Separate under the prerequisite of fully dispersing or reuniting at the Nanodiamond as mentioned earlier, adopt film pipe separate mode by the classification of cross-flow separation equipment; after the type, the average particulate diameter is a controllable adjustment between 7～200 nanometers. Film pipe cross-flow hierarchy system is adopted in the category of Nanodiamond, block fenestra for preventing thick nanodiamond particles; there is the pulse recoiling device in this system, which can be in the classification process towards the opposite direction of permeate flow, the fluid pressure pulse of implementation cycle property outside in recoil, thus guarantee the high efficiency of the not blocked and classification of fenestra. During the native system classification, an applied pressure is about 2.5~3.0 bar, and the liquid flowing speed is adjustable between 4.0～8.0m/s.During category, the concentration of Nanodiamonds should be controlled between 0.01～10%wt. Nano diamond and sodium stearyl sulfate are prepared into suspension, the weight concentration of Nano diamond is 1%, the percentage by weight of sodium stearyl sulfate is 0.05%, the weight ratio of sodium stearyl sulfate and Nano diamond 0.05: 1, by booster it is pressurizeed, when pressure reaches 200Mpa, spray to the diamond target plate at a high speed by injector, the Nano diamond aggregate smashed and in time stable, then, centrifugation, remove the coarse granule that particle diameter surpasses 500nm, it is sneaked into citric acid, and to regulate the pH value be in 3.5 the deionized water, add surfactant oleic acid and stable dispersant polyvinyl alcohol, the addition of oleic acid is 0.1%wt, the addition of polyvinyl alcohol is 0.05%wt, oleic acid: Nano diamond is 0.1: 1, polyvinyl alcohol: Nano diamond is 0.05: 1, regulating the pH value with NaOH is 10, and ultrasonic dispersion 15 minutes makes the diamond suspension that particle mean size is 98.7nm (seeing accompanying drawing 3), after the cross-flow classification, can get narrower particle size distribution, particle mean size is in the diamond suspension (seeing attending drawing 4) of 82.1nm. If you are looking for high quality, high purity and cost-effective Diamond Nanoparticles, or if you require the latest price of Diamond Nanoparticles, please feel free to email contact mis-asia.