Stability of emulsion liquid membrane using blended nonionic surfactant and multi-walled carbon nanotubes (MWCNTs) for methylparaben removal

Abstract

The emulsion instability is a significant drawback of the emulsion liquid membrane (ELM) technique for large-scale industrial separations. The synergistic effect of blended surfactant (Span 80 and Span 20) and multi-walled carbon nanotubes (MWCNTs) on ELM stability for methylparaben removal were studied. Emulsion (Span 80 + Span 20 + MWCNTs; HLB 5.7) possesses the highest ESI values at all time intervals. The %swelling of emulsion is reduced by 42% by using blended surfactants (Span 80 and Span 20) and nanoparticles (MWCNTs). The overall mass transfer coefficient is increased by 4.746% by adding MWCNTs to the ELM system. The energy (E) needed to detach a particle from the interface is estimated as 0.7286 × 10⁻¹³ J (1.7727 × 10⁷ kT). This indicates effective irreversible adsorption of particles at the interfaces and influences the particles capability to stabilize the emulsion.

Graphical abstract

Keywords:

• Emulsion liquid membrane (ELM)
• emulsion stability index
• emulsion swelling
• methylparaben removal

Disclosure statement

The authors declare that they have no conflict of interest.

Additional information

Funding

The authors thank the Ministry of Human Resource Development, Government of India, for their support.