Influence of surface modification adopting thermal treatments on dispersion of detonation nanodiamond

• Published in: Journal of solid state chemistry 2005-03, Vol.178 (3), p.688-693
• Main Authors: Xu, Xiangyang, Yu, Zhiming, Zhu, Yongwei, Wang, Baichun
• Format: Article
• Language: English
• Subjects: AGGLOMERATION; Cross-disciplinary physics: materials science; rheology; DIAMONDS; DIFFERENTIAL THERMAL ANALYSIS; Dispersion; DISPERSIONS; DISTRIBUTION; Exact sciences and technology; FOURIER TRANSFORMATION; GRAPHITIZATION; HEAT TREATMENTS; INFRARED SPECTRA; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; Materials science; Nanocrystalline materials; Nanodiamond; Nanoscale materials and structures: fabrication and characterization; NANOSTRUCTURES; Other heat and thermomechanical treatments; Physics; Powders; SMALL ANGLE SCATTERING; Surface modification; SURFACE POTENTIAL; SURFACES; TEMPERATURE RANGE 0400-1000 K; Thermal treatment; TRANSMISSION ELECTRON MICROSCOPY; Treatment of materials and its effects on microstructure and properties; X-RAY DIFFRACTION; X-RAY PHOTOELECTRON SPECTROSCOPY
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2004.12.025

In order to improve the dispersion of detonation nanodiamonds (ND) in aqueous and non-aqueous media, a series of thermal treatments have been conducted in air ambient to modify ND surface. Small angle X-ray scattering (SAXS) technique and high resolution transmission electron microscopy (HRTEM) were introduced to observe the primary size of ND. Differential thermal analysis (DTA), X-ray diffraction (XRD) methodology, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy were adopted to analyze the structure, bonds at surfaces of the treated ND. Malvern instrument Zetasizer3000HS was used for measuring the surface electric potential and the size distribution of ND. As thermal treatments can cause graphitization and oxidization of functional groups at the surface, ND treated at high temperature is correspondingly more negatively charged in an aqueous medium, and the increased absolute value of zeta potential ensures the electrostatic stability of ND particles. Specially, after being treated at a temperature more than 850 K, ND can be well dispersed in various media. Detonation synthesized diamond has a primary particle size of around 10 nm, but serious agglomeration both in air and liquid media hinders its application as a nanoscaled material. As thermal treatments can cause graphitization and oxidization of functional groups at nanodiamond surface, the nanodiamond treated at high temperature is correspondingly more negatively charged in an aqueous medium, and the increased absolute value of zeta potential ensures the electrostatic stability of particles. Well-dispersed nanodiamond suspension can be prepared in aqueous medium. When a polymer dispersant was introduced, excellent dispersion in a non-aqueous medium, white oil, can also be realized.