Nano-heat-sink thin film composite of PC/three-dimensional networked nano-fumed silica with exquisite hydrophobicity

Abstract

Efficient utilization of fumed silica with thermoset resins had been investigated for high temperature applications, which led to extensive exploration of newer materials. The present prospect represents a similar progress in the field of thermoplastic material and focuses on the burgeoning field of heat sinking materials and hydrophobicity. Nanoscale coalescence of Nano Fumed Silica (NFS) filler in a polycarbonate (PC) matrix is ameliorated by two different techniques viz. solvent casting and spray coating. The spray-coating technique was reconnoitred by numerical modelling parameters. The characteristic peak appears at 1094 cm⁻¹ and 3821 cm⁻¹ in the FTIR which corroborate the interaction between PC and NFS. PC/NFS solution with workable viscosity 25 cP exemplifies homogeneous dispersion in the PC matrix ascertained by FESEM with utmost loading of 10 wt% NFS. An 85% increment in contact angle was observed which justified with accretion in surface roughness (12.5 nm) of the composite as well as from the Cassie–Baxter model. Effective thermal conductivity of the composite was mathematically computed with 46% decrement as compared to a pristine PC counterpart, which is in agreement with the TGA results as char residue is enhanced from 22% to 49%. The results affirm that the spray-coated samples give more efficacy in terms of heat sinking capacity and hydrophobic characteristics as compared to solvent-casted films and justifies its competency to replace conventional thermoplastic composites. So, these membranes can be effectively and economically employed as heat sinking source in automotive/automobile industry, electronic gadgets and defence electronics.