【作者】 刘佳；

【导师】 李优鑫； 张鉴；

【作者基本信息】 天津大学 ， 药学， 2022， 硕士

【摘要】 多糖是自然界中一类重要的化合物,是一切生命活动的主要能量来源,大多数多糖必须在体内或体外被分解成它们的组成成分——单糖,才能被人体吸收。纤维素和半纤维素是生物质中的主要多糖,通过水解可以得到大量葡萄糖、木糖和其他单糖,对这些单糖的选择性分离无疑会带来巨大的经济效益。目前对单糖的分离多采用色谱法或膜过滤法,但都存在选择性不足或成本过高等问题。分子印迹技术是基于模拟生物体内抗原与抗体相互作用原理而发展起来的一种新兴技术,近年来在分离科学领域备受关注。本论文制备了以葡萄糖和木糖为模板的分子印迹聚合物（MIP）,并对其吸附性能进行了研究。首先本文以甲基丙烯酰胺基苯硼酸和甲基丙烯酸为单体,二甲基丙烯酸乙二醇酯和亚甲基双丙烯酰胺为交联剂,葡萄糖为模板分子,采用悬浮聚合法制备了一种新型硼酸和羧酸双官能团修饰的葡萄糖分子印迹聚合物（G-MIP）。所制备的G-MIP粒径为25-70μm,在215℃以下热稳定,其比表面积为174.82 m²/g,平均孔径约为9.48 nm。吸附实验表明在p H 11和20℃下,G-MIP对10 mg/m L葡萄糖溶液4 h的最大吸附量可达236.32 mg/g,对葡萄糖和果糖的选择因子为2.71。其次,本文将所制备的G-MIP用于纤维素水解产物中葡萄糖的提纯。在优化的水解条件下（0.5 mol/L H₂SO₄催化,150℃下反应4h）对0.5 g微晶纤维素重复水解4次,葡萄糖产率由7.61%提升至15.37%。将G-MIP加入纤维素水解液中进行吸附,其对葡萄糖与木糖的选择性可达4.12。同时开发了新型色谱填料（G-MIP）介导的中空纤维膜分离体系,并获得了浓度为3.84 mg/m L的纯化葡萄糖溶液。第三,本文以聚丙烯胺盐酸盐为单体,环氧氯丙烷为交联剂制备了木糖分子印迹聚合物水凝胶（X-MIP）,并探究和考察了p H值、温度和模板分子添加量对所制备X-MIP吸附量和选择性的影响。吸附实验表明,在p H 11和60℃条件下,X-MIP对15 mg/m L木糖溶液12 h的吸附量高达398.68 mg/g,对木糖和葡萄糖的选择因子可达4.70,对模拟的实际样品的分离因子可达591.05（木糖:葡萄糖=99:1）和15.42（木糖:葡萄糖=3:1）,该数据表明X-MIP可以有效分离木糖。本文成功地制备了新型葡萄糖MIP和木糖MIP,并开发了色谱介导的中空纤维膜分离体系,有望应用于工业生产中葡萄糖和木糖的分离纯化。更多还原

【Abstract】 Polysaccharide is an important class of compounds in nature,which can provide energy for life-sustaining activities.Most of the polysaccharides have to be broken down,either in vivo or in vitro,into their compositional constituents,sugars,before they can be absorbed by the human body.Cellulose and hemicellulose,the primary polysaccharides in biomass,can be hydrolyzed to a mass of glucose,xylose,and other monosaccharides.The selective separation of these monosaccharides will undoubtedly bring enormous economic benefits.At present,the separation of sugars is mostly performed by chromatography or membrane filtration,but they all suffer from insufficient selectivity or high cost.Molecular imprinting technology is an emerging technique based on the principle of simulating the interaction between antigens and antibodies in living organisms,it has attracted much attention in the field of separation science in recent years.In this thesis,molecularly imprinted polymers（MIPs）were prepared using either glucose or xylose as template molecules,and their adsorption properties were investigated.First,a novel bifunctional group modified glucose MIP（G-MIP）was prepared by suspension polymerization method,with methylacrylamide phenylboronic acid and methacrylic acid as monomers,ethyleneglycol dimethacrylate,and methylene-bis-acrylamide as crosslinkers,and glucose as template molecule.The prepared G-MIP had a particle size of 25-70μm,and was thermally stable below 215°C,with a specific surface area of 174.82 m²/g and an average pore size of 9.48 nm.Adsorption experiments showed that the maximum adsorption capacity of G-MIP to glucose（10mg/m L,p H 11）at 20°C for 4 h was up to 236.32 mg/g,and the selection factor for glucose and fructose was 2.71.The prepared G-MIP was then used for the purification of glucose from cellulose hydrolysates.Under the optimized hydrolysis conditions（catalyzed by 0.5 mol/L H₂SO₄,and reacted at 150°C for 4 h）,microcrystalline cellulose（0.5 g）was hydrolyzed continuously for 4 times,and the glucose yield increased from 7.61%to 15.37%.The prepared G-MIP was used for the capture of glucose from cellulose hydrolysates,and the selectivity to glucose over xylose could reach 4.12.Meanwhile,the novel chromatography（G-MIP）mediated hollow fiber membrane separation system was developed,and purified glucose solution with a concentration of 3.84 mg/m L was obtained.Next,xylose MIP hydrogel（X-MIP）was prepared with polyallylamine hydrochloride as monomer and epichlorohydrin as cross-linker,the effects of synthetic p H,temperature,and addition amount of template molecule on the adsorption capacity and selectivity of the prepared X-MIP were investigated.Adsorption experiments showed that the adsorption capacity of X-MIP hydrogel to xylose（15 mg/m L,p H 11）at 60℃ for 12 h was up to 398.68 mg/g.The selectivity for xylose and glucose could reach 4.70,and the separation factors of X-MIP hydrogels in simulated practical samples,were 591.05（xylose:glucose=99:1）and 15.42（xylose:glucose=3:1）,respectively,which indicates that the prepared X-MIP hydrogels are very effective for the purification of xylose.In this thesis,novel glucose MIP and xylose MIP were successfully prepared,and a chromatography-mediated hollow fiber membrane separation system was developed,which is expected to be applied in the separation and purification of glucose and xylose in industrial production.更多还原