Study Of Complexation Of Tannic Acid With Amine-terminated Polypropylene Glycol And Its Properties

Compared with uncomposited polymers,polymer complexes formed based on intermolecular complexation through noncovalent interactions,such as hydrogen bonding,ionic interaction and hydrophobic interaction,have large scales,rich structures and compositions,and are highly controllable.In addition,polymer complexes have good application prospects in coating modification,drug delivery and other fields.Our group's early research was based on the complexation behaviour of tannic acid(TA)and polyether poloxamer 188 in aqueous solution.In order to further endow TA-polyether complexes with functionalizable groups,this paper has been expanded the research object to amino-terminated water-soluble polyether,a low molecular weight polyoxypropylene diamine(Jeffamine D400),and its complexation behaviors with TA in aqueous solutions were studied,as well as potential properties and applications.Firstly,complexation behaviors of TA and D400 in aqueous solutions were investigated,including factors affecting the complexation of TA and D400,driving forces of complexation,pH sensitivity,chemical compositions and structure morphology of TA-D400 complexes.The results showed that the initial pH,concentrations and mixing ratios of TA and D400 aqueous solutions have varying degrees of influence on complexation behaviors.It has found that pH 5TA aqueous solution and pH 7 D400 aqueous solution can readily form complexes relied on ionic interaction and hydrophobic interaction,and as the solution concentration increased,the dispersion state of complexes solution was gradually stable.With the increasing of TA content and mixing time,hydrodynamic diameters of TA-D400 complex particles and turbidity of complexes solution gradually increased,and zeta potentials exceeded +20 m V.And TA-D400 complexes solution can remain stable in a weakly acidic environment at pH 5.Transmission electron microscopy,Uv-vis spectroscopy and FTIR spectroscopy showed that the TA-D400 complexes were spherical nanoparticles composed of ionic TA and D400.Subsequently,on the basis of the above-mentioned solution study,the surface modification of materials with TA-D400 complexes that prepared by equal mass mixing of 4mg/mL pH 5 TA aqueous solution and 4 mg/mL pH 7 D400 aqueous solution used as a coating was explored.It was found that TA-D400 complexes can be prepared into a coating by a simple deposition method,which has a certain degree of substrate universality.The morphology,TA content and hydrophilicity of TA-D400 coating are directly affected by temperature,deposition time,and placement method.Preliminary cell experiments showed that the number and morphology of mouse L929 fibroblast cells attached to the coating are affected by the substrate.In addition,the adhesion and differentiation of chick cortical neurons are supported by the coating on the silicon substrate.TA-D400 coating has certain antioxidant property,antibacterial property,and the ability to load hydrophobic drugs.Besides,TA-D400 coating can be doped with gold nanoparticles in situ,which is beneficial to expand functions of the modified surface.