Study of chemically induced pressure generation of hydrogels under isochoric conditions using a microfabricated device
Study of chemically induced pressure generation of hydrogels under isochoric conditions using a microfabricated device
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DOI：
10.1063/1.1773153
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发表时间：
2004-08-08
影响因子：
4.4
通讯作者：
van den Berg, A
中科院分区：
文献类型：
--
作者：
Herber, S;Eijkel, J;van den Berg, A
提出了一种研究等容条件下刺激敏感性水凝胶行为的方法。通过将水凝胶封闭在微压传感器和多孔覆盖物之间，在所有方向上限制这种水凝胶的溶胀运动的自由度。水和外部刺激可以通过覆盖物的孔施加到水凝胶以引起溶胀，这导致压力传感器测量的压力产生。通过检查pH敏感性水凝胶对周围溶液的pH、离子强度和缓冲液浓度变化的响应来证明该方法。平衡和动态压力的产生进行了观察。结果表明，通过将更多的可电离基团引入到水凝胶网络中或通过降低外部溶液的离子强度来获得更高的压力。此外，它被证明，压力更快地达到平衡时，更少的可滴定的基团被纳入或在周围的溶液中存在较高的缓冲液浓度。通过使用微制造技术，水凝胶的尺寸可以保持小，具有响应快的优点。当施加从9到6的pH阶跃时，具有2.5%可质子化基团和15 μ m厚度的DMAEMA-共-HEMA水凝胶在12分钟内产生0.67 × 10（5）Pa的Δ压力。所提出的方法是一种简单，快速的方式来表征静态和动态的刺激依赖性行为的水凝胶。(C)2004年，美国物理学会。
A method is proposed to study the behavior of stimulus-sensitive hydrogels under isochoric conditions. Freedom of swell movement of such a hydrogel was restricted in all directions by enclosing the hydrogel between a micropressure sensor and a porous cover. Water and external stimuli can be applied to the hydrogel through the pores of the cover to provoke swelling, which results in pressure generation measured by the pressure sensor. The method was put to the proof by examining the response of a pH-sensitive hydrogel to changes in pH, ionic strength, and buffer concentrations of the surrounding solution. Both equilibrium and dynamic pressure generation were observed. The results show that higher pressures are obtained by incorporating more ionizable groups into the hydrogel network or by lowering the ionic strength of the external solution. Furthermore it was proven that pressures reach equilibrium faster when less titratable groups are incorporated or at the presence of higher buffer concentrations in the surrounding solution. By using microfabrication techniques the dimensions of the hydrogel could be kept small with the advantage that responses are fast. A DMAEMA-co-HEMA hydrogel with 2.5% protonable groups and a thickness of 15 mum generated a Deltapressure of 0.67x10(5) Pa in 12 min when a pH step from 9 to 6 was applied. The presented method is a simple and fast manner to characterize the static and dynamic stimulus-dependent behavior of hydrogels. (C) 2004 American Institute of Physics.