The Synthesis Of Fluorosilicone-zwitterion Random/block Copolymers And Their Protein-resistant Performance

Non-specific protein adsorption on the surface of solid materials has brought a lot of disadvantages to our life.The development of stable and efficient anti-protein adsorption materials has a broad application prospect in the anti-fouling coating fields.Studies have shown that hydrophilic polyethylene glycol(PEG)is non-toxic and good for antifouling but it is unstable and easy to be automatically oxidized into aldehydes or acids in human body,which is not conducive to its long-term use.However,zwitterion polymers such as PCBMA have been proved to show superior and durable anti-protein adsorption properties.The main works are shown as follows:Firstly,reversible addition-fragmentation chain transfer(RAFT)radical random copolymerization was used to synthesize a series of random PDMSMA-co-PAF6-co-PMMA-co-PCBMA copolymers with different compositions.Fourier transform infrared spectroscopy(FTIR)and X-ray photoelectron spectroscopy(XPS)were used to characterize the chemical composition of the polymers before and after the quaternary amination.It was found that carbonyl absorption peak of-COOH appeared in the FTIR spectra and the N~+peak of N element appeared in the XPS spectra,which confirmed the quaternary amination of PDMAEMA chain segment and the zwitterion chain segment of PCBMA.The study on copolymer coatings shows that the wettability of polymer surface is affected by the surface chemical composition.The introduction of fluorosilicone reduces the surface energy of polymers,which has good water-repellent and solvent-resistant properties.The coating hydrophilicity was enhanced after the quaternary amination of random copolymers.Studies on the anti-protein adsorption performance of fluorosilicone-zwitterion random copolymer coatings showed that the composition of copolymer significantly influenced its anti-protein adsorption performance.When the ratio of copolymer components was(PDMS-MA):(PAF6):(PMMA):(PCBMA)=2:20:56:190,the coating exhibits excellent performance of anti-BSA and anti-Lys adsorption.The anti-protein performance of fluorosilicone-zwitterion random copolymer coatings is due to the comprehensive interaction among hydrophilic PCBMA chain segment and hydrophobic PAF6 chain segment and flexible chain PDMS-MA.Secondly,RAFT radical block copolymerization and quaternary amination of the products were used to prepare a series of PDMSMA-co-PAF6-b-PMMA-b-PDMAEMA block copolymers with different compositions.The contact angle measurements showed that the surface energy of the copolymers increased from 22.71mN/m to 24.94 mN/m with the increase of PDMAEMA chain component.After the modification of quaternary amine,the hydrophilicity of the amphiphilic coating was enhanced,which was conducive to anti-protein adsorption.AFM test results show that when the content of fluorosilicate component increase,the microstructure of the surface presents pore structure.The content of fluorosilicone decreased,the pore structure reduce and the coating surface was relatively flat.The anti-protein adsorption performance of amphiphilic block copolymers is closely related to the length of hydrophilic chain segments.Among them,copolymer iR5 with moderate length of polymer chain segments can exhibit excellent anti-adsorption performance for BSA and Lys.For the short length of hydrophilic segments,the coating has poor anti-protein adsorption performance because of the lack of intermolecular interaction which prevents the surface of hydrophilic chain segment from accumulating.When the chain segment is too long,hydrophilic side chains also have strong electrostatic force among them,resulting in aggregating and poor anti-protein adsorption.The fluorosilicone-zwitterion random/block copolymer coatings obtained in this work can show excellent anti-protein properties and have a good application prospect.