Controlled Preparation and Characterization of Aspirin Surface Molecularly Imprinted Separating Medium Based on Halloysite Nanotubes
The molecularly imprinted separating medium with halloysite nanotubes as carrier,which were environmentally friendly natural silica substrate nano-materials,aspirin as template molecule and acrylamide as functional monomer was synthesized using reversible addition fragmentation chain transfer polymerization. The template molecule and monomer were bound to stable composite at 1 ∶ 2 using the method of ultraviolet spectroscopy combined with Lamber-Beer theory at molecular level. The morphology and adsorption capacity of imprinted material was studied with Fourier transform infrared spectrometer( FT-IR),transmission electron microscope( TEM),static adsorption and selective adsorption. The experimental results showed that a good uniformity of imprinted layer with the thickness of 38 nm was coated steadily on the halloysite nanotubes surface. Compared with the conventional surface imprinted material and the material with silica gel as carrier,our molecularly imprinted material had the characteristics of high adsorption capacity and favorable imprinted effect. Its imprinted factor achieved to 3. 5. The molecularly imprinted material was applied for mimetic intestinal juice diffusion experiment. The experimental results indicated that the imprinted material release the aspirin for 12 h,which was 2 times for non imprinted material for only 6 h,demonstrating excellent drug release result,which provided basic data for potential applications of drug carrier.