The Study On Synthesis,Preparation And Property Of Self-Healing Materials Based On Bipyridine/Terpyridine Metal Coordination

Most organisms in nature have the ability to heal themselves.Specifically,their biological tissues can implement self-healing process through a certain process after being injured.The wound is gradually shrinking,because biomolecules gather around the wound to restore the integrity of the body's tissue structure and function.Some organisms can even survive after several times of truncation.The development of new materials with"biological"self-healing functions will help the further development in many fields such as optoelectronic devices and biomedicine.Therefore,the research of self-healing materials has aroused the interest of the majority of researchers.Metal-ligand coordination is an important non-covalent interaction due to its small bond energy and good reversibility feature.Thus,self-healing materials based on this principle have the advantages of good environmental adaptability and easy preparation.It has great potential for building self-healing materials.Therefore,the development of self-healing materials based on metal-ligand coordination are of great significance to further understand the self-healing mechanism and expanding potential applications.In this thesis,terpyridines,bipyridines,monopyridines,and diquinolines with different chemical coordination structures are introduced into the polydimethylsiloxane(PDMS)matrix,and materials with self-healing ability are prepared based on metal-ligand coordination.In addition,their mechanical and self-healing performance was studied in detail.1.The study of self-healing materials based on terpyridine,bipyridine and pyridine liagndsWe have designed and synthesized polydimethylsiloxane(PDMS)matrix with terpyridine,bipyridine,and monopyridine ligands,to construct self-healing material system by using the metal-ligand coordination.First of all,preliminary studies on their mechanical properties have been carried out,and it was found that the different coordination capabilities of the terpyridines have great effects on their mechanical properties.Specifically,the coordination ability of the three pyridines decreases,leading to reduced mechanical properties;among them,the material prepared from pyridine has lost its normal mechanical properties compared with terpyridine ones.Different metal ions also have great impacts on the coordination ability and mechanical properties of polymer materials.Compared to zinc ions,materials formed by iron ion coordination show reduced self-healing properties.2.The study of self-healing materials based on dipyridine and diquinoline ligandsAccording to the results obtained by chapter 2,PDMS matrix containing bipyridine and diquinolines have been designed and synthesized.By coordination of different metal ions Zn²⁺,Fe²⁺and Pt²⁺,various self-healing materials of PD1,PD2,and PE1 were obtained.According to mechanical property study,a simple structure of bipyridine is used to construct self-healing material.Comapre to diquinoline liand,it has better self-healing property,poorer mechanical strength,and higher energy dissipation and stress relaxation.Through the optimization of chemical structure,stretchable self-healing material with good performance has been perpared and obtained.