Surfactant removal with multiwalled carbon nanotubes

Area of Science:

• Environmental Science
• Materials Science
• Chemistry

Background:

• Surfactants are widely used but pose environmental challenges.
• Mutiwalled carbon nanotubes (MWCNTs) show potential for water remediation.
• Understanding MWCNT-surfactant interactions is crucial for effective removal.

Purpose of the Study:

• To investigate MWCNT efficacy in removing different surfactant types (TX100, SDBS, CTAB).
• To compare the performance of various functionalized MWCNTs.
• To establish a relationship between MWCNT concentration, surfactant type, and removal efficiency.

Main Methods:

• Testing removal of TX100, SDBS, and CTAB using untreated and functionalized MWCNTs.
• Varying initial concentrations of surfactants and MWCNTs to determine the optimal ratio (Rc).
• Analyzing removal efficiency (E) based on surfactant and MWCNT characteristics.

Main Results:

• TX100 removal efficiency was highest (52.3%), followed by SDBS (26.2%) and CTAB (3.8%) at Rc=0.8.
• TX100's higher removal is attributed to its hydrophobicity and π-π interactions.
• Maximum removal efficiencies ranged from 55.88-87.17%, limited by MWCNT aggregation.

Conclusions:

• MWCNTs are effective for removing non-ionic surfactants, with efficiency varying by surfactant type.
• Functionalization and outer diameter of MWCNTs influence surfactant removal.
• MWCNT aggregation limits complete surfactant removal, highlighting the need for improved dispersion techniques.