# Optimisation of Interfacial Modification by Two-Stage Microwave Irradiation

## TL;DR

This paper explores using two-stage microwave irradiation to improve oil/water separation by maintaining surfactant modification at the interface.

## Contribution

The novel approach of two-stage microwave irradiation with varying power levels is introduced to sustain interfacial modification.

## Key findings

- High-power followed by low-power microwave irradiation achieves quick and sustained interfacial modification.
- Moderate power in the second stage suppresses re-adsorption or re-structure processes after the first irradiation.
- This method opens new opportunities for optimizing microwave operations in oil/water systems.

## Abstract

Microwave-assisted de-emulsification is attractive in the processes of petroleum production and refining. The main advantage of microwaves is their direct influence on the surfactant layer at the oil/water interface. Previously, an effective interfacial modification was demonstrated by pulsed microwave irradiation. However, the effect of the modification diminished during the off interval of the pulse irradiation. In this study, two-stage microwave irradiation with different powers and durations was applied as a method to maintain an interfacial effect. The power of the second stage was changed to optimise the modification. Quick modification was obtained by high-power irradiation followed by low-power irradiation. It was confirmed a sustained modification was maintained by a moderate power of the second irradiation. This observation indicates a re-adsorption or re-structure process after the first irradiation is suppressed by the second irradiation. The results open new opportunities to optimise microwave operation in oil/water systems.