双孔道管状有序介孔炭对维生素B12的吸附缓释性能

通过纳米铸型法,以硅基介孔分子筛SBA-15为模板,糠醇为碳源,草酸作为聚合催化剂合成了具有双孔道管状有序介孔炭CMK-5.利用粉末X射线衍射(XRD)、扫描电子显微镜(SEM)和氮气物理吸附法等对其结构进行了表征.结果表明合成的CMK-5具有有序结构,比表面积和孔容积分别高达1856 m2·g-1和2.10 cm3·g-1,在3.1和5.5nm具有集中的双孔分布.由于独特的双孔道结构特点,CMK-5在120 min内快速吸附维生素B12至平衡,吸附量高达943 mg·g-1,远高于商用活性炭.CMK-5吸附维生素B12后可以直接用于缓释,动态缓释浓度维持在～9 mg·L-1,适用于维生素B12分子在人体内的缓释.

Adsorption and Release Behavior of Vitamin B12 in Tubular Structured Ordered Mesoporous Carbon

Ordered mesoporous carbon with hexagonal arrays consisting of tubular-type pores (CMK-5) was synthesized via a nanocasting process by the direct use of SBA-15 as a template, furfuryl alcohol as a carbon source and oxalic acid as the catalyst. The structure of CMK-5 was analyzed by different techniques including scanning electron microscopy, powder X-ray diffraction and N₂ adsorption analysis. The specific surface area and pore volume were found to be 1856 m²·g^-1 and 2.10 cm³·g^-1, respectively, with mesopore sizes concentrated at 3.1 and 5.5 nm. Because of the unique structure the adsorption capacities of CMK-5 towards vitamin B12 was found to be as high as 943 mg·g^-1 in a short period of 120 min, which is significantly higher than that of commercial activated carbon. The composites of CMK-5 and vitamin B12 without any treatment gave slow-release performance in a simulated body fluid. The concentration of the release solutions remained 9 mg·L^-1 under dynamic conditions. A high loading capacity and slow release rate of vitamin B12 on the CMK-5 support suggested that CMK-5 might have a potential application in drug delivery.