| Summary: | 碩士 === 國立成功大學 === 化學工程學系碩博士班 === 93 === Silica particles are hydrophobilize by physical adsorption of cationic surfactants, alkyltrimethylammonium bromide. The effects of surface modification, as well as the length of alkyl chain, on the monolayer behavior of silica particle at the air/water interface, and the packing structure of the particulate films are studied first. The particulate films were then used to prepare superhydrophobic surfaces by surface modification an alkyl silane monolayer. The results show that the particle modified by adsorption of ionic surfactants have an amphiphilic property at the air/water interface. Such monolayer exhibits low compressibility, low hysteresis, higher re-spreading characteristic, and low collapse pressure. The LB films of silica particles exhibit an uniform morphology and closely-packed structure. The wettability of the particulate films based on the surface structure of silica particles of single size exhibit a high advancing contact angle (θA) to the water (θA≒160°), but with high hysteresis. When the film structure is constructed by particles of multiscale, with particles of small size assembled on large ones, a surface with high contact angles and smaller hysteresis can be prepared.
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