The overall aim of our research is to understand and control the structure and dynamics of soft matter at interfaces in dimensions ranging from nano- to macroscale and engineer new functional materials. A key aspect of our research is the preparation of well-defined molecules, materials, emulsions and surfaces, which leads to desired function.
I. Functional Thin Films via Directed Assembly of Polymers
The performance of functional materials is governed by their ability to interact with the surrounding environments in a well-defined and controllable manner. Whether it is selectively interacting with a biomolecule or a solute, or responding to light or temperature, the environment-material interface is essential in determining the performance of the materials in various applications. Films provide the means to control the surface of a material, thus creating composite materials where the surface and the bulk of the material can be engineered and controlled independently. However, very few have thoroughly investigated the structure-property relationship of nanostructured polymer thin films in conjunction with their ability to independently tune the surface and the bulk properties of the film. For this research project, we will study polymer complexation, molecular rearrangement of polymers at surfaces and utilize Layer-by-Layer assembly technique to design and fabricate novel functional films.
II. Microfluidic Design of Multiple Emulsion Drops for Functional Materials Production
Multiple emulsion drops or “emulsions of emulsions,” are complex systems in which dispersed drops contain smaller drops inside. These complex emulsions have recently gained significant attention due to their highly controllable and reconfigurable morphologies upon tuning the balance of interfacial tensions controlled through mixtures of surfactant or by stimuli such as light or pH. However, even more flexibility can be achieved by utilizing the middle phases that separate the inner drops from the outer phase in these multiple emulsion drops; the middle phase in double emulsion drops can serve as a template to form polymeric shell in microcapsules for encapsulation of actives. Yet, there has been little progress toward the production of microcapsules with membranes that fulfills the practical demands. Moreover, many well-known scientific findings such as microphase separation of block copolymers, and polymer network formation using various chemistries can be translated into this compartment provided by the multiple emulsion drops. This will span a wide range of new interesting scientific and engineering questions which will open the door in the field by creating a new route to design and fabricate advanced particles with unique functionalities.