Yang Dayong research group developed a new system of dynamic chemical materials Tianjin University: tellurium, platinum coordination system and the dynamic mechanical properties of reversible regulation of intelligent hydrogels

Recently, Yang Dayong School of Chemical Engineering of Tianjin University research group has made new progress in the field of dynamic chemical materials, research results published in the authoritative journal Chemistry chemical material field of Materials, relevant achievements China has applied for patents for inventions. The main authors include associate professor of Chemical Engineering and Technology Li Feng, Zhang Xue graduate and Beijing computing Science Research Center researcher Hu Shuxian. Study was funded by the National Natural Science Foundation. Body structure can be achieved when the mechanical strength of the wild, some organisms (such as sea cucumber) encounters external stimuli reversible dynamic adjustment to better adapt to the environment and survive. Inspired by the dynamic structure of such organisms, it has been designed and synthesized a variety of smart materials biomimetic polymer, which can be the same organism as \”sense\” various external stimuli, thereby changing its mechanical properties. Biological oxidation-reduction reaction is an important regulatory mechanism to achieve a steady state, so the development of smart materials based tunable redox mechanical properties in response to stimuli is important for the development and function of biological tissue repair devices and other biological applications. At present, there are still challenges based on the redox response of the mechanical properties of the material of construction of intelligent design adjustable. School of Chemical Engineering and Technology, Professor Yang Dayong research group developed the redox chemistry of new materials in response to dynamic system – based on tellurium platinum coordination role of dynamic system and synthesized dynamic hydrogels, dynamic mechanical properties of the hydrogel by stimulating redox regulation. The organic tellurium having low electrical resistance and excellent negative σ electron donating ability, can form a good complexation with ions of some transition metals (e.g., platinum ion). More importantly, this complexation with redox sensitive stimulus responsive: when tellurium is oxidized, the oxidized tellurium lost complexation of the platinum ions; and when tellurium oxide is reduced, but also tellurium coordinated action to recover the platinum ions. By molecular dynamics simulation, molecular level illustrates this dynamic coordination mechanism. Further, at both ends of the molecular modification of a tellurium-containing acrylamide groups, the use of a radical polymerization organic tellurium is introduced into the hydrogel backbone, while adding platinum ion in the hydrogel systems, the hydrogel achieved by platinum coordination tellurium further crosslinked gel system. Such hydrogel microstructure and mechanical properties of the stimuli-responsive redox: under oxidation conditions, oxidation of tellurium, tellurium platinum coordination effect disappears, the hydrogel reducing the degree of crosslinking, a three-dimensional pore network is increased, decrease in mechanical strength ; under reducing conditions, tellurium are reduced, the restoring platinum coordination tellurium, increased degree of crosslinking hydrogels, A three-dimensional pore network is reduced, the mechanical strength is improved. Mechanical properties of the dynamically adjustable hydrogel has great potential in the field of application of bionic drive, soft robot.

Original link: https: //pubs.acs.org/doi/pdf/10.1021/acs.chemmater.9b05375