Schmid, Philipp and Buchecker, Thomas and Khoshsima, Ali and Touraud, Didier and Diat, Olivier and Kunz, Werner and Pfitzner, Arno and Bauduin, Pierre (2021) Self-assembly of a short amphiphile in water controlled by superchaotropic polyoxometalates: H4SiW12O40 vs. H3PW12O40. JOURNAL OF COLLOID AND INTERFACE SCIENCE, 587. pp. 347-357. ISSN 0021-9797, 1095-7103
Full text not available from this repository. (Request a copy)Abstract
Nanometric ions, such as polyoxometalates (POMs) or ionic boron clusters, with low charge density have previously shown a strong propensity to bind to macrocycles and to adsorb to neutral surfaces: micellar, surfactant covered water-air and polymer surfaces. These association phenomena were shown to arise from a solvent-mediated effect called the (super-)chaotropic effect. We show here by combining cloud point (CP) measurements, scattering (SAXS/SANS) and spectroscopic techniques (NMR) that Keggin POMs: H4SiW12O40 (SiW) and H3PW12O40 (PW), induce the self-assembly of an organic solvent: dipropylene glycol n-propylether (C3P2), in water. The strong interaction between SiW/PW with C3P2 leads to a drastic increase in the CP, and aqueous solubility, of C3P2, e.g. SiW enables reaching full water-C3P2 co-miscibility at room temperature. At high POM concentrations, SiW leads to a continuous increase of the CP, forming SiW-[C3P2](1-2) complexes, whereas PW produces a decrease in the CP attributed to the formation of nearly "dry" spherical [PW]n[C3P2]m colloids, with n similar to 4 and m similar to 30. At high C3P2/PW contents, the [PW]n[C3P2]m colloids turn into large interconnected structures, delimiting two pseudo-phases: a PW-C3P2-rich phase and a water-rich phase. It is proposed that the stronger electrostatic repulsions between SiW (4-), compared to PW (3-), prevents the formation of mesoscopic colloids. (c) 2020 Elsevier Inc. All rights reserved.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | PROTEIN ADSORPTION; HYDRATION FORCES; HETEROPOLYANIONS; TEMPERATURE; NANOZYME; SALTS; DLVO; PH; Superchaotropicity; Polyoxometalates; Mesoscopic structuring; Colloids; Adsorption; Self-assembly |
| Subjects: | 500 Science > 540 Chemistry & allied sciences |
| Divisions: | Chemistry and Pharmacy > Institut für Anorganische Chemie > Chair Prof. Dr. Arno Pfitzner Chemistry and Pharmacy > Institut für Physikalische und Theoretische Chemie > Chair of Chemistry VI - Physical Chemistry (Solution Chemistry) > Prof. Dr. Werner Kunz |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 07 Sep 2022 09:10 |
| Last Modified: | 07 Sep 2022 09:10 |
| URI: | https://pred.uni-regensburg.de/id/eprint/46764 |
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