4results about How to "Increase nucleation sites" patented technology

The application provides a heat-conducting material suitable for local micro heat sources of integrated chips and a preparation method thereof, and the preparation method comprises the following steps: S1, obtaining a topological structure of a heat-conducting filler framework according to the parameters of the local micro heat source; S2, designing an ice template mold, comprising a heat-conducting metal block with a cavity protrusion on the upper surface and a heat insulation plate, the heat insulation plate is covered on the upper surface of the heat-conducting metal block and exposes the cavity protrusion as a cold source; S3, controlling the temperature to form uniform crystal nuclei on the cavity protrusion, adding a heat-conducting filler dispersion liquid, controlling the temperature of the cavity protrusion to be close to the freezing point, directional freezing, forming an ice template-heat-conducting filler composite, freeze-drying, and obtaining the heat-conducting filler framework; and S4, treating the heat-conducting filler framework and a polymer matrix prepolymer by a vacuum impregnation method to obtain the heat-conducting material. The heat-conducting material and method solve the problems of poor heat-conducting strengthening effect, and mismatching between the structure and the heat source of the existing material, and realize efficient reduction of the temperature of the micro heat source.

The invention belongs to the technical field of cementing materials, and particularly relates to an organic-inorganic composite alkali-activated cementing material and a preparation method thereof. The modified wollastonite added into the organic-inorganic composite alkali-activated cementing material has a large amount of silicon hydroxyl (Si-OH), and the groups are high in activity, so that the compatibility and binding force of the wollastonite and the styrene butadiene rubber emulsion can be greatly improved. The modified wollastonite provides CaO and SiO2 at the same time, a hybridization system composed of N-A-S-H gel, C-A-S-H gel and unreacted wollastonite needle-shaped particles is formed, the hybridization system can force cracks to deflect, bypass and branch in the expansion process, more fracture energy is consumed, and therefore the fracture toughness and toughness of the material are improved.

The invention relates to a preparation method of high-porosity ceramic with controllable pore diameter and structure. The preparation method comprises the following steps: taking the following raw materials in percentage by mass: 85-95% of alpha-powder, 0.5-5% of carbon black, 3-6% of camphor, 0.5-2% of powder and 1-3% of MgO powder; mixing and pretreatment: spheroidizing the raw materials by taking absolute ethyl alcohol as a medium to obtain slurry, and drying and sieving the slurry to obtain composite ceramic powder; molding: performing dry pressing molding on the composite ceramic powder to obtain a green body; and rubber discharging and sintering are conducted, specifically, the green body is placed in a high-temperature sintering furnace, heat treatment is conducted under the air atmosphere, and the heat treatment is divided into four steps including the stepped rubber discharging stage, the pre-sintering stage, the final sintering stage and the cooling stage.

The application provides a method for preparing a defect-free MOF membrane by a MOF gradient distribution seeding method. According to the fact that the density of ZIF-8 seeds is greater than the density of a polymer solution, a gradient distribution of the ZIF-8 seeds in a phase inversion membrane is obtained, and abundant nucleation sites are provided for subsequent ZIF-8 layer growth. The distribution of the ZIF-8 seeds in the membrane holes increases the rigidity of the phase inversion base membrane, and simultaneously increases the adhesion of the surface of the base membrane and the ZIF-8 layer. The addition of tannic acid in the ZIF-8 precursor solution assists the growth of the ZIF-8 layer, the tannic acid has abundant hydroxyl groups, provides CO2 groups, and improves the selectivity of the membrane for separating H2 / CO2. The ZIF-8 seeds in the compact defect-free ZIF-8 membrane rich in hydroxyl groups have a gradient distribution, which improves the mechanical properties of the base membrane and the adhesion of the ZIF-8 layer, and the ZIF-8 membrane prepared by directly seeding ZIF-8 seeds on the base membrane shows obvious superiority.