Surface modification of steel with carbon nanomaterials to minimize scale formation in sugar cane industry evaporators

Abstract

The novelty of the Thesis lies in the concept of process and method of surface modification or treatment of steel using carbon nanomaterials for significant reduction or prevention of the scaling deposition or fouling or choking of the heating surface of the heat exchangers. The different methods like oxyfuel heat treatment and chemical treatment of steel with graphene and carbon nanofibers have been adopted for steel surface modification to optimize contact angle of steel with cane juice indicating that the smooth surface of steel which reduces the scaling or fouling or choking during heat exchange of industrial evaporators. Contact angle measurement is the simplest routine measurement to give information about the success of the modified surface of the steel substrate with nanomaterials. Diffusion or coating of nanomaterials like graphene, carbon nano powder, carbon nanofiber, carbon nanotube into steel surface greatly enhances the properties of steels, by modifying the surface structure layer. A sessile drop technique was used for measuring the contact angles of steel with cane juice solution, and a linear relation between solution surface tension and contact angle is observed in the modified steel surface. The study of three types of normal steel surface (Mild Steel, SS304L and SS316L) show hydrophilic performance (and#952;and#8239;ltand#8239;90°), whereas the modified steel surface with nanomaterials shows hydrophobic performance (and#952;and#8239;gt90°). It provides technological advances in the use of nanomaterials to produce high performance steels with outstanding mechanical properties or corrosion resistance to prevent scaling of heat exchangers. The use of nanomaterials on the surface of steel reduces the surface roughness of steel which in turn diminishes the pin holes and hence limits fatigue cracking.