材料科学
保温
复合材料
热导率
气凝胶
纤维素
抗压强度
水分
热阻
化学工程
热稳定性
淀粉
热的
化学
有机化学
物理
工程类
气象学
图层(电子)
作者
Yanwen Zhao,Mingzhen Tian,Pei Huang
出处
期刊:Cellulose
[Springer Nature]
日期:2021-02-17
卷期号:28 (6): 3505-3513
被引量:27
标识
DOI:10.1007/s10570-021-03750-9
摘要
Characterized by low cost, flame resistance and mild processing procedure, freeze-dried clay aerogel is an ideal alternative for thermal insulation in building sector. However, the negatively charged surface of clay platelet and high freezing rate require the addition of a high amount of polymer to ensure the integrity of aerogel during freezing stage, which inevitably increases the density as well as the thermal conductivity of aerogel. Herein, we reported a green and versatile strategy to fabricate crack-free yet thermal insulative aerogel by introducing cellulose nanofibrils (CNFs) into starch/clay system. Owing to the abundant hydroxyl groups, high aspect ratio and excellent mechanical strength of CNFs, the CNF/starch/clay aerogels prepared exhibit enhanced crack resistance and compressive strength, enabling the reduction of starch content from 4 to 2% while maintaining the integrity of aerogel in the process of freezing. As a result, the density and thermal conductivity of aerogel significantly decrease from 0.12 to 0.05 g/cm3 and 48.3 to 41.5 mW/mK respectively. Further crosslinked by glutaraldehyde, the CNF/starch/clay aerogels display improved moisture resistance, shape recovery and thermal stability. Being versatile and cost-effective, the present approach is thought-provoking for the up-scale production of freeze-dried clay aerogel for thermal insulation.
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