Fly Ash Particles Modified with Various Surface Coupling Densities and Its Thermal Stability Mechanism of Oil-in-Water Emulsion

The fly ash particle was modified with various surface coupling densities and IR testified that γ-glycidoxy propyl trimethoxy silane (GPMS) is located on the surface of it Vis chemical bond. The surface GPMS-coupling density could influence the hydrophilic–lipophilic properties of the particles. The contact angles increase with the increase of additive amounts of modifiers. It indicates the surface of fly ash changed from water wetting to oil gradually. Using DLS, the dispersion state of fly ash with different GPMS-coupling densities was studied. A suitable modification of fly ash with GPMS did not change the dispersion state significantly. To achieve good dispersibility in HPAM solution, the surface GPMS-coupling density should be controlled within the range of 1.4–3 μmol (m2 FA)−1. Using fly ash particle–surfactant–polymer system, the O/W emulsion stabilized is investigated to stable Pickering emulsion. The particle in surfactant and polymer solution synergistically interacted at the oil/water interface. The emulsion system of GPMS (2.98)-FA particles in PAM and SDS solution shows higher thermal stability as compared to other particles as it was dispersed very well on the emulsion interface.