Inorganic Salts Induce Thermally Reversible and Anti‐Freezing Cellulose Hydrogels. Issue 22 (18th April 2019)

• Record Type: Journal Article
• Authors: Zhang, Xiong‐Fei; Ma, Xiaofeng; Hou, Ting; Guo, Kechun; Yin, Jiayu; Wang, Zhongguo; Shu, Lian; He, Ming; Yao, Jianfeng
• Is Part Of: Angewandte Chemie international edition. Volume 58:Issue 22(2019)
• Page Start: 7366
• Page End: 7370
• Publication Date: 2019-04-18
• Subjects: anti-freezing properties -- cellulose -- hydrogels -- sol–gel processes; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201902578
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Inspired by the anti‐freezing mechanisms found in nature, ionic compounds (ZnCl2 /CaCl2 ) are integrated into cellulose hydrogel networks to enhance the freezing resistance. In this work, cotton cellulose is dissolved by a specially designed ZnCl2 /CaCl2 system, which endows the cellulose hydrogels specific properties such as excellent freeze‐tolerance, good ion conductivity, and superior thermal reversibility. Interestingly, the rate of cellulose coagulation could be promoted by the addition of extra water or glycerol. This new type of cellulose‐based hydrogel may be suitable for the construction of flexible devices used at temperature as low as −70 °C. Abstract : "Hotspot" in materials science : Anti‐freezing and thermally reversible cellulose hydrogels were fabricated in an aqueous ZnCl2 /CaCl2 solution, whereby the Zn 2+ ions contribute to the cellulose dissolution and the Ca 2+ ions act as a gelling agent. These new cellulose‐based hydrogels may find application in flexible and wearable devices for use at temperatures as low as −70 °C.