文献类型：期刊文献

英文题名：Fe3+-induced oxidation and coordination cross-linking in catechol-chitosan hydrogels under acidic pH conditions

作者：Guo, Zhongwei[1];Ni, Kefeng[1];Wei, Dongzhi[1];Ren, Yuhong[1]

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China

年份：2015

卷号：5

期号：47

起止页码：37377

外文期刊名：RSC ADVANCES

收录：;EI(收录号：20151900833620);WOS:【SCI-EXPANDED(收录号:WOS:000353653200028)】；

基金：This work was funded by the National Special Fund for the State Key Laboratory of Bioreactor Engineering (2060204), the National Natural Science Foundation of China (no. 21076079), the National major science and technology projects of China (no. 2012ZX09304009), and the Fundamental Research Funds for the Central Universities of China.

语种：英文

外文关键词：pH - Self assembly - Phenols - Chitosan - Hydrogels - Gelation

摘要：Mussel byssus is rich in Fe3+ and catechol-containing proteins; chemical interactions between these components vary widely with respect to changes in pH during byssal maturation. Previous studies have indicated the key role played by Fe3+-catechol interactions in regulating many attributes of biological materials, such as toughness, extensibility, and self-assembly. In this study, a platform based on a highly substituted catechol-modified chitosan (70%, CCS) was used to investigate the effect of pH on the reactions between Fe3+ and catechols. This study demonstrated that the Fe3+-induced CCS hydrogel is essentially a dual cross-linking system composed of covalent and coordination crosslinks, under acidic pH conditions. Variations in the Fe3+-catechol molar ratios could strongly affect the gelation time, physical properties, and UV-vis and Raman spectra. These changes represent different balance states between oxidation and coordination mechanisms in the hydrogel network. In addition, the system was subjected to optical microscopy and SEM in order to obtain a visual description of the dual-crosslinking mechanism.