【作者】 张若娣；

【导师】 张淑芬；

【作者基本信息】 大连理工大学 ， 化学工程与技术， 2014， 硕士

【摘要】 淀粉及淀粉衍生物微球因具有生物相容、可生物降解、无毒、贮存稳定、原料来源广泛、价格低廉等优点,已在药物控释、重金属吸附和污水处理等方面得到了广泛应用。本论文根据疏水化淀粉衍生物微球的制备方法特点,采用透析和纳米沉淀法制备碳链最短的疏水化淀粉酯—乙酰化淀粉微球,详细研究了微球形貌、尺寸和单分散性的影响因素。以淀粉为原料,冰乙酸为溶剂,甲基磺酸为催化剂,乙酸酐为酯化试剂,加热条件制备乙酰化淀粉。当淀粉糖单元与乙酸酐和甲基磺酸的摩尔比为1：5.3：0.06时,温度为75℃时,反应时间3h,可制备出取代度为2.89的产品。通过红外光谱(FTIR)和1H-NMR对产物结构进行了表征。以上述方法制备的不同取代度的乙酰化淀粉为原料,采用透析法和纳米沉淀法制备乙酰化淀粉微球。这两种方法都是运用原料在两种可以混溶的溶剂里的溶解性不同,淀粉衍生物溶解在有机溶剂里形成溶液,然后向溶液里加入不良溶剂水,当良溶剂和不良溶剂达到一定比例时,溶质开始从体系中析出,发生沉降,进而形成微球。这两种方法都不需要加入表面活性剂和交联剂,微球的形貌、尺寸和单分散性可以通过实验条件有效地控制。采用透析法制备乙酰化淀粉微球,主要研究了取代度、良溶剂、溶液的浓度和分子量对微球的形貌、尺寸和单分散性的影响。实验结果表明随着取代度升高,制备的产品形貌越接近球形,当取代度为2.89时,乙酰化淀粉微球的形貌最好。良溶剂丙酮和DMSO比较,丙酮可以得到形貌规则的球形,且同浓度下尺寸较二甲基亚砜的大。微球的尺寸随着溶液的浓度增加而增大,随着乙酰化淀粉的分子的增大而减小。微球尺寸的单分散性采用动态光散射测定,采用扫描电镜测定微球的形貌。采用纳米沉淀法制备乙酰化微球时,主要研究微球的形貌、尺寸和单分散性的影响因素,实验内容包括滴加去离子水的比例,制备温度,分子量大小,以及乙酰化淀粉的浓度。实验结果表明滴加水的比例对微球的形貌和单分散性影响较大,当V水：V丙酮=1：2时,可以制备出单分散性好和形貌规则的乙酰化淀粉微球。微球的尺寸随着浓度的增加而变大,随着分子量的增大而减小,分子量高出两个数量级,微球的尺寸减小100nm左右。微球尺寸的单分散性采用动态光散射测定,采用扫描电镜测定微球的形貌。更多还原

【Abstract】 Starch and starch derivatives nanospheres have been widely used in the release of drug, the adsorption of heavy metals and the treatment of sewage, owing to their significant advantages, such as biocompatible, biodegradable, non-toxic, storage stability, extensive source, low cost. We synthesized shortest carbon chain hydrophobic acetylated starch and fabricated acetylated starch nanospheres by dialysis and nanoprecipitation. The method was based on the hydrophobic starch derivatives nanospheres prepared. The paper gave a detail study on the effects of particle morphology, monodisperse and size.With glacial acetic acid as the solvent, methanesulphonic as the catalyst, acetylated corn starches were synthesized with starch and acetic anhydride. When the molar ratio of the starch saccharide units to acetic anhydride to methyl sulfonic acid was1:5.3:0.06, the temperature was75℃for3h, the degree of substitution reached2.89. The products were characterized by FTIR spectroscopy and1H-NMR.Taking acetylated starch of variant DS as raw materials, acetylated starch nanospheres were fabricated by dialysis and nanoprecipitation. The two methods maked use of the different solubility of acetylated starch in the two miscible solvents which were named the solvent and non-solvents. When they encountered, the natural mixing of the interface between the two non-equilibrium phase, including flow, diffusion and interface action, the precipitation occured followed by the forming of the acetylated starch microspheres. Without the surfactants and crosslinkers, the morphology, size and monodisperse of the microspheres obtained could be easily controlled by a number of simple and efficient modifications.When we prepared acetylated starch microspheres by dialysis, we studied the influencing factors of morphology, size and monodiepersity of the microspheres, which included the DS of the starch esters, the type of solvent, the concentration of acetylated starch in solvent and its molecular weight. The results showed that the morphology of the product was close to spherical with increasing DS, when the DS was2.89, we could obtain the best spherical morphology microspheres. The morphology of the microsphere was better and the size was larger acetone as good solvent than DMSO. The size of the microspheres increased with increasing concentration, and decreased with increasing molecular weight. The particle size and polydispersity of nanospheres in aqueous solution were measured by dynamic light scattering, The appearance of nanospheres was characterized by scanning electron microscopy (SEM). When preparing acetylated starch microspheres by nanoprecipitation, we studied the influencing factors of morphology, size and monodiepersity of the microspheres, including the ratio of deionized water, the preparation temperature, molecular weight, and the concentration of acetylated starch. The results showed that the proportion of water had significant effect on microsphere morphology and monodispersity. When the Vwatei:Vacetone was1:2, monodisperse acetylated starch nanospheres could be prepared. The size of the microspheres increased with increasing concentration, and decreased with increasing molecular weight. The molecular weight was higher by two orders of magnitude, the size of microspheres decreased by about100nm. The particle size and polydispersity of nanospheres in aqueous solution were measured by dynamic light scattering, The appearance of nanospheres was characterized by scanning electron microscopy (SEM).更多还原