Interfacial activity of phosphonated-PEG functionalized cerium oxide nanoparticles

Area of Science:

• Materials Science
• Surface Chemistry
• Nanotechnology

Background:

• Phosphonic acid terminated polyethylene glycol (PEG) oligomers can functionalize cerium oxide nanoparticles.
• These functionalized nanoparticles form stable, redispersible suspensions in various solvents.

Purpose of the Study:

• To investigate the interfacial activity of functionalized ceria nanoparticles.
• To demonstrate their potential for modifying hydrophobic surfaces and controlling self-assembly.

Main Methods:

• Investigated phosphonated-PEG oligomers as surface-active species.
• Studied the adsorption behavior of functionalized nanoparticles at different interfaces (air/water, polystyrene/water, oil/water).
• Utilized Langmuir trough and Grazing-Incidence Small-Angle X-ray Scattering (GISAXS) for monolayer characterization.

Main Results:

• Functionalized ceria nanoparticles exhibit significant interfacial activity.
• Addition of PEG oligomers with aliphatic chains (stickers) tunes nanoparticle adsorption and interparticle interactions.
• Dense, ordered 2D nanoceria monolayers with hexagonal organization were formed.
• Stable mono- or multilayers were formed and transferred onto solid surfaces.

Conclusions:

• Functionalized ceria nanoparticles possess tunable interfacial properties for surface modification.
• These nanoparticles are effective in creating ordered supracolloidal assemblies and stabilizing emulsions.
• The findings are significant for polymer surface modification, Pickering emulsions, and supracolloidal assembly applications.