Novel Dry-Powder Pickering Emulsion Approach for Efficient Hydrogen Peroxide Encapsulation and Polymer Schmoo Degradation

A simple single-step method to microencapsulate an aqueous hydrogen peroxide (H2O2) solution and form a water-in-air emulsion is presented based on the Pickering emulsion technology to address handling, transport, and controlled release of hydrogen peroxide in oil fields. The encapsulation was performed by mixing a 5-weight percent H2O2 solution with hydrophobic silica nanoparticles in a highspeed blender. Droplet morphology was examined using optical microscopy. The efficacy of retarding corrosion by microencapsulating H2O2 was performed on mild steel sample blocks by following the specific ASTM standard. The release of encapsulated H2O2 droplets was visibly observed by mixing a small amount of coloring dye. It was quantified by conductivity measurements owing to the presence of salt in the aqueous solution of H2O2 prior to encapsulation. Finally, field polymer deposit samples were subjected to degradation tests by immersing them in the H2O2 solution. The silica nanoparticles synthesized via the sol-gel method exhibited an average primary particle diameter of approximately 38.59 nm. Microscopic analysis indicated that the Pickering emulsion droplet sizes were in the order of a few microns. An addition of a small amount of hydrophilic surfactant effectively changed the wetting nature of the hydrophobic silica nanoparticles, consequently breaking the emulsion as reflected by the conductivity measurement results. Corrosion inhibition results suggest significant corrosion mitigation. Additionally, field-deposited polymers successfully degraded upon treatment with H2O2, validating its practical utility.