Quantitative 1H NMR analysis of reacted silanol groups in silica nanoparticles chemically modified with monochlorosilanes |
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Authors: | Yoshio Nakahara Tsutomu Takeuchi Shoutaro Yokoyama Keiichi Kimura |
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Institution: | Department of Applied Chemistry, Faculty of Systems Engineering, Wakayama University, 930 Sakae‐dani, Wakayama 640‐8510, Japan |
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Abstract: | Quantitative analysis of reacted silanol groups in silica nanoparticles modified chemically with monochlorosilanes was performed by 1H NMR after treatment with cesium fluoride. Silica nanoparticles were modified chemically by the reaction between the silanol groups and monochlorosilanes, and the structure of the organic moiety anchored onto the silica surface was confirmed with solid‐state 13C NMR. As monochlorosilanes react with silanol groups at 1:1 ratio unlike di‐ or trichlorosilanes, the number of the silanes introduced into silica nanoparticles equals that of reacted silanol groups. Organically modified silica nanoparticles were dissolved using cesium fluoride, and the amount of the soluble organic compounds originated from the introduced silanes was determined by a 1H NMR internal standard method using pyrene as the reference. Those values determined by 1H NMR were in good agreement with those determined by elemental analysis. Thus, the number of reacted silanol groups per one particle was calculated on the basis of the results obtained by the 1H NMR method, and the values were highly dependent on the steric structure of the introduced silanes. Copyright © 2010 John Wiley & Sons, Ltd. |
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Keywords: | silica nanoparticle silanol monochlorosilane 1H NMR elemental analysis |
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