ISSN:
1435-1536
Keywords:
Key words 3-aminopropyltriethoxy silane
;
silica gel
;
interaction
;
kinetics
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Three silica gel sample systems, modified with 3-amino-propyltriethoxy silane (APTS), were prepared by sequentially sampling the reaction mixture at various time intervals. The concentrations of 3-aminopropylsilyl groups (APS) bound on the silica surface were determined by elemental analysis. For the same sample systems, 29Si NMR intensities of an (–O)4Si species belonging only to the silica gel particles and corrected by a cross-polarization correction factor were also measured. Both the APS-concentrations and the correc-ted 29Si NMR intensities depended upon reaction time, reflecting the rate of the APTS–silica gel reaction. Kinetic analysis of these data was made by use of the Gauss–Newton method, and the overall reaction was found to consist of three reaction processes (an initial fast reaction, a slower second reaction and a much slower third reaction). In particular, the conversion of (–O)3SiOH to (–O)4Si is predominant in the second reaction process and the pore size of a silica gel particle affects the reaction mechanism.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s003960050134
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