Cross-Condensation Reactions in an Organically Modified Silica Sol-Gel

ABSTRACTHigh resolution 29Si NMR has been used to study the extent of cross condensation taking place in a hybrid organic/inorganic sol-gel system. Tetraethoxysilane (TEOS) and methyltriethoxysilane (MTEOS) sol-gels were chosen for this purpose. The sols were prepared by acid catalyzed hydrolysis of TEOS and MTEOS with a H2O/Si ratio of 0.3. 29Si NMR shows signals due to both self-condensation and cross-condensation between TEOS and MTEOS. Resonance assignments were made by comparing the positions and intensities of peaks in the spectra of single and multicomponent systems. It was found that, within experimental error, the self- and cross-condensation rates are equal and that extensive molecular level mixing takes place during the early stages of the reaction.

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Effects of Surface Functional Groups on the Adhesion of SiO2 Nanospheres to Bio-Based Materials

Nanomaterials ◽

10.3390/nano9101411 ◽

2019 ◽

Vol 9 (10) ◽

pp. 1411

Author(s):

Xiao ◽

Xu ◽

Niu ◽

Zhu ◽

Kou

Keyword(s):

Adsorption Process ◽

Sol Gel ◽

Functional Materials ◽

Inorganic Materials ◽

Silica Nanospheres ◽

Surface Functional Groups ◽

Modified Silica ◽

Adsorption Experiment ◽

Organically Modified ◽

Organically Modified Silica

The interactions between nanoparticles and materials must be considered when preparing functional materials. Although researchers have studied the interactions between nanoparticles and inorganic materials, little attention has been paid to those between nanoparticles and bio-based protein materials, like leather. In this study, organically modified silica nanospheres (SiO2 nanospheres) loaded with rose fragrance were prepared using (3-aminopropyl) triethoxysilane (APTES), (3-mercaptopropyl) triethoxysilane (MPTES), or 3-(2, 3-epoxypropyloxy) propyl triethoxysilane (GPTES) using the sol-gel method. To study the interactions between the modified SiO2 nanospheres and leather, a non-cross-linking adsorption experiment was conducted. According to the Dubinin–Radushkevich isotherm calculation, we found that the adsorption process of leather fiber and organically modified silica nanospheres is physical. The average adhesion energies of APTES-, MPTES-, and GPTES-modified SiO2 nanospheres on the leather are 1.34016, 0.97289, and 2.09326 kJ/mol, respectively. The weight gain, adsorption capacity, and average adhesion energy show that the modified SiO2 nanospheres can be adsorbed on leather in large quantities. The sensory evaluation confirmed that GPTES-modified SiO2 nanospheres endowed the leather with an obvious rose aroma.

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Characterization of the sol-gel process using raman spectroscopy organically modified silica gels prepared via the formic acid-alkoxide route

Journal of Sol-Gel Science and Technology ◽

10.1007/bf02437188 ◽

1997 ◽

Vol 9 (3) ◽

pp. 251-263 ◽

Cited By ~ 5

Author(s):

Jan-Christoph Panitz ◽

Alexander Wokaun

Keyword(s):

Raman Spectroscopy ◽

Sol Gel ◽

Silica Gels ◽

Modified Silica ◽

Sol Gel Process ◽

Organically Modified ◽

Organically Modified Silica ◽

Alkoxide Route ◽

Modified Silica Gels

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Preparation of Thick Inorganic-organic Composite Films by Electrophoretic Sol-gel Deposition Using Organically Modified Silica Particles and Polyethylene Maleate

Chemistry Letters ◽

10.1246/cl.1997.1115 ◽

1997 ◽

Vol 26 (11) ◽

pp. 1115-1116 ◽

Cited By ~ 3

Author(s):

Koichi Hasegawa ◽

Shunsuke Kunugi ◽

Masahiro Tatsumisago ◽

Tsutomu Minami

Keyword(s):

Sol Gel ◽

Composite Films ◽

Silica Particles ◽

Modified Silica ◽

Organically Modified ◽

Organically Modified Silica

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New Catalyst Series from the Sol-Gel-Entrapment of Gold Nanoparticles in Organically Modified Silica Matrices: Proof of Performance in a Model Oxidation Reaction

ChemCatChem ◽

10.1002/cctc.201402861 ◽

2014 ◽

Vol 7 (2) ◽

pp. 254-260 ◽

Cited By ~ 10

Author(s):

Rosaria Ciriminna ◽

Alexandra Fidalgo ◽

Valerica Pandarus ◽

François Béland ◽

Laura M. Ilharco ◽

...

Keyword(s):

Gold Nanoparticles ◽

Oxidation Reaction ◽

Sol Gel ◽

Modified Silica ◽

Gel Entrapment ◽

Organically Modified ◽

Organically Modified Silica ◽

Silica Matrices

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Structural Characterization of Gels Prepared from Co-Hydrolysis of Tetraethoxysilane and Dimethyldiethoxysilane.

MRS Proceedings ◽

10.1557/proc-271-237 ◽

1992 ◽

Vol 271 ◽

Cited By ~ 11

Author(s):

Florence Babonneau ◽

Laurence Bois ◽

Jacques Livage

Keyword(s):

Structural Characterization ◽

Silica Gels ◽

Condensation Process ◽

Modified Silica ◽

Polymeric Gels ◽

Organically Modified ◽

Organically Modified Silica ◽

Hydrolysis Of ◽

Modified Silica Gels

ABSTRACTThis work is part of a more general study on the structural characterization of organically modified silica gels that are usually prepared from tetrafunctional, trifunctional and difunctional alkoxides. The systems that were investigated in this paper are gels prepared from co-hydrolysis of dimethyldiethoxysilane (DEDMS) and tetraethoxysilane (TEOS). The condensation process was followed by 29Si and 17O liquid NMR and shows clearly evidence for co-condensation reactions. Gels with various DEDMS/TEOS ratios were studied by 29Si and 1H MAS-NMR. The results are clearly correlated to the change in physical properties of the materials, from flexible polymeric gels at high DEDMS content to crosslinked brittle networks at low DEDMS content.

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