Center for Molecular Modeling - C. Martineau

Alternating Copolymer of Double Four Ring Silicate and Dimethyl Silicone Monomer - PSS-1

steven — Mon, 29 May 2017 10:03:44 +0000

S. Smet, S. Vandenbrande, P. Verlooy, S. Kerkhofs, E. Breynaert, C. Kirschhock, C. Martineau, F. Taulelle, V. Van Speybroeck, J.A. Martens

Chemistry - A European Journal

23 (47), 11286-11293

2017

Abstract

A new copolymer consisting of double four ring (D4R) silicate units linked by dimethylsilicone monomer referred to as polyoligosiloxysilicone number one (PSS-1) was synthesized. The D4R building unit is provided by hexamethyleneimine cyclosilicate hydrate crystals, which were dehydrated and reacted with dichlorodimethylsilane. The local structure of D4R silicate units and dimethyl silicone monomers was revealed by multidimensional solid-state NMR, FTIR and modeling. On average, D4R silicate units have 6.8 silicone linkages. Evidence for preferential unidirectional growth and chain ordering within the PSS-1 copolymer was provided by STEM and TEM. The structure of PSS-1 copolymer consists of twisted columns of D4R silicate units with or without cross-linking. Both models are consistent with the spectroscopic, microscopic and physical properties. PSS-1 chains are predicted to be mechanically strong compared to silicones such as PDMS, yet more flexible than rigid silica materials such as zeolites.

DOI

http://dx.doi.org/10.1002/chem.201701237

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Smet_et_al-2017-Chemistry_-_A_European_Journal.pdf

A breathing zirconium metal-organic framework with reversible loss of crystallinity by correlated nanodomain formation

jelle — Tue, 02 Feb 2016 07:37:01 +0000

B. Bueken, F. Vermoortele, M.J. Cliffe, M.T. Wharmby, D. Foucher, J. Wieme, L. Vanduyfhuys, C. Martineau, N. Stock, F. Taulelle, V. Van Speybroeck, A.L. Goodwin, D. De Vos

Chemistry - A European Journal

2016, 22, 1-5

2016

Abstract

The isoreticular analogue of the metal–organic framework UiO-66(Zr), synthesized with the flexible trans-1,4-cyclohexanedicarboxylic acid as linker, shows a peculiar breathing behavior by reversibly losing long-range crystalline order upon evacuation. The underlying flexibility is attributed to a concerted conformational contraction of up to two thirds of the linkers, which breaks the local lattice symmetry. X-ray scattering data are described well by a nanodomain model in which differently oriented tetragonal-type distortions propagate over about 7–10 unit cells.

DOI

http://dx.doi.org/10.1002/chem.201600330

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chem.201600330 Bart Bueken Zrcdc.pdf

Flexibility versus rigidity: what determines the stability of zeolite frameworks? A case study

michel — Tue, 29 Apr 2014 19:07:20 +0000

E. Verheyen, L. Joos, C. Martineau, C.J. Dawson, C. Weidenthaler, W. Schmidt, R. Yuan, E. Breynaerts, V. Van Speybroeck, M. Waroquier, F. Taulelle, M.M.J. Treacy, J.A. Martens, C. Kirschhock

