Construction And Performance Of Antifouling Coatings With Multienzyme System

Biofouling is the attachment and growth of various microscopic and macroscopicorganisms and extracellular polymeric substance, which is widely adsorbed on the surfacesof equipments immersed in the water. Biofouling has negative effects on submergedstructures, such as ships, pipelines, cables and oil platforms. For instance, higher fuelconsumption, declined heat exchanger performance and materials corrosion can be causedby the increased attachment of biofouling. Thus, in order to control the problem ofbiofouling, it is essential to use antifouling coatings.Traditional antifouling technologies through application of antifouling paints relied onthe release of toxins to kill the attaching organisms. In many cases metals or organometalliccompounds are essential parts of biofouling inhibiting agents. However, the toxins areprone to bioaccumulation and will ultimately be harmful to the environment. Therefore, it isrequired to develop environmental-friendly alternatives to metal-based antifouling agents.Enzyme-based antifoulings are expected to be environmentally friendly. Enzymaticantifoulings are those antifouling coatings in which enzymes are an essential part of thebiofouling inhibiting properties. In this paper, the bienzyme system can produce H2O2fromstarch based on the action of both α-Amylase, which promotes the hydrolysis of thepolymeric chain, and glucose oxidase (GOD), which oxidizes the glucose to produce H2O2,which can deter fouling organisms by the toxicity of H2O2. The details of this paper weresummarized as follows:Firstly, from the property research of α-Amylase and glucose oxidase (bienzymesystem) achieved the optimal proportion of bienzyme and the effect of the reactioncondition on the releasing rate of H2O2.Secondly, we encapsulated bienzyme in silica by a biomimetic silicification process.The experiment results showed that: thermal stability, pH stability, Recycling stability andstorage stability of A-G@BS was higher than free enzyme in the same conditions.A-G@BS showed a higher tolerance from the attack of xylene and methylisobutylketonecompared with free enzyme.Thirdly, we obtained the CLEAs of bienzyme, The results showed that: thermalstability, pH stability, Recycling stability and storage stability of GOD-α-Amylase-CLEAswas higher than free enzyme in the same conditions. GOD-α-Amylase-CLEAs showed ahigher tolerance from the attack of xylene and methylisobutylketone compared with freeenzyme.Fourthly, construction of the antifouling coating with immobilized enzyme. Releasingrate of H2O2from antifouling coating showed that: the antifouling coating can thus be expected to have a lifespan of90days; the GOD-α-Amylase-CLEAs in the coating can thusbe expected to have a lifespan about days; The plates were immersed in the river for10,20,40and80days, The results demonstrate that the method developed in this study is apromising coating technology for entrapping active enzymes, presenting an interestingavenue for enzyme-based antifouling solutions.