School of Chemical Engineering, Sichuan University, Chengdu, Sichuan, 610065, P.R. China.
J Phys Chem B. 2012 Jan 26;116(3):974-9. doi: 10.1021/jp209699g. Epub 2012 Jan 11.
Conversion of chemical signals into mechanical force is very important for implementation of stimuli-responsive hydrogels. We design a core-shell hydrogel capsule that can translate the variations of alcohol concentration into mechanical force. Oil-in-water-in-oil (O/W/O) emulsions are prepared with microfluidic technique and serve as templates for the synthesis of the core-shell capsules. The oil core is ejected from the capsule by the mechanical force generated from the deswelling of the capsule membrane upon increasing the alcohol concentration at a certain temperature below the lower critical solution temperature. The influences of alcohol concentration and temperature on the deswelling process of capsule membranes are investigated systematically. The deswelling rate also plays an important role in the ejection of the oil core. These demonstrations of conversion of alcohol concentration variations into mechanical force provide proof that these core-shell capsules can function as both sensors and actuators of alcohols.
将化学信号转化为机械力对于实现对刺激响应水凝胶非常重要。我们设计了一种核壳水凝胶胶囊，可以将酒精浓度的变化转化为机械力。我们使用微流控技术制备油包水包油（O/W/O）乳液，并将其用作核壳胶囊合成的模板。当温度低于下临界溶液温度时，通过增加酒精浓度使胶囊膜溶胀，从而产生机械力将油芯从胶囊中挤出。系统研究了酒精浓度和温度对胶囊膜溶胀过程的影响。溶胀速率对油芯的挤出也起着重要作用。这些将酒精浓度变化转化为机械力的演示证明了这些核壳胶囊可以作为酒精的传感器和致动器。
