超临界流体辅助雾化法制备壳聚糖—香精超细颗粒

发布时间：2018-05-02 09:45

  本文选题：超细颗粒 + 超临界CO_2辅助雾化法　； 参考：《华东理工大学》2011年硕士论文

【摘要】：近年来,采用超临界流体技术制备功能性超细颗粒一直是研究的热点,该类技术拥有操作条件温和、操作条件可控与颗粒制备的形貌和大小可控的优点。其中一种较为先进的方法-超临界辅助雾化法(全称Supercritical assisted atomization,简称SAA)是此类方法中的最有潜力的。它是主要从超临界抗溶剂法中衍生出来的一种新工艺方法。一方面,它克服了传统颗粒制备工艺中制备得到的颗粒粒径大,并且粒径分布不集中的缺点；另一方面,它弥补了超临界流体快速膨胀法和超临界抗溶剂法在材料选择中的不足,既可以用于脂溶性产品颗粒的制备,也可以用于水溶性产品颗粒的制备。 本论文讨论了SAA方法的工艺基础和工艺发展过程,并主要对SAA法制备功能性材料壳聚糖-香精超细颗粒的过程进行了研究。本论文从两种体系(分别为固液互相包埋和固固互相包埋的体系)出发,以壳聚糖为载体,采取互相包埋的形式制备以香兰素固体、薰衣草液体香精为香精主料的超细颗粒。讨论了引起颗粒粒径改变、粒径分布变化以及颗粒粘连程度的各种操作因素,包括沉降室温度,物料配比,预膨胀温度,预膨胀压力和溶液流量等。采用扫描电镜对制备得到的颗粒进行形貌观察,同时以扫描电镜照片为基础进行粒径大小和分布统计,采用气相色谱考察其缓释效果。 本论文最后结果表明：保持一定范围内的沉降室温度,升高预膨胀压力和溶液流量,降低壳聚糖/香精的物料配比和预膨胀温度都有利于制备颗粒粒径较小的颗粒。操作条件对两种体系的颗粒粒径分布和颗粒间粘连程度的影响则不同：对壳聚糖/薰衣草颗粒来说,降低壳聚糖/薰衣草的物料配比和预膨胀温度有利于得到粒径分布集中,粘连程度小的颗粒；但升高预膨胀压力和溶液流量,颗粒粒径的分布则会先变集中变分散,粒径分布相对集中的颗粒同时颗粒粘连程度也低。对壳聚糖/香兰素颗粒来说,降低壳聚糖/香精的物料配比和预膨胀温度,升高预膨胀压力和溶液流量有利于制备得到颗粒粒径分布窄的颗粒。但过低的物料配比和过高的溶液流量溶液得到相互粘连的颗粒。 最终得到的产物颗粒基本为球形,对壳聚糖/薰衣草颗粒来说,在物料配比0.8/1、预膨胀温度50℃,预膨胀压力10.5Mpa,溶液流量1.5mL/min条件下,颗粒的平均粒径在2.2μm左右。对壳聚糖/香兰素颗粒来说,物料配比0.8/0.8,预膨胀温度50℃,预膨胀压力10.5Mpa,溶液流量1.5mL/min条件下,壳聚糖/香兰素颗粒的平均粒径在2.0μm左右。颗粒存在一定的内部结构,为香精缓释提供了结构基础。通过气相色谱考察得知：壳聚糖/薰衣草香精颗粒的香气保持时间较长,能在5个月以上；而壳聚糖/香兰素颗粒的香气保持时间则只在4个月内。
[Abstract]:In recent years, the preparation of functional ultrafine particles by supercritical fluid technology has been a hot topic. This kind of technology has the advantages of mild operating conditions, controllable operating conditions and controllable morphology and size of particles. One of the more advanced methods, Supercritical assisted atomization (SAA), is the most promising one. It is a new process derived mainly from supercritical anti-solvent method. On the one hand, it overcomes the shortcoming that the particle size is large and the particle size distribution is not concentrated in the traditional particle preparation process; on the other hand, It can be used in the preparation of liposoluble product particles as well as in the preparation of water-soluble product particles because of the deficiency of supercritical fluid rapid expansion method and supercritical anti-solvent method in material selection. In this paper, the technological basis and development process of SAA method are discussed, and the process of preparing functional material chitosan-essence ultrafine particles by SAA method is mainly studied. In this paper, starting from two systems (solid liquid and solid mutually entrapped), superfine particles with vanillin solid and lavender liquid flavor as main ingredient were prepared by using chitosan as carrier. Various operating factors, such as settling chamber temperature, material ratio, preexpansion temperature, preexpansion pressure and solution flow rate, are discussed which cause particle size change, particle size distribution change and particle adhesion degree. The morphology of the prepared particles was observed by scanning electron microscope (SEM), and the particle size and distribution were analyzed based on SEM photos. The sustained release effect was investigated by gas chromatography. The results show that maintaining the temperature of the settling chamber, increasing the pre-expansion pressure and the flow rate of solution, reducing the ratio of chitosan to flavor and the pre-expansion temperature are all beneficial to the preparation of the smaller particle size. The effect of operation conditions on particle size distribution and particle adhesion was different. For chitosan / lavender particles, reducing the ratio of chitosan / lavender and pre-expansion temperature was beneficial to the concentration of particle size distribution. The particles with small adhesion degree, but with the increase of preexpansion pressure and solution flow rate, the particle size distribution will first change into concentration and dispersion, and the particle size distribution with relatively concentrated particle size distribution at the same time the degree of particle adhesion is also low. For chitosan / vanillin granules, reducing the ratio of chitosan to essence and preexpansion temperature, increasing preexpansion pressure and solution flow rate are beneficial to the preparation of narrow particle size distribution. However, too low material ratio and too high solution flow rate to obtain mutually adhesive particles. For chitosan / lavender particles, the average particle size was about 2.2 渭 m under the conditions of 0.8 / 1 material ratio, 50 鈩，

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