50results about How to "Improve skeleton strength" patented technology

The invention relates to a metal-doped nitrogen-containing carbon-based catalyst of a fuel cell and application of the catalyst. The catalyst adopts organic surface active agents as a protection agent and a structural guide agent and adopts an aromatic compound and aldehyde as reaction monomers, metal elements are added in the reaction process to obtain a polymer-metal compound, and the polymer-metal compound is dried and then is subjected to high-temperature processing with inert gas or/and ammonia gas to finally obtain the metal-doped nitrogen-containing carbon-based catalyst. When the metal-doped nitrogen-containing carbon-based catalyst is used as a cathode catalyst of a proton exchange membrane fuel cell and a direct-methanol fuel cell, the oxide reduction activity, stability and toxicity resistance are excellent; moreover, the catalyst has an environment-friendly effect, is low in cost, controllable in aperture, high in specific surface area and rich in resource and can substitute for platinum to serve as an electric catalyst of the proton exchange membrane fuel cell.

The invention provides a method for preparing a phenolic aerogel by normal pressure drying. The method comprises the following steps: preparing a graft reaction solution including a phenolic novolac resin, a silane grafting agent and a first organic solvent, and carrying out a grafting reaction the phenolic novolac resin and the silane grafting agent in the graft reaction solution to obtain a silane-grafted phenolic resin; adding a curing agent and a second organic solvent to form a curing reaction solution, and performing a curing reaction to obtain a phenolic gel; and drying the phenolic gelunder normal pressure to obtain the phenolic aerogel. The invention also provides the phenolic aerogel produced by the method. The method of the invention realizes normal pressure drying, greatly shortens the preparation cycle, reduces the preparation cost, solves the problems of microscopic phase separation and too fast gelling, and leaves sufficient operation time for practical application. Theprepared phenolic aerogel has a significantly improved framework strength, a remarkably reduced shrinkage, good oxidation resistance and good ablation resistance.

The invention belongs to the field of aerogel felts, and discloses a preparation method for a high-temperature-resistant thermal-insulation aerogel felt. The preparation method comprises the followingsteps that SiC whiskers and cellulose are dispersed in a graphene aqueous suspension so as to obtain a suspension A; hollow glass micro-beads are added into the suspension A under the action of stirring so as to obtain a suspension B; n-silicate, ethanol and water are uniformly mixed, then a NH4F solution and ammonia water are sequentially added and uniformly stirred so as to obtain silica sol C;the suspension B is added into the silica sol C under the action of stirring, after uniform stirring is carried out, the mixture is used for soaking a fibrofelt, and immersion treatment is carried out on the fibrofelt under the vibration condition, after the fiber felt is completely soaked, the fibrofelt is taken out, and standing is carried out until a fibrofelt-gel complex is obtained; aging treatment is carried out at room temperature or under heating condition; solvent replacement is carried out for multiple times, and excessive moisture in the fibrofelt-gel complex is removed; and dryingtreatment is carried out so as to obtain the high-temperature-resistant thermal-insulation aerogel felt. According to the preparation method, the mechanical strength of the aerogel felt is improved,and meanwhile, the high temperature resistance and the heat insulation effect are good.

The invention discloses a refractory wear-resistant pouring material and a preparation method thereof. The refractory wear-resistant pouring material comprises the following raw material components in percentage by mass: 60-80% of graded ceramic particles, 5-25% of mixed matrix slurry, 4-15% of an adhesive and 6-10% of water, wherein the graded ceramic particles are divided into four granularity grades, and comprise ceramic particles of 8-5mm, ceramic particles of 5-3mm, ceramic particles of 3-1mm and ceramic particles of 1-0mm; and the mixed matrix slurry comprises milled natural river sand, alumina micro powder of 5-10 microns, silica fume, micro steel fibers and a dispersing agent solution. The fire resistance of silicon carbide ceramics is utilized, the cracking phenomenon caused by excessive CaO doping in the traditional cement refractory castable is avoided by adopting a complex adhesive, and steel fibers and boron fibers are introduced, so that the strength and wear resistance of the pouring material are improved on the basis of ensuring the fire resistance.

The invention discloses a soft-soil foundation treatment method for expressway engineering, which belongs to the field of foundation treatment. The method includes the following steps: a preparing filler: preparing lime improved soil according to volume ratio of powder lime and soil mass as 4-8%:92-96%; b adopting a method of dot interlace ramming through a hammer to conduct ramming and pore forming on the soft-soil foundation; and c filling the lime improved soil into rammed pores, using the hammer to ram continuously, and performing filling, ramming, refilling and reramming to form a pile to reach the surface of the foundation. The soft-soil foundation treatment method for the expressway engineering has the advantages of treating on site, compacting deeply, using local materials, and being easy in quality controlling, high in pile strength and economical in investment.

