β-环糊精磁性复合微球的制备及用于柯里拉京的分离

发布时间：2019-03-30 16:22

【摘要】：磁性聚合物微球因其较强的磁响应性、易于表面功能化以及良好的生物相容性等特点受到广泛的关注。环糊精是具有“内疏水,外亲水”特殊结构的环状低聚糖,能选择性地与多种有机物形成主-客体包合物。将两者有机结合制备环糊精磁性复合微球,既保留了磁性粒子的磁响应性,又可拥有环糊精的分子识别、包结等功能,有望应用于天然产物的吸附和分离。本论文采用共沉淀法制备Fe3O4粒子,然后以六亚甲基二异氰酸酯为交联剂,将?-环糊精进行预聚合得到预聚物β-CDPU,再通过包埋法将β-CDPU与Fe3O4粒子相连接,制备?-环糊精磁性复合微球(β-CDPU/MP)。利用X射线粉末衍射、傅里叶变换红外光谱、扫描电镜、热重和差热分析、总有机碳分析等手段对复合微球进行分析表征,结果表明β-CDPU成功包埋到Fe3O4粒子上,β-CDPU的包覆没有改变Fe3O4粒子的晶型。复合微球是一种表面多孔材料,其中β-CD约占总质量的14.0%~17.2%。以柯里拉京为模型化合物,考察β-CDPU/MP的吸附性能,评价环糊精磁性复合微球作为磁性吸附剂的可行性。结果表明,β-环糊精与柯里拉京可以形成1:1的包合物,包合常数K值为1.19×104 L/mol,表明两者之间相互作用良好,且形成的包合物较稳定。β-CDPU/MP吸附剂对柯里拉京的吸附类型符合Langmuir型吸附等温线。以珠子草中有效成分柯里拉京的富集分离为应用实例,考察β-CDPU/MP对天然产物的分离富集能力。将吸附剂直接加入到珠子草乙醇粗提液中吸附柯里拉京,经纯水、20%(w/w)乙醇水溶液和50%乙醇水溶液三次洗脱,β-CDPU/MP吸附剂对粗提液中柯里拉京的吸附率为63.6%,总脱附率为17.0%。而未包埋上β-CD的Fe3O4粒子对乙醇粗提液中柯里拉京的吸附率高达98.1%,却几乎不能进行脱附。分析原因可能是Fe3O4磁核与柯里拉京直接接触,生成较稳定的复合物致使溶剂脱附基本无效。本论文设计在Fe3O4磁核表面预先包覆二氧化硅隔离层,制备?-环糊精二氧化硅磁性复合微球(β-CDPU/SiO2/MP)。表征结果显示,Fe3O4粒子表面成功包覆上SiO2,β-CDPU成功连接到SiO2/MP上。SiO2和β-CDPU的包覆均没有改变Fe3O4粒子的晶体结构。β-CDPU/SiO2/MP中β-CD约占总质量的6.8%~9.3%。与β-CDPU/MP吸附剂类似,β-CDPU/SiO2/MP吸附剂对柯里拉京的吸附类型也属于Langmuir型。吸附-脱附实验结果显示,β-CDPU/SiO2/MP吸附剂对珠子草粗提液中柯里拉京的吸附率为65.2%,脱附率为41.0%。与β-CDPU/MP相比,脱附率得到大幅度提高。实验证明β-CDPU/SiO2/MP吸附剂能够实现珠子草中柯里拉京的快速富集。本课题的研究表明环糊精磁性复合微球作为磁性吸附剂在天然产物分离纯化方面具有潜在的应用前景。
[Abstract]:Magnetic polymer microspheres have attracted much attention because of their strong magnetic responsiveness, easy surface functionalization and good biocompatibility. Cyclodextrin is a kind of cyclic oligosaccharide with the special structure of "internal hydrophobic, external hydrophilic", which can selectively form host-guest inclusion complex with a variety of organic compounds. The preparation of cyclodextrin magnetic composite microspheres by organic combination not only retains the magnetic responsiveness of magnetic particles, but also has the functions of molecular recognition and inclusion of cyclodextrin. It is expected to be applied to the adsorption and separation of natural products. In this paper, Fe3O4 particles were prepared by co-precipitation method, and then prepolymerized with hexamethylene diisocyanate as cross-linking agent to obtain 尾-CDPU, prepolymer, then 尾-CDPU was connected with Fe3O4 particles by embedding method. ?-cyclodextrin magnetic composite microspheres (尾-CDPU/MP) were prepared. The composite microspheres were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetry (TG), differential thermal analysis (DTA) and total organic carbon (TC) analysis. The results showed that 尾-CDPU was successfully embedded on Fe3O4 particles. The coating of 尾-CDPU did not change the crystal form of Fe3O4 particles. The composite microsphere is a kind of surface porous material, in which 尾-CD accounts for 14.0% of the total mass and 17.2% of the total mass. The adsorption properties of 尾-CDPU/MP were investigated and the feasibility of using cyclodextrin magnetic composite microspheres as magnetic adsorbents was evaluated by using Corilagin as a model compound. The results show that 尾-cyclodextrin can form an inclusion compound of 1:1 with a inclusion constant of 1.19 脳 104L / mol, indicating that the interaction between 尾-cyclodextrin and corilagin is good. The adsorption type of 尾-CDPU/MP adsorbents to Corilagin is in accordance with Langmuir adsorption isotherm. The ability of 尾-CDPU/MP to separate and concentrate natural products was investigated by using the enrichment and separation of active components of Corilagin as an example. The adsorbents were directly added to the crude ethyl alcohol extract and eluted with pure water, 20% (w / w) ethanol solution and 50% ethyl alcohol solution for three times, and the adsorbents were eluted by pure water, 20% (w / w) ethanol solution and 50% ethyl alcohol solution for three times. The adsorption rate of 尾-CDPU/MP to the crude extract was 63.6% and the total desorption rate was 17.0%. However, the adsorption rate of Fe3O4 particles without 尾-CD on the crude ethanol extract was 98.1%, but could hardly be desorbed. The analysis may be due to the direct contact between the magnetic core of Fe3O4 and Corilagin and the formation of a stable complex which results in the solvent desorption being basically ineffective. In this paper, we designed the preparation of 尾-cyclodextrin silica magnetic composite microspheres (尾-CDPU/SiO2/MP) by pre-coating silica isolation layer on the surface of Fe3O4 magnetic nucleus. The characterization results showed that SiO2, was successfully coated on the surface of Fe3O4 particles. 尾-CDPU was successfully connected to SiO2/MP. The coating of Sio _ 2 and 尾-CDPU did not change the crystal structure of Fe3O4 particles. 尾-CD accounted for 6.8% of the total mass of 尾-CDPU/SiO2/MP and 9.3% of the total mass. Similar to 尾-CDPU/MP adsorbents, 尾-CDPU/SiO2/MP adsorbents also belong to Langmuir type. The results of adsorption-desorption experiment showed that the adsorption rate of 尾-CDPU/SiO2/MP to Corilagin was 65.2% and the desorption rate was 41.0%. Compared with 尾-CDPU/MP, the desorption rate was greatly increased. It has been proved that 尾-CDPU/SiO2/MP adsorbent can realize the rapid enrichment of Corilagin. The study in this paper shows that cyclodextrin magnetic composite microspheres as magnetic adsorbents have potential application prospects in the separation and purification of natural products.
【学位授予单位】：华侨大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O636.1
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本文编号：2450263