薄荷香精纳米胶囊体系流变特性研究
时间:2018-05-11 12:00 来源:毕业论文 作者:毕业论文 点击:次
| 摘要： 本文选用海藻酸钠为壁材、薄荷香精为芯材，通过乳液聚合法制备纳米胶囊。采用AR-G2 Rheometer 型流变仪考察了海藻酸钠含量，氯化钙含量，芯壁比和乳化剂用量对体系流变性能的影响。应变扫描测试结果表明，随着海藻酸钠含量，氯化钙含量，芯壁比和乳化剂用量的提高，体系的复合模量在一定的应变范围内保持不变，然后随之下降，并选取0.1%的应变作为频率扫描测试的应变数值。频率扫描测试结果表明，随着海藻酸钠含量和乳化剂用量的增大，贮能模量G’和损耗模量G”均减小；随着CaCl2含量增大，G’和G”均增大；随着芯壁比增大，G’和G”无明显线性关系。稳态测试结果表明，随着剪切速率的增大，体系的表观黏度随之下降，体系呈现出假塑性流体剪切变稀的流变特征，该纳米香精符合幂律模型；随着海藻酸钠含量，芯壁比和乳化剂用量的增大，体系的表观黏度减小，随着CaCl2含量增大，体系的表观黏度增大，且该体系为强剪切稀化体系。22716 毕业论文关键词： 海藻酸钠；纳米香精；黏度；流变性 Research on the Rheological Properties of Nano-Mint Flavor Abstract: The nano-capsule was prepared by emulsion polymerization using SALG (sodium alginate) as the wall material and Jasmine essence as the core material. The influence of the content of sodium alginate, calcium chloride,emulsifier and core-wall ratio on rheological property of nano-mint capsule system was studied. Strain sweep test shows that with the increase of the content of sodium alginate , calcium chloride,emulsifier and the core-wall ratio, complex modulus of the system remains constant in a certain strain range and then decreased. 0.1% strain was chosen as the strain value of frequency sweep tests. Frequency sweep test shows that with the increase of the amount of sodium alginate and emulsifier, storage modulus G ' and loss modulos G " decreased; With the increase of the content of CaCl2 , G' and G" increased. As the core-wall ratio increased, G ' and G " had no significant linear relationship with it. Steady state test results show that with the increase of shear rate, the apparent viscosity decreased; the system exhibits a rheology feature of shear-thinning like pseudoplastic fluid, and the rheological was fitted to the power-law model. With the increase of sodium alginate content, core-wall ratio and emulsifier, the apparent viscosity of the system decreased. With the increase of CaCl2 content , the apparent viscosity of the system increased . And it was found that the nanoflavors belongs to the highly shear thinning system. Keywords : sodium alginate ; nanoflavors ; viscosity ; rheology 目录 第一章 绪论 1 1.1 纳米香精胶囊 1 1.2 纳米香精胶囊的制备 3 1.3 流变学 4 1.4 国内外流变性研究 5 1.5本课题的研究目的和意义 7 第二章 材料与方法 8 2.1 实验试剂与仪器 8 2.1.1 材料试剂 8 2.1.2 仪器设备 8 2.2 实验方法 8 2.3 纳米胶囊制备 8 2.3.1 预实验 8 2.3.2 单因素实验 9 2.3.3 单因素实验方案 10 2.4 纳米胶囊表征检测 10 2.4.1 纳米香精胶囊粒度测定 10 2.4.2 纳米胶囊表面结构观察 10 2.5纳米胶囊流变性能测定 11 2.5.1 动态流变学测试 11 2.5.2 静态流变学测试 11 第三章 结果与分析 12 3.1 纳米胶囊溶液外观描述 12 (责任编辑：qin) |