Versatile Aerogels for Sensors

Abstract

Aerogels are unique solid‐state materials composed of interconnected 3D solid networks and a large number of air‐filled pores. They extend the structural characteristics as well as physicochemical properties of nanoscale building blocks to macroscale, and integrate typical characteristics of aerogels, such as high porosity, large surface area, and low density, with specific properties of the various constituents. These features endow aerogels with high sensitivity, high selectivity, and fast response and recovery for sensing materials in sensors such as gas sensors, biosensors and strain and pressure sensors, among others. Considerable research efforts in recent years have been devoted to the development of aerogel‐based sensors and encouraging accomplishments have been achieved. Herein, groundbreaking advances in the preparation, classification, and physicochemical properties of aerogels and their sensing applications are presented. Moreover, the current challenges and some perspectives for the development of high‐performance aerogel‐based sensors are summarized.

Recent Progress on Nanocellulose Aerogels: Preparation, Modification, Composite Fabrication, Applications

“…[ 133a,157 ] In recent years, considerable progress and encouraging accomplishments have been achieved in terms of aerogel‐based sensing materials, owing to their highly porous, continuous, and homogeneous structure. [ 158 ] Nanocellulose aerogels, as a kind of important polymeric aerogel, have revealed advantages such as biocompatibility, degradability, and renewability for sensing applications. [ 30b,110,140,159 ] Based on functions, the main categories of sensors using nanocellulose include strain and pressure sensors, chemical sensors, and biosensors.…”

Printed aerogels: chemistry, processing, and applications

“…Their skeletal and pore structure can be regulated at the nanoscale to achieve a number of extraordinary physical properties, including ultra-low density and thermal conductivity, ultra-high specific surface area and ultra-strong adsorption capacity. These properties make aerogels an ideal material family for a wide range of potential applications, including energy storage, 1 catalyst supports, 2 sensors, 3 chemical adsorption, 4 thermal insulation, 5 biomedical, 6 and shock absorption, 7 thereby promoting the development of industries such as environmental protection, 4 construction, 8 chemical, 9 aerospace, 10 transportation, 1 artificial intelligence, 11 and medicine. 6 Because of the controllability of the nanostructures, excellent physical properties, and potential application scopes, aerogels have attracted increasing interest from both the academic and industrial communities in the past two decades.…”

Structural Diversity in Cryoaerogel Synthesis

“… 6 , 7 Furthermore, a variety of sensing applications were reported. 8 − 10 Owing to the good accessibility of the surface, thin films or coatings from these materials experience an increasing interest. 11 − 13 In most cases, the aerogel coating is prepared by dropcasting and drying a slurry consisting of an aerogel material, solvents, and a binding substance like Nafion.…”