| Summary: | 碩士 === 國立成功大學 === 化學工程學系碩博士班 === 92 === Silica particles with different surface wettabilities were prepared by surface esterification with butanol, octanol, and dodecanol. Such silica particles were dispersed in chloroform and spread on the air/water interface to prepare the particle monolayer. The effects of surface wettability on the behavior of the particle monolayer and the characteristic of corresponding Langmuir-Blodgett film were studied. The results show that the particles modified by octanol and dodecanol have higher hydrophobicility than that modified by butanol. The monolyer of particles with higher hydrophobicility show the characteristics of large lift-off point, higher compressibility, and significant hysteresis. The LB films prepared by the more hydrophobic particles exhibit 2-dimentional (2D) aggregative domains with low ratio of surface coverage. Such properties can be attributed to the higher Van der Waals attraction among the particles comparing with the interaction between the particles and water subphase. The monolayer prepared by butanol-modified silica particles shows a contrary behavior due to the higher interaction of silica particles with water. The LB films of butanol-modified silica particles exhibit a more uniform morphology without 2D aggregative domains. However, 3D aggregative structure can be inspected on the LB film, which is probably due to the less dispersion condition of these particles in chloroform.
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