Study On Fouling Inhibition And Corrosion Resistance Of Ni-P-TiO₂-PTFE Modified Surface To Iron Bacteria

Microbial fouling is a widespread problem in heat exchange equipment.Because it can increase the flow resistance of working medium on the surface of heat exchange equipment,reduce the efficiency of heat transfer and heat transfer of heat exchange equipment,and cause serious energy and economic losses,it has always been a research hotspot of researchers.In order to realize energy saving and consumption reduction and low carbon circular economy,surface modification technology with unique advantages in chemical industry,medicine,aerospace and other fields emerged at the right moment,which provided a new idea to suppress microbial fouling aggregation and adhesion on the surface of heat exchange equipment and reduce the corrosion of heat exchange equipment.In this paper,Q235 carbon steel,which is common in heat exchange equipment,was selected as the base material,and Ni-P-TiO₂-PTFE composite coating was obtained by surface modification of carbon steel using electroless plating technology.The microstructure,structure and element content of Ni-P-TiO₂-PTFE composite coating were analyzed.The stability of the composite coating was verified by ultrasonic oscillation cleaning experiments.The results showed that the Ni-P-TiO₂-PTFE composite coating has good adhesion to the substrate and can be used in the actual production and operation of heat exchange equipment.First,the fouling inhibition and corrosion resistance of Ni-P-TiO₂-PTFE composite coating in iron bacteria environment were studied.The results showed that compared with the carbon steel sample,the fouling deposition amount of Ni-P-TiO₂-PTFE composite coating decreases by89.78-94.38%,and the corrosion loss weight decreases by 86.29-93.67%,indicating that the Ni-P-TiO₂-PTFE composite coating shows superior ability to inhibit fouling adhesion and corrosion resistance.The influence of surface energy of Ni-P-TiO₂-PTFE composite coating on fouling adhesion was further analyzed.The results showed that in different particle content of the Ni-P-TiO₂-PTFE composite coating has a best surface energy(17.82 m J/m~2)to achieve the minimum amount of fouling deposited on the surface of the sample and in the total surface energy and the components that component,CQ value but highly related with fouling adhesion ability,it can be as inhibition of iron bacteria theory parameters for further analysis.The corrosion behavior and corrosion resistance of Ni-P-TiO₂-PTFE composite coating in iron bacterial suspension were studied.The results showed that the corrosion resistance of carbon steel samples to iron bacteria decreases gradually with the extension of immersion time,while the corrosion resistance of Ni-P coating decreases gradually at first and then increases,and the Ni-P-TiO₂-PTFE composite coating increases at first,then decreases and finally increases.The effect of the concentration of nano-TiO₂ and PTFE particles on the fouling inhibition and corrosion resistance of Ni-P-TiO₂-PTFE composite coating was studied.The results showed that the fouling inhibition and corrosion resistance of Ni-P-TiO₂-PTFE composite coating increased firstly and then decreased with the increase of nano-TiO₂ particle concentration.With the increase of PTFE particle concentration,the fouling inhibition and corrosion resistance of Ni-P-TiO₂-PTFE composite coating gradually increased.Finally,the effect of the concentration of iron bacteria on the fouling inhibition and corrosion resistance of Ni-P-TiO₂-PTFE composite coating was studied.The results showed that with the increase of the concentration of iron bacteria suspension,the fouling inhibition and corrosion resistance of carbon steel and Ni-P-TiO₂-PTFE composite coating on iron bacteria gradually weaken,and the Ni-P coating show a change law of first weakening and then strengthening.