A review on multifunctional aerogel fibers: processing, fabrication, functionalization, and applications

Aerogels have been frequently reported in three-dimensional (3D) monolith bulk, granule, and twodimensional (2D) thin-film geometries. However, their commercialization has been widely restricted due to the lack of flexibility, extensibility, and fragile network structures. Recently, a new class of aerogels, i.e. aerogel fibers has emerged. When conventional aerogels are transformed into fibers (sub micron or nanofibers), their performance may enhance remarkably. Therefore, such aerogel fibers can exhibit improved mechanical performance, favorable flexibility, higher tensile strength, and enhanced extensibility. This will make them a suitable candidate for applications that require high mechanical flexibility and to be stretchable. In conjunction with the superior thermal insulation performance of aerogels, aerogel fibers can be extensively used in other commercial sectors where load-bearing is crucial. In this short review, we intend to assess the current technologies for the production of aerogels in fiber geometry, called aerogel fiber. Materials used for this purpose, along with the post-processing and functionalization methods, are also evaluated. Their recent breakthroughs in emerging applications in a variety of engineering fields are covered. A discussion of current challenges, limitations, and the urgent need for the development of new technologies for the continuous production of aerogel fibers is provided. A road map pointing to a future direction in aerogel fiber field will be discussed. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

Aerogel fibers, as a new class of materials, have superior mechanical performance and flexibility, making them suitable for applications requiring high flexibility and stretchability. This review assesses the current technologies for producing aerogel fibers, the materials used, and the methods of post-processing and functionalization. It covers the recent breakthroughs in emerging applications and discusses the current challenges and the need for new technologies in continuous production of aerogel fibers. A roadmap for the future direction in the field of aerogel fibers is also discussed.