Nanosized Emulsions Stabilized by Semisolid Polymer Interphase

详细信息    查看全文

• 作者：Yoon Sung Nam ; Jin-Woong Kim ; Jongwon Shim ; Sang Hoon Han ; Han Kon Kim
• 刊名：Langmuir
• 出版年：2010
• 出版时间：August 17, 2010
• 年：2010
• 卷：26
• 期：16
• 页码：13038-13043
• 全文大小：971K
• 年卷期：v.26,no.16(August 17, 2010)
• ISSN：1520-5827

文摘

We introduce a new approach for stabilizing oil-in-water nanoemulsions using a semisolid interphase formed by the phase separation of amphiphilic block copolymers from the organic phase. This system is illustrated using an amphiphilic diblock copolymer, poly(ethylene oxide)-block-poly(ε-caprolactone) (PEO-b-PCL), with commonly used oils. PEO-b-PCL can be miscible with oil at elevated temperatures (70−80 °C); however, polymer/oil demixing occurs as the temperature drops below the melting temperature of PEO-b-PCL (55 °C). A homogeneous polymer/oil mixture was dispersed in water at 80 °C to generate embryonic emulsions, and then the emulsion size was reduced to a nanometer range through microfluidic homogenization. The structure of the generated nanoemulsions is irreversibly frozen as they are cooled down to ambient temperature. The nanoemulsions stabilized by PEO-b-PCL show the excellent colloidal stability against thermal and chemical stresses, exhibiting no significant changes in the size distribution during incubation for 4 months at ambient temperature or 10 days at 60 °C. This study demonstrates that PEO-b-PCL is an attractive emulsifying material for practical nanoemulsion formulations requiring structural stability under a broad range of conditions.