A review on preparation of nanocellulose for new green working fluid in heat transfer application

Cellulose is one of the sustainable raw materials and natural polymers as it can be abundantly found in biomass products. Nanocellulose consist of three categories which are bacterial nanocellulose (BNC), cellulose nanofibrils (CNF), and cellulose nanocrystalline (CNC) has the potential to be used for working fluid in heat transfer application with nanofluid characteristics. Nanofluid is defined as a fluid that has nanoparticle dispersed in it. This nanoparticle will enhance the thermophysical properties of the base fluid. Many types of nanofluid have been used widely in heat transfer applications such as Al2O3, TiO2, CuO and CNT but only a few studies had been done using green and environmentally friendly materials. Therefore, nanocellulose is one of the best candidates as one of the nanofluid's materials which has green and environmentally friendly properties. The preparation of nanofluid is very crucial because improper preparation will lead to deterioration of nanofluid and decrease the thermal performance as heat transfer working fluid. Other than that, low stability cause nanoparticle to form clusters and sediment due to its strong van der Waals interaction. Therefore, this study will focus on the preparation method of the nanocellulose for heat transfer application. Other than that, methods of stability analysis for nanocellulose also presented in this paper.