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1.
In this study, microcapsules were prepared by spray drying and embedding hemp seed oil (HSO) with soy protein isolate (SPI) and maltodextrin (MD) as wall materials. The effect of ultrasonic power on the microstructure and characteristics of the composite emulsion and microcapsules was studied. Studies have shown that ultrasonic power has a significant impact on the stability of composite emulsions. The particle size of the composite emulsion after 450 W ultrasonic treatment was significantly lower than the particle size of the emulsion without the ultrasonic treatment. Through fluorescence microscopy observation, HSO was found to be successfully embedded in the wall materials to form an oil/water (O/W) composite emulsion. The spray-dried microcapsules showed a smooth spherical structure through scanning electron microscopy (SEM), and the particle size was 10.7 μm at 450 W. Fourier transform infrared (FTIR) spectroscopy analysis found that ultrasonic treatment would increase the degree of covalent bonding of the SPI-MD complex to a certain extent, thereby improving the stability and embedding effect of the microcapsules. Finally, oxidation kinetics models of HSO and HSO microcapsules were constructed and verified. The zero-order model of HSO microcapsules was found to have a higher degree of fit; after verification, the model can better reflect the quality changes of HSO microcapsules during storage. 相似文献
2.
Microencapsulation of cinnamon leaf (Cinnamomum zeylanicum) and garlic (Allium sativum) oils in β-cyclodextrin 总被引:1,自引:0,他引:1
J. Fernando Ayala-Zavala Herlinda Soto-Valdez Alberto González-León Emilio Álvarez-Parrilla Olga Martín-Belloso Gustavo A. González-Aguilar 《Journal of inclusion phenomena and macrocyclic chemistry》2008,60(3-4):359-368
Cinnamon leaf (CLO) and garlic oils (GO) are good antimicrobials, however, their volatility complicates their application
as food preservatives. Hence, microencapsulation of CLO and GO with β-cyclodextrin (β-CD) was studied at 4:96, 8:92, 12:88,
and 16:84 (oil:β-CD) percent weight ratios. Microcapsule characterization included gas chromatography analysis, moisture sorption–desorption
isotherms, infrared spectroscopy (IR), and antifungal activity against Alternaria alternata. Major oil constituents were eugenol for CLO and allyl disulfide for GO. The 16:84 ratio (CLO:β-CD) showed the highest eugenol
content; the allyl disulfide content was higher, but not significantly different (P > 0.05) for the 12:88 and 16:84 ratios. Microcapsules showed lower moisture sorption than β-CD, although during water desorption
there were no difference between them. Hydrogen bonds were detected between oil constituents and β-CD by IR spectroscopy.
CLO:β-CD and GO:β-CD microcapsules displayed good antifungal activity against Alternaria alternata. Therefore, CLO and GO microcapsules can have important applications in the food industry as stable natural antimicrobial
compound systems. 相似文献
3.
采用界面聚合法,以薄荷素油为芯材,以异佛尔酮二异氰酸酯为壁材单体,在催化剂四甲基乙二胺作用下和水反应形成聚脲外壳,制备出了薄荷素油微胶囊.通过扫描电镜、激光粒度分析仪、傅里叶红外光谱仪及热重分析仪分别对香精微胶囊的表面形貌、粒径分布、单体反应情况和热稳定性进行了分析表征.通过紫外可见分光光度计对香精微胶囊包覆率进行了测定.并分析了均质化速率和微胶囊平均粒径的关系以及不同乳化剂种类和芯壁比条件下微胶囊的形貌特征.结果表明,微胶囊平均粒径随均质化速率的增大而减小,下降到1μm左右时趋于平稳,当乳化剂采用聚乙烯醇且芯壁比为4∶1时,微胶囊形貌最佳,为规整球形.最终测得微胶囊芯材包覆率为84.09 wt%,粉末状微胶囊样品含油率为72.64 wt%,并且微胶囊芯材具有良好的热稳定性. 相似文献
4.
A strategy to incorporate and release anti-cancer drugs of daunorubicin (DNR) and doxorubicin (DOX) in preformed microcapsules is introduced, which is based on charge interaction mechanism. Oppositely charged poly(allylamine hydrochloride) (PAH) and poly(styrene sulfonate) (PSS) were assembled onto PSS doped-CaCO3 colloidal particles in a layer-by-layer manner to yield core-shell particles. After removal of the carbonate cores, hollow microcapsules with entrapped PSS were fabricated, which showed spontaneous loading ability of positively charged DNR and DOX. The drug loading was confirmed quantitatively by observations under confocal laser scanning microscopy, transmission electron microscopy and scanning force microscopy. Quantification of the drug loading was performed under different conditions, revealing that a larger amount of drugs could be incorporated at higher drug feeding concentrations and higher salt concentrations. However, putting additional polyelectrolyte layers on the microcapsules after core removal resulted in weaker drug loading efficiency. The drug release behaviors from the microcapsules with different layer numbers were studied too, revealing a diffusion controlled release mechanism at the initial stage (4 h). 相似文献
5.
6.
