Title:	Molecular level investigations of (organo)clays
DNr:	SNIC 2019/3-487
Project Type:	SNIC Medium Compute
Principal Investigator:	Michael Holmboe <michael.holmboe@umu.se>
Affiliation:	Umeå universitet
Duration:	2019-10-01 – 2020-10-01
Classification:	10506 10404 10406
Homepage:	http://moleculargeo.chem.umu.se/holmboe/
Keywords:

Abstract

This medium allocation proposal aims to continue our on-going research efforts enabled by previous allocations SNIC 2018/3-454, SNIC 2017/1-369 and SNIC 2016/1-375, investigating the molecular organization and mobility of small inorganic solutes and organics in zeolites and sheet silicate interlayers (i.e. in lamellar pores between 1nm thick clay layers). Zeolite and smectite silicate clays have nanoporous structures and an extremely high surface area, enabling intercalation of large quantities of molecular substances leading to nanomaterials with novel and/or improved properties. Using primarily molecular dynamics simulations we will study adsorption and interaction behavior of these nanoporous minerals with a range of inorganic and organic molecules, using methods developed during our previous (and ongoing) work of similarly hydrated systems, such as calculation of theoretical XRD diffractograms, vibrational powerspectra as well as free energy perturbation and umbrella sampling methods, see: Holmboe+Bourg, J. Phys. Chem. C 2014, 118, 1001−1013 doi: dx.doi.org/10.1021/jp408884g Tinnacher+Holmboe et al, 2016 Geo. et Cosm. Acta 177 (2016) 130–149 doi: 10.1016/j.gca.2015.12.010 Tournassat+Holmboe et al, 2016, Clays and Clay Min. 64, 4, 374–388 doi: 10.1346/CCMN.2016.0640403 Hellrup+Holmboe et al, Langmuir 2016, 32, 13214−13225 doi:10.1021/acs.langmuir.6b01967 Holmboe et al., Langmuir 2016, 32, 12732−12740 doi: 10.1021/acs.langmuir.6b03008 Yang+Holmboe, Journal of Chem. Phys. 2017, 147, 084705 doi: 10.1063/1.4992001 Yeşilbaş+Holmboe+Boily, ACS Earth Space Chem. 2018, 2, 38−47 doi: 10.1021/acsearthspacechem.7b00103 Yeşilbaş+Holmboe+Boily, Residence times of nanoconfined CO 2 in layered aluminosilicates Doi: 10.1039/C8EN01156G Submitted papers: Deconvolution of Smectite Hydration Isotherms, Jerry Lindholm, Jean-François Boily, and Michael Holmboe*, under review in ACS Earth and Space Chemistry. Michael Holmboe, atom: A Matlab package for manipulation of molecular systems, submitted in Aug 2019 to special edition of Clay Minerals, Teaching Clay Science. Our group at Umeå University have implemented two clay-specific forcefields, Clayff (Cygan, 2004) and the charmm-like INTERFACE ff (Heinz, 2005, 2013) for Gromacs. As an initial benchmarking study, we are studying i) smectite solvation (of clay surfaces + counter-cations) of pure alcohol and mixed water/alcohol mixtures, to find the dependence on clay basal spacings versus loading, to aid interpretation of experimental XRD diffraction data on the corresponding systems. In a new project, we are using MD to study interactions of different aminoacids with zeolites, in the context of organic-N-fertilizers, in a new collaboration with the SLU start-up Arevo (www.arevo.se) and Prof. Torgny Näsholm. In yet another project, we also collaborate with US researchers on uranykcomplex diffusion through compacted Bentnite clay, as highlighted in the national press: www.forskning.se/2019/08/26/studerar-uran-i-bentonit-for-slutforvaring-av-karnavfall/ www.expressen.se/nyheter/klimat/umeas-superdator-ska-granska-slutforvaring-av-karnavfall/