Aerogels Derived from Polymer Nanofibers and Their Applications

• Published in: Macromolecular rapid communications. Vol. 39; no. 14; pp. e1700724 - n/a
• Main Authors: Qian, Zhenchao, Wang, Zhen, Zhao, Ning, Xu, Jian
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.07.2018
• Subjects: aerogels; Brittleness; Bulk density; Carbon fibers; Cellulose - chemistry; Chemical composition; Chemical reduction; Construction; Elasticity; Electrocatalysts; Fabrication; Gels; Gels - chemistry; Nanofibers; Nanofibers - chemistry; Organic chemistry; Oxygen - chemistry; Oxygen reduction reactions; Polymers; Polymers - chemistry; Porosity; Silica; Silica aerogels; Silicon dioxide; Silicon Dioxide - chemistry; Solvents - chemistry; Surface Properties; Tissue engineering; aerogels; nanofibers; polymers
• ISSN: 1022-1336; 1521-3927; 1521-3927
• DOI: 10.1002/marc.201700724

Aerogels are gels in which the solvent is supplanted by air while the pores and networks are largely maintained. Owing to their low bulk density, high porosity, and large specific surface area (SSA), aerogels are promising for many applications. Various inorganic aerogels, e.g., silica aerogels, are intensively studied. However, the mechanical brittleness of common inorganic aerogels has seriously restricted their applications. In the past decade, nanofibers have been developed as building blocks for the construction of aerogels to improve their mechanical property. Unlike traditional frameworks constructed by interconnected particles, nanofibers can form chemically cross‐linked and/or physically entangled 3D skeletons, thus showing flexibility instead of brittleness. Therefore, excellent elasticity and toughness, ultralow density, high SSA, and tunable chemical composition can be expected for the polymer nanofiber‐derived aerogels (PNAs). In this review, recent research progress in the fabrication, properties, and applications of PNAs is summarized. Various nanofibers, including nanocelluloses, nanochitins, and electrospun nanofibers are included, as well as carbon nanofibers from the corresponding organic precursors. Typical applications in supercapacitors, electrocatalysts for oxygen reduction reaction, flexible electrodes, oil absorbents, adsorbents, tissue engineering, stimuli‐responsive materials, and catalyst carriers, are presented. Finally, the challenges and future development of PNAs are discussed. Polymer nanofibers are employed as building blocks to construct aerogels, which exhibit excellent elasticity and toughness, low density, high porosity, and tunable chemical composition. Various species of nanofibers, including nanocelluloses, nanochitins, electrospun nanofibers, and carbon nanofibers are involved. The aerogels also have great potential in electrochemical applications, water purification, biomedical applications, and smart materials.