A building unit(defined as SBU) synthesized from 1,2,4,5-benzene tetracarboxylic acid and 4-hydroxy pyridine was used as the gelator with low molecular weight to form supramolecular hydrogels at various concentrations.The dried hydrogels(xerogels) were observed by scanning electron microscope(SEM).The results indicate that the xerogels possess network structures composing of intertwined fibers and the dimension of the fibers can be regulated by the concentration of SBU.Powder X-ray diffraction(XRD) analysis indicates that the fibers are connected by SBU building units.The reversible sol-gel transition of the supramolecular system with the change of temperature was also noticed.
A simple drug compound, 4-oxo-4-（2-pyridinylamino） butanoic acid （defined as AP）, was able to gel water at 4 wt% concentration under various conditions. In the superstructure, AP molecules assembled into fibrous aggregates driving by hydrogen bonds and π-π stacking interaction. The gels with different backbone structures released drug molecules in different speeds.
The title block copolymer (defined as PSUEA) containing pendant,self-complementary quadruple hydrogen bonding sites has been prepared successfully by three steps.First,poly(styrene-b-2-hydroxyethyl acrylate) (defined as PSHEA) was prepared by living radical polymerizing 2-hydroxyethyl acrylate (HEA) initiated by polystyrene (PSt) macro- initiator,which was prepared via nitroxide-mediated polymerization (NMP) technique.After treated by excessive 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI),...
New hydrogen bonded supramolecular hydrogels were formed through simultaneously gelating two isomeric building units, 4-oxo-4-（2-pyridinylamino）butanoic acid （G1） and 4-oxo-4-（3-pyridinylamino）butanoic acid （G2） at various molar ratios in water.
Ji Wei WU Li Ming TANG Kai CHEN Liang YAN Yu Jiang WANG
Hyperbranched poly（amine-ester）s bearing self-complementary quadruple hydrogen bonding units display excellent mechanical and temperature-dependent melt rheological properties, which make them suitable as novel hot-melting materials.
