Superhydrophobic Silicon Nanocrystal–Silica Aerogel Hybrid Materials: Synthesis, Properties, and Sensing Application

Abstract

Silicon nanocrystals (SiNCs) are abundant and exhibit exquisitely tailorable optoelectronic properties. The incorporation of SiNCs into highly porous and lightweight substrates such as aerogels leads to hybrid materials possessing the attractive features of both materials. This study describes the covalent deposition of SiNCs on and intercalation into silica aerogels, explores the properties, and demonstrates a prototype sensing application of the composite material. SiNCs of different sizes were functionalized with triethoxyvinylsilane (TEVS) via a radical grafting approach and subsequently used for the synthesis of photoluminescent silica hybrids. The resulting SiNC-containing aerogels possess high porosities, SiNC-based size-dependent photoluminescence, transparency, and a superhydrophobic macroscopic surface. The materials were used to examine the photoluminescence response toward low concentrations of 3-nitrotoluene (270 μM), demonstrating their potential as a sensing platform for high-energy materials.

Super pressure-resistant superhydrophobic fabrics with real self-cleaning performance

“…Once immersed in the acidic SiO 2 @HD-POS emulsion, the -OH groups on the surface of the PET microfibers could adsorb SiO 2 @HD-POS ( Rahman Bhuiyan et al., 2018 ; Tian et al., 2020 ; Zhang et al., 2021 ). The bonding between PET and SiO 2 @HD-POS was enhanced by curing at 140°C ( Hong et al., 2016 ; Kehrle et al., 2018 ). During subsequent immersion in the SiO 2 @FD-POS emulsion, SiO 2 @FD-POS was adsorbed on the PET@HD fabric by hydrogen bonding of the -OH groups between them ( Liu et al., 2017 ; Tian et al., 2020 ).…”

Durable, self-cleaning and anti-fouling superhydrophobic coating based on double epoxy layer

“…Compared to covering the surface with low surface energy epoxy, constructing micro-nano scale rough structure on the surface by adding silica nanoparticles is a more efficient way to enhance the non-wettability of the coating [34][35][36]. Figure 4 shows the effect of increasing the SiO 2 content on the coating wettability.…”

Aerogels for Sensor Application

“…Silicon nanocrystals having excellent optoelectronic properties, when incorporated in lightweight aerogels having a high porosity, resulted in a hybrid composite material having the properties of both silicon nanocrystals and aerogels. Different sized silicon nanocrystals were formulated with triethoxyvinylsilane and finally used to develop highly porous photoluminescent silica hybrids, which a potent sensor for high-energy materials [66].…”