Comparison of hydrophobicity studies of silica aerogels using contact angle measurements with water drop method and adsorbed water content measurements made by Karl Fischer’s titration method
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Hydrophobic silica aerogels possesses potential applications as insulating materials for refrigerators, furnaces and thermos flasks. In such applications, aerogel materials may get exposed for longer time to atmosphere and the adsorbed water content from surroundings may deteriorate its properties. Therefore, hydrophobicity of the arogels becomes crucial parameter and needs to be evaluated critically. In the present works, silica alcogels were prepared using the mixture of tetramethoxysilane and methyltrimethoxysilane (MTMS) as precursor chemicals for silica. The concentration of MTMS, which is used as hydrophobic reagent, in the said mixture of silicon alkoxide was varied between 0 and 100% in steps of 25%. After gelation, the alcogels were dried supercritically by solvent extraction method. Resulted aerogels were exposed to relative humidity of 90% for a period of one month which were then characterized to assess hydrophobicity by the contact angle using water drop method and adsorbed water content measurements by Karl Fischer’s Titration method. Observed contact angle and water content measurements were compared and the results are reported in the present research paper.
KeywordsSupercritical Hydrophobic aerogels Contact angle Karl Fischer’s titration
Authors are thankful to Ratanesh Kumar, I. K. Singh, Rakesh Patel, APD, BARC, and D. B. Mahadik, Air Glass Laboratory, Department of Physics, Shivaji University, Kolhapur, for their assistance during the present research work.
- 10.Latthe SS, Dhere SL, Kappenstein C, Imai H, Ganesan V, Venkateswara Rao A, Wagh PB, Gupta SC (2010) 256(10):3259Google Scholar