Title page for 953209009


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Student Number 953209009
Author Yi-ju Shen(沈怡如)
Author's Email Address No Public.
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Department Graduate Institute of Materials Science and Engineering
Year 2007
Semester 2
Degree Master
Type of Document Master's Thesis
Language zh-TW.Big5 Chinese
Title Preparation of superhydrophobic film by two-step sol-gel process
Date of Defense 2008-06-04
Page Count 46
Keyword
  • superhydrophobic
  • Tetraethoxysilane
  • two-step sol-gel process
  • Abstract   Preparation of superhydrophobic tetraethoxylsilane(TEOS)-based silica surfaces by a two-step sol-gel process has been developed. The coating solution was prepared by adding water and acid into TEOS and reacted firstly, then adding ammonia and water into the above solution and reacted again. The roughness surface with hydroxyl groups was obtained by coating this solution onto the glass. Then the hydroxyl groups on the roughness surface were terminated by trimethylchlorosilane(TMCS) to produce a hydrophobic surface.
      The effect of synthesis parameters, H2O/TEOS (Ra), amount of HCl, and types of solvent of the first step, H2O/TEOS (Rb) and NH4OH/HCl of the second step on the gelation time (tG) and onset time (tS¬¬) of the coating solution were studied. The influence of reaction time of the second step on structure and contact angle of films were also investigated.
      The results showed that tG and tS¬¬ of coating solution were decreased with increasing Ra, amount of HCl, Rb and NH4OH/HCl. Superhydrophobic surface was obtained when the contact angle of the surface kept a constant value during the early stage of the coating solution. The silica films with contact angle 151° was obtained when preparation conditions TEOS:EtOH:Ra:HCl:Rb:NH4OH were 1:3.9:0.5:3.36x10-4:3:3.78x10-3. On the other hand, in order to obtain silica films with higher contact angle easily, various alcohol with long carbon chain were added into coating solution to increase tG and tS.
    Table of Content 中文摘要 ......................................i
    英文摘要 .....................................ii
    謝誌 ........................................iii
    目錄 .........................................iv
    圖索引 ........................................v
    表索引 ......................................vii
    第一章 前言 ...................................1
    第二章 實驗
     2.1 實驗藥品 ................................4
     2.2 實驗儀器 ................................5
     2.3 實驗步驟 ................................5
     2.4 實驗分析儀器 ............................6
    第三章 結果與討論
     3.1 溶液黏度的變化與凝膠時間 ................8
     3.2 第一步驟水添加量對反應與接觸角之影響 ...12
     3.3 酸添加量對反應與接觸角之影響 ...........15
     3.4 第二步驟水添加量對反應與接觸角之影響 ...19
     3.5 鹼添加量對反應與接觸角之影響 ...........23
     3.6 溶劑對反應與接觸角之影響 ...............30
    第四章 結論 ..................................35
    參考文獻 ......................................36
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    3. Collinson, M.M., "Sol-gel strategies for the preparation of selective materials for chemical analysis", Critical Reviews in Analytical Chemistry, 29(4), p.289-311, 1999
    4. Iler, R.K., "The Chemistry of Silica ", Wiley, 1979
    5. Brinker, C.J., "Hrdrolysis and condensation of silicates:effect on structure", non-crystalline solids, 100, p.31-50, 1988
    6. Hegde, N.D., H. Hirashima, and A.V. Rao, "Two step sol-gel processing of TEOS based hydrophobic silica aerogels using trimethylethoxysilane as a co-precursor", Journal of Porous Materials, 14(2), p.165-171, 2007
    7. Rao, A.V., et al., "Synthesis of flexible silica aerogels using methyltrimethoxysilane (MTMS) precursor", Journal of Colloid and Interface Science, 300(1), p.279-285, 2006
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    9. Hegde, N.D. and A.V. Rao, "Effect of processing temperature on gelation and physical properties of low density TEOS based silica aerogels", Journal of Sol-Gel Science and Technology, 38(1), p.55-61, 2006
    10. Rao, A.P., A.V. Rao, and G.M. Pajonk, "Hydrophobic and physical properties of the two step processed ambient pressure dried silica aerogels with various exchanging solvents", Journal of Sol-Gel Science and Technology, 36(3), p.285-292, 2005
    11. Rao, A.P., G.M. Pajonk, and A.V. Rao, "Effect of preparation conditions on the physical and hydrophobic properties of two step processed ambient pressure dried silica aerogels", Journal of Materials Science, 40(13), p.3481-3489, 2005
    12. Rao, A.V. and S.D. Bhagat, "Synthesis and physical properties of TEOS-based silica aerogels prepared by two step (acid-base) sol-gel process", Solid State Sciences, 6(9), p.945-952, 2004
    13. Keesman, M.J., P.H.G. Offermans, and E.P. Honig, Mat. Lett, 5, p.140, 1987
    14. Lee, J.K. and G.L. Gould, "Viscosity behaviors of rapidly curable silica sols", Journal of Sol-Gel Science and Technology, 34(3), p.281-291, 2005
    15. Boonstra, A.H. and C.A.M. Mulder, "Effect of hydrolytic polycondensation of tetraethoxysilane on specific surface area of silica gels", Journal of non-crystalline solids, 105(3), p.201-206, 1988
    Advisor
  • Hui Chen(陳暉)
  • Files
  • 953209009.pdf
  • approve in 2 years
    Date of Submission 2008-06-20

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