title: Gelation process visualized by aggregation-induced emission fluorogens.
abstract: Alkaline-urea aqueous solvent system provides a novel and important approach for the utilization of polysaccharide. As one of the most important polysaccharide, chitosan can be well dissolved in this solvent system, and the resultant hydrogel material possesses unique and excellent properties. Thus the sound understanding of the gelation process is fundamentally important. However, current study of the gelation process is still limited due to the absence of direct observation and the lack of attention on the entire process. Here we show the entire gelation process of chitosan LiOH-urea aqueous system by aggregation-induced emission fluorescent imaging. Accompanied by other pseudo in situ investigations, we propose the mechanism of gelation process, focusing on the formation of junction points including hydrogen bonds and crystalline.
authors.affiliation: MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China.|Key Laboratory of Adsorption and Separation Materials and Technologies of Zhejiang Province, Hangzhou 310027, China.
authors.forename: Zhengke
authors.initials: Z
authors.lastname: Wang
authors.affiliation: MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China.|Key Laboratory of Adsorption and Separation Materials and Technologies of Zhejiang Province, Hangzhou 310027, China.
authors.forename: Jingyi
authors.initials: J
authors.lastname: Nie
authors.affiliation: Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong 999077, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Qin
authors.affiliation: MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China.|Key Laboratory of Adsorption and Separation Materials and Technologies of Zhejiang Province, Hangzhou 310027, China.
authors.forename: Qiaoling
authors.initials: Q
authors.lastname: Hu
authors.affiliation: Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong 999077, China.
authors.forename: Ben Zhong
authors.identifier: 0000-0002-0293-964X
authors.initials: BZ
authors.lastname: Tang