Vapor phase versus liquid phase grafting of meso-porous alumina

V.G.P. Sripathi, Barbara Mojet, Arian Nijmeijer, Nieck Edwin Benes

Research output: Contribution to journalArticleAcademicpeer-review

10 Citations (Scopus)

Abstract

Functionalization of meso-porous c-alumina has been performed by grafting of 3-Aminopropyltrimethoxysilane (3APTMS) simultaneously from either the liquid phase or from the vapor phase. In both cases, after grafting nitrogen physisorption indicates that the materials remain meso-porous with significant differences in pore morphology, and infrared spectroscopy analysis reveals the presence of adsorbed APTMS in different quantities. Grafting from the liquid phase is affected by pronounced oligomerization of the precursor molecules, resulting in relatively non-homogeneous grafting and ultimately in pore blocking. In contrast, grafting via the vapor phase results in a homogeneous layer of grafted molecules on the surface of the pores, with a thickness similar to the length of the 3APTMS molecule. Grafting via the vapor phase is relatively insensitive to the reaction temperature (50 or 80 C) and the presence of water (50 ppm). This is explained by the low concentration of oligomers in the vapor phase, due to their low vapor pressure. This study clearly shows that for obtaining a thin layer on the pore surface of c-alumina vapor phase silanization is highly preferable.
Original languageEnglish
Pages (from-to)1-6
JournalMicroporous and mesoporous materials
Volume172
DOIs
Publication statusPublished - 2013

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Aluminum Oxide
liquid phases
Alumina
aluminum oxides
Vapors
vapor phases
Liquids
porosity
Molecules
molecules
Oligomerization
Physisorption
Vapor pressure
oligomers
Oligomers
vapor pressure
low concentrations
Infrared spectroscopy
Nitrogen
low pressure

Keywords

  • METIS-294373
  • IR-84199

Cite this

@article{3c1f2e508de445d597dc0cd3bf43e252,
title = "Vapor phase versus liquid phase grafting of meso-porous alumina",
abstract = "Functionalization of meso-porous c-alumina has been performed by grafting of 3-Aminopropyltrimethoxysilane (3APTMS) simultaneously from either the liquid phase or from the vapor phase. In both cases, after grafting nitrogen physisorption indicates that the materials remain meso-porous with significant differences in pore morphology, and infrared spectroscopy analysis reveals the presence of adsorbed APTMS in different quantities. Grafting from the liquid phase is affected by pronounced oligomerization of the precursor molecules, resulting in relatively non-homogeneous grafting and ultimately in pore blocking. In contrast, grafting via the vapor phase results in a homogeneous layer of grafted molecules on the surface of the pores, with a thickness similar to the length of the 3APTMS molecule. Grafting via the vapor phase is relatively insensitive to the reaction temperature (50 or 80 C) and the presence of water (50 ppm). This is explained by the low concentration of oligomers in the vapor phase, due to their low vapor pressure. This study clearly shows that for obtaining a thin layer on the pore surface of c-alumina vapor phase silanization is highly preferable.",
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author = "V.G.P. Sripathi and Barbara Mojet and Arian Nijmeijer and Benes, {Nieck Edwin}",
year = "2013",
doi = "10.1016/j.micromeso.2013.01.013",
language = "English",
volume = "172",
pages = "1--6",
journal = "Microporous and mesoporous materials",
issn = "1387-1811",
publisher = "Elsevier",

}

Vapor phase versus liquid phase grafting of meso-porous alumina. / Sripathi, V.G.P.; Mojet, Barbara; Nijmeijer, Arian; Benes, Nieck Edwin.

In: Microporous and mesoporous materials, Vol. 172, 2013, p. 1-6.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Vapor phase versus liquid phase grafting of meso-porous alumina

AU - Sripathi, V.G.P.

AU - Mojet, Barbara

AU - Nijmeijer, Arian

AU - Benes, Nieck Edwin

PY - 2013

Y1 - 2013

N2 - Functionalization of meso-porous c-alumina has been performed by grafting of 3-Aminopropyltrimethoxysilane (3APTMS) simultaneously from either the liquid phase or from the vapor phase. In both cases, after grafting nitrogen physisorption indicates that the materials remain meso-porous with significant differences in pore morphology, and infrared spectroscopy analysis reveals the presence of adsorbed APTMS in different quantities. Grafting from the liquid phase is affected by pronounced oligomerization of the precursor molecules, resulting in relatively non-homogeneous grafting and ultimately in pore blocking. In contrast, grafting via the vapor phase results in a homogeneous layer of grafted molecules on the surface of the pores, with a thickness similar to the length of the 3APTMS molecule. Grafting via the vapor phase is relatively insensitive to the reaction temperature (50 or 80 C) and the presence of water (50 ppm). This is explained by the low concentration of oligomers in the vapor phase, due to their low vapor pressure. This study clearly shows that for obtaining a thin layer on the pore surface of c-alumina vapor phase silanization is highly preferable.

AB - Functionalization of meso-porous c-alumina has been performed by grafting of 3-Aminopropyltrimethoxysilane (3APTMS) simultaneously from either the liquid phase or from the vapor phase. In both cases, after grafting nitrogen physisorption indicates that the materials remain meso-porous with significant differences in pore morphology, and infrared spectroscopy analysis reveals the presence of adsorbed APTMS in different quantities. Grafting from the liquid phase is affected by pronounced oligomerization of the precursor molecules, resulting in relatively non-homogeneous grafting and ultimately in pore blocking. In contrast, grafting via the vapor phase results in a homogeneous layer of grafted molecules on the surface of the pores, with a thickness similar to the length of the 3APTMS molecule. Grafting via the vapor phase is relatively insensitive to the reaction temperature (50 or 80 C) and the presence of water (50 ppm). This is explained by the low concentration of oligomers in the vapor phase, due to their low vapor pressure. This study clearly shows that for obtaining a thin layer on the pore surface of c-alumina vapor phase silanization is highly preferable.

KW - METIS-294373

KW - IR-84199

U2 - 10.1016/j.micromeso.2013.01.013

DO - 10.1016/j.micromeso.2013.01.013

M3 - Article

VL - 172

SP - 1

EP - 6

JO - Microporous and mesoporous materials

JF - Microporous and mesoporous materials

SN - 1387-1811

ER -