Abstract:
A mesoporous shell structure was synthesized using carbon spheres and cetyltrimethylammonium bromide (CTAB) as dual templates, and hollow magnetic nanoparticles (HMNPs) were subsequently prepared by etching. Hollow magnetic nanoparticles functionalized by graphene oxide (HMNPs-GO) were synthesized via the functionalization of HMNPs with NH
2 groups and the activation of carboxyl groups of graphene oxide by
N-ethyl-NO-(3-(dimethylamino)propyl) carbodiimide/
N-hydroxysuccinimide (EDC/NHS). HMNPs and HMNPs-GO were characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), Raman, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). Upon the investigations on the adsorption isotherm of HMNPs-GO, it was found that the adsorption of GA by HMNPs-GO was mainly attributed to the π-π accumulation between each other and was refer to Freundlich adsorption. The diffusion mechanism and release kinetics of GA in HMNPs-GO were studied based on Bhaskar model, quasi-first-order, and quasi-second-order kinetic model, respectively. The release of GA showed pH dependence in HMNPs-GO, and the sustained release at different pH followed the quasi-second-order dynamics model.