Ming Li,Xiaohong Liu,Ning Liu,Zihe Guo,Puneet Kumar Singh,Shiyu Fu
Cellulose nanocrystals (CNCs) is a kind of natural, renewable, and biocompatible materials that can be functional via the surface modification. A covalently bonded CNCs-g-PDMAEMA was prepared by grafting 2-(dimethyl-amino) ethyl methacrylate (DMAEMA) on the CNCs’ surface via atom transfer radical polymerization (ATRP). Subsequently, the tertiary amino groups of the CNCs-g-PDMAEMA were transferred to quaternary ammonium groups by adding alkyl bromides with different carbon chain lengths (C10-C18). It was found that the antibacterial activity of the prepared materials is related to the quaternary group structure. The material containing C10 alkyl in quaternary group exhibited the best antibacterial efficiency, which was closely associated with the wettability of the quaternary CNCs-based polymers. The lower wettability of materials with higher hydrophobicity may impose a restriction on the polymeric antibacterial groups’ accessibility to the cytoplasmic membrane of bacteria. The antimicrobial CNCs-based composites may be potential to apply as coating agents for aseptic packaging.
Zhenguang Wang,Yu-e Shi,Xuming Yang,Yuan Xiong,Yanxiu Li,Bingkun Chen,Wing-Fu Lai,Andrey L. Rogach
A water-soluble, positively charged polymer is obtained by copolymerizing chitosan with hypromellose, and the evaluation of its biocompatibility and the capacity for the loading of exogenous agents is performed. Films based on hypromellose grafted chitosan (HGC) are employed as a matrix to fabricate composite films by dehydration-triggered aggregation of copper nanoclusters (NCs). The resulting HGC/Cu NC films are transparent and exhibit an aggregation-induced emission enhancement of copper NCs, with a resulting photoluminescence quantum yield of 42%. The application of these orange emitting films as color converters for fabrication of remote light-emitting devices is demonstrated.
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