Polysaccharides Based Random and Unidirectional Aerogels for Thermal and Mechanical Stability

• 作者: CHAUDARY Aneeba CHUDHARY Tayba FAROOQ Amjad ZHANG Meiling PATOARY Mohammed Kayes LIU Lifang
• 来源期刊: 东华大学学报（英文版）
• 学科: 工学
• 年，卷（期）: 2022,（2）
• 所属期刊栏目: Fiber Materials and Membrane Science
• 页码范围: 103-109
• 页数: 7页
• 分类号: TS102.9
• 语种: 英文
• DOI: 10.19884/j.1672-5220.202109005

摘要

Owing to the increasing energy demands and the environmental constraints, the need for bio-based materials has been on the rise due to their variety of favorable properties like biocompatibility, cost-effectiveness, large specific surface area, high porosity, and non-toxicity. Thermal stability and mechanical strength of aerogels are highly dependent on their micro-porous structures. A three-dimensional structure based on cellulose nanofiber/chitosan ( CNF/CS) aerogels was built using two different freezing methodologies, namely random freezing, and unidirectional freezing techniques, by changing mold shapes. The unidirectional aerogels ultimately resulted in high-temperature stability and mechanical strength. The results show that the unidirectional CNF/CS( u-CNF/CS) aerogels contain controlled micro porous orientation relative to random-CNF/CS ( r-CNF/CS) aerogels with the disordered porous distribution. The high-temperature stability with an increase of glass transition temperature Tg from 275 ℃( CNF ) to 283 ℃ ( CNF/CS ) , the ultra-low thermal conductivity of 0. 030 W/( m · K ) , and mechanical robustness of u-CNF/CS aerogels make them quite favorable for practical applications.