1.the Design And Synthesis Of Soluble Two-Dimensional Polymers 2.Construction Of Low-Molecular-Weight Photoresponsive Supramolecular Hydrogel

The research content of this thesis is mainly focused on two aspects:?1?the design and synthesis of soluble two-dimensional polymers;and?2?construction of low-molecular-weight photoresponsive supramolecular hydrogel.In the first part,we have designed and synthesized a series of C₃ symmetric aromatic triamine derivatives,which were furthered reacted with aromatic dialdehyde compounds to produce two-dimensional polymers?2DP?.Alkyl chains with steric hindrance were incorporated into the triamines,in order to diminish the the?-?stacking interactions between the aromatic systems,and improve the solvation effect.The ¹H NMR experiments were performed to track the condensation reaction procedures,which indicated the formation soluble 2D polymers whose solution exhibited significant Tyndall phenomenon.Based on these observations,X-ray diffraction,as well as high resolution TEM experiments were going to be carried out for the characterization of the ordered structures of such soluble 2D polymers.In the second part,a water soluble azobenzene-bridged pyridium derivative was synthesized,which was used for the fabrication of novel low-molecular-weight photoresponsive hydrogel.The ¹H NMR,UV/Vis,SEM and PXRD experimental investigations have revealed that the E-isomer of such azobenzene-derived hydrogelator could form linear fibrous assembles,which further generated supramolecular hydrogel.This could be attributed to the hydrophobic interactions as well as the strong?-?stacking interactions between the planar aromatic system of the E-isomers.Upon the irradiation with alternative UV?365 nm?and visible?>400 nm?lights,the reversible E/Z photoisomerization of the hydrogelator could be triggered,resulting in the reversible gel/sol inter-conversion of such supramolecular hydrogel.It is expected that the findings in this research will provide a new strategy for the construction of novel smart soft maters.