Preparation and surface encapsulation of hollow TiO nanoparticles for electrophoretic displays 总被引:1,自引:0,他引:1
Qian ZhaoTingfeng Tan Peng QiShirong Wang Shuguang BianXianggao Li Yong AnZhaojun Liu 《Applied Surface Science》2011,257(8):3499-3503
Hollow black TiO nanosparticles were obtained via deposition of inorganic coating on the surface of hollow core-shell polymer latex with Ti(OBu)4 as precursor and subsequent calcination in ammonia gas. Hollow TiO particles were characterized by scanning electron microscope, transmission electronic microscopy, X-ray diffraction, and thermogravimetric analysis. Encapsulation of TiO via dispersion polymerization was promoved by pretreating the pigments with 3-(trimethoxysilyl) propyl methacrylate, making it possible to prepare hollow TiO-polymer particles. When St and DVB were used as polymerization monomer, hollow TiO-polymer core-shell particles came into being via dispersion polymerization, and the lipophilic degree is 28.57%. Glutin-arabic gum microcapsules containing TiO-polymer particles electrophoretic liquid were prepared using via complex coacervation. It was founded that hollow TiO-polymer particles had enough electrophoretic mobility after coating with polymer. 相似文献
7.
原位凝聚法制备聚电解质微胶囊——模板中掺杂聚电解质量对微胶囊结构与性能的影响 总被引:1,自引:0,他引:1
通过在CaCO3制备过程中加入不同浓度聚苯乙烯磺酸钠(PSS)的方法来控制掺杂进CaCO3粒子中的PSS含量,得到了PSS掺杂量为4%~11%,尺寸均匀的CaCO3球形微粒.在微粒表面仅吸附一层聚烯丙基胺盐酸盐(PAH)后,用乙二胺四乙酸二钠(EDTA)使碳酸钙溶解;释放出的PSS与PAH原位凝聚制备得到了分散良好且完整的聚电解质复合物微胶囊.在所研究的范围内,模板微粒中PSS的含量对微胶囊的形态结构和性能没有明显影响.与传统的层层组装微胶囊相比,聚电解质复合物微胶囊有较好的热稳定性,但在高盐浓度下尺寸收缩程度较大.由于和层层组装微胶囊相比缺乏结合紧密的有序结构,原位凝聚法制备的微胶囊囊壁的截留分子量较大. 相似文献
8.
以高效氯氰菊酯为芯材, 乙基纤维素为壁材, 采用溶剂蒸发法制备了微胶囊, 并对其理化性能进行表征, 通过单因素实验研究了工艺参数对微胶囊外观形貌、 粒径大小及分布、 包封率、 载药量和缓释性能的影响. 结果表明, 乳化剂种类和剪切时间可以显著影响微胶囊的外观形貌; 随着乳化剂用量增大, 微胶囊粒径减小, 分布变窄, 当Tween-80用量从4%增加至8%时, 微胶囊平均粒径从59.9 μm减少到29.8 μm, 跨距也从1.21减少到0.72. 随着芯壁比(质量比)减小, 微胶囊粒径和包封率均逐渐增大, 载药量逐渐减小, 当芯壁比为1:1.75时, 包封率可以达到70%以上. 微胶囊释放动力学模型符合Ritger-Peppas模型(lgQ=lgk+nlgt); 平均粒径相近而载药量不同时, 初期载药量最小的样品释放速率慢, 累积释放率低; 载药量相近而平均粒径不同时, 粒径大的样品释放速率低, 累积释放率也低. 相似文献
9.
固体芯材微胶囊制备技术研究进展 总被引:1,自引:0,他引:1
文章主要介绍了微胶囊研究背景、用途及制备方法。从固体芯材料水溶性的角度,可把芯材分为亲水性和疏水性两种类型。对于水溶性芯材微胶囊的制备方法,介绍了原位聚合法、油相相分离法、喷雾干燥法和喷雾冷凝法的技术进展;对于疏水性芯材,介绍了界面聚合法、原位聚合法、水相相分离法等方法包覆微胶囊的技术进展。此外,本文还对不同类型的固体芯材所适应的制备方法及壳材料进行了探讨,从试验条件、芯材料的特性及目标产品性能等角度来选取适当的微胶囊壳材及制备方法,以期探索出更经济、实用、高效的固体芯材微胶囊化制备方法。 相似文献
10.
Rong Lu Hongjing Dou Yuanyuan Qiu Dong Zhang Kang Sun Yuqi Zhang Kun Sun 《Colloid and polymer science》2009,287(6):683-693
Polymeric microcapsules are of great potential in ultrasonic imaging due to their characteristic hollow structure. Water-in-oil-in-water
(W1/O/W2) double emulsion-solvent evaporation technique is a versatile strategy applicable to most hydrophobic polymers for fabricating
microcapsules; however, the adjustment of the size and inner structure of resultant microcapsules have not been systematically
studied until now. Here, we evaluate in detail the parameters in double emulsification and find that the W1/O volume ratio is a pivotal parameter which controls the hollow structure of microcapsules. In addition, an appropriate concentration
of emulsifier in W2 is essential to guarantee the hollow structure as well. For quantitatively characterizing the hollow structure of microcapsules,
we propose the concept of Hollow Ratio (HR) and Hollow Degree (HD) to evaluate the percent of hollow microcapsules in products
and the hollow characteristic of the microcapsules. Our study demonstrates that the HR of microcapsules can vary between 25%
and 98% by only adjusting the W1/O volume ratio. The size of microcapsule has a close relationship to its HD. Moreover, the microcapsules with both single
cavity and multicavities have been fabricated by altering the energy of the second emulsification. Further, acoustic studies
reveal that the microcapsules with different HD display obviously different sound attenuation spectrum and resonance frequency,
which demonstrates that the adjustment of hollow structure should be an effective approach to control the acoustical properties
of microcapsules for ultrasonic imaging. 相似文献