【摘要】：磁性聚合物微球因其較強(qiáng)的磁響應(yīng)性、易于表面功能化以及良好的生物相容性等特點(diǎn)受到廣泛的關(guān)注。環(huán)糊精是具有“內(nèi)疏水,外親水”特殊結(jié)構(gòu)的環(huán)狀低聚糖,能選擇性地與多種有機(jī)物形成主-客體包合物。將兩者有機(jī)結(jié)合制備環(huán)糊精磁性復(fù)合微球,既保留了磁性粒子的磁響應(yīng)性,又可擁有環(huán)糊精的分子識(shí)別、包結(jié)等功能,有望應(yīng)用于天然產(chǎn)物的吸附和分離。本論文采用共沉淀法制備Fe3O4粒子,然后以六亞甲基二異氰酸酯為交聯(lián)劑,將?-環(huán)糊精進(jìn)行預(yù)聚合得到預(yù)聚物β-CDPU,再通過(guò)包埋法將β-CDPU與Fe3O4粒子相連接,制備?-環(huán)糊精磁性復(fù)合微球(β-CDPU/MP)。利用X射線粉末衍射、傅里葉變換紅外光譜、掃描電鏡、熱重和差熱分析、總有機(jī)碳分析等手段對(duì)復(fù)合微球進(jìn)行分析表征,結(jié)果表明β-CDPU成功包埋到Fe3O4粒子上,β-CDPU的包覆沒(méi)有改變Fe3O4粒子的晶型。復(fù)合微球是一種表面多孔材料,其中β-CD約占總質(zhì)量的14.0%~17.2%。以柯里拉京為模型化合物,考察β-CDPU/MP的吸附性能,評(píng)價(jià)環(huán)糊精磁性復(fù)合微球作為磁性吸附劑的可行性。結(jié)果表明,β-環(huán)糊精與柯里拉京可以形成1:1的包合物,包合常數(shù)K值為1.19×104 L/mol,表明兩者之間相互作用良好,且形成的包合物較穩(wěn)定。β-CDPU/MP吸附劑對(duì)柯里拉京的吸附類型符合Langmuir型吸附等溫線。以珠子草中有效成分柯里拉京的富集分離為應(yīng)用實(shí)例,考察β-CDPU/MP對(duì)天然產(chǎn)物的分離富集能力。將吸附劑直接加入到珠子草乙醇粗提液中吸附柯里拉京,經(jīng)純水、20%(w/w)乙醇水溶液和50%乙醇水溶液三次洗脫,β-CDPU/MP吸附劑對(duì)粗提液中柯里拉京的吸附率為63.6%,總脫附率為17.0%。而未包埋上β-CD的Fe3O4粒子對(duì)乙醇粗提液中柯里拉京的吸附率高達(dá)98.1%,卻幾乎不能進(jìn)行脫附。分析原因可能是Fe3O4磁核與柯里拉京直接接觸,生成較穩(wěn)定的復(fù)合物致使溶劑脫附基本無(wú)效。本論文設(shè)計(jì)在Fe3O4磁核表面預(yù)先包覆二氧化硅隔離層,制備?-環(huán)糊精二氧化硅磁性復(fù)合微球(β-CDPU/SiO2/MP)。表征結(jié)果顯示,Fe3O4粒子表面成功包覆上SiO2,β-CDPU成功連接到SiO2/MP上。SiO2和β-CDPU的包覆均沒(méi)有改變Fe3O4粒子的晶體結(jié)構(gòu)。β-CDPU/SiO2/MP中β-CD約占總質(zhì)量的6.8%~9.3%。與β-CDPU/MP吸附劑類似,β-CDPU/SiO2/MP吸附劑對(duì)柯里拉京的吸附類型也屬于Langmuir型。吸附-脫附實(shí)驗(yàn)結(jié)果顯示,β-CDPU/SiO2/MP吸附劑對(duì)珠子草粗提液中柯里拉京的吸附率為65.2%,脫附率為41.0%。與β-CDPU/MP相比,脫附率得到大幅度提高。實(shí)驗(yàn)證明β-CDPU/SiO2/MP吸附劑能夠?qū)崿F(xiàn)珠子草中柯里拉京的快速富集。本課題的研究表明環(huán)糊精磁性復(fù)合微球作為磁性吸附劑在天然產(chǎn)物分離純化方面具有潛在的應(yīng)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.
【學(xué)位授予單位】：華僑大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2016
【分類號(hào)】：O636.1
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本文編號(hào)：2450263