POLYAMINES ADSORBED ONTO SILICA-GEL - A RAMAN MICROPROBE ANALYSIS

Polyamine [especially poly(ethylenimine) and poly(4-vinylpyridine)] ad sorption onto silica gels for chromatography and water-decontamination experiments, using a Raman microprobe, is reviewed. First, the bare s ilica are characterized. Then, the polyamines and the adsorbed polyami nes spectra are compared. We show that polyamine adsorption onto silic a occurs with two kinds of polymer populations: chemisorbed (trains du e to important interactions between silanol and the nitrogen atom) and physisorbed (multilayers) polymer. The modifications of chemisorbed p olymer bands are stronger than are the physisorbed ones. (C) 1997 John Wiley & Sons, Inc.