Surface hydroxylation and silane grafting on fumed and thermal silica
Surface hydroxylation and silane grafting on fumed and thermal silica
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DOI：
10.1016/s0021-9797(03)00552-6
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发表时间：
2003-08-15
影响因子：
9.9
通讯作者：
Chevalier, Y
中科院分区：
文献类型：
--
作者：
Dugas, V;Chevalier, Y
研究了硅烷对平面热氧化硅表面功能化的优化。困难是在热二氧化硅的表面上的硅烷醇的低密度，缺乏热二氧化硅的实际表面化学及其羟基化的精确知识，以及在小面积的平坦表面上的可能的化学分析的有限数量。这使我们的研究转向热二氧化硅和众所周知的气相二氧化硅的羟基化和硅烷接枝的比较研究。气相法白炭黑经脱羟基热处理后的硅烷接枝密度与硅烷醇的表面密度有关。通过FTIR-ATR光谱法测量的在平坦热二氧化硅上的硅烷的表面密度为1.4 μ mol/m2，与在1000 ℃下脱羟基的气相二氧化硅的表面密度相似。该中等值与这种二氧化硅表面上存在的低硅烷醇密度有关。证明其对脱羟基气相二氧化硅的效率的几种再羟基化处理并没有导致对热二氧化硅的任何明显改善。(C)2003年爱思唯尔公司All rights reserved.
The optimization of the surface functionalization of flat thermal silicon oxide by silanes was investigated. The difficulties are the low density of silanols at the surface of thermal silica, the lack of precise knowledge of the actual surface chemistry of thermal silica and of its hydroxylation, and the limited number of possible chemical analyses at flat surfaces of small area. This steered our study toward a comparative investigation of the hydroxylation and silane grafting of thermal silica and the well-known fumed silica. The silane grafting density for fumed silica that had undergone thermal treatments of dehydroxylation was related to the surface density of silanols. The surface density of silane on the flat thermal silica as measured by FTIR-ATR spectroscopy was 1.4 mumol/m(2), similar to that of fumed silica dehydroxylated at 1000 degreesC. This moderate value was related to the low silanol density present on such silica surfaces. Several rehydroxylation treatments that proved their efficiency on dehydroxylated fumed silica did not lead to any noticeable improvement on thermal silicon dioxide. (C) 2003 Elsevier Inc. All rights reserved.