| dc.description.abstract | Janus colloidal surfactants with opposing wettability on two structural parts are receiving attention for their intriguing structural and practical application in various industries. Combining the advantages of molecular surfactants and particle-stabilized Pickering emulsions, Janus colloidal surfactants generate remarkably stable emulsions. This dissertation developed a straightforward and cost-efficient strategy to develop Janus nanoplate surfactants (JNPS) from aluminosilicate nanoclays materials, including Kaoinite and Halloysite, by stepwise surface modifications, including an innovative selective surface modification step. Such colloidal surfactants are found to be able to stabilize Pickering emulsions of different oil/water systems. The microstructural characterization of solidified polystyrene emulsions indicates that the emulsion interface is evenly covered by JNPS. The phase behaviors of water/oil emulsion generated by these novel platelet surfactants were also investigated. Furthermore, this dissertation demonstrated the application of JNPS for enhanced oil recovery with a microfluidic flooding test, showing a dramatic increase of oil recovery ratio. This research provides important insights for the design and synthesis of two-dimensional Janus colloidal surfactants, which could be utilized in biomedical, food and mining industries, especially for circumstances where high salinity and high temperature are involved. | en |
