Superhydrophobically-Modified Polylactic Acid Films with Natural Additives from Walnut Shells

In this study, a natural additive was prepared from the walnut shells and it is blend with polylactic acid (PLA) to fabricate a composite film to improve mechanical properties and creating self-cleaning surfaces with hydrophobic silica nanoparticles. The surface of the PLA films was modified to be superhydrophobic by applying embedded method with polydimethylsiloxane-coated silica nanoparticles (i.e., ca. 14 nm). Compared to bare PLA films, the treated PLA films demonstrated over 90% reduction in bacteria attachment on the surfaces. Furthermore, the film obtained through the embedded method had superior coating durability compared to the film obtained through dip-coating method. Overall, our superhydrophobically-modified PLA films is expected to be used as food packaging materials, food storage materials, and food contact materials in food industry because it complements the weak mechanical properties of bare PLA films and has durable anti-biofouling and self-cleaning properties.