具有环境响应性的纤维素基水凝胶

Environmentally Responsive Hydrogels Based on Cellulose

随着对可再生资源开发利用的逐渐重视,基于纤维素环境响应型水凝胶结构设计及其响应性能的研究备受关注.环境响应纤维素基水凝胶不仅具有良好的生物相容性和生物可降解性,还表现出对环境因素特定的检出识别能力及明显响应性,拓展了水凝胶材料在生物医用、仿生智能材料等领域的应用.本综述首先从环境响应型纤维素水凝胶材料的结构设计出发,以交联方式分类简要介绍了纤维素基水凝胶的合成方法,具体包括物理交联、化学交联和其他交联方式等.接着,从水凝胶功能性入手,重点介绍了以一种或多种化学信号、物理信号为刺激源响应的纤维素基水凝胶材料;并以药物载体、形状记忆材料和伤口敷料等方面研究成果为例,阐述了环境响应型纤维素基水凝胶的相关应用,以及其在智能软体机器人和环保生物传感器等领域的巨大应用潜力.

With the emphasis on the development and utilization of renewable energy, environmentally responsive hydrogels based on cellulose have attracted much attention with their structure design and response performance. Besides the good biocompatiblity and biodegradablity, cellulose-based environmentally responsive hydrogels show excellent abilities in detection, recognition and response behaviors to environmental and biomedical relevant stimuli, which expands the applications of these hydrogels as biomedical smart materials and in other fields. In this article, we summarized the design and applications of environmentally responsive hydrogels, where cellulose could work as the cross-linkage in the 3 D network or the nanofillers to improve properties, especially mechanical properties of hydrogels. Classified by crosslinking methods including physical or/and chemical crosslinking, the structural design and fabrications of these cellulose-based hydrogels were first discussed. Physical cellulose-based hydrogels constructed by supramolecular interactions usually exhibited more flexibility, and their responsiveness to external stimuli might depend on changes among the interactions in networks, while the chemical hydrogels showed responsiveness due to the cellulose skeleton mostly like pH responsive carboxymethyl cellulose. Moreover, focusing on their properties and functions, several types of cellulose-based hydrogels and their responses to chemical, physical and multi-stimuli were described, such as pH responsive, redox responsive, CO2 responsive and temperature responsive hydrogels. Taking some biomedical researches as examples, it was expounded in this paper that the environmentally responsive hydrogels based on cellulose could be applied as drug delivery carriers, shape memory devices and wound dressing, etc. To broaden the use of environmentally responsive cellulose-based hydrogels, it’s of great importance to design the hydrogel networks with multiple responsiveness and to improve the speed and sensitivity of the response process. With the development of artificial intelligence, it’s believed that environmentally responsive cellulose-based hydrogels will have great potential in applications for 3 D printing, electronic skins, intelligent soft robots and so on in the future.