Harnessing the Flexibility of Lightweight Cellulose Nanofiber Composite Aerogels for Superior Thermal Insulation and Fire Protection

Abstract

Thermally insulating materials from renewable and readily available resources are in high demand for ecologically beneficial applications. Cellulose aerogels made from lignocellulosic waste have various advantages. However, they are fragile and breakable when bent or compressed. In addition, cellulose aerogels are flammable and weather-sensitive. Hence, to overcome these problems, this work included the preparation of polyurethane (PU)based cellulose nanofiber (CNF) aerogels that had flexibility, flame retardancy, and thermal insulation. Methyl trimethoxysilane (MTMS) and water-soluble ammonium polyphosphate (APP) were added to improve the cross-linking, hydrophobicity, and flame-retardant properties of aerogels. The flexibility of chemically cross-linked CNF aerogels is enhanced through the incorporation of polyurethane via the wet coagulating process. The aerogels obtained during this study have exhibited low weight (density: 35.3− 91.96 kg/m 3 ) together with enhanced hydrophobic properties, flame retardancy, and decreased thermal conductivity (26.7−36.7 mW/m K at 25 °C). Additionally, the flame-retardant properties were comprehensively examined and the underlying mechanism was deduced. The aerogels prepared in this study are considered unique in the nanocellulose aerogel category due to their integrated structural and performance benefits. The invention is considered to substantially contribute to the large-scale manufacture and use of insulation in construction, automobiles, and aerospace.

Chemically tuned cellulose nanocrystals/single wall carbon nanosheet based electrodes for hybrid supercapacitors

“…The fabrication of 9 wt% MACNC to CNT surfaces has been observed to exhibit exceptional electrochemical behavior due to factors such as strong interaction modified CNC and CNTs leading to a more stable and uniform distribution of CNTs within the MACNC matrix, 47 enhanced mechanical/thermal properties of the CNT-based nano-composites, 47–49 optimized porosity and high surface area, 50 which facilitates the adsorption of electrolyte ions thereby enhancing the performance. 51 These findings suggest that the 9 wt% cellulose content may be an optimal choice, and the optimal charge transfer can be attributed to the synergistic effect of MACNC and CNTs, which can lead to enhanced electrochemical performance, as shown in Fig.…”

Stimuli-Responsive Chiral Cellulose Nanocrystals Based Self-Assemblies for Security Measures to Prevent Counterfeiting: A Review

“…Recently, there has been a growing interest in the luminous response of biopolymers like cellulose to external stimuli, demonstrating their potential for use in anticounterfeiting measures . Cellulose, a naturally occurring polymer characterized by its renewable nature and ample availability, possesses remarkable mechanical qualities, distinctive optical properties, and favorable biocompatibility, rendering it a highly appealing medium for the conveyance of intelligent optically active substances. − At the nanoscale, the orderly arrangement of cellulose molecules gives rise to observable coloration. NC can be roughly categorized into cellulose nanocrystals (CNCs) and cellulose nanofibers (CNFs) .…”