Research & Initiatives

We plan to apply synthetic organic, polymer, macrocyclic and supramolecular chemistry to the  design and synthesis of functional dynamic materials and catalysts for environmental, energy, and nature-inspired biomedical applications. Our interdisciplinary research program addresses challenges in materials sustainability and healthcare issues through the marriage of fundamental and applied sciences. The methodological development of how to install mechanical bonds precisely into polymers and polymer networks, along with investigation of the mechanical bond in detail in terms of its impact on materials properties, will be the central themes of our research. In particular, we are interested in employing the mechanical bond to tune materials properties and tame catalysis/polymerization processes.

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Controlled Synthesis of Mechanically Interlocked Polymers

Controlled Synthesis of Mechanically Interlocked Polymers

A polyrotaxane is a necklace-like polymer in which many rings (macrocycles) are threaded onto a single polymer chain capped with bulky stoppers at both ends, and as such, is one of the most important members in the family of mechanically interlocked polymers (MIPs). Its unique structure gives rise to complex architectural characteristics once the rings are crosslinked, forming the so-called slide-ring gels. These mechanically interlocked gels can find various applications in films, super-soft materials, scratch-resisting coatings, and polymer binders for batteries. This research involves the production of polyrotaxanes with control over molecular weights, dispersities and microstructures by employing a chain-growth polymerization protocol. Such an approach affording well-defined mechanically interlocked polymers is rare, and these new syntheses and designs would represent a significant advance beyond the research already described in the literature.

Controlled Synthesis of Mechanically Interlocked Polymers

Precision Polymer Synthesis Enabled by Artificial Molecular Machines

The advent of precision polymer synthesis relies on the rational design of monomers and specific catalytic systems. Compared with conventional step-growth methods of polymerization, controlled chain-growth methods, such as RAFT, ATRP, and ROMP, are advantageous in affording well-defined polymers with tailored structures. The development of such controlled polymerization techniques, however, is challenging and monomers that can undergo chain-growth polymerizations are limited in the literature. A typical metal-catalyzed chain-growth polymerization involves the metal center attaching to the terminus of the growing polymer chain without ever falling off the chain, thus differentiating the reactivity between the growing polymer chain and the monomer. The strength of the binding interactions between the metal complex and the polymer chain end has a profound impact on the chain-growth/living process. The utilization of artificial molecular machines to aid and regulate chain-growth polymerization processes should lead to major advances in precision polymer synthesis.

Controlled Synthesis of Mechanically Interlocked Polymers

A polyrotaxane is a necklace-like polymer in which many rings (macrocycles) are threaded onto a single polymer chain capped with bulky stoppers at both ends, and as such, is one of the most important members in the family of mechanically interlocked polymers (MIPs). Its unique structure gives rise to complex architectural characteristics once the rings are crosslinked, forming the so-called slide-ring gels. These mechanically interlocked gels can find various applications in films, super-soft materials, scratch-resisting coatings, and polymer binders for batteries. This research involves the production of polyrotaxanes with control over molecular weights, dispersities and microstructures by employing a chain-growth polymerization protocol. Such an approach affording well-defined mechanically interlocked polymers is rare, and these new syntheses and designs would represent a significant advance beyond the research already described in the literature.

Two-Dimensional and Three-Dimensional Conjugated Frameworks

Synthetic porous materials, such as metal-organic frameworks (MOFs), covalent organic frameworks (COFs) and conjugated microporous polymers (CMPs), have found various applications. The bottom-up design and synthesis of these materials depends on the self-organization or polymerization of small and rigid subcomponents into larger assemblies under thermodynamic control, retaining their permanent porosity in the solid state. Synthetic approaches exploited to link monomer precursors can be quite varied, ranging from strong covalent bonds in polymers to metal-organic coordination interactions or dynamic covalent chemistry, or even weak supramolecular forces such as π–π interactions, halogen bonding, and hydrogen bonding. We aim to develop simple and easy-to-access methods to build 2D and 3D conjugated frameworks and subsequently apply principles found in host–guest chemistry to these materials in order to produce functional solids for various applications in surface chemistry.