Fabrication Of Folic Acid Based Supramolecular Hybrid Gels And Their Applications In Drug Controlled Release And Dyes Adsorption

Supramolecular gels,structured in the form of three-dimensional network,are formed by small molecular weight organic compounds through non-covalent interactions between molecules,such as hydrogen bonds,van der Waals forces,?-?stacking,hydrophilic/hydrophobic effects.This kind of supramolecular gel is characterized by sensitivity to external stimuli such as temperature,pH and modifiability,which can play a role in biological medicine,template materials.However,the weak mechanical strength greatly restricts its application in the meantime.In the present study,supramolecular hybrid gels are obtained by adding other macromolecular compounds to supramolecular gels to enhance the mechanical strength,as well as test the application effects on drug release and dye adsorption.We chose folic acid?FA?as the gelator,agar as the second component to form a FA-agar?FAG?hybrid gel in the mixed solvent of DMSO/H₂O.In addition,FT-IR,UV-vis,XRD,rheology,SEM,TEM were used to demonstrate the self-assembly process,gel strength and the surface features of the gel.Furthermore,Rhodamine B was selected as a mimic model drug to investigate the drug release properties of FAG hybrid gel.The results showed that the FAG hybrid gel had gained much more mechanical strength and better controlled release property than the FA gel with the addition of agar.We explored the gelation ability of FA in different mixed solvents by changing its volume ratios.The results showed FA performed best in NMP/H₂O?volume ratio is 1:1?with the critical gelation concentration of 0.4%?w/v?.Since the pure FA gels are often brittle and instable,we added gelatin?GA?,chitosan?CS?respectively to form FA-GA,FA-CS hybrid gels to improve its strength.FT-IR,UV-vis,fluorescence spectrum,SEM were adopted to show the formation processes and surface features.The results showed that the strength of pure FA gels was greatly improved with the addition of the additives.Both GA and CS were involved in the self-assembly process of the gel and formed extremely dense network structures,and the fibres of network structures are helical.At the same time,Congo red?CR?,methylene blue?MB?,methyl orange?MO?were employed to study the dye adsorption ability of the two hybrid gels.The results showed that FA-GA hybrid gels had better adsorption effects on the high concentration of MB with the adsorption rate reaching more than70%.FA-CS hybrid gels had better adsorption effects on high concentration of CR with the adsorption rate reaching more than 95%.