Preparation of Highly Adhesive and Superhydrophobic Epoxy-Based Thin Film by Sol–Gel Process

In this study the preparation of a superhydrophobic epoxy-based thin film with excellent high adhesion properties was carried out by mixing epoxy polymer solution, MTMOS solution, and silica powder. It was found that the adhesion between the film and a substrate could be improved by adding PET fibers to the above solution. The characteristic properties of the as-prepared films were analyzed by contact angle measurements, scanning electron microscopy (SEM) and by atomic force microscopy (AFM). The adhesion between the film and the substrate was estimated by the cross-cut method. The experimental parameters were: the mole fraction of MTMOS, weight fraction of silica powder, weight fraction of PET fibers, and the curing temperature. The result indicated that the contact angle and the sliding angle of the hybrid film were 153° and 4°, respectively, and the adhesion test result was very good (5B degree), while the mole fraction of MTMOS was 0.4, the silica powder concentration was 30 wt%, and the PET fibers concentration was 0.15 wt%, with the curing temperature in the range of 130–180°C.