beijing 100084

Stimuli-responsive material can be introduced into the self-assembled monolayer (SAM) to realize the control of the structures and properties of SAM under different external stimuli. The pH-responsive surface that can undergo a change of the wetting properties from near superhydrophobicity at low pH, to superhydrophilicity at high pH, has been reported. We are wondering if we can realize a pH-responsive surface with completely uncommon response behavior, i.e. from near superhydrophobicity at high pH, to superhydrophilicity at low pH. For this purpose, we have designed and synthesized a stimuli-responsive malachite green terminated alkanethiol. For the SAM of this alkanethiol on rough gold covered surface, a large contact angle of about 146.8º is observed for a pH=13 water droplet, while a very small contact angle of about 0º is observed for a pH=1 water droplet. Moreover, the malachite green terminated alkanethiol is dual stimuli-responsive, the wetting properties of the SAM can be controlled and fine-tuned by the UV irradiation.

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