Promotion and inhibition of gas hydrate formation by oxide powders

Synergistic effect of combination of surfactant and oxide powder on enhancement of gas hydrates nucleation

“…A detailed description of the experimental set-up and the procedure of hydrate formation was presented elsewhere [35] . Experiments were carried out in a cylindrical reactor 50 cm 3 in volume, made of stainless steel.…”

“…The authors of Ref. [35] studied the effect of a number of water suspensions of oxide nanopowders on the induction period of hydrate formation. It was demonstrated that the ability of oxide nanoparticles to act as the inducers of hydrate formation is determined not by the material of the particle but by the state and properties of its surface.…”

“…Analysis of the works considered above shows that at present there is a lack of data on the induction periods of hydrate formation obtained with the same equipment separately for: ( 1 ) water; ( 2 ) water with the nanopowder added; ( 3 ) water with surfactant; and (4) water with the nanopowder and surfactant added together. Indeed, the works cited above are focused either on the effect of solid particles (metals, metal oxides etc., [34][35][36][37][38][39][40]42] ) on hydrate formation or on the effect of surfactants [38][39][40]43] . In some works, experimental data on the induction period of hydrate formation for pure water, for a solution of surfactant and for the combinations of surfactants with solid particles are presented [44][45][46] , but the information on the effect of solid particles on the nucleation is absent from these works.…”

Analysis and Alternate Selection of Nanopowder Modifiers to Improve a Special Protective Coating System

“…X-ray emission spectroscopy was employed to measure the energy SiK and \P spectra of the nanoparticles and thus to compare the forces of chemical bonds in the modified liquid compositions [26][27][28]. The potentials were measured in reverse AOT micelles (aqueous dispersions) for silica nanoparticles [29,30]. To avoid the particle agglomeration, each nanopowder sample was exposed with ultrasound for 30 min, after that it was dispersed.…”

“…This difference is confirmed with measurement of -potential values. The potentials were measured in reverse AOT micelles (aqueous dispersions) as −73 mV for PSNP and −27 mV for CSNP [29,30]. In the PSNP, the surface quadrivalent ions increase the electrostatic attraction couplings, which cause greater compression of the diffusion layer and reducepotential.…”