Preparation And Properties Of Polyaldehyde-based Sodium Alginate Nanofiber Membranes

Sodium alginate(SA),as a marine biopolymer,it has been a wide range of attention because it is a rich renewable resource and has a flame retardant,biocompatibility and other important features.SA nanofibers can combine the characteristics of high specific surface area and porosity of nanostructures and the biotic properties of biobased materials themselves,so it applied to a variety of fields,such as tissue engineering because of their good biological characteristics and bionic structure.However,electrospinning of pure alginate from its aqueous solution is difficult owing to insufficient entanglement arising from the rigidity of saccharide rings.Alginate dialdehyde(ADA)was prepared by periodate-oxidation of sodium alginate,in the oxidation process,improvement of the flexibility of molecular chains induced by the occurrence of ring-opening reaction,and at the same time,some of the inactive carboxyl groups were oxidized became relatively active aldehyde group.With the help of ethanol as co-solvent,ADA is used for electrospinning to obtain uniform nanofibers without beads.The solution can obtain homogeneous nanofibers with a spinning concentration in the range of about 15-17.5 wt%.The optimum formulation conditions for ADA spinning solutions were systematically studied.The results showed that proper amount of ethanol and near neutral pH had a decisive effect on the electrospinning ability of ADA.In order to broaden the range of electrospinning of ADA and film-forming properties,we had added adipic acid dihydrazide(AAD)and polyethylene oxide(PEO)through its chemical crosslinking and physical crosslinking with ADA,to prepare the uniform nanofibers adjustable diameter,and broaden the range of ADA electrospinning to meet the biomedical and other areas of different needs.ADA nanofibers membrane were prepared with AAD as crosslinker,its mechanical properties,degradation behavior and adsorption properties were also investigated,the results show that the mechanical properties and degradation stability of the ADA nanofiber membrane after crosslinking increase with the increase of the concentration of the crosslinking agent.The adsorption performance of the crosslinked agent is 0.1 wt%,it can reach the complete adsorption,the maximum theoretical adsorption capacity of 1869 mg/g.