【摘要】 采用乳化-化学交联法,以壳聚糖为原料,戊二醛为交联剂,邻苯二甲酸二丁酯(DBP)为致孔剂,在乳化聚合条件下成功制备出多孔复合微球,拟将作为营养物质载体用于植物的根部吸收。通过单因素研究,得到了复合微球最佳致孔条件:壳聚糖溶液浓度为1.8%~2.0%(质量分数),O/W比例为5∶1,转速为900 r/min,乳化温度为45℃,DBP体积占O/W总体积比例为1∶7.5,浓度为50%(v/v)戊二醛体积占O/W总体积比例为1∶40。通过扫描电镜(SEM)对复合微球的形貌和结构进行分析;采用透射电镜(TEM)及element mapping检测含N、P、K复合肥成功包裹于壳聚糖微球中;利用元素分析,ICP(电感耦合等离子发射光谱)对复合微球的缓释性能进行测试与表征。研究结果表明,复合微球球形规整度良好;大部分微球直径在50μm左右;微球表面粗糙不平且有部分孔隙结构;微球释放规律符合希古契提出的Higuchi骨架模型,在132 h后释放逐渐趋于平稳,表明制备的复合微球具备良好的缓释效果。更多还原

【Abstract】 In this paper,the emulsification-chemical crosslinking method is successfully used to prepare the porous composite microspheres under the emulsion polymerization situation with chitosan,glutaraldehyde and dibutyl phthalate acetate(DBP) as raw material,cross-linking agent and hole agent,respectively,and the prepared composite microspheres will be applied as nutrient support for the roots of plants. Through the single factor study,the best preparation conditions for hole formation of composite microspheres are obtained:chitosan solution concentration is 1.8- 2.0wt%,O/W ratio is 5∶ 1,the stirring speed is 900 r/min,emulsification temperature is 45 ℃,the volume ratio of DBP to O/W is 1 ∶ 7.5,and the volume ratio of glutaraldehyde with 50%(v/v) concentration to O/W is 1 ∶ 40. Scanning electron microscopy(SEM)was used to analyze the morphology and structure of the composite microspheres. Transmission electron microscopy(TEM) and element mapping were supplied to make certain that the N,P,K containing compound fertilizer is successfully packaged in chitosan microspheres. The slow release properties of the composite microspheres were tested by elemental analyzer and ICP(inductively coupled plasma). The results prove that the spherical structured degree of composite microspheres is good,most of particle size is around 50 μm,microsphere surface is rough and part of the structure is with pore. The release rule of composite microspheres conforms to the Higu- chi skeleton model,release gradually becomes stable after 132 hours,and the prepared composite microspheres have good slow release effect.更多还原