Abstract: Silica polyamine composites (SPC) made from silanized amorphous nano-porous silica gel and poly(allylamine) (BP-1) were functionalized with phosphorus acid using the Mannich reaction, resulting in a phosphonic acid modified composite (BPAP). Zirconium (IV) was immobilized on BPAP. Arsenate anions strongly adsorbed on the ZrBPAP composite in the pH range 2 to 8, while arsenite only adsorbed well at pH 10. Regeneration of the resin was carried out successfully for As(V) and As(III) using 2M-H2SO4. Four adsorption/desorption cycles were performed for As(V) at pH 4 without significant decrease in the uptake performance. ZrBPAP capture capacity and kinetics for arsenate were tested for longevity over 1000 cycles with only a marginal loss of performance.

Abstract: Silica polyamine composites (SPC) made from silanized amorphous nano-porous silica gel and poly(allylamine) (BP-1) were functionalized with phosphorus acid using the Mannich reaction, resulting in a phosphonic acid modified composite (BPAP). Zirconium (IV) was immobilized on BPAP. Arsenate anions strongly adsorbed on the ZrBPAP composite in the pH range 2 to 8, while arsenite only adsorbed well at pH 10. Regeneration of the resin was carried out successfully for As(V) and As(III) using 2M-H2SO4. Four adsorption/desorption cycles were performed for As(V) at pH 4 without significant decrease in the uptake performance. ZrBPAP capture capacity and kinetics for arsenate were tested for longevity over 1000 cycles with only a marginal loss of performance.

Abstract: Methods of producing semiconductor materials via polymerization techniques are provided. The methods include reacting a precursor compound containing a metalloid semiconductor element, such as silicon or germanium, with a catalyst to form a polymer composition. The polymer precursor is then decomposed to form an electrically conductive hydrogenated composition containing silicon or germanium. The methods employ relatively safe raw materials and products and result in high yield reactions. Moreover, the polymers can be applied in liquid form and can be used as an “ink” or liquid to selectively coat a substrate.