STRNADOVA, M and LEIMBACH, J and RUPPRECHT, H (1995) ADSORPTION OF CODEINE ON HYDROPHILIC SILICA AND SILICA SURFACE-MODIFIED BY HYDROPHOBIC GROUPS IN THE PRESENCE OF ELECTROLYTES. COLLOID AND POLYMER SCIENCE, 273 (7). pp. 687-692. ISSN 0303-402X,
Full text not available from this repository.Abstract
The adsorption of codeine from aqueous solution onto colloidal silica and silica surface-modified with chemiadsorbed octadecyl dimethyl silane (ODDMS) or dimethyl silane (DMS) groups was studied in the presence of neutral electrolytes at different pH values. From codeine-hydrochloride solutions codeine cations are strongly bound to negatively charged silica surfaces. Inorganic salts (NaCl, NaNO3) reduce the adsorption of the organic cation. On silica modified by ODDMS (10% of surface silanol groups are occupied), codeine cations are adsorbed to a higher extent at pH 6, while at pH 8 the adsorbed amounts are lower than on the bare silica surface. Neutral electrolytes reduce codeine adsorption on the ODDMS modified silica. On the hydrophobic silica, completely covered by DMS groups, codeine adsorption is considerably lower than on the bare silica, but neutral salts increase the adsorption. The adsorption of codeine is compared with the adsorption of aggregating surfactant ions. Common and different features of their interactions with silica surfaces are outlined.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | IONIC SURFACTANTS; MODEL; INTERFACE; ADSORPTION; CODEINE; SURFACE MODIFIED; SILICA; ALKYL GROUP; ELECTROLYTE; PH |
| Depositing User: | Dr. Gernot Deinzer |
| Last Modified: | 19 Oct 2022 08:37 |
| URI: | https://pred.uni-regensburg.de/id/eprint/52446 |
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