Understanding the wetting properties of nanostructured strontium titanate and its application for recyclable oil/water separation

Abstract

In the present work, we have investigated the oil and water wetting properties of strontium titanate nanoparticles. The as-synthesized nanoparticles were coated on the stainless steel mesh to investigate wetting properties. The coated mesh was found to have superhydrophilic and superoleophilic behavior with a contact angle value of nearly zero degree for both water as well as oil. Further underwater oil contact angle was measured, showing underwater superoleophobic behavior of the coated mesh. The underlying mechanism was studied for the wetting behavior of strontium titanate coated mesh. The coated mesh was then utilized for the gravity-driven separation of different oil/water mixtures. The separation mesh can be used multiple times showing its antifouling property along with recyclability. Further, a capillary pressure based model was developed to explain the wettability contrast for water and oil as well as separation of the two liquid phases on passing through the separation device. The approach here used for fabrication is applicable for large-area fabrication making it convenient and cost-effective towards oil/water separation at large scale.