Aerogels are nanoporous materials with excellent properties, especially super thermal insulation. However, owing to their serious high brittleness, the macroscopic forms of aerogels are not sufficiently rich for the application in some fields, such as thermal insulation clothing fabric. Recently, freeze spinning and wet spinning have been attempted for the synthesis of aerogel fibers. In this study, robust fibrous silica-bacterial cellulose (BC) composite aerogels with high performance were synthesized in a novel way. Silica sol was diffused into a fiber-like matrix, which was obtained by cutting the BC hydrogel and followed by secondary shaping to form a composite wet gel fiber with a nanoscale interpenetrating network structure. The tensile strength of the resulting aerogel fibers reached up to 5.4 MPa because the quantity of BC nanofibers in the unit volume of the matrix was improved significantly by the secondary shaping process. In addition, the composite aerogel fibers had a high specific area (up to 606.9 m²/g), low density (less than 0.164 g/cm³), and outstanding hydrophobicity. Most notably, they exhibited excellent thermal insulation performance in high-temperature (210 °C) or low-temperature (−72 °C) environments. Moreover, the thermal stability of CAFs (decomposition temperature was about 330 °C) was higher than that of natural polymer fiber. A novel method was proposed herein to prepare aerogel fibers with excellent performance to meet the requirements of wearable applications.

A large quantity of coal fly ash is generated worldwide from thermal power plants, causing a serious environmental threat owing to disposal and storage problems. In this work, for the first time, coal fly ash is converted into advanced and novel aerogel fibers and high-purity α-Al₂O₃. Silica–bacterial cellulose composite aerogel fibers (CAFs) were synthesized using an in situ sol-gel process under ambient pressure drying. Due to the unique “nanoscale interpenetrating network” (IPN) structure, the CAFs showed wonderful mechanical properties with an optimum tensile strength of 5.0 MPa at an ultimate elongation of 5.8%. Furthermore, CAFs with a high porosity (91.8%) and high specific surface area (588.75 m²/g) can inherit advanced features, including excellent thermal insulation, stability over a wide temperature range, and hydrophobicity (contact angle of approximately 144°). Additionally, Al₂O₃ was simultaneously extracted from the coal fly ash to ensure that the coal fly ash was fully exploited. Overall, low-cost woven CAFs fabrics are suitable for wearable applications and offer a great approach to comprehensively use coal fly ash to address environmental threats.

A high-efficiency composite adsorbent was synthesized by mixing cellulose and graphene oxide (GO) in the lithium chloride/N,N-dimethyl-acetamide system. The cellulose/GO composite (D-RCGO) was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, elemental analysis, and thermal gravimetric analysis. The influences of various parameters on the removal of Ce(III), such as the adsorbent dosage, temperature, initial Ce(III) concentration, contact time, and pH, were optimized using a range of batch adsorption experiments. Adsorption kinetics displayed adsorption behavior according to the Langmuir isotherm model and pseudo-second-order model. The X-ray photoelectron spectroscopy analysis showed that the two peaks of Ce-3d almost disappeared after the desorption in NaCl solution, which indicated that the adsorption belonged to the ion exchange adsorption mechanism. Furthermore, the theoretical maximum capacity of the adsorption of Ce(III) onto D-RCGO was 225.8 mg·g-1. This work suggested that the D-RCGO composite membranes could serve as an effective and eco-friendly adsorbent for rare earth pollutant removal in wastewater treatment.