Cellulose nano-fiber and fly-ash based nanohybrids: a facile and sustainable thermal insulating material

Recent years have witnessed a huge surge in energy consumption by the building sector, for maintaining a pleasant atmosphere inside the building. Keeping in mind the possible energy crisis in future, the use of thermal insulators can present an extensive solution to reduce energy consumption. Due to the high demand for energy, a higher amount of coal is used in thermal power plants, which produce a huge amount of fly-ash as industrial waste that poses a serious environmental problem. In this direction, the extensive utilization of fly-ash to make useful materials is highly demanding for societal benefits. This strategy will offer a dual advantage in transforming waste to wealth coupled with potential to serve in the energy sector through effective thermal insulation. On this similar line, we have fabricated biomass-derived cellulose nano-fiber based thermal insulators and incorporated fly-ash as a reinforcer to increase the mechanical strength and fire-retardancy. Interestingly, after incorporation of fly-ash, low thermal conductivity of 0.034 W m − 1 K − 1 was achieved in the nanohybrid material with reinforcement of mechanical strength up to 2.9 MPa. Furthermore, the thermal stability was enhanced in this novel organic-inorganic nanohybrid, which may create a sustainable solution for energy related issues in future.