Campus Units

Chemistry, Physics and Astronomy, Ames Laboratory

Document Type

Article

Publication Version

Accepted Manuscript

Publication Date

4-30-2020

Journal or Book Title

Microporous and Mesoporous Materials

First Page

110276

DOI

10.1016/j.micromeso.2020.110276

Abstract

The post-synthesis functionalization (grafting) kinetics of mesoporous silica nanoparticles (MSN) with organo-trimethoxysilanes (R-TMS) is studied via solution 1H NMR spectroscopy. The process involves a rapid adsorption/desorption pre-equilibrium followed by reaction of R-TMS with surface silanols. Grafting rates are affected by the functional group in R-TMS. For example, the grafting rate of aminopropyl-trimethoxysilane (AP-TMS) is one order of magnitude higher than other R-TMS. High concentrations of AP-TMS result in substrate-inhibition kinetics, likely due to steric and mobility constraints for reactant alignment at high coverage. The higher rates of AP-TMS grafting indicate a catalytic effect of amine groups. This effect depends on the amine's basicity and can be used to control the grafting rates and degree of condensation of other R-TMS. Adjusting the rate of mercaptopropyl-trimethoxysilane (MP-TMS) grafting using amines gives MP-MSN materials of varying adsorptive and catalytic activities, illustrated by Pd scavenging experiments and use of Pd@MP-MSN as catalysts for a Suzuki-Miyaura cross-coupling reaction.

Comments

This is a manuscript of an article published as Manzano, J. Sebastián, Hsin Wang, Takeshi Kobayashi, Pranjali Naik, King C. Lai, James W. Evans, and Igor I. Slowing. "Kinetics of the functionalization of mesoporous silica nanoparticles: Implications on surface group distributions, adsorption and catalysis." Microporous and Mesoporous Materials (2020): 110276. DOI: 10.1016/j.micromeso.2020.110276. Posted with permission.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Copyright Owner

Elsevier Inc.

Language

en

File Format

application/pdf

Available for download on Saturday, April 30, 2022

Published Version

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