Materials Horizons

Vol. 1 , 582 - 587

2014

Abstract

All silica COK-14/-COK-14 with OKO topology is the first case of a zeolite which reversibly transforms from a systematically interrupted to a fully connected state and back. Analysis of the opening/closing behavior allowed the study of entropy and framework flexibility as determinants for the stability of zeolite topologies, which, until now, has been experimentally inaccessible. Interconversion of the all-silica COK-14 zeolite with fully connected OKO topology and its -COK-14 variant with systematic framework interruption was investigated using high-temperature XRD, thermogravimetric analysis, Si-29 MAS NMR, nitrogen adsorption and a range of modelling techniques. Specific framework bonds in the OKO framework can be reversibly hydrolyzed and condensed. Structural silanols of the parent -COK-14, prepared by degermanation of the IM-12 zeolite, were condensed by heating at 923 K, and hydrolyzed again to the initial state by contacting the zeolite with warm water. Molecular modelling revealed an inversion of the relative stabilities for both variants depending on temperature and hydration. Condensation of the structural silanols in -COK-14 to COK-14 is entropy driven, mainly resulting from the release of water molecules. Framework reopening in the presence of water is spontaneous due to the high rigidity of the fully connected OKO framework. Isomorphous substitution was demonstrated as a viable option for stabilization of the fully connected OKO framework as this renders the closed framework flexible.

DOI

http://dr.doi.org/10.1039/c4mh00127c

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manuscript mat Hor.pdf

Computational Study of the Reversible Opening and Closing of the COK-14 zeolite

wim — Wed, 15 Oct 2014 06:48:18 +0000

L. Joos, E. Verheyen, C. Martineau, C.J. Dawson, C. Weidenthaler, W. Schmidt, R. Yuan, E. Breynaerts, M. Waroquier, F. Taulelle, M.M.J. Treacy, J.A. Martens, C. Kirschhock, V. Van Speybroeck

ISBN/ISSN:

Talk

Conference / event / venue

WATOC 2014 Satellite Meeting on Large Condensed and Biological Systems

Concepción, Chili

Monday, 13 October, 2014 to Tuesday, 14 October, 2014

Abstract (private)

2014_watoc_LJ4.pdf

Conference reference

WATOC 2014 Satellite Meeting on Large Condensed and Biological Systems

Computational Study of the Reversible Opening and Closing of the COK-14 zeolite

wim — Mon, 13 Oct 2014 07:10:43 +0000

L. Joos, E. Verheyen, E. Breynaerts, C. Kirschhock, J.A. Martens, C. Martineau, F. Taulelle, C.J. Dawson, M.M.J. Treacy, C. Weidenthaler, W. Schmidt, M. Waroquier, V. Van Speybroeck

ISBN/ISSN:

Poster

Conference / event / venue

WATOC 2014

Santiago de Chile, Chile

Sunday, 5 October, 2014 to Friday, 10 October, 2014

Abstract (private)

2014_watoc_LJ4.pdf

Conference reference

WATOC 2014

Computational study of the reversible opening-closing of the COK-14 zeolite

lennart — Mon, 30 Jun 2014 19:04:12 +0000

L. Joos, E. Verheyen, E. Breynaerts, C. Kirschhock, J.A. Martens, C. Martineau, F. Taulelle, C.J. Dawson, M.M.J. Treacy, C. Weidenthaler, W. Schmidt, M. Waroquier, V. Van Speybroeck

ISBN/ISSN:

Talk

Conference / event / venue

ACS Fall 2014

San Francisco, USA

Sunday, 10 August, 2014 to Thursday, 14 August, 2014

Design of zeolite by inverse sigma transformation

wim — Mon, 12 Aug 2013 14:09:45 +0000

E. Verheyen, L. Joos, K. Van Havenbergh, E. Breynaerts, N. Kasian, E. Gobechiya, K. Houthoofd, C. Martineau, M. Hinterstein, F. Taulelle, V. Van Speybroeck, M. Waroquier, S. Bals, G. Van Tendeloo, C. Kirschhock, J.A. Martens

p. 70

ISBN/ISSN:

Talk

Conference / event / venue

IZC17

Moscow, Russia

Sunday, 7 July, 2013 to Friday, 12 July, 2013

Conference reference

IZC-17

Computational Approach of the Inverse Sigma Transformation of Zeolites

wim — Mon, 12 Aug 2013 14:07:29 +0000

p. 219

ISBN/ISSN:

Poster

Conference / event / venue

IZC17

Moscow, Russia

Sunday, 7 July, 2013 to Friday, 12 July, 2013

Conference reference

IZC-17