Alcoholic solvent effect on silica synthesis - NMR and DLS investigation
Alcoholic solvent effect on silica synthesis - NMR and DLS investigation
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DOI：
10.1023/a:1008659708390
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发表时间：
1998-09-01
影响因子：
2.5
通讯作者：
Rasmussen, DH
中科院分区：
文献类型：
--
作者：
Sadasivan, S;Dubey, AK;Rasmussen, DH
通过分别利用硅 - 29核磁共振（Si - 29 NMR）和动态光散射研究考察水解速率和颗粒生长，阐明了在各种醇类溶剂中溶剂对二氧化硅颗粒合成的影响。从核磁共振实验获得的动力学数据表明，在1 - 丁醇中水解速率最快，且速率呈现出不寻常的顺序：1 - 丁醇＞甲醇＞乙醇＞2 - 丙醇＞1 - 丙醇。水解速率的这种顺序可通过两个相反的因素来解释，即空间位阻降低速率以及氢键减少提高速率。最终颗粒尺寸随着醇分子量的增加而增大，这可能是由于醇的极性降低所致。
The solvent effect on the synthesis of silica particles has been elucidated through the examination of hydrolysis rate and particle growth by Si-29 NMR and Dynamic Light Scattering studies, respectively, in various alcoholic solvents. Kinetic data obtained from the NMR experiments indicate that the rate of hydrolysis is fastest in 1-butanol and the rates follow an unusual order of 1-butanol > methanol > ethanol > 2-propanol > 1-propanol. This order of the rates of hydrolysis is rationalized with two opposing factors, steric hindrance reducing the rate and decrease of hydrogen bonding enhancing the rate. The final particle size increases as the alcohol molecular weight increases. This might be due to decrease in polarity of the alcohols.