Surface Modification And Biocompatibility Of Polydimethylsiloxane Elastomer

PDMS has the characteristics of chemical stability,non-toxic,biocompatibility,optical transparency and easy processing,and is widely used as a biomedical material.However,the low polarity of PDMS molecules shows strong hydrophobicity,which makes it easy to adsorb liposomes,proteins and other biomolecules to limit its application.Therefore,hydrophilic modification of its surface is needed.In this paper,a simple,effective and economical method of surface modification of PDMS is found through a lot of attempts.The main contents of the experiment are as follows:Firstly,PDMS with excellent properties were prepared,and in order to improve its hydrophilicity and resistance to protein adsorption,a superspreading surfactant,polyether modified siloxane,was coated on the surface of PDMS by swelling and deswelling method.In this method,the cross-linked polymer PDMS film is swelling immersed in organic solvents such as hexane,heptane or chloroform,but it will not dissolve.In the absence of other information about the solvent,the solubility parameter can be used to predict the swelling degree of the polymer in the solvent.In this case,we assume that polyether modified siloxane containing hydrophilic group EO and hydrophobic group(methyl siloxane)are dispersed in solvent containing swollen PDMS.The modifier is embedded on the surface of silicone rubber by swellingdeswelling process and the hydrophilic end is exposed to the PDMS’ surface.The surface water contact angle of modified PDMS is about 50 °.The second method is to increase the surface energy of PDMS by adding a small amount of solubilizer to the PDMS prepolymer.Then this kind of silicone rubber was put into the modifier modified solution with water as the solvent,and the modifier was wrapped on the surface of the material by physical adsorption method.In addition,solubilizer with different mass fraction was added to the PDMS prepolymer to investigate the effect of solubilizer on PDMS.The extraction experiment was used to investigate whether solubilizer reacts completely with PDMS molecular chain.The surface WAC of the modified sample was about 30 °,and the relative protein adsorption decreased.The method had no cytotoxicity.