Journal of Colloid and Interface Science, Vol.314, No.1, 38-45, 2007
n-propylpyridinium chloride-modified poly (dimethylsiloxane) elastomeric networks: Preparation, characterization, and study of metal chloride adsorption from ethanol solutions
An n-propylpyridinium chloride-modified PDMS elastomeric network, PDMS/Py+Cl-, was prepared from linear PDMS chains containing Si(CH3)(2)-OH end-groups cross-linked by 3-chloropropyltrimethoxysilane and posterior reaction with pyridiDe. PDMS/Py+CI- material was structurally characterized by infrared spectroscopy (IR) and solid state C-13 and Si-29 NMR. Thermogravimetric analysis of the product showed good thermal stability, with the initial temperature of weight loss at 450 K. The ion-exchange capacity of the PDMS/Py+Cl- was 0.65 mmol g(-1). Metal halides, MClz, [M = Fe3+, CU2+, and CO2+], were adsorbed by the modified solid from ethanol solutions as neutral species by forming the surface anionic complexes MClz+nn-. The nature of the anionic complex structure was proposed by UV-vis diffuse reflectance spectra. The species adsorbed were FeCl4-, CuCl42-, and CoCl42-. The specific sorption capacities and the heterogeneous stability constants of the immobilized metal complexes were determined with the aid of computational procedures. The trend in affinities of PDMS/Py+Cl- for the metal halides were found to be FeCl3 > CUCl2 similar to COCl2. (c) 2007 Elsevier Inc. All rights reserved.
Keywords:poly(dimethylsiloxane);n-propylpyridinium chloride;elastomeric network;metal adsorption;stability constants