Preparation And Properties Of Polysaccharide/Polydopamine Composite Antifouling Coatings

Marine biofouling has caused great distress to human society.The application of existing antifouling coatings will damage the marine ecosystem and even affect human health.This thesis was inspired by the strong adhesion of dopamine in the mussel adhesion protein.Polydopamine(PDA)and polymer polysaccharides with good biocompatibility were used to construct different antifouling coatings on various substrates.At the same time,antifouling multilayer films were also prepared by repeating the deposition process.The coating inhibits the initial formation of marine organism fouling.The XPS,SEM,AFM,Zeta potential test,contact angle test were used to characterize the elemental composition,micromorphology,surface roughness,potential,surface wettability of the coating.The ability of the coating to inhibit the adhesion of marine microalgae was tested by Nitzschia closterium,Phaeodactylum tricornutum,Navicula exigua;The antibacterial ability of the coating was tested by Staphylococcus aureus and Escherichia coli.The specific experiment contents were as follows:The dextran(Dex)/ PDA and sodium alginate(Alg)/ PDA coatings were formed on glass slides and polyethylene terephthalate(PET)substrates by a one-step method.The test proves that PDA and two kinds of polymer polysaccharides can form a stable coating with good biocompatibility.The presence of polysaccharides makes the agglomeration of polydopamine weaken,which makes the coating more uniform.With the increase of the number of deposition times,the adhesion inhibition rate of Nitzschia closterium increased.After one week of testing,the Alg/PDA coating had stronger seaweed adhesion inhibition ability than the Dex/PDA coating.The adhesion inhibition rates of Dex/PDA-6 and Alg/PDA-6 on Nitzschia closterium were 70.24% and 96.59%,respectively.Dex/PDA and Alg/PDA coatings had certain antibacterial ability.Based on the research in the previous chapter,the CMCS / Alg / PDA ternary composite coating with long-term antifouling effect was prepared on the glass slide by a two-step method.With the increase of deposition times,the antifouling ability of the coating increased.The results of the 30-day microalgae adhesion test showed that the adhesion inhibition rates of CMCS/Alg/PDA-6 coating on Nitzschia closterium,Phaeodactylum tricornutum,Navicula exigua were 99.80%,71.32% and 93.39%,respectively.The ternary composite coating had a certain inhibitory effect on the growth of Staphylococcus aureus and Escherichia coli but the effect is not obvious.The antibacterial rates of CMCS/Alg/PDA-6 coating on the two were54.54% and 56.44%,respectively.The Alg / ZnO / PDA composite coating was formed on the surface of the substrate by the physical blending method.The relevant characteristics and antifouling tests were performed on each coating.The seaweed adhesion test showed that with the increase of deposition times,the coating's inhibition rate on seaweed and the bacteriostasis rate increased.The coatings have different anti-adhesion effects on different seaweeds.The adhesion inhibition rates of Alg/ZnO/PDA-6 on Nitzschia closterium,Phaeodactylum tricornutum,Navicula exigua were 94.91%,69.92%,92.17%.The antibacterial rates of Alg/ZnO/PDA-6coating on Staphylococcus aureus and Escherichia coli were 38.02% and 40.04%,respectively.