Fluorine-free superhydrophobic characterized coatings: A mini review

Abstract

The scientific fraternity and coating companies have researched and developed coatings with superhydrophobic features for a wide range of applications, varying from automotive, oceanic, pharmaceutical, and thermal and power sectors, over the preceding few years. The self-cleaning features of superhydrophobic surfaces exhibit pronounced dust repelling and lower dust adhesiveness qualities, along with incomparable water repellence for maritime, automotive, and pharmaceutical applications. The advancement of super-hydrophobic surfaces for averting the accrual of impurities on surfaces is an active space of exploration globally. A lesser hysteresis of contact angle leads to drops of water sliding effortlessly on such surfaces. The solid surfaces’ surface energy can be weakened by fixing materials of lesser surface energy on the exterior, which can be performed by the following dual methods; either by fixing materials of reduced surface energy straight onto the exterior of a substrate in the form of a coating of that material, or by fixing materials of less surface energy on the exterior of nano-architectural structures and then dropping the coating of those nanoscale materials on the exterior of the substrate. The generation of nanoscale irregularities on substrates by dropping nanostructure layers on surfaces makes it an attractive option since, usually, nanomaterials have a minimum of one dimension, ranging from 1 - 100 nm. The nanostructures’ sizes unveil exceptional physical and chemical characteristics, principally owing to their greater specific surface area to volume quotient. This review encompasses the non-fluorinated superhydrophobic coatings developed to date.