Polydopamine Functionalized Graphene Oxide as Membrane Nanofiller: Spectral and Structural Studies

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Graphene oxide (GO) nanoparticles are explored for various applications.
• Functionalization of GO can enhance its properties for specific uses.
• Polydopamine (PDA) is a versatile biomimetic coating material.

Purpose of the Study:

• To synthesize and characterize polydopamine functionalized graphene oxide nanoparticles (GO-PDA NPs).
• To investigate the potential of GO-PDA NPs as nanofillers in membrane separation.
• To analyze the spectral and structural properties of the synthesized GO-PDA NPs.

Main Methods:

• Graphene oxide (GO) nanoparticles prepared using a modified Hummers method.
• GO functionalization with polydopamine (PDA) at a 1:2 ratio.
• Characterization using XRD, FTIR-UATR, Raman spectroscopy, SEM, TEM, XPS, and CHNSO elemental analysis.
• Preparation of GO and GO-PDA coated membranes via pressure-assisted self-assembly (PAS).
• Contact angle measurements for hydrophilicity assessment.

Main Results:

• FTIR spectra confirmed high functionalization degree due to emerging amine group bands.
• Raman spectra and XRD patterns indicated altered crystalline structures, defects, and increased interlayer spacing in GO-PDA.
• XPS and elemental analysis verified changes in elemental composition with the presence of nitrogen from PDA.
• GO-PDA NPs demonstrated improved dispersibility in both polar and nonpolar solvents.
• GO-PDA coated membranes exhibited excellent hydrophilic properties with a contact angle of 27.8°.

Conclusions:

• Successful high-degree functionalization of GO nanoparticles with PDA was achieved.
• GO-PDA NPs possess enhanced structural, elemental, and dispersion properties compared to GO.
• The improved hydrophilicity of GO-PDA suggests significant potential as nanofillers in membrane separation technologies.