碩士 / 國立雲林科技大學 / 化學工程與材料工程系 / 104 / Stability is one of the most important factors that must be considered in making emulsions. Nowadays, a wide variety of foods, pharmaceuticals, cosmetics, and agro- and petro-chemical products are constituted of emulsions. Nano-emulsions are a new type of emulsions with a particle size in the range between 10 and 300 nanometers. Because of their small-sized droplet, nano-emulsions exhibit transparent or translucent appearance. Moreover, nano-emulsions are not physically thermodynamic equilibrium but kinetically stable. The purpose of this study is to evaluate the possibility of ulvan extracted from Ulva lactuca as emulsion stabilizer. Nano-emulsions prepared under design conditions with or without the addition of ulvan were investigated for their stability. Cationic surfactant dihexadecyldimethyl ammonium bromide (DHDAB) and non-ionic surfactant polyethylene glycol stearate 40 (PEG-stearate 40) were independently applied to prepare O/W nano-emulsions composed with Tamanu oil and ultrapure water. Response surface analyses were employed to investigate the effects of oil content (%) and oil-to-surfactant ratio (SOR, %) on the particle size distributions. The results showed that the SOR is the most significant factor influencing the particle size of prepared nano-emulsions. Mathematical model predicted the particle size prepared by DHDAB and S-PEG40 will be respectively around 239.4 nm and 75.1 nm when the optimal conditions were applied. The actual particle sizes obtained from experiments using predicted condition were in good agreement with the model predicted values. All emulsion-gels exhibited elastic gel-like rheological properties. The storage modulus (G′) of emulsion-gel with a emulsion-to-ulvan ratio (EUR) at 1:3 were higher than those with EUR at 1:1 and 3:1, which could be attributed to the ordered spatial structure of emulsions. The emulsion-gel with EUR at 1:3 had a better elastic property than those with EUR at 1:1 and 3:1. The result also suggested that the emulsion-gel with EUR at 1:3 was relatively stable in comparison to other emulsion-gels obtained with EUR at 1:1 and 3:1.
| Identifer | oai:union.ndltd.org:TW/104YUNT0661019 |
| Date | January 2016 |
| Creators | GE,SIH-CHI, 葛思齊 |
| Contributors | CHENG,YU-SHEN, CHOU,TZUNG-HAN, 鄭宇伸, 周宗翰 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 87 |
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