19TH Asian Chemical Congress, İstanbul, Türkiye, 9 - 14 Temmuz 2023, ss.255
Superhydrophobic (SHP) surfaces are non-wettable by water and have great significance for a broad range of technological applications. Existing methods of fabricating SHP surfaces have limitations in terms of excessive usage of solvents, need for tedious and lengthy chemical processes and cost of materials. Herein, we present mechanochemical grafting of methyl terminated poly(dimethylsiloxane) (PDMS) to nanoparticles for practical and sustainable fabrication of SHP surfaces. Methyl-terminated polydimethylsiloxane is usually considered to be inert and, thus, not reactive with surfaces. The grafting of silicone to the nanoparticles is achieved by using a planetary ball mill. During the ball milling, collisions between tungsten carbide balls and walls of the chamber results in hydrolytic rupture of siloxane bonds and mechanochemical generation of free radicals in the silicone, which grafts to the surface of nanoparticles. The entire process consists of mixing of two widely available components, PDMS and nanoparticles, followed by agitation in a planetary ball mill for 5 min. The SHP powder with a water contact angle of 165o and sliding angle of 2o is readily obtained at the end of the process without need for any washing, separation and drying steps. The mechanistic force suggest that generation of free radicals induced by mechanochemical pathways enables covalent grafting of PDMS. The use of non-functional and lowcost PDMS is an enabling aspect for applications. The superhydrophobic powder fabricated with a mechanochemical approach offers enormous potential with scalability, sustainability, cost-effectiveness, simplicity, and universality.
Keywords: Mechanochemistry, superhydrophobic surfaces,
PDMS, sustainable