Research

Research Directions

MOF - Polymer Interfaces

Porosity is a material property closely associated with rigidity. Processability, however, is strongly related to ductility and flexibility. Benefiting from the rigid molecular construct through strong coordination bonds, most metal-organic frameworks (MOFs) gain their permanent porosity at the cost of material flexibility and processsability. On the other hand, many polymers inherit excellent processability at the cost of porosity. Combining MOFs and polymers is a promising way to bring these two contradictory properties together.

This part of our research focuses on bridging the interface between MOFs and polymers. By doing so, we aim to 1) understand the fundamental aspects of MOF-polymer interfaces; 2) engineer composite materials interfaces to maximize material properties and 3) create well-defined hierarchical MOF-polymer composite materials with unique properties for energy and environmental related applications.

Selected Publications

A generalizable method for the construction of MOF@polymer functional composites through surface-initiated atom transfer radical polymerization. S. He, H. Wang, C. Zhang, S. Zhang, Y. Yu, Y. Lee, T. Li*, Chem. Sci., 2019, 10, 1816-1822

Adhesive bacterial amyloid nanofiber-mediated growth of metal–organic frameworks on diverse polymeric substrates. C. Zhang, Y. Li, H. Wang, S. He, Y. Xu, C. Zhong*, T. Li*, Chem. Sci., 2018, 9, 5672-5678

General Way To Construct Micro- and Mesoporous Metal-Organic Framework-Based Porous Liquids. S. He, L. Chen, J. Cui, B. Yuan, H. Wang, F. Wang, Y. Yu, Y. Lee*, T. Li*, J. Am. Chem. Soc., 2019, DOI: 10.1021/jacs.9b08458

Hierarchical Porous Composites

The physical and chemical properties of a porous material are encoded not only at the molecular scale (atomic or molecular assembly) but also at the mesoscale. Hierarchical arrangement of porous materials at the mesoscale can often lead to the emergence of unexpected properties specific to such architecture.

The extreme diversity of metal-organic framework (MOF) and covalent-organic framework (COF) structures rooted in the endless combinations between organic linkers and metal building units. Nevertheless, for a given application, it is still challenging to find a MOF that meets all the requirements. By arranging different MOFs at a specific mesoscopic hierarchical order, it is possible to combine their merits that are usually contradictory to each other.

This part of research focuses on the fundamental understanding of the interfaces between MOFs and COFs. Meanwhile, we aim to develop new strategies to construct hierarchical MOF/COF composites and pursue their unique properties thereafter.

Selected Publications

Seaming the Interfaces between Topologically Distinct Metal-Organic Frameworks Using Random Copolymer Glues. F. Wang, H. Wang, T. Li*, Nanoscale, 2019, 11, 2121-2125

Uncovering Two Kinetic Factors in the Controlled Growth of Topologically Distinct Core-Shell Metal-Organic Frameworks. F. Wang, S. He, H. Wang, S. Zhang, C. Wu, H. Huang, Y. Pang, C. Tsung, T. Li* Chem. Sci., 2019, 10, 7755-7761

Structural Control of Uniform MOF-74 Microcrystals for the Study of Adsorption Kinetics. C. Wu,† L. Chou,† L. Long, X. Si, W. Lo, C. Tsung,* T. Li*. ACS Appl. Mater. Interfaces, 2019, 11, 35820-35826

Directional Engraving within Single Crystalline Metal-Organic Framework Particles via Oxidative Linker Cleaving. L. Luo, W. Lo, X. Si, H. Li, Y. Wu, Y. An, Q. Zhu, L. Chou*, T. Li*, C. Tsung*, J. Am. Chem. Soc., 2019, DOI: 10.1021/jacs.9b10499

Tracking and Visualization of Functional Domains in Stratified Metal-Organic Frameworks Using Gold Nanoparticles. X. Qin, S. He, J. Wu, Y. Fan, F. Wang, S. Zhang, S. Li, L. Luo, Y. Ma,Y. Lee, T. Li*. ACS Central Sci., 2020, 6, 2, 247-253.

Enhancing the Gas Separation Selectivity of Mixed-Matrix Membranes Using a Dual-Interfacial Engineering Approach. C. Wu, K. Zhang, H. Wang, Y. Fan, S. Zhang, S. He, F. Wang, Y. Tao, X. Zhao, Y. Zhang, Y. Ma, Y. Lee, T. Li* J. Am. Chem. Soc., 2020, DOI:10.1021/jacs.0c07378

Gas Separation Membranes

Natural gas sweetening, H2/N2 separation, and olefin/parafin separation are some of the most energy intensive gas separation processes in industry. Practicing other separation such as CO2 removal from flue gas and direct air capture of CO2 may have a direct impact on mitigating global warming.

Compared to traditional separation technologies (e.g. cryogenic distillation and wet scrubbing), membrane gas separation using composite materials is an attractive alternative to considerably lower the energy consumption of these processes. The idea of compositing rigid crystalline porous fillers with soft polymeric matrix creates new possibilities to continuously improve membrane performance. However, the addition of a new phase also generates new problems including non-ideal filler distribution, interfacial compatibility and reduced mechanical properties, which complicate the rational design of materials.

We are interested in constructing well-defined composite membranes using various synthetic tools to simplify these problems and then subsequently find their structure-property correlations.

Selected Publications

Interfacial Engineering in Metal-Organic Framework-Based Mixed Matrix Membranes Using Covalently Grafted Polyimide Brushes. H. Wang, S. He, X. Qin, C. Li, T. Li*, J. Am. Chem. Soc., 2018, 140,17203-17210

Engineering Plasticization Resistant Gas Separation Membranes Using Metal-Organic Nanocapsules. H. Wang, K. Zhang, P. H. Li, J. Huang, B. Yuan, C. Zhang, Y. Yu, Y. Yang, Y. Lee, T. Li* Chem. Sci., 2020, 11, 4687