Study on the Mechanism of Procyanidins Adsorption onto Chitosan Microflower

In order to understand the adsorption mechanism of chitosan microflower (CSMF) on procyanidins (PC), CSMF was used as an adsorbent to adsorb PC solutions under different adsorption conditions. The drug-loaded particles were characterized by scanning electron microscopy (SEM), Fourier infrared (FTIR), X-ray diffraction (XRD), etc. Through adsorption kinetics, adsorption isotherm, and adsorption thermodynamics, the mechanism of CSMF adsorption PC was systematically studied. The results showed that the FTIR pattern of the drug-loaded particles produced a new characteristic peak at 1456 cm⁻¹, indicating that the PC was successfully loaded onto the CSMF. The results of SEM and XRD analysis showed that the morphology and crystallinity of CSMF did not change after loading. The adsorption kinetics showed that the adsorption of PC by CSMF conformed to the pseudo-second-order kinetic model, and the adsorption rate was affected by the interaction between particle diffusion and boundary layer diffusion. The adsorption isotherm showed that the Freundlich adsorption isotherm model could more accurately reflect the entire adsorption process, indicating that the adsorption process of CSMF to PC was multilayer adsorption with surface energy inhomogeneity. Finally, adsorption thermodynamics showed that the adsorption of PC by CSMF was a spontaneous physical adsorption process with reduced entropy.