以丝素蛋白为模板的中空介孔二氧化硅纳米材料的制备及表征

发布时间：2018-03-10 16:13

本文选题：丝素蛋白　切入点：微球　出处：《太原理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：中空结构的介孔二氧化硅纳米材料具有比表面积大、稳定性及生物相容性好的特点,在催化剂载体、药物输送、固定化酶以及基因分离等领域具有广阔的应用前景。目前制备中空介孔二氧化硅纳米材料主要采用模板法,其中利用硬模板制备的微球或微管,一般尺寸分布均一,形态相对稳定,但在制备中通常需要引进偶联剂或表面活性剂,从而引导二氧化硅在其表面黏附,使得制备过程复杂,制备成本提高;而且在去除模板时,如采用化学刻蚀法,容易对中空结构的二氧化硅微球或微管的形貌、孔径分布造成一定的破坏。为此,本论文以来源广,价格低的家蚕丝为原料,利用丝素蛋白分子主肽链和侧链中含有显著数量的-OH、-COOH和-NH_2等活性基团的特点,以其为模板,采用溶胶-凝胶法制备中空介孔二氧化硅纳米球和纳米管。讨论了在不添加任何偶联剂或表面活性剂的情况下,SiO_2胶粒在丝素微球及纤维模板表面的涂覆情况,并对物理煅烧后的中空介孔二氧化硅纳米球和纳米管的表面形貌、比表面积及孔体积等进行了考察。首先,采用9.3M的溴化锂溶液溶解脱胶丝,制备再生丝素蛋白。通过调节丝素蛋白/乙醇的比例,采用自组装方法制备丝素蛋白微球。DLS及SEM表征显示:丝素蛋白微球的粒径大小随着乙醇添加量增大而减小,粒径在0.25～1.5μm之间。微球表面电荷-34±2 mv,微球形貌整体较规整,表面平滑。其次,以丝素微球为模板,以TEOS为有机硅源、氨水为催化剂、在不添加任何表面活性剂或偶联剂的条件下,利用微球表面带负电荷的特点制备中空介孔二氧化硅微球。SEM、TEM及BET表征说明:SiO_2胶粒可以直接在丝素蛋白微球表面沉积,经物理煅烧后可获得中空介孔二氧化硅微球,且丝素微球尺寸越小,生成的介孔二氧化硅空心微球的比表面积和孔体积越大,以小微球为模板可获得表面积为92.127 m2/g、孔体积为0.477cm3/g,平均孔径为4.56 nm的中空介孔二氧化硅微球。进一步,采用甲酸/氯化钙体系溶解脱胶丝,荧光显微镜观察可知,丝素纤维在该体系中会以“剥离”方式分解为原纤或微原纤,丝素溶液经SEM表征可观察到纳米微纤的存在。采用含有纳米微纤的丝素溶液可直接进行静电纺丝,SEM表征显示:纺出的纤维表面光滑,直径150 nm～330 nm之间。同时,纺丝液中CaCl2(3 w/v%～8 w/v%)含量越高,纺丝纤维直径越大,丝素浓度(15 w/v%～25w/v%)越高,纤维直径越大。最后,以电纺丝纤维作模板,采用Stober法制备SiO_2@SF复合纤维,经SEM、EDS及FTIR等表征说明,SiO_2胶粒在纤维模板上涂覆饱满。煅烧后经TEM和BET表征显示:二氧化硅管呈中空结构,管径在340 nm左右。硅管形状保持良好;硅管管壁厚度可以通过添加TEOS量来调控,其值在45±2 nm至61±3 nm之间,所获硅管比表面积最大为199.68 m2/g,孔体积为1.109 cm3/g,平均孔径为5.49 nm。另外,通过将姜黄素装载到硅纳米管上,对其载药和释药性能进行了初步的研究,结果表明:其最大载药率和包埋率分别为14.3%和38.7%,其药物缓释时间可由释放介质中的乙醇含量来控制。总之,本文报道的中空介孔二氧化硅纳米球及纳米管的制备方法,工艺简单,成本低廉,为今后制备中空介孔二氧化硅纳米材料提供了一个简单、高效的方法。
[Abstract]:Mesoporous silica nanomaterials with hollow structure with a large surface area, good safety and stability of biological drug delivery in the catalyst carrier, and has the broad application prospect of immobilized enzyme and gene separation. The preparation of hollow mesoporous silica nano materials by template method, which using the hard template method the preparation of microspheres or microtubules, generally uniform size, shape is relatively stable, but in the process of preparation, it is necessary to introduce coupling agent or surfactant, so as to guide the silica on the surface adhesion, the complicated preparation process, the preparation cost increase; and in the removal of the template, such as the use of chemical etching, easy to shape hollow silica microspheres or microtubules, pore size distribution caused some damage. Therefore, this thesis has wide source, low price of silk as raw material, using silk fibroin molecular peptide A significant number of containing chain and the side chain of -OH, -COOH and -NH_2 characteristics of active groups, with the template, the preparation of hollow mesoporous silica nanospheres and nanotubes by sol-gel method were discussed. Without adding any coupling agent or surfactant, SiO_2 particles in the surface of silk fibroin microspheres and the coated fiber template, and the surface morphology of the calcined physical hollow mesoporous silica nanospheres and nanotubes were investigated. The specific surface area and pore volume. Firstly, the degumming LiBr solution dissolved 9.3M, preparation of regenerated silk fibroin. By adjusting the proportion of