Fabrication Of Mechanically Enhanced Organic Silicone Coatings And Its Anti-biofouling Performance

Marine biofouling can dramatically increase the economic and environmental burdens,becoming a serious obstacle in the realm of maritime related industries.Marine biofouling is formed by the undesirable accumulation of marine microorganisms,animals,and plants on the submerged surface.To date,marine antifouling coating is an effective way to protect marine facilities from marine biofouling.However,traditional marine antifouling coatings can release biocides with toxic effects,which will cause serious damage to the marine environment and ecological balance.Thus,it is urgent to develop environmentally friendly and economic antifouling coatings.As one of environmentally friendly coatings,polydimethylsiloxane(PDMS)has gained widely attentions and applications in the field of marine antifouling.However,the “non-stick” nature of PDMS elastomer also leads to low adhesion force to the substrate.In addition,the elastic material can only play a dynamic fouling release performance under the shear forces of water flow,but the anti-fouling performance is poor with the static condition.Therefore,this thesis takes the preparation of silicone antifouling coating with high adhesion and high anti-fouling performance as the main research goal.Through a simple and efficient preparation method,the marine antifouling coating with strong adhesion and stability is prepared by using the network interpenetrating structure formed by silicone resin and epoxy resin(EP)or acrylic resin(AR)during curing.All the raw materials are environmentally friendly and economical.At the same time,natural antifouling agent is introduced to enhance the static antifouling performance of the coating.The main research contents include the following parts:1.Preparation of network interpenetrating composite antifouling coating.Silicone/epoxy composite antifouling coating containing natural antifouling agent is prepared by layer coating method.Epoxy resin(EP)is chosen as binder,and forms network interpenetrating structure with PDMS during curing process,enhancing the interfacial bonding property of PDMS.Meanwhile,different contents of capsaicin(CAP),a natural antifouling agent,is doped into the PDMS coating to improve the static antifouling performance of PDMS.The EP-PDMS/CAP coating shows a remarkably improved adhesion strength to the substrate(1.97 MPa).The anti-bacterial adhesion test shows that EP-PDMS/CAP coating obtains excellent anti-fouling performance with good static anti-bacterial adhesion rate(80.2%)and dynamic anti-bacterial adhesion rate(96.6%).Moreover,the anti-fouling coating is proven to be extremely stable in harsh environments(such as different p H,heating,and physical wear).Overall,the construction of the network interpenetrating silicone composite antifouling coating can provide excellent antifouling performance and adhesion performance to the pure silicon coating,which has great development prospect in practical application.2.Preparation of organic silicon/acrylic resin self-stratified anti-fouling coating.We prepare a mechanically enhanced fouling-releasing coating(PDMS/AR)by a simple one-step method.After the blend solution of PDMS and acrylic resin(AR)is coated on the substrate,the PDMS with low surface energy is enriched to the coating surface,contributing to active fouling releasing behaviors.Meanwhile,the acrylic components with relatively high surface energy,readily settle down to the substrate to enhance interfacial adhesion during the curing process of the coating.Due to the synchronous curing and self-stratification of the coating,PDMS and AR are not completely separated at the completion of curing,and a more complex network interpenetrating structure is formed between the interfaces,which is beneficial to the stability of the composite coating.The resultant coating shows a remarkably improved adhesion strength to the substrate(2.0 MPa),as compared to a pure PDMS coating(0.4 MPa).The anti-bacterial adhesion test shows that PDMS/AR coating has excellent anti-fouling performance.Moreover,the coating exhibits good physicochemical and mechanical properties.Overall,a mechanically enhanced AR/PDMS fouling-releasing coating is prepared by a simple and inexpensive preparation method,which shows wide application prospect in the design,preparation and practical application of marine antifouling coatings.This scheme not only simple and economical,but also gives the silicone coating excellent interface adhesion and mechanical stability,providing a new idea for the design of marine antifouling coating.