Adsorption of Bovine Hemoglobin by Sulfonated Polystyrene Nanospheres

Abstract

AbstractIn this work, the authors attempted to present a detailed study on the adsorption of bovine hemoglobin (BHB) by sulfonated polystyrene nanospheres (SPS NSs). The adsorption characteristics including adsorption isotherms, kinetics and thermodynamics were studied in detail. The adsorption isotherms were better fitted by the Langmuir model, leading to a remarkable adsorption capacity of 2831.4 mg g−1. Such an adsorption capacity is among the highest values reported in the literature. The adsorption kinetics was analyzed by the pseudo‐first‐order, pseudo‐second‐order and intra‐particle diffusion equations. The thermodynamic parameters including binding site, binding affinity, and changes of enthalpy, entropy and Gibbs free energy were determined by isothermal titration calorimetry measurements. The electrostatic interaction of BHB and SPS NSs was identified as the major adsorption mechanism. The effects of solution pH, temperature and competitive metal ions in the adsorption process were studied. Based on the Arrhenius equation, the activation energy of the adsorption process was determined to be 2.34 kJ mol−1.