Imperial College London
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Dr Andrew Cairns

Faculty of Engineering, Department of Materials

Lecturer in Materials Chemistry
 
 
 
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Contact

 

+44 (0)20 7594 9528a.cairns Website

 
 
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Location

 

107Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Nearchou:2019:10.3390/molecules24030641,
author = {Nearchou, A and Cornelius, M-LU and Skelton, JM and Jones, ZL and Cairns, AB and Collings, IE and Raithby, PR and Wells, SA and Sartbaeva, A},
doi = {10.3390/molecules24030641},
journal = {Materials},
title = {Intrinsic flexibility of the EMT zeolite framework under pressure},
url = {http://dx.doi.org/10.3390/molecules24030641},
volume = {24},
year = {2019}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - The roles of organic additives in the assembly and crystallisation of zeolites are still not fully understood. This is important when attempting to prepare novel frameworks to produce new zeolites. We consider 18-crown-6 ether (18C6) as an additive, which has previously been shown to differentiate between the zeolite EMC-2 (EMT) and faujasite (FAU) frameworks. However, it is unclear whether this distinction is dictated by influences on the metastable free-energy landscape or geometric templating. Using high-pressure synchrotron X-ray diffraction, we have observed that the presence of 18C6 does not impact the EMT framework flexibility—agreeing with our previous geometric simulations and suggesting that 18C6 does not behave as a geometric template. This was further studied by computational modelling using solid-state density-functional theory and lattice dynamics calculations. It is shown that the lattice energy of FAU is lower than EMT, but is strongly impacted by the presence of solvent/guest molecules in the framework. Furthermore, the EMT topology possesses a greater vibrational entropy and is stabilised by free energy at a finite temperature. Overall, these findings demonstrate that the role of the 18C6 additive is to influence the free energy of crystallisation to assemble the EMT framework as opposed to FAU.
AU  - Nearchou,A
AU  - Cornelius,M-LU
AU  - Skelton,JM
AU  - Jones,ZL
AU  - Cairns,AB
AU  - Collings,IE
AU  - Raithby,PR
AU  - Wells,SA
AU  - Sartbaeva,A
DO  - 10.3390/molecules24030641
PY  - 2019///
SN  - 1420-3049
TI  - Intrinsic flexibility of the EMT zeolite framework under pressure
T2  - Materials
UR  - http://dx.doi.org/10.3390/molecules24030641
UR  - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000458934000265&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR  - http://hdl.handle.net/10044/1/69708
VL  - 24
ER  -
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