3results about How to "Large average pore size" patented technology

This application relates to a silicon-modified macroporous pseudoboehmite and its preparation method, belonging to the technical field of pseudoboehmite preparation. The method includes: mixing an aluminum salt solution and a sodium aluminate solution in parallel flow and performing a low-temperature neutralization reaction; adding a low-concentration water glass 5-8 minutes after the start of the reaction, ensuring the water glass addition ends before the neutralization reaction ends, to obtain an amorphous precursor; separating the amorphous precursor into a liquid and solid state to obtain a filter cake; mixing the filter cake with deionized hydrated slurry to obtain a slurry; adding sodium carbonate to the slurry to adjust the pH to 8-9 to obtain an alkaline slurry; subjecting the alkaline slurry to an aging and crystallization reaction at high temperature to obtain a pseudoboehmite slurry; filtering and washing the pseudoboehmite slurry to obtain a silicon-modified macroporous pseudoboehmite filter cake, and then drying it to obtain silicon-modified macroporous pseudoboehmite.

This invention discloses a method for preparing silica microspheres, the prepared silica microspheres, and their applications. The method for preparing silica microspheres includes: (1) heating a mixture of n-alkane and pitch under reflux to separate a solid product; (2) mixing the solid product from step (1) with a mixture of aromatics I, a first silicon source, a polyoxyethylene-polyoxypropylene-polyoxyethylene copolymer, and water to obtain a crystallization solution, followed by hydrothermal crystallization and calcination to obtain an intermediate product; (3) mixing the intermediate product from step (2), a second silicon source, a pore-forming agent, and water to obtain a slurry; then, spray-drying and calcining the slurry to obtain the silica microspheres. The silica microspheres prepared by this method have the advantages of large specific surface area, large pore volume, and large average pore size, which significantly improves polymerization activity in olefin polymerization reactions.

The invention relates to a method for preparing a nanofiltration membrane by using sodium p-styrenesulfonate as a water phase additive. Infiltrating the support membrane in a water phase solution containing sodium p-styrenesulfonate and piperazine so that the support membrane is fully infiltrated by the water phase solution; coating the surface of the membrane with the oil-phase solution, and carrying out interfacial polymerization reaction to form an aromatic polyamide separation layer; and placing the membrane in an oven at 70-90 DEG C for heat treatment to prepare the aromatic polyamide composite nanofiltration membrane. Sodium p-styrenesulfonate can reduce the interfacial tension of a water / oil phase in the interfacial polymerization process, promote diffusion and uniform distribution of piperazine, strengthen the interfacial polymerization reaction and improve the cross-linking degree of a separation layer. The aromatic polyamide composite nanofiltration membrane prepared by the method has the characteristics of high flux and high selectivity at the same time. The method has the advantages of being simple in preparation process, low in cost and easy to implement. In addition, reference can be provided for preparation of other high-performance interfacial polymerization nanofiltration membranes.