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

Nilsson, Emelie J. LU ; Huber, Marina ; Carlström, Göran LU orcid ; Söderman, Olle LU ; Bowron, Daniel T. ; Edler, Karen J. LU orcid and Alfredsson, Viveka LU (2019) In Physical Chemistry Chemical Physics 21(12). p.6732-6742
Abstract


The aqueous behaviour of the anionic octa-tetramethylammonium substituted cubic silsesquioxane, [N(CH
3
)
4
]
8
[Si
8
O ... (More)


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.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Chemistry Chemical Physics
volume
21
issue
12
pages
11 pages
publisher
Royal Society of Chemistry
external identifiers
  • pmid:30860209
  • scopus:85063286250
ISSN
1463-9076
DOI
10.1039/c8cp05682j
language
English
LU publication?
yes
id
4aaeb35d-6d15-4b42-a971-7216e309963e
date added to LUP
2019-04-02 14:25:47
date last changed
2025-01-09 05:21:28
@article{4aaeb35d-6d15-4b42-a971-7216e309963e,
  abstract     = {{<p><br>
                                                         The aqueous behaviour of the anionic octa-tetramethylammonium substituted cubic silsesquioxane, [N(CH                             <br>
                            <sub>3</sub><br>
                                                         )                             <br>
                            <sub>4</sub><br>
                                                         ]                             <br>
                            <sub>8</sub><br>
                                                         [Si                             <br>
                            <sub>8</sub><br>
                                                         O                             <br>
                            <sub>20</sub><br>
                                                         ], was studied with quantitative                              <br>
                            <sup>29</sup><br>
                                                         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                             <br>
                            <sup>+</sup><br>
                                                          ions coordinates to all different silica species, with approximately three TMA                             <br>
                            <sup>+</sup><br>
                                                          per cube. These are located at the faces of the cube.                         <br>
                        </p>}},
  author       = {{Nilsson, Emelie J. and Huber, Marina and Carlström, Göran and Söderman, Olle and Bowron, Daniel T. and Edler, Karen J. and Alfredsson, Viveka}},
  issn         = {{1463-9076}},
  language     = {{eng}},
  number       = {{12}},
  pages        = {{6732--6742}},
  publisher    = {{Royal Society of Chemistry}},
  series       = {{Physical Chemistry Chemical Physics}},
  title        = {{Stability and behaviour in aqueous solutions of the anionic cubic silsesquioxane substituted with tetramethylammonium}},
  url          = {{http://dx.doi.org/10.1039/c8cp05682j}},
  doi          = {{10.1039/c8cp05682j}},
  volume       = {{21}},
  year         = {{2019}},
}