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Updated: Jun 7, 2026

Double Emulsion Generation Using a Polydimethylsiloxane (PDMS) Co-axial Flow Focus Device
Published on: December 25, 2015
Water-in-oil-in-water double nanoemulsion induced by CO(2)
Yueju Zhao1, Jianling Zhang, Qian Wang
1Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Colloid and Interface and Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing, China.
Abstract:
The cetyltrimethylammonium bromide (CTAB)/water/heptane emulsion system with different CO(2) pressure has been studied. The phase behavior investigation shows the nanoemulsion can be formed at suitable pressure range. The generalized indirect Fourier transformation (GIFT) analysis of the small-angle X-ray scattering (SAXS) data has drawn a clear picture of the structural information of the nanoemulsion, which reveals that the droplet of emulsion has a double structure with both the outer and inner droplet size in nanometre range. Furthermore, the investigation of the heptane/CTAB/water/CO(2) emulsion system by using electrical conductivity confirms the emulsion type transforms from O/W to W/O/W. In addition, the effect of different CTAB concentration on the nanoemulsion formation has been studied. It is found that enough CTAB concentration is necessary for the inclusion of continuous water into oil droplets. We also explored the application of the W/O/W double nanoemulsion in material synthesis. Interestingly, the hollow silica spheres with double shells were obtained in this CO(2)-induced double nanoemulsion.
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