fibroin protein / ethanol, using self assembling preparation method of silk fibroin microspheres.DLS and SEM characterization showed that silk fibroin microspheres particle size with ethanol content decreases, the particle size is in the range 0.25 ~ 1.5 m. The surface charge of -34 microspheres was 2 MV, microspherically The overall appearance is neat, smooth surface. Secondly, the silk fibroin microspheres as template, using TEOS as silicon source, ammonia as catalyst, without any surfactant or the coupling agent under the condition of negatively charged microspheres by the characteristics of the surface preparation of hollow mesoporous silica microspheres of.SEM, TEM and BET showed that: the SiO_2 particles can be directly in the silk fibroin microspheres surface deposition, can obtain hollow mesoporous silica microspheres by physical calcination, and the smaller the size of silk fibroin microspheres, mesoporous silica hollow microspheres generated pore volume and specific surface area is larger, with small spheres as templates available surface area of 92.127 m2/g, pore volume for 0.477cm3/g, the average pore size of hollow mesoporous silica microspheres of 4.56 nm. Further, using formic acid / calcium chloride dissolved the system degumming by fluorescence microscopy, silk fibroin fiber in the system will be "stripped" Decomposition of fibrils or microfibril, silk fibroin solution was characterized by SEM can be observed in nano fiber. With nano fiber silk fibroin solution can be directly used for electrospinning, SEM characterization showed that the spun fiber has smooth surface, between the diameter of 150 nm to 330 nm. At the same time, CaCl2 spinning solution (3 w/v% ~ 8 w/v%) the higher the concentration, the larger diameter fiber spinning, silk fibroin concentration (15 w/v% ~ 25w/v%) is high, the fiber diameter increases. Finally, the electrospun fibers as templates, using Stober preparation of SiO_2@SF composite fiber, SEM, EDS and FTIR characterization shows that the SiO_2 particles in the fiber template coated full. After calcination by TEM and BET characterization showed that the silica tube is a hollow structure, the diameter of around 340 nm. The silicon tube shape keep good; silicon tube wall thickness can be adjusted by the addition of TEOS, whose value is between 2 nm and 61 nm in 45 + + 3, the ratio of silicon tube the maximum surface area is 199. 68 m2/g, pore volume is 1.109 cm3/g, the average pore size is 5.49 nm.. In addition, the curcumin loaded into the silicon nanotubes, the drug loading and release properties were studied, the results showed that the maximum drug loading rate and entrapment rate were 14.3% and 38.7%, the content of ethanol in the release medium to control the drug release time. In a word, this paper reports the method, preparation of hollow mesoporous silica nanospheres and nanotubes has the advantages of simple process, low cost, for the preparation of hollow mesoporous silica nanomaterials provides a simple and efficient method.

【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ127.2;TB383.1

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