In this work, stimuli-responsive, superabsorbent materials are created by copolymerization of stimuli-responsive poly(n-isopropyl acrylamide) (PNIPAM) in combination with superabsorbent sodium acrylate (SA) via photopolymerization in lyotropic liquid crystal (LLC) templates. Templating PNIPAM in LLC mesophases imparts nanostructure to the polymer that significantly increases transport and swelling when compared to isotropic hydrogels. These materials exhibit twice the equilibrium swelling of analogous non-templated materials and show a dynamic range between the swollen and deswollen state that is 5 times greater. To further augment this stimuli-responsive range, LLC-templated PNIPAM was combined with the superabsorbent monomer sodium acrylate (SA). As SA concentration is increased, significant structure changes are observed during polymerization that leads to less-defined nanostructure and lower stimuli response. Maximum swelling and temperature response are observed at low concentrations of SA (∼2 wt%). These LLC-templated copolymers exhibit stimuli-responsive volume transitions up to 40 times and equilibrium swelling ratios of 60 times their dry mass. This 600% increase in thermal response is due to the combined high swelling capabilities of SA with the enhanced thermal-response behavior induced by the LLC-templated nanostructure. Additionally, the nanostructure induces fast deswelling rates at temperatures above the lowest critical solution temperature of PNIPAM. The high dynamic range and quick response of this composition could allow for the development of superabsorbent, stimuli-responsive hydrogels in a variety of biomaterial, microfluidic, and water remediation applications.

在这项工作中，通过对刺激敏感的聚（n-异丙基丙烯酰胺（PNIPAM）与超吸收性丙烯酸钠（SA）组合，通过在溶致液晶（LLC）模板中进行光聚合。与各向同性水凝胶相比，在LLC中间相中对PNIPAM进行模板化可为聚合物赋予纳米结构，从而显着增加运输和溶胀。这些材料的平衡膨胀是类似非模板材料的两倍，并且在溶胀和脱溶胀状态之间的动态范围大5倍。为了进一步扩大该刺激响应范围，将LLC模板的PNIPAM与超吸收性单体丙烯酸钠（SA）结合使用。随着SA浓度的增加，在聚合过程中观察到显着的结构变化，这导致定义较不明确的纳米结构和较低的刺激响应。在低浓度的SA（〜2 wt％）下观察到最大的溶胀和温度响应。这些LLC模板共聚物表现出高达40倍的刺激响应体积跃迁和60倍于干质量的平衡溶胀比。热响应的这种600％的增加归因于SA的高溶胀能力与LLC模板纳米结构诱导的增强的热响应行为的结合。另外，纳米结构在高于PNIPAM的最低临界溶解温度的温度下引起快速的溶胀率。该组合物的高动态范围和快速响应性可以允许在多种生物材料，微流体和水修复应用中开发超吸收，刺激响应性水凝胶。这些LLC模板共聚物表现出高达40倍的刺激响应体积跃迁和60倍于干质量的平衡溶胀比。热响应的这种600％的增加归因于SA的高溶胀能力与LLC模板纳米结构诱导的增强的热响应行为的结合。另外，纳米结构在高于PNIPAM的最低临界溶解温度的温度下引起快速的溶胀率。该组合物的高动态范围和快速响应性可以允许在多种生物材料，微流体和水修复应用中开发超吸收，刺激响应性水凝胶。这些LLC模板共聚物表现出高达40倍的刺激响应体积跃迁和60倍于干质量的平衡溶胀比。热响应的这种600％的增加归因于SA的高溶胀能力与LLC模板纳米结构诱导的增强的热响应行为的结合。另外，纳米结构在高于PNIPAM的最低临界溶解温度的温度下引起快速的溶胀率。该组合物的高动态范围和快速响应性可以允许在多种生物材料，微流体和水修复应用中开发超吸收，刺激响应性水凝胶。热响应的这种600％的增加归因于SA的高溶胀能力与LLC模板纳米结构诱导的增强的热响应行为的结合。另外，纳米结构在高于PNIPAM的最低临界溶解温度的温度下引起快速的溶胀率。该组合物的高动态范围和快速响应性可以允许在多种生物材料，微流体和水修复应用中开发超吸收，刺激响应性水凝胶。热响应的这种600％的增加归因于SA的高溶胀能力与LLC模板纳米结构诱导的增强的热响应行为的结合。另外，纳米结构在高于PNIPAM的最低临界溶解温度的温度下引起快速的溶胀率。该组合物的高动态范围和快速响应性可以允许在多种生物材料，微流体和水修复应用中开发超吸收，刺激响应性水凝胶。