| Marine facilities and equipment are important material guarantees for the development and utilization of the ocean.However,biological fouling seriously limits the efficient service life of marine facilities and equipment and is one of the main factors restricting marine facilities and equipment development.It is economical and efficient to apply antifouling coating on the surface of equipment and facilities,which is the most widely used antifouling protection technology at present.Among many antifouling coating technologies,the surface of degradable polymer antifouling coating will be spontaneously updated,which can avoid microbial adhesion and fouling,and the degradation products are small molecules,which meet the increasingly stringent environmental regulations.However,how to further improve the antifouling performance and environmental protection of degradable polymer antifouling coating is a problem that needs to be solved.In this paper,the structure design and antifouling mechanism of green poly-Schiff base coating are studied by using the concept of green antifouling and cooperative antifouling strategy.The main research contents are as follows:（1）Green poly-Schiff base metal complex-based antifouling coating:A Schiff base compound（TOB-PR）was prepared by the dehydration condensation reaction of protocatechuic aldehyde（PR）extracted from the natural black fern multiflora and tobramycin（TOB）from Streptomyces.The Schiff base material is taken as a main body,Fe3+is taken as a linker,and the Schiff base metal composite coating-（Fe/TOB-PR）n is prepared through a layer-by-layer self-assembly（LBL）method through a step complexation reaction.The coating structure was further characterized,the complexation ratio was investigated,and the adhesion level on the surfaces of various materials was evaluated.The results showed that the Schiff base coating had excellent adhesion on the surfaces of stainless steel,polyamide fiber,glass,polystyrene,and other materials.The Schiff base characteristic bonds in the coating could be hydrolyzed.In artificial seawater,the degradation rate was faster in the first 48 h and then tended to uniform degradation.After 24 h of the antibacterial coating experiment,the antibacterial rate of（Fe/TOB-PR）20coating reaches ninety-seven percent,and it is found that the durability of antibacterial property is highly related to the activity and the coating thickness and TOB monomer.The antibacterial and anti-algae adhesion properties of the Schiff base metal complex coating were further tested,and the results showed that the material had an excellent adhesion inhibition rate,and the anti-fouling ability was improved with the increase of the coating thickness.In addition,the coating is finally degraded into a natural micromolecule monomer,and the accumulation of microplastics in seawater is avoided.（2）Anti-fouling coating of biological polypeptide poly-Schiff base:Using polyether amine（PEA）with good toughness,glutaraldehyde（GD）with the antibacterial ability,and biological polypeptideε-polylysine（ε-PL）with broad-spectrum antibacterial ability as raw materials,poly-Schiff base antifouling coating（n-ε/GD-PEA）crosslinked with biological polypeptide was prepared by condensation reaction.The structure,thermal stability,and binding force of the n-ε/GD-PEA coating were investigated using the grafting ratio ofε-PL as the independent variable.With the increase ofε-PL content,the coating roughness decreases from 14.23μm to 1.93μm,the contact angle decreases from 55.9°to 48.8°,and the surface is hydrophilic and relatively flat.The proportion of grafting epsilon-pl is higher,the more unreacted active amino groups are,the stronger the binding force with the primer is,and the binding force reaches 7.6 MPa at most.The grafting ratio ofε-PL can adjust the degradation rate of poly-Schiff base coating,among which 15-ε/GD-PEA and20-ε/GD-PEA have faster degradation rate,while 10-ε/GD-PEA has relatively slower degradation rate.Finally,Escherichia coli,Phaeodactylum tricornutum and Chlorella sp.were used as representatives of fouling organisms to investigate the antifouling performance.It was found that the antibacterial rate of the coating with differentε-PL content reached 100%for 12 h,and it showed excellent antibacterial and algae adhesion resistance under shaking conditions. |
