Wetting effect of branched anionic Gemini surfactant aqueous solution on PMMA surface

Area of Science:

• Surface Chemistry
• Materials Science
• Polymer Science

Background:

• Surfactant adsorption and surface modification are crucial in materials science.
• Polymethyl methacrylate (PMMA) is a widely used polymer requiring surface property tuning.
• Understanding surfactant behavior in solution and at interfaces informs material applications.

Purpose of the Study:

• To investigate the adsorption behavior of GeminiC3, GeminiC6, and monomeric surfactants on PMMA surfaces.
• To evaluate the wetting modification ability of these surfactants on PMMA.
• To correlate surfactant molecular structure and spacer length with adsorption and surface properties.

Main Methods:

• Surface tension measurements to analyze adsorption at the gas-liquid interface.
• Contact angle measurements to assess surface wettability.
• Adhesion tension and interfacial tension analysis to determine adsorption structures (monolayer/bilayer).

Main Results:

• GeminiC3 and GeminiC6 surfactants formed saturated monolayers at low concentrations and bilayer structures at high concentrations on PMMA.
• Monomeric surfactants exhibited heavy adsorption, forming semi-colloidal aggregates with a contact angle of 38°.
• Both monomeric and Gemini surfactants demonstrated superior hydrophilic modification of the PMMA surface compared to literature.

Conclusions:

• Spacer length in Gemini surfactants influences self-aggregation and vesicle formation.
• Surfactant concentration dictates the formation of monolayer or bilayer structures on PMMA.
• Monomeric and Gemini surfactants offer highly effective hydrophilic modification for PMMA surfaces.