Synthesis Of Pyridine-containing Polymer Materials And Electronic Memory Characteristics Manipulation Through Structural Design

In recent decades, organic and polymeric materials-based memory devices are advantageous due to their low-cost potential, flexibility, high-density data storage and miniaturization in size, which have attracted most attention and gained many results. To some extent, polymers containing pyridine group can adjust molecule structures and optimize electrical properties through the coordination between the pyridine group and metal iron. Throughout the research progress of polymer memory devices, the molecular structures, thickness of films, annealing temperature and electrodes have a certain influence on memory performances. Therefore, we synthesized a series of pyridine-based polymers through the methods of RAFT polymerization and polycondensation. To regulate and control the storage characteristics, we study the factors of optimization memory performance from the multi-angles of molecular structure, annealing temperature and coordination environment. The main research works in the following points:(1) On the basis of polymer containing pendant chalcone groups(PStCH), we synthesized a series of 4-vinylpyridine based block copolymers PStCH-b-P4 VP with different block ratios by the methods of RAFT polymerization. We selected the copolymer with a longer P4 VP chain in order to improve the diffusion and solubility of Hemin in the polymer DMF solution via coordination and hydrogen bond to investigate the redox capacity of iron ion in different coordination environments. The films of the PStCH-b-P4VP: Hemin and P4VP: Hemin composites were fabricated by spin coating. Through further studying the electric performance, the mechanisms of CT and redox effect are the main reasons for these memory devices.(2) We synthesized a kind of alternating copolymer(polyamide) PA-m-Ph with the pyridine group in the main chain through the polycondensation between the acyl chloride and amino group. The results reveal that the annealing temperature can change the morphology of the films, even the memory performance. We also analysis the factors from two aspects of the solvents and molecular structure.(3) On the basis of polyamide, two kinds of polyimides were designed and fabricated into “sandwich” devices. I-V measurements indicated that these polymers exhibited different electrical switching phenomenon. Due to the distinct degrees of π-π* conjugacy, they can form various charge transfer complexes. We investigated the mechanism by the characterization of ultraviolet, cyclic voltammogram, surface morphology and so on.Learning from the above system research, the pyridine group based polymers can optimize electrical properties via adding some special ligand metals. Besides, the changes of polarity of the solvent, stacking of the side groups, annealing temperature, coordination environment, film morphology and molecular conjugacy can also influence the memory performances. It provides new ideas for the design of storage materials.