Simplified surface wettability determination defined by new interfacial interaction compatibility expressions for composites

To date, the compatibility of two different materials of composites has been determined solely by the empirical surface wettability approach, using methods such as contact angle measurement. However, this method can be quite cumbersome, requiring specific equipment and different liquid probes. Therefore, this paper aims to develop a simplified approach to determining surface wettability, incorporating novel generalized expressions that account for the interfacial interaction compatibility of various constituents within composites. First, an economical, simplistic, and verified water probe method is employed to measure apparent contact angles. The determined apparent contact angles are shown to fit well within the thresholds established from the available findings. Then, new mathematical expressions incorporating the adhesion concept are derived to describe the constitutive relationship between the ratios of apparent contact angles of two materials for composites formation and their liquid-solid interfacial tension by fitting data gathered from existing studies. The newly developed constitutive equations offer a convenient and reliable means to determine the compatibility relationships of numerous composite constituent mixes for varying contact angle ratios. This approach enables a simple and cost-effective estimation of surface interaction via the apparent contact angle between water and the composite constituents.