Foam stabilisation using surfactant exfoliated graphene

Area of Science:

• Materials Science
• Colloid and Surface Science

Background:

• Foam stabilization is crucial in various industrial applications.
• Graphene's unique properties offer potential for advanced material stabilization.
• Controlling foam structure and longevity requires understanding particle-interface interactions.

Purpose of the Study:

• To investigate the efficacy of graphene particles in stabilizing liquid-air foams.
• To explore the relationship between graphene concentration and foam stability.
• To examine the influence of alkali metal chlorides on graphene-stabilized foam properties.

Main Methods:

• Liquid phase exfoliation of graphite using Pluronic® F108 surfactant.
• Characterization of graphene particle aspect ratio using Transmission Electron Microscopy (TEM).
• Surface tension measurements to assess particle surface activity.
• Foam stability analysis, including bubble size distribution and half-life measurements.
• Investigation of foam stability with varying alkali metal chloride concentrations.

Main Results:

• Graphene particles, prepared via surfactant exfoliation, effectively stabilized liquid-air foams at low loadings.
• High-aspect ratio graphene particles exhibited surface activity, adsorbing at the air-water interface.
• Foam stability showed a non-linear dependence on graphene concentration, linked to adsorption rates.
• Alkali metal chlorides altered particle wettability, enhancing foam stability in the order Na(+) > Li(+) > K(+) > Cs(+).

Conclusions:

• Surfactant-exfoliated graphene particles are efficient stabilizers for liquid-air foams.
• The high aspect ratio and surface activity of graphene contribute to improved foam stability.
• Ionic interactions with the surfactant-adsorbed graphene surface influence foam enhancement.