Possessing characteristics of nanometer size, superhardness, excellentchemical stability, thermal conductivity and biocompatibility, nanodiamond is apromising and valuable powder material. Using negative-oxygen-balanced explosives a s carbon sources, detonationnanodiamond (DND) can be prepared instantaneously in an anoxic environmentunder high temperature and high pressure. Grain size of DND is around 2-6 nm,and the particles are uniform in morphology and size distribution, while theprimary size is less than 60 nm. But, as the dispersion of nanopowder with highsurface energy is a common puzzle because of particle surface effect, DNDparticles tend to form aggregates and hence their characteristics as a nanoparticlecannot be employed. That is one of the main reason that, although the synthesisof DND has been industrialized in early 1990"s, the application progress is yetcurrently still dropped far behind. This is why it is of great importance toactualize the deagglomeration, dispersion and stable suspension of DNDparticles in a variety of solvents. Measures such as the surface oxidation and the mechanochemicalmodification were introduced to modify the components of surface elements andfunctional groups on DND, and to realize the homogeneous and stable dispersionof particles. To evaluate the deagglomeration effect, photon correlation spectrum(PCS) method was used to measure the size distribution of DND particles in theas-prepared suspensions, and Atomic Force Microscopy (AFM), ScanningElectron Microscope (SEM) and Transmission Electron Microscopy (TEM) wereintroduced t o measure and compare the morphology and size of the p articles.Fourier Transform Infrared Spectroscopy (FTIR), Raman Spectroscopy andX-ray Photoelectron Spectroscopy (XPS) were introduced to analyze the surfaceelements and their chemical environments, and to investigate the solutionchemistry, the adsorption mechanism of surface-active reagents on DND surfaceand the influence of surface modification on particle interactions. After surface oxidation of DND using oxidative acids and salts in aqueousmedia, or adopting thermal treatment in ambient atmosphere, the acidicfunctional groups on DND can be increased, then, the increased polarity andascended absolute value of surface potential can be observed, and the staticrepulsion was strengthened. Deagglomeration can be realized using thermaltreatment, as suspensions with more fine particles can be prepared using the heated powder. X-ray diffraction (XRD) and FTIR show that, the amorphouscarbon and graphite on black powder can be oxidized and removed during thethermal treatment aider the layer-by-layer oxidation of DND particles, while, forgray powder, the main surface phenomenon is the formation of oxygenousgroups such as carboxyl. While ultrasonic and ball milling were utilized to comminute the aggregatesin aqueous media, surfactants such as STA-10 and CR-0704 were added tomodify DND surface. This identical mechanochemical process was used to treata pre-oxidized powder adopting thermal modification. The absolute value ofparticle surface potential can be heightened, and the interparticle static repulsionforce was then increased, therefore the dispersion and suspension behavior canbe improved. According PCS and AFM measurements, DND particles in thesuspensions are less than 100 nm with average sizes of 40-50 nm. Using ballmilling or liquid-phase reactions, DND particles can be coated with a shell ofnano-oxide layer. Polymer dispersants were used to form a coating on DND surface duringmechanochemical modification in apolar solvents, the steric repulsion betweenparticles were intensified, and therewith the particles can be well dispersed.Average size of DND particles in suspensions of n-octane, petroleum ether andtoluene are around 20-50 nm. According XRD and thermal analysis (DTA/TG),noncrystalline coating was found to form on DND surface. Abundant oxygenousgroups on pre-heated samples may benefit the adsorption of dispersants andconsequently, improve the dispersion of DND in apolar solvents. The synergismeffect, which may attribute to the electronic interaction of dispersants, may alsobenefit the surface modification and particle dispersion. In short, deagglomeration technologies of commercial value wereintroduced in this dissertation, and well-dispersed suspensions of aqueous andapolar solvents can be prepared, which can accelerate the application researchesand promote the development of DND industry. The mechanism investigationson surface modification can provide reference, technically and academically, forthe dispersion practices of nanopowders such as DND.