Mechanically Tough, Thermally Activated Shape Memory Hydrogels
Mechanically Tough, Thermally Activated Shape Memory Hydrogels
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DOI：
10.1021/mz3006389
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发表时间：
2013-01-01
影响因子：
7.015
通讯作者：
Weiss, R. A.
中科院分区：
文献类型：
--
作者：
Hao, Jinkun;Weiss, R. A.
研究了由N，N-二甲基丙烯酰胺（DMA）、甲基丙烯酸2-（N-乙基全氟辛磺酰氨基）乙酯（FOSM）、丙烯酸羟乙酯和丙烯酸2-肉桂酰氧基乙酯四元共聚物共价交联制备的一系列坚韧杂化水凝胶的形状记忆行为。具有物理和共价交联的杂化水凝胶含有类似于60-70%的水，相对柔软且有弹性，并表现出高的机械强度、延展性和断裂韧性。由于FOSM物种的微相分离，临时网络来自玻璃状纳米畴。形状记忆的转换温度是纳米畴的玻璃化转变温度。由于纳米域交联的粘弹性效应，在固定形状中发生了一些蠕变松弛，但是在10 ℃下24小时后，固定形状实现了84-88%的形状固定效率。通过将水凝胶再加热至65 ℃实现形状恢复至永久形状，并且基本上是定量的。
The shape memory behavior of a series of strong, tough hybrid hydrogels prepared by covalently cross-linking quad-polymers of N,N-dimethylacrylamide (DMA), 2-(N-ethylperfluoro-octanesulfonamido) ethyl methacrylate (FOSM), hydroxyethyl acrylate, and 2-cinnamoyloxyethyl acrylate was investigated. The hybrid hydrogels, which had physical and covalent cross-links, contained similar to 60-70% water, were relatively soft and elastic, and exhibited high mechanical strength, extensibility, and fracture toughness. The temporary network was derived from glassy nanodomains due to microphase separation of the FOSM species. The switching temperature for shape memory was the glass transition temperature of the nanodomains. Some creep relaxation occurred in the fixed shape due to viscoelastic effects of the nanodomain cross links, but shape fixing efficiencies of 84-88% were achieved for the fixed shape after 24 h at 10 degrees C. Shape recovery to the permanent shape was achieved by reheating the hydrogel to 65 degrees C and was essentially quantitative.