[关键词]
[摘要]
以竹笋下脚料为原料提取纤维素并进行改性后,添加κ-卡拉胶并在环氧氯丙烷交联下通过反相悬浮聚合法,成功制备出pH敏感型竹笋复合水凝胶,并使用FT-IR、热重分析、扫描电镜对该复合水凝胶进行表征,研究水凝胶的溶胀性能与动力学,并以亚甲基蓝为模型药物分子,研究不同初始浓度和初始pH对水凝胶吸附性能影响。实验发现:改性竹笋纤维素与κ-卡拉胶发生化学交联,形成具有固定分解温度的三维网状结构水凝胶。该复合水凝胶由于其带负电荷侧链基团在不同pH溶液中静电斥力的差异不同使得其溶胀行为具有pH敏感性,在溶胀初始阶段服从Fickian扩散,在整个阶段符合Schott模型。复合水凝胶具有多孔性能和溶胀性能,使其具有较强吸附性能,吸附实验发现该复合水凝胶对模型药物亚甲基蓝吸附性能良好,该复合水凝胶在药物吸附与缓释领域具有潜在应用价值。
[Key word]
[Abstract]
A composite hydrogel displaying pH sensitivity was successfully prepared from bamboo cellulose extracted from bamboo off-cuts, with added κ-carrageenan (κ-CN) by inverse suspension polymerization, and using epichlorohydrin (ECH) as a crosslinking agent. The prepared composite hydrogels and their swelling kinetics were characterized by Fourier transform infrared spectroscopy (FT-IR), thermo-gravimetric analysis, and scanning electron microscopy. In addition, methylene blue was used as a model drug molecule to study the effects of different initial concentrations and initial pH values on the adsorption capacity of the hydrogel. The results of these analyses showed that modified bamboo cellulose and κ-CN underwent chemical cross-linking, forming a hydrogel with a three-dimensional network structure with a fixed decomposition temperature. The hydrogel showed pH-sensitive swelling behavior, caused by the variations in electrostatic repulsion exhibited by its negatively-charged side chain groups in solutions with varying pH. The initial swelling phase complied with the Fickian diffusion model, while the entire swelling process complied with the Schott model. The hydrogel was porous and displayed swelling capacity, which enabled it to express high adsorption capacity. The adsorption test showed it had a high adsorption capacity to the model drug (methylene blue). Therefore, this composite hydrogel could potentially be applied to facilitate drug adsorption and sustained release.
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[基金项目]
教育部博导基金项目(20120172110017);国家自然科学基金项目(31271978);国家自然科学基金项目(31471673)