Spataru C.I.,National Institute of Chemical and Petrochemical Research |
Purcar V.,National Institute of Chemical and Petrochemical Research |
Ghiurea M.,National Institute of Chemical and Petrochemical Research |
Somoghi R.,National Institute of Chemical and Petrochemical Research |
Donescu D.,National Institute of Chemical and Petrochemical Research
Journal of Optoelectronics and Advanced Materials | Year: 2013
There have been studied hybrids obtained from hydrophobic modified silica nanoparticles with alkyltrialkoxysilanes and bilayered hybrids prepared by co-hydrolysis from hexadecyltrimethoxysilane and tetramethoxysilane (C 16TMS/TMOS=1/4). Two approaches were followed to achieve superhydrophobicity: (i) nanoparticles were deposited on smooth or microroughened substrates, under controlled conditions, to induce nanoscale surface roughness on substrates; (ii) particles were mixed with bilayered hybrids solutions and then deposited on smooth glass surfaces. The hydrophobization of silica nanoparticles prepared by sol-gel process was performed with alkyltrimethoxysilanes (C1-C16), aminopropyltrimethoxysilane (APTMS) or fluorooctyltriethoxysilane (OFTES). By mixing 80wt% filler (silica particles modified with octyltrimethoxysilane (OTMS)) with 20wt% binder-(C 16TMS/TMOS hybrid) there were obtained continuous heterogeneous thin films with a contact angle towards water of 158. The deposition of nanofillers modified with specific silanes (having alkyl chains between 3 and 16 carbon atoms) on C16TMS/TMOS films leads also to superhydrophobic surfaces. The obtained hybrids were finally studied by infrared spectroscopy (FT-IR), thermal analyzes, refractometry, and scanning electron microscopy (SEM). The refractometric analyzes for alkyltrialkoxysilanes dispersed in ethanol has revealed the nanostructuration of the precursors used for the hydrophobic process of the silica particles.