| dc.description.abstract | In this research, sol-gel process was utilized to fabricate organic/inorganic nano-composite material and superhydrophobic film. Organic/Inorganic composite material included two separate parts, one was Epoxy/SiO2 hybrid material and the other one was PMMA/SiO2 composite sphere. The fabrication of superhydrophobic film also discussed with hydrophobic and superhydrophobic film individually.
Sol-gel process was utilized to synthesize epoxy-silica hybrid materials in nanoscale in recent years. The purpose of this part is to fabricate hybrid material in nanoscale and improve the thermal property of epoxy resin. From these results, the epoxy and silica could hybrid in nanoscale under extensive pH value of the system in one-step process. On the other hand, the two-step process led to a phase separation phenomenon after mixing epoxy resin and precursor without coupling agent γ-glycidoxypropyl-methyldiethoxysilane (GMPDES). GPMDES was utilized to modify the surface properties of the silica via the sol-gel process. The role of the GPMDES is to provide covalent bonding between the epoxy resin and silica and avoid the aggregation of silica. The GPMDES could avoid the phase separation problem of hybrid materials and enhance the thermal stability of the materials through this process. At the same time, the Glass transfer temperature(Tg) of the materials also increased proportionally to the content of silica from 80℃ to 113℃.
In the recent research on fabrication method of composite sphere, the core sphere should be modified the surface property by polymerization method first. In this part, the PMMA/SiO2 composite sphere was synthesized by sol-gel process with the mono-disperse PMMA sphere (300nm) without any surface modify successfully. In this research, the coupling agent with amine group, N-β(aminoethyl)-γ-aminopropyltrimethoxysilane (AAPTMS), was utilized with TEOS to synthesize PMMA/SiO2 composite sphere. From the result, when the mole ratio between AAPTMS/TEOS was 1/9 and the ratio between PMMA and silica was 1/2, the diameter of the composite sphere will be 400nm. The thickness of the silica shell structure influenced with the concentration of surfactant in the system, the ratio of AAPTMS/TEOS and PMMA/Silica in this study. The thickness of the silica shell structure also influenced the thermal stability of the composite sphere. The silica hollow sphere was obtained by removing PMMA sphere by calcinations.
In the research field of superhydrophobic film, the fabricate process should be divided into two steps. First one is the fabrication of roughness of the surface and the second part is coating the low surface energy material. In this research, we expect to fabricate superhydrophobic film by one step.
The film with hydrophobic property could be synthesized with methyltriethoxysilane (MTES) by sol-gel process. The film could fabricate with extensive conditions and exist hydrophobic property. From the results, the hardness of the film could achieve 5H and the transparency of the film was 98%. The average roughness (Ra) increased by raising the reaction temperature. The film will be hydrophilic when the reaction temperature higher than 450℃ due to the decompose of methyl group of the film surface.
The film with superhydrophobic property could be synthesized by MTES and silica powder. From the results, the contact angle higher than 150° when the ratio of SiO2/MTES = 21.8 wt%. Hardness of the film could achieve 3H by adjusting TEOS/MTES mole ratio = 3.42 and contact angle still maintain above 150°. Taguchi Quality Method was used to find the optimum operation conditions in this study. Two of Taguchi Quality Methods were used in this research to find the optimum production conditions for four different fabricate conditions of high contact angle and hardness of superhydrophobic film respectively. In order to fabricate superhydrophobic film of high transparency, the study also explored into the effect of rotation rate of the spin coater and concentration of the coating solution. When the coating solution was diluted to 1/2 and the spin rate at 4000rpm, the film produced possessed continuous roughness layer, the transparency under visible light was 76.5% and contact angle of 158°. | en_US |