Investigation On The Construction,Properties And Performance Of Polymer Hydrogels

In this thesis,the gelators with special functional groups were synthesized,and the gelation behavior in different solvents was studied.Typically,the hydrogels formed by AT-PEG and the derivatives of tripyridine（terpy）was studied systematically.PEG,nonionic polyether surfactants,has been widely used in biomedical and pharmaceutical areas,and materials science.The end hydroxyl group of the PEG chain can always be modified,implanting the polymer novel characterization and function.Terpyridine（TP）,a typicalπ-conjugated molecule,has rich coordination and high binding affinity with metal ions,and have been widely used in supramolecular chemistry and catalysis field.The AT-PEG/PPCT hydrogels was formed driven by comprehensive noncovalent interaction,including the hydrogen bonding,electrostatic interaction,van der wall forces and etc.The formation mechanism and functions of the gels was mainly investigated,which enrich the application of gels in waste water purification.The main research contents and conclusions were shown in the following:（1）In order to obtain the double-end amino polyethylene glycol（AT-PEG）gels,the terminal of the polyethylene glycol（6000）was modified by two-step method.First,PEG was modified by sulfonylation reaction,and then the sulfonyl group was converted into amino by amination reaction.The amination of polyethylene glycol was confirmed by IR and NMR analysis,and the conversion rate of the amino group was measured by elemental analysis.（2）The derivatives of terpyridy,4′-para-phenylcarboxyl-2,2′:6′,2″-terpyridine（PPCT）,and terpyridyl-based liquid-liquid gels,and which were characterized by NMR and MS.（3）AT-PEG/PPCT hydrogels were prepared by 4′-para-phenylcarboxyl-2,2′:6′,2″-terpyridine（PPCT）,and amino-terminated poly（ethylene glycol）（AT-PEG）in water.Scanning electron microscopy（SEM）,infrared spectrum（FT-IR）and rheology were used to detect the microstructures and rheological property.The formation mechanism of the gels was discussed,and the application of the gel in the purification of wastewater was explored.（4）Terpyridinel fluorescence ionic liquid was used to prepare organogel in acetonitrile,and the formation conditions of the gel were studied.The results show that the conversion rate of the amino group is 89.7%,which indicates a very high use value.Microstructures determined by SEM observations demonstrated that the polymer hydrogels were formed by intertwined fibrils.The formation of fibrils was considered to be mainly driven by the electrostatic interaction with the assistance of a delicate balance of multiple noncovalent interactions,including hydrogen bonding,hydrophobic interaction,van der Waals forces,and etc.The rheological measurements show a strong mechanical strength with an elastic modulus exceeding 5000 Pa and a yield stress exceeding 100 Pa,and which can be regulated by changing the proportion of the gelators.The xerogels exhibited excellent adsorption capability of anionic dyes,which can be used as promising candidate adsorbents for toxic dyes.Terpyridinel fluorescence ionic liquid gelators can be complexed with Zn²⁺to form fluorescent organic gel,and the concentration range of gel formation is small.The gels was prepared in organic solvents,which can prohibit fluorescence quenching of terpyridine molecule.Terpyridinel has has rich coordination and high binding affinity with metal ions,making it become an excellent gelator to produce hydrogels,and which should have breakthrough in catalytic applications.