BIT research group publishes review article in ionogels field

News Source & Photographer:School of Life Science

Editor: News Agency of BIT

Translator: Zhao Jingmiao, News Agency of BIT


Recently, the green bio-manufacturing research group in the School of Life Science of Beijing Institute of Technology published a review entitled "Roles of Ionic Liquids in Adjusting Nature of Ionogels: A Mini Review" in the top international journal Advanced Functional Materials (Impact Factor 18.808). The article reviews the role of ionic liquids in regulating the structure and properties of ionogels. Corresponding authors of the article are Associate Professor Yan Jipeng and Professor Sun Jian, and the first author is Luo Zhihong, a 2020 Master in the School of Life Science of BIT.


Scheme 1. Some typical features of IL-based ionogels as compared to hydrogels.

Ionogels are a kind of solid mixture with gel-like structures and ion-conductivity, usually made by mixing high organic polymers with salt electrolyte materials that can be electrolyzed as ions. The ionic liquids (ILs) confined in the 3D crosslinking network can form ionogels with specific structures and properties. Due to the presence of ionic liquids, ionogels have many unique properties, such as conductivity, excellent electrochemical stability, antifreezing capability and antibacterial performance. It can also remain stable in a wide temperature range. And it has a very wide range of applications in energy storage, sensing, 3D printing and biomedicine fields. Studying and understanding the influences and mechanisms of IL on the structure, properties and applications of ionogels is of great significance for the development of high-performance ionogels and the broadening and deepening of their applications. Based on many research advances in recent years and by focusing on the possible different functions of ILs of hydrogen bond, electrostatic interaction, host-guest interaction, IL-philic and IL-phobic interaction, solvation, etc, this review comprehensively summarizes and discusses the influence mechanism of IL on the structure and functions of ionogels. The relevant challenges and future development trends are also preliminarily discussed.


Scheme 2. Schematic image of roles of ILs in adjusting nature of ionogels.

ILs play a very important role in adjusting the structure and nature of ionogels. The designability of ILs offers many possibilities for developing ionogels with specific structures and functions to meet different application requirements. Ionogels differ significantly from hydrogels in terms of structure and function. 1) As dispersing medium, most ILs have a plasticizing effect on ionogels due to the interactions between strong hydrogen bond and electrostatic. This effect can change their crystallization structure and thus make ionogels have different structures and properties such as higher stretchability, lower Young's modulus, larger pore size and lower crystallinity, compared to hydrogels; 2) as component of polymer network, the hydrogen bonding and electrostatic interactions between polyionic liquids and other components can not only improve the mechanical strength of ionogels, but also regulate the morphology (such as laminar stacking, spherical micelle or wormlike micelle, etc.) and structure (such as smaller pore size, higher pore density, etc.) of ionic gels; 3) through host-guest interactions (such as cyclodextrin-IL, etc.), different intelligent ionogels can be designed and synthesized, which can react to different external stimuli (e.g., light and heat); 4) by using the affinity interaction between polymer components and ILs, block copolymer ionogels with different structures and properties can be designed and synthesized; 5) based on the strong solubility of ILs for biomass molecules (cellulose, lignin, and chitin, etc.), different biomass ionogels can be obtained.

Currently, ionogels with unique properties such as thermal stability, antifreezing capability, conductivity and antibacterial performance can be made by structural design and force regulation of ILs. To address the problems of water-absorbing during the application process of most ionogels and difficulties in gel synthesis due to high viscosity of ILs, further research on the structure-activity relationship of ILs is needed to design and synthesize high-performance ionogels for a wider range of applications.

Paper Details:

Zhihong Luo, Wenjin Li, Jipeng Yan,* and Jian Sun*, Roles of Ionic Liquids in Adjusting Nature of Ionogels: A Mini Review, Advanced Functional Materials, 2022, 2203988.

About the research group:

The Green Bio-manufacturing Group focuses on the national strategic needs of "carbon peaking and carbon neutrality " and sustainable development, emphasizing on the interdisciplinary fusion of chemistry, biology, chemical engineering, materials science and engineering and other disciplines. This group also carries out basic and applied research on functionalized ionic liquids, and their specific research directions include functionalized ionic liquid design and microenvironment effects, bio-based chemical and material synthesis, optical, electrical, thermal and biological process coupling, and construction of bionic functional devices. Leader of this group is Professor Sun Jian, doctoral supervisor and TELI Young Scholar of BIT. He is also the deputy director of the Technical Committee of China Cellulose Industry Association, a member of the Ionic Liquid Committee of The Chemical Industry and Engineering Society of China, and a member of the Biomedical Membrane Technical Committee of the Membrane Industry Association of China. Dedicating himself in studying green processes based on ionic liquids for a long time, he has published more than 80 academic papers in international journals such as Chem. Soc. Rev., Energy Environ. Sci., Chem. Eng. J., Adv. Funct. Mater. etc, with more than 20 Chinese patents, 3 US patents and 1 Japanese patent having been granted; he has presided over and participated in more than 10 projects, such as The National Natural Science Foundation of China. He is currently serving as a young editorial board member of journal like Energy Environ., Mater., Chinese J. Chem. Eng., Green Chem. Eng. In the research group, Associate Professor Yan Jipeng, PhD, is a young member of the Process Intensification Committee of The Chemical Industry and Engineering Society of China. He has long been engaged in the efficient green transformation of biomass and the development and utilization of bio-based materials and chemicals. He has published more than 20 SCI papers in important journals of related fields. He has presided over and participated as a backbone in 25 projects on bio-based materials and commercial transformation of chemicals. He has also received awards for outstanding contributions from the U.S.Lawrence Berkeley Laboratory several times.