Transparent, Aldehyde-Free Chitosan Aerogel
Transparent, Aldehyde-Free Chitosan Aerogel
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DOI：
10.1016/j.carbpol.2020.117089
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发表时间：
2021-01-01
影响因子：
11.2
通讯作者：
Malfait, Wim J.
中科院分区：
文献类型：
--
作者：
Takeshita, Satoru;Zhao, Shanyu;Malfait, Wim J.
报道了无醛透明壳聚糖气凝胶。该气凝胶是通过尿素的热分解来诱导壳聚糖溶液的凝胶化，然后通过溶剂交换到乙醇，和超临界干燥来制备的。低尿素浓度（= 30 g L--（1））产生不透明的，更大孔的气凝胶。低脲凝胶的高表面积（> 400 m2 g-1）、大的中孔体积（高达3.5 cm 3 g-1）和光学透明度表明在中尺度下具有高的结构均匀性，并且性质与先前报道的用甲醛交联制备的透明壳聚糖凝胶相当。湿凝胶的宏观尺寸变化表明，微结构的形成是由壳聚糖凝固的时间，这取决于尿素浓度等控制。这种无凝胶、微结构可调的工艺提供了一系列新的具有“真气凝胶”中孔结构的透明生物聚合物凝胶。
Aldehyde-free, transparent chitosan aerogel is reported. The aerogel was prepared by thermal decomposition of urea to induce gelation of a chitosan solution, followed by solvent exchange to ethanol, and supercritical drying. Low urea concentrations (= 30 g L--(1)) produce opaque, more macroporous aerogels. The high surface areas of > 400 m(2) g(-1), large mesopore volumes up to 3.5 cm(3) g(-1), and optical transparency of the low-urea aemgels indicate a high structural homogeneity at the mesoscale, and the properties comparable to previously reported transparent chitosan aemgels prepared with formaldehyde crosslinking. The macroscopic size changes of the wet gels indicate that microstructure formation is controlled by the timing of chitosan coagulation, which depends among others on urea concentration. The aldehyde-free, microstructure-tunable process provides a new series of transparent biopolymer aemgels with "true aerogel" mesoporous structures.