Kinetics of Nitrites Adsorption on AB2 Type Hyperbranched Poly(Amine Ester) Modified by Trichloroctadecylsilan

Abstract

The AB2 type hyperbranched poly(amine ester) (HBPAE) can be used as adsorbent to adsorb nitrite from aqueous solution due to a large number of terminal hydroxyl groups, where the hydrogen-bonds could formed between OH and NO2-. However, the hydrophilic properties of HBPAE limited their utility in the application because of the difficulties in removing adsorbent from nitrite solution after the adsorption was finished. The hydrophilic properties of the HBPAE were changed by means of end capping method, where the trichloroctadecylsilan (OTS) was adopted as the hydrophobic alkyl chains. The modified HBPAE by OTS can be separated from the aqueous solution. The adsorption kinetics of nitrite from aqueous solutions onto modified HBPAE was investigated to show the pseudo-first-order kinetic mechanism. The equilibrium adsorption data were found to be well fitted by Freundlich isotherm equation.