Yang Jun, Zhang Xueming, Ma Mingguo, Xu Feng
Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing, 100083, China.
ACS Macro Lett. 2015 Aug 18;4(8):829-833. doi: 10.1021/acsmacrolett.5b00422. Epub 2015 Jul 20.
The biologically inspired dynamic materials offer principles for designing man-made systems by using assembly approach. In this work, the hybrid hydrogels consist of cellulose nanofibrils (CNFs) that combine a mechanically strong skeleton with flexible PEG chains. The distinct gel state is observed at room temperature with ' > ″ and an order of magnitude higher ' values from 0.08 to 0.93 kPa upon increasing CNF concentration from 0.2 to 2 wt % at constant 2 wt % PEG. Combined with mechanically strong CNFs and dynamic ionic bridges through amine-terminated tetra-arm PEG adsorption to TEMPO-oxidized colloidal nanofibrils surface, the assembled colloidal hydrogels show high modulus, reversible gel-sol transition, and rapid self-recovery properties. It is envisioned that simply mixing hard CNF and soft polymeric matrix would lead to a facile method to bridge reversible dynamic bonds in a cellulose-based hybrid network and broad cellulose applications in the preparation of high performance supramolecular systems.
受生物启发的动态材料为通过组装方法设计人造系统提供了原理。在这项工作中，混合水凝胶由纤维素纳米纤维（CNF）组成，它将机械强度高的骨架与柔性聚乙二醇（PEG）链结合在一起。在室温下观察到明显的凝胶状态，在PEG含量恒定为2 wt%的情况下，随着CNF浓度从0.2 wt%增加到2 wt%，‘>″，并且‘值从0.08到0.93 kPa高出一个数量级。通过胺基封端的四臂PEG吸附到TEMPO氧化的胶体纳米纤维表面，结合机械强度高的CNF和动态离子桥，组装的胶体水凝胶表现出高模量、可逆的凝胶-溶胶转变和快速的自我恢复特性。可以设想，简单地混合硬CNF和软聚合物基质将导致一种简便的方法，在基于纤维素的混合网络中桥接可逆的动态键，并在高性能超分子系统的制备中拓宽纤维素的应用。
