Enhancement of hydrophobicity of natural rubber latex films using diatomaceous earth

Enhancement of the hydrophobic nature of natural rubber latex (NRL) films will open up a wide range of applications for them. Incorporating hexadecyltrimethoxysilane treated superhydrophobic diatomaceous earth (DE) in NRL, resulted in films with increased hydrophobicity. The nano-scale surface roughness for the superhydrophobic surface was provided by DE and low surface energy was achieved by treating DE with hexadecyltrimethoxysilane (treated DE). Surface wettability and morphology were analyzed by water contact angle (WCA) measurements and scanning electron microscopic analysis, respectively. About 38% wt/wt hexadecyltrimethoxysilane to DE ratio could make superhydrophobic DE with WCAs larger than 150 degrees. A dispersion of treated DE was incorporated into NRL resulting in hydrophobic NRL films possessing WCAs greater than 110 degrees with 41% treated DE particle loading. The resulting NRL films were harder and had smaller tensile strength compared to normal NRL film.