42results about How to "Good surface modification" patented technology

The invention provides a superfine powder cooling method. The method comprises the following steps of: atomizing a liquid phase protecting medium into particles with the diameter of 10 to 5,000 microns, spraying the particles into a cooler between a gas phase particle generator and a collector, coating the liquid phase protecting medium on the surface of superfine powder, cooling the superfine powder, and depositing the cooled superfine powder in the collector, wherein the tap volume ratio of the liquid phase protecting medium to the superfine powder is more than 50. The liquid phase protecting medium is water or an aqueous solution or organic liquid or an organic solution. By the superfine powder cooling method, material consumption and energy consumption are low, and the cooled superfine powder is strong in stability and good in dispersity.

The invention discloses a method to produce nanometer graphite sol. It supplies a system which includes highly pure graphite as anode, inert materials as cathode and electrolytical aqueous solution. There is an impulsing power source to connect the anode and cathode. The pulse period of the power source is 0.05-0.5 second, effective voltage 2-10V (3-5V is prelatered) and effective amphere density 15-75A (25-35 is prelatered). The efficiency of this invention is higher than common direct-current electrode method. The produced nanometer graphite sol is stable and disperses so it can produce nanometer graphite powder whose diameter is under 15nm.

The invention discloses a surface modification method for nano calcium carbonate, which is characterized by comprising the following steps of: adding inorganic alkali into nano calcium carbonate slurry, uniformly stirring, heating the slurry, adding fatty acid and performing surface modification. The method comprises the following specific steps of: adding a certain amount of nano calcium carbonate slurry into a reaction kettle, adding 0.00004 to 0.00040mol of inorganic alkali into 1g of CaCO3, and uniformly stirring; heating to the temperature of between 75.0 and 90.0 DEG C, adding 0.00005 to 0.00035mol of fatty acid or fatty acid salt into 1g of nano calcium carbonate (CaCO3) slurry, reacting, and continuously stirring for 30 to 120 minutes; and after surface modification reaction is finished, cooling, filtering, washing, drying and grinding the slurry to obtain the nano calcium carbonate subjected to surface modification. The method is simple and practicable, a modifier can form a uniform and complete coating layer on the surface of the nano calcium carbonate, and the modified product has a good application effect in polymer such as silicone sealant, polyvinyl chloride (PVC) paste resin and the like.

The method for preparing nano-graphite sol by passing a pulsed DC bias current through double graphite electrodes disclosed by the present invention is to put two graphite plates side by side in parallel into an electrolytic cell equipped with an aqueous electrolyte solution, and connect the positive and negative pulsed DC bias power supplies respectively. Negative electrode, at room temperature, apply a pulsed DC bias current with a square wave waveform, a pulse frequency of 20-50Hz, a pulse amplitude of 8-12V, a bias voltage of 2-5V, and a bias current density of 0.5-3mA / cm2 , to obtain a graphite sol with a graphite particle size of 10-30 nm. The nano-graphite sol obtained by the invention has good dispersibility and stability, saves energy, has low production cost, and is suitable for large-scale industrial production. The prepared nano-graphite sol has a wide range of applications.

The invention discloses a method for preparing nickel-cobalt-manganese carbonate. The method is simple and convenient in process and low in preparation cost. Nano-scale nickel-cobalt-manganese carbonate with excellent surface modification effect. The invention also discloses a method for surface modification of high-nickel ternary nickel-cobalt manganese oxide lithium, specifically the nickel-cobalt-manganese carbonate prepared by the invention is used to modify the surface of high-nickel ternary nickel-cobalt lithium manganese oxide, the method It effectively improves the stability of the surface structure of the high-nickel ternary nickel-cobalt lithium manganese oxide, reduces the residual lithium on the surface, and improves the electrochemical performance and safety factor of the high-nickel ternary nickel-cobalt lithium manganese oxide. Using the modified high-nickel ternary nickel-cobalt lithium manganese oxide as the positive electrode material of the ternary lithium-ion battery can solve the problem of flatulence of the battery, greatly improve the safety performance of the battery, and provide help for its application in the field of power batteries .

The invention discloses a surface treatment method of nano-calcium carbonate used for polyvinyl chloride plastisol. The surface treatment method comprises the following steps: adding nano-calcium carbonate serous fluid into a reaction kettle, wherein the specific surface area (BET) of nano-calcium carbonate in the serous fluid is 18.0-60.0m<2> / g and the pH of the nano-calcium carbonate serous fluid is 8.5-9.5; heating to 70-95 DEG C, stirring, adding a mixed modifier accounting for 1.8-6.0% of the mass of the nano-calcium carbonate in the serous fluid, continuing stirring for 30-180 minutes, thus completing surface treatment. The mixed modifier is a mixture of stearic acid alkali metal saponified matter and calcium stearate, the mass ratio of fatty acid to calcium stearate in the complex modifier is 20-70%, and the proportion of the using quantity of the fatty acid to a saponifier is 1: 1. According to the method, the fatty acid is saponified by a strong base, so that the shortcoming that the fatty acid is difficult to react with the surface of calcium carbonate in water to generate the calcium stearate during wet process surface modification of the nano-calcium carbonate can be overcome; and the calcium stearate is directly introduced through fatty acid saponification liquor, so that a significant surface modification effect is obtained. The method has the advantages that raw materials are low in price and easy to obtain, the processes are simple and feasible, and the quality of a product is state. The method has significant economic benefits and social benefits.

The invention discloses a composite material belonging to the field of surface engineering, and in particular relates to a TiC-Cr7C3-CNTs / iron based surface composite material and a preparation method thereof. The preparation method comprises the following steps: pretreating an Fe-Cr-Ni stainless steel material, then reacting for 18-22 hours in a 680-700 DEG C supersaturated carbon atmosphere containing 68% of CO, 31% of H2 and 1% of H2O to obtain uniformly distributed CNTs on the surface of the stainless steel, and weighing the stainless steel before and after the reaction to obtain a difference value namely the weight of increased carbon; and according to the weight of the increased carbon, weighing Ti powder and Ni powder, mixing the Ti powder and Ni powder, and preparing the TiC-Cr7C3-CNTs / iron based surface composite material by adopting a laser cladding synchronous powder feeding technology. The composite material prepared by the method disclosed by the invention has strong cohesive force with the surface of a metal matrix, is difficult to fall off, and is high in hardness and excellent in acid corrosion resistance. The composite material disclosed by the invention has an extremely significant effect on modifying the surface of a steel and iron material, and expands the application field of steel and iron.