Stability and behaviour in aqueous solutions of the anionic cubic silsesquioxane substituted with tetramethylammonium

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Bibtex

@article{4aaeb35d6d154b42a9717216e309963e,
title = "Stability and behaviour in aqueous solutions of the anionic cubic silsesquioxane substituted with tetramethylammonium",
abstract = "The aqueous behaviour of the anionic octa-tetramethylammonium substituted cubic silsesquioxane, [N(CH 3 ) 4 ] 8 [Si 8 O 20 ], was studied with quantitative 29 Si-NMR. This molecule partially fragments in aqueous solutions, forming several smaller entities. The most abundant silica species are the monomer, dimer, cyclic trimer, cyclic tetramer and double three-ring. Higher concentrations are required in order to prevent complete fragmentation of the cubic structure. Additives such as alcohols and tetraalkylammonium salts have a stabilising effect on the cubic silsesquioxane, unlike sodium salts that destabilise it. A high concentration solution, containing the non-fragmented molecule as well as entities resulting from fragmentations, was investigated with neutron scattering coupled with modelling, using empirical potential structure refinement (EPSR). The modelling reveals that TMA + ions coordinates to all different silica species, with approximately three TMA + per cube. These are located at the faces of the cube.",
author = "Nilsson, {Emelie J.} and Marina Huber and G{\"o}ran Carlstr{\"o}m and Olle S{\"o}derman and Bowron, {Daniel T.} and Edler, {Karen J.} and Viveka Alfredsson",
year = "2019",
doi = "10.1039/c8cp05682j",
language = "English",
volume = "21",
pages = "6732--6742",
journal = "Physical chemistry chemical physics : PCCP",
issn = "1463-9084",
publisher = "Royal Society of Chemistry",
number = "12",

}