Chemical surface modifications for highly reflective glass/vinyl ester composites with improved silver film adhesion

Silvered glass/vinyl ester composite was developed in this study as a novel approach, to achieve highly reflective surfaces with improved adhesion. As a prerequisite, surface properties of vinyl ester and the changes occurring after the required modifications need to be well understood, but have not been investigated so far. Therefore, one-step and simple pretreatments -alkali or tin-, were applied to modify the composites in short durations. Atomic force microscopy revealed that tin treatment did not change the surface roughness considerably, but increase in O/C ratio was determined by x-ray photoelectron spectroscopy. This led to higher adhesion strength (∼5B) at the silver/polymer interface and a smooth silver film having a reflectance of 95.4% at 550 nm. Alkaline treatment caused more micro holes and layered etchings on the surfaces and thus the resultant silver film was less smooth. The reflectance could reach 94.5% but after 4-folds of duration. No significant change in the composite interlaminar mechanical properties was determined. Fourier transform infrared spectroscopy, scanning electron microscopy, and contact angle measurements were also performed to further characterize the polymer surfaces. The results indicate the potential of these composites for highly reflective and conductive materials to be used in solar energy and aeronautics applications.