Research
Our research focuses on the design, synthesis, and characterization of functional polymeric materials with dynamically re-arrangeable structures. At the interface of synthetic chemistry, polymer chemistry, and soft materials, the pursuit of using dynamic molecular interactions to control macroscopic properties of polymers represents an exciting new direction in chemistry of materials. Unlike manmade materials, macromolecules in biological systems undergo constant dissociation, association, and reconfigurations to perform living functions. By incorporating dynamic chemistry, such as reversible covalent bonds or supramolecular interactions, into polymer networks with precise structural control, novel functionalities similar to biological systems can be achieved.
1) Recyclable Polymers
From plastics, foams, and elastomers, to adhesives, polymers play key roles in every aspect of our daily lives. Eighty percent of petrochemicals are used to produce polymer products, but the majority of these products are non-recyclable and non-degradable. Efficient and economical technologies to treat end-of-life polymer materials are in urgent need to address today’s global plastic waste crisis. Our lab is developing polymers capable of depolymerizing into the composing monomers with high efficiency. The monomers can be repolymerized into the same polymers, representing a circular economy.
2) Mechano-adaptive polymers
Instead of using rigid steel and motors, soft robotics are constructed of compliant materials mimicking living organisms. They offer unprecedented ability to adapt to the surroundings. One challenge in materials design is to create soft materials similar to living tissue, which is also of interest for wearable devices. Materials that are currently used are mainly silicone based which is tough and flexible but does not resemble tissue behaviors. Our lab is developing materials using dynamic chemistry to mimic the biomechanics of tissue and create stress-strain behaviors that will allow for mechano-activated shape adaption. These polymers will be formulated into 3D printable materials.
3) Photochromic materials
Photochromic molecules, which undergo reversible photoswitches between two states, such as spiropyran, azobenzene, diarylethene, and Stenhouse adducts, are essential building blocks for photoresponsive materials. They exhibit a wide range of tunable properties applicable for data storage, optoelectronic devices, controlled assembly, catalysis, sensing, and actuating. Therefore, the discovery and study of robust photochromic systems are essential for these applications. The group is interested in bipyridine-based metal-free photo-responsive systems. Our ongoing work involves studying their novel photochromic mechanisms, photoluminescence, and catalytic properties.
