7results about How to "Uniform pore structure" patented technology

The invention discloses a preparation method and application of a porous para-aramid nanofiber membrane. The preparation method of the para-aramid nanofiber membrane comprises the following steps: placing a substrate coated with an aramid nanofiber solution in an aprotic solvent to obtain an aramid nanofiber membrane containing the aprotic solvent; and immersing the aramid nanofiber membrane containing the aprotic solvent into a protic solvent, replacing the aprotic solvent in the nanofiber membrane with the protic solvent, and heating and drying to obtain the para-aramid nanofiber membrane. The para-aramid nanofiber membrane prepared by the preparation method of the para-aramid nanofiber membrane has highly adjustable porosity and pore structure, and has a huge application prospect in the fields of battery diaphragm and membrane separation and the like, and the preparation method is simple and suitable for large-scale industrial application.

This invention provides a method for screening the stability of biomass shell-derived hard carbon raw materials. The method investigates the optimal ratio and relationship between the lignin content and sugar content measured after alkali treatment in biomass shell materials, thereby screening the stability of biomass shell materials from different sources and batches. When the lignin content of the biomass shell material itself and the sugar content measured after alkali treatment satisfy the relationship 15≤β×L≤60, an effective balance between the lignin and sugar content in the biomass shell material can be achieved, resulting in a good porous structure. This method provides a simple and rapid screening process to obtain biomass shell materials with better stability. When biomass shell materials with better stability are subsequently used to prepare hard carbon battery materials, the resulting hard carbon battery materials exhibit good overall performance in terms of cycle life, capacity, and coulombic efficiency.

The invention relates to the technical field of capacitor electrode material preparation, and particularly discloses a high-performance coal pitch-based supercapacitor electrode material and a preparation method thereof. The preparation method of the electrode material comprises the following steps: mixing asphalt, an activating agent and a template agent, and carrying out ball milling treatment to obtain a first mixture; and carrying out heat treatment on the first mixture in an inert atmosphere, and then washing with a weak acid solution to obtain the electrode material with uniform pores. The activating agent and the template agent are synergistically mixed with the asphalt for pore forming, so that the pore structure of the electrode material can be accurately regulated and controlled, and the electrode material with uniform pore distribution and excellent electrical properties is obtained; meanwhile, the preparation method disclosed by the invention has the characteristics of simple process and environmental friendliness. The technical problems that an existing coal pitch-based capacitor carbon material is small in specific surface area, uneven and uncontrollable in pore structure, tedious in preparation process and not environmentally friendly are solved.

The invention discloses citrus pectin-polyvinyl alcohol / chitosan composite hydrogel, a preparation method and application, and relates to the technical field of hydrogel, the preparation method of the citrus pectin-polyvinyl alcohol / chitosan composite hydrogel comprises the following steps: uniformly mixing a polyvinyl alcohol solution with a chitosan solution, and carrying out freezing-unfreezing circulation treatment to obtain the citrus pectin-polyvinyl alcohol / chitosan composite hydrogel. Polyvinyl alcohol / chitosan mixed gel is obtained; soaking the polyvinyl alcohol / chitosan mixed gel in a citrus pectin solution, performing ultrasonic treatment, filtering and drying to obtain the citrus pectin-polyvinyl alcohol / chitosan composite hydrogel. The prepared citrus pectin-polyvinyl alcohol / chitosan composite hydrogel is uniform in pore structure, good in water-retaining property, more stable in mechanical property and chemical property and good in biocompatibility.

This invention relates to the field of silicone technology, specifically to a silicone composite thermally conductive material and its preparation process. The preparation process of a silicone composite thermally conductive material includes: pretreatment of graphene filler, preparation of modified graphene filler, preparation and modification of heterogeneous filler, and preparation of the silicone composite thermally conductive material. This invention utilizes modified graphene and the construction of a boron nitride-silica heterogeneous filler to form a multi-level thermally conductive network. Combined with electric field-induced ordered arrangement of fillers and pretreatment of graphene with chemically reduced gel and directional ice template, multiple methods are used synergistically to reduce interfacial thermal resistance and phonon scattering, constructing continuous thermally conductive channels. Simultaneously, it improves the structural uniformity, thermal conductivity stability, and mechanical properties of the composite material, effectively solving problems such as filler agglomeration and migration, and significantly improving the thermal conductivity of the silicone composite material.

This invention relates to a multi-layer coated gas-generating aluminum paste, its preparation method, and its application. The preparation method includes the following steps: dry ball milling spherical aluminum powder under an inert gas atmosphere, adding a ball milling aid during the dry ball milling process, resulting in pre-coated aluminum powder; the dry ball milling includes ball milling using a single milling medium and / or a mixed milling medium; stirring and kneading the pre-coated aluminum powder, passivating agent, surfactant, and organic solvent under an inert gas atmosphere, and sieving to obtain a kneaded product, which is the multi-layer coated gas-generating aluminum paste. This invention utilizes a segmented combination of single-medium ball milling ("stearic acid-steel balls") and mixed-medium ball milling ("zinc stearate-zirconia beads and glass beads") to construct a gradient coating structure on the surface of the aluminum powder, achieving "slow release in the early stage and high efficiency in the later stage" gas-generating characteristics, which can meet the stringent requirements for gas generation rate in low-density autoclaved aerated concrete.

This invention relates to an ordered macroporous polysaccharide microsphere chromatographic medium and its preparation method, belonging to the field of chromatographic medium technology. The preparation method includes the following steps: dissolving polysaccharide powder in an alkaline urea solution to obtain a polysaccharide solution; adding regular calcium carbonate whiskers as pore-forming templates to the polysaccharide solution and stirring to obtain a mixed solution; adding the mixed solution as an aqueous phase to an oil phase, forming a water-in-oil emulsion under the action of a surfactant; emulsifying for a period of time, solidifying the microspheres using an acid regeneration method and removing the calcium carbonate whiskers; using the length of the calcium carbonate whiskers as a sieving standard, sieving using a filter screen with a pore size equal to the length of the calcium carbonate whiskers; the microspheres with a size smaller than the length of the calcium carbonate whiskers are the ordered macroporous polysaccharide microsphere chromatographic medium. Compared with the prior art, the preparation process of this invention is simple, the pore structure is interconnected and uniform, and there are no narrow pore throats, significantly improving mass transfer performance, and it is expected to serve as a high-performance chromatographic medium platform-type microsphere.