Alginate hydrogel is a soft material with a 3D porous network structure, which has a wide range of applications in many fields such as biomedicine, optics, electricity, and carriers. However, most of the alginate hydrogels have low mechanical strength, are prone to mechanical damage during use, and their performance is greatly reduced after damage, which cannot continue to meet the requirements of use. Therefore, it is of great significance to develop and prepare hydrogel multifunctional materials with self-healing properties and high strength. Recently, the Green Biomanufacturing Research Group of the School of Life Sciences, Beijing Institute of Technology used the in-situ multilayer self-assembly technology of alginate, combined with polyacrylamide with abundant hydroxyl sites, and used a simple method to construct a high-strength self-assembly with a regular layer structure. Healing hydrogel. The characterization of the system revealed the driving mechanism of dynamic hydrogen bonding on the self-assembly of sodium alginate (SA) into a porous polyacrylamide (PAM) matrix into a layered structure. In addition, hydrogen bonds also play a key role in enhancing the self-healing effect of hydrogels, and the self-healing ability of hydrogels reaches 99%. At the same time, this ordered layer structure also enables the tensile strength of the alginate-based hydrogel to reach 266 kPa. The above work provides new ideas and methods for the development of hydrogels with orderly multilayer structures with high mechanical strength and self-healing properties, and helps to realize the diversity of hydrogel functions.

Figure 1 Schematic diagram of self-healing hydrogel preparation process and multilayer structure formation
Related results were published online in the top journal Carbohydrate Polymers (IF= 7.18, instant IF=8.0) in the field of polymer science and engineering technology. The first author of the paper is 2018 master student Zhao Dingwei, and the corresponding author is Professor Sun Jian. Link to the paper: https://www.sciencedirect.com/science/article/pii/S0144861720317537. Sun Jian: Ph.D., professor, doctoral tutor, leader of the green biomanufacturing research group, selected into the National Young Talents Program, Beijing Institute of Technology Special  Young scholar. He received a PhD in Engineering from the Graduate School of the Chinese Academy of Sciences in 2009, and his supervisor is Academician Zhang Suojiang. He is currently a member of the Ionic Liquid Professional Committee of the China Chemical Industry Association, a member of the Medical Biomembrane Technology Committee of the China Membrane Industry Association, and the second China Cellulose Industry Association Technology Committee members, Chinese J. Chem. Eng. and Green Chem. Eng. Youth Editors, etc. Presided over a number of national science fund projects, participated in 973, 863, support programs and other major projects. Has long been engaged in ionic liquid green process research, in Chem. Soc. Rev., Energy Environ. Sci., Green Chem., ChemSusChem, Chem. Commun., ACS Sustainable Chem. Eng., Carbohyd. Polym., Biotechnol. Biofuels, I&ECR and other top international or important journals published SCI papers More than 50 articles, 21 authorized Chinese invention patents, 2 US patents, 1 Japanese patent, and 2 provincial and ministerial awards. Participated in the completion of 1 10,000-ton EG/DMC industrialization demonstration project. The main research direction of the research group is Based on the design of functional media such as ionic liquids and nanomaterials, develop new processes and new technologies for the separation-utilization-transformation of renewable carbon resources; including the design, synthesis and ionic microenvironment regulation of new functional ionic liquids, synthesis of bio-based functional materials, and bionics Enzyme or loaded enzyme construction and application, chemical-biological process coupling and enhancement, light, electricity, heat and biological clean catalytic conversion of renewable carbon resources such as CO2, biomass, etc. The research group welcomes those with relevant research or professional backgrounds Students and researchers joined.