Type of Publication: | Journal article |
Publication status: | Published |
Author: | Fratini, Emiliano; Page, Miles G.; Giorgi, Rodorico; Cölfen, Helmut; Baglioni, Piero; Demé, Bruno; Zemb, Thomas |
Year of publication: | 2007 |
Published in: | Langmuir ; 23 (2007), 5. - pp. 2330-2338. - ISSN 0743-7463. - eISSN 1520-5827 |
Pubmed ID: | 17269801 |
DOI (citable link): | https://dx.doi.org/10.1021/la062023i |
Summary: |
Calcium hydroxide forms unstable reactive nanoparticles that are stabilized when they are dispersed in ethylene glycol or 2-propanol. The aggregation behavior of these particles was investigated by contrast-variation small-angle neutron scattering (SANS), combined with small-angle X-ray scattering (SAXS). Nanoparticles on the order of 100 nm were found to aggregate into mass-fractal superstructures in 2-propanol, while forming more compact agglomerated aggregates with surface fractal behavior in ethylene glycol. Commensurate specific surface areas evaluated at the Porod limit were more than an order of magnitude greater in 2-propanol (approximately 200 m2.g-1) than in ethylene glycol (approximately 7 m2.g-1). This profound microstructural evolution, observed in similar solvents, is shown to arise from competitive solvent adsorption. The composition of the first solvent layer on the particles is determined over the full range of mixed solvent compositions and is shown to follow a quantifiable thermodynamic equilibrium, determined via contrast-variation SANS, that favors ethylene glycol over 2-propanol in the surface layer by about 1.4 kJ.mol-1 with respect to the bulk solvent composition.
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Subject (DDC): | 540 Chemistry |
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FRATINI, Emiliano, Miles G. PAGE, Rodorico GIORGI, Helmut CÖLFEN, Piero BAGLIONI, Bruno DEMÉ, Thomas ZEMB, 2007. Competitive Surface Adsorption of Solvent Molecules and Compactness of Agglomeration in Calcium Hydroxide Nanoparticles. In: Langmuir. 23(5), pp. 2330-2338. ISSN 0743-7463. eISSN 1520-5827. Available under: doi: 10.1021/la062023i
@article{Fratini2007-02Compe-40269, title={Competitive Surface Adsorption of Solvent Molecules and Compactness of Agglomeration in Calcium Hydroxide Nanoparticles}, year={2007}, doi={10.1021/la062023i}, number={5}, volume={23}, issn={0743-7463}, journal={Langmuir}, pages={2330--2338}, author={Fratini, Emiliano and Page, Miles G. and Giorgi, Rodorico and Cölfen, Helmut and Baglioni, Piero and Demé, Bruno and Zemb, Thomas} }