Study On Regulation Of Hydrophilic Properties Of Metal Surface Modified By Peptides

The surface of solid materials such as ships sailing on the ocean and marine immersion facilities is easy to be attached and contaminated by marine organisms.For ships,the attachment of marine organisms will increase the weight of the ship,make the surface of the ship rough,increase the friction resistance of the ship,and increase the fuel consumption.Attaching organisms attach to and grow on the ship’s underwater devices,such as pipelines,valves,and sonar baffles,will lead to blockage,corrosion and even damage,thus affecting the safety and service life of the ship.There are many methods to remove biofouling,which often include high technical content and expensive equipment and that restricts their development and application to some extent.The content of this paper mainly includes the following aspects:Using the specific binding properties of some biological peptides,this paper proposes a simple and easy method of biological peptide modified metal materials.By Scanning Electron Microscopy（SEM）,Atomic Force Microscope（AFM）,Fourier Infrared Spectrum（FTIR）and Contact Angle（CA）method,it determines the appropriate reaction conditions of the method:peptide solution concentration for 10mu g/m L,time of peptide solution containing metal materials for 80 min.The modification effect of binding peptides on the surface of 304 stainless steel was realized by this method.The the hydrophilic/hydrophobicity of modified 304 stainless steel is the same with the binding peptide used in the experiment.In order to further explore the effects of binding peptides on non-ferrous metal materials and the feasibility of surface modification by peptide,two non-ferrous metal materials,namely 2024 aluminum alloy and TC4 titanium alloy,were respectively taken to interact with the corresponding metal binding peptides SCSDCLKSVDFIPSSLASS and VPSSGPQDTRTT by the above method.Through characterizing the performance of two kinds of modified sample surface,it turned out that the proposed method modified non-ferrous metal material surface,and to a certain extent,the method is of generality.And it found that after modification the hydrophilic/hydrophobic of the non-ferrous metal material surface is the same with the binding peptide,which confirms the previous conclusions.Based on the effects of disulfide bond on the protein activity and the stability of the protein conformations,it studied the reaction of the binding peptide added the disulfide bond and the corresponding metal.The study found that disulfide bond influenced the reaction of metal and the binding peptide by reducing the ability of modifying function.FTIR found that the organic groups on the surface decreased significantly.The SEM observation results showed that the surface morphology of the modified material changed little compared with that of the original sample.The CA measurement results further confirmed the above conclusions.It can be seen that disulfide bonds have a negative effect on the modification by binding peptides.The antibacterial experiments showed that although the reaction of the binding peptide containing disulfide bond with the metal was weakened,the modified surface still had good antibacterial properties.In order to further study the effect of the binding peptide with improved hydrophobicity on the surface hydrophobicity of the modified metal material,the hydrophobic group C2F3O2-was grafted onto the side chain of the previously used stainless steel binding peptide to improve its hydrophobicity.The gotten peptide was used to interact with stainless steel.Experiments showed that the hydrophobicity of the stainless steel metal material modified by the peptide was also improved.The hydrophobicity of the surface modified by N3F was the highest whose contact Angle reached above 100°,which was significantly higher than that of the stainless steel modified by the original peptide N（above 65°）.After peptide N2S3F interacts with the metal material,the contact angle of the material surface gets to more than 90°,significantly increasing,which is higher than that of the sample treated by N2S（82°）.The hydrophobicity of modified metal surface can be regulated by modifying the binding peptides used,which provides data support for the study of adjusting the hydrophobicity of metal surface modified by peptide.The antibacterial experiments of N3F modified metal materials were carried out.The effect of the different structure of the same peptide on the surface hydrophobicity of the metal modified by the peptide was studied.L-peptide and D_D-peptide were selected,of which L-peptide and D-peptide were enantiomeric.D_D-peptide is a peptide with a new structure which is the reverse arrangement of D-peptide.Acetylation and amidation were performed on both ends of the two structural peptides.The side chains of the two known peptides were respectively connected with the residue of the hydrophobic group dodecanoic acid C₁₂H₂₃O₂-.Two new structural peptides,L’-peptide and D_D’-peptide,were obtained,respectively acting on metal materials to determine the effect of different structural peptides on the hydrophobicity of the peptide-modified stainless steel surface.The antibacterial samples of D_D’-peptide modified metal materials with the best hydrophobicity were studied.In this study,the hydrophobicity of metal material surface is regulated in a better way,which provides a basis and a new idea for the design of environmental protection antifouling metal material.