Thin Films of Uniform Hematite Nanoparticles: Controls on Surface Hydrophobicity and Self-Assembly

Journal Article · Tue Jan 01 04:00:00 EST 2008 · Journal of Materials Chemistry

DOI:https://doi.org/10.1039/b810164g· OSTI ID:966101

Wang, Wei ^[1]; Liang, Liyuan ^[1]; Johs, Alexander ^[1]; Gu, Baohua ^[1]

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1. ORNL

In this study we show that uniform hematite ( -Fe2O3) nanoparticle thin films with controlled layer thickness can be formed by Langmuir-Blodgett (LB) monolayer deposition on surface areas of several square centimeters. The technique involves synthesis of uniform hematite nanoparticles by forced hydrolysis and surface modifications for increased hydrophobicity to bring the particles to the air-water interface. Methods of thermal treatment, stepped solvent exchange, and oleate surfactant coating were studied for their effectiveness in increasing hydrophobicity by removing surface adsorbed water and OH groups and were subsequently validated by Fourier-transform infrared (FTIR) spectral analysis. Surface pressure-area ( -A) and surface pressure-time ( -t) isotherms indicate that the stability of the particle monolayer at the air-water interface depends on the method of surface modification. Thermal evaporation treatment was found to produce thin films of hematite nanoparticles with the greatest uniformity and surface coverage as characterized by UV-visible spectroscopic, scanning electron microscopic (SEM) and atomic force microscopic (AFM) analyses.

• Research Organization: Oak Ridge National Laboratory (ORNL); Center for Nanophase Materials Sciences
• Sponsoring Organization: ORNL LDRD Director's R&D; SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 966101
• Journal Information: Journal of Materials Chemistry, Journal Name: Journal of Materials Chemistry Journal Issue: 47 Vol. 18; ISSN JMACEP; ISSN 0959-9428
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
77 NANOSCIENCE AND NANOTECHNOLOGY
COATINGS
DEPOSITION
HEMATITE
HYDROLYSIS
ISOTHERMS
NANOSTRUCTURES
SURFACE TREATMENTS
SYNTHESIS
THIN FILMS
WETTABILITY