The invention provides a method for preparing zirconium oxide aerogel through combination of a secondary gelling method and ambient-pressure drying and relates to a preparation method of the zirconium oxide aerogel. The problems that an existing super-critical drying method is high in cost, equipment is expensive, and large-scale production can not be easily achieved are solved. The method includes the steps of 1, preparation of zirconium oxide wet gel; 2, re-gelling and modification of ZrO2 thick-soup-shaped gel; 3, drying of the ZrO2 aerogel. The secondary gelling method is adopted, the stirring speed is controlled, two gelling processes are generated to a system, the frame strength of the aerogel is improved to avoid the influences of capillary force in the following ambient-pressure drying process on the material pore structure, and it is guaranteed that the pore structure of the aerogel is not collapsed. According to the method, ambient-pressure drying is adopted, the problems of high energy consumption and cost existing in the process of preparing zirconium oxide aerogel through super-critical drying are solved, and large-scale production can be easily achieved. The method is used for preparing the zirconium oxide aerogel.

The invention belongs to the field of heat insulation materials, and discloses a preparation method of an enhanced silicon dioxide aerogel composite material. A fiber material is pretreated through a two-step pretreatment method to enable hydroxyl groups and Si-OR groups to be attached to surface of the fiber material, and then an enhanced silicon dioxide aerogel composite material is prepared through sol-gel and drying processes. The prepared silicon dioxide aerogel composite material has a high-strength, more complete and uniform aerogel network framework, the framework strength between fibers and silicon dioxide particles and the framework strength between the silicon dioxide particles are greatly improved, and compared with an existing silicon dioxide aerogel composite material, the silicon dioxide aerogel composite material has excellent compression performance.

The invention discloses a preparation method cellulose / polyimide composite aerogels, and belongs to the technical field of materials. The preparation method includes the following steps: polyamic acid is dissolved in a cellulose aqueous dispersion through a solubilizer; through freezing, drying, and thermal imidization, the cellulose / polyimide composite aerogels are obtained. The preparation method has the advantages of simpleness, high efficiency, low requirements for equipment, an extensive application scope and friendly environment. The problem that traditional polyimide type high-performance composite aerogels are difficult to prepare is effectively avoided. The obtained composite aerogels can be applied to air adsoprtion, organic substance adsorption, heat insulation materials andthe like and have great potential application value in the field of air pollution treatment, water pollution treatment, heat insulation structured materials and the like.

The invention belongs to the technical field of preparation of carbon aerogel, and specifically relates to a method for preparing carbon aerogel by using normal-pressure drying. The preparation methodcomprises the following steps: introducing a reinforcing agent into a reaction monomer and catalyst system, preparing wet gel by using a sol-gel method, carrying out aging treatment on the wet gel, replacing moisture in the wet gel by using a low-surface-tension solvent, putting the wet gel into air, carrying out normal-pressure drying to obtain organic aerogel, and carbonizing the organic aerogel to obtain carbon aerogel, wherein the reaction monomers are resorcinol and formaldehyde, and the reinforcing agent is high-molecular polymer F127; according to the method disclosed by the invention,complex processes of a conventional supercritical drying method and a freeze drying method are avoided, meanwhile, the shrinkage rate of the carbon aerogel material in a normal-pressure drying process is greatly reduced, and the supercapacitor electrode material with excellent performance can be obtained at a low price.

The invention provides an automobile back-row seat cushion framework assembly which comprises a supporting assembly, a cushion frame and a cushion grid assembly. The supporting assembly is connected with the cushion frame. The cushion grid assembly is connected with the cushion frame. The cushion frame comprises a cushion pipe frame, a cushion rear supporting pipe and cushion supporting longitudinal beams. The two ends of the cushion pipe frame are connected with the two ends of the cushion rear supporting pipe respectively. A closed frame is defined by the cushion pipe frame and the cushion rear supporting pipe. One end of each cushion supporting longitudinal beam is connected with the cushion pipe frame, and the other end of each cushion supporting longitudinal beam is connected with the cushion rear supporting pipe. The cushion grid assembly is erected on the cushion supporting longitudinal beam. The automobile back-row seat cushion framework assembly has the advantages that the framework strength is improved, the structure is simplified and precision requirements are lowered.

The invention discloses a polylactic acid scarf polyurethane environment-friendly waterproof coating and a preparation process thereof. The waterproof coating comprises, by weight, 100 parts of polytetramethylene ether glycol, 25-45 parts of isophorone diisocyanate, 30-50 parts of hydroxyl-terminated polylactide, 7-15 parts of nano-scale oxidized graphene, 0.15-0.3 part of dibenzoyl peroxide, 4-8parts of tetrahydrofuran, 2-6 parts of chain extenders, 16-20 parts of acetone, 4-10 parts of triethylamine, 0.02-0.5 part of catalysts, 2-4 parts of defoaming agents, 1-3 leveling agents, 9-15 partsof deionized water and 40-60 parts of inorganic fillers. Graphene grafted polylactic acid copolymers are embedded into a polyurethane main chain, active groups such as ester bonds and carboxyl are introduced, the biological degradability and compatibility of the polyurethane coating are improved, and a degradation product is poisonless, harmless, green and environmentally friendly.

The invention discloses coordination crosslinking type polyimide aerogel and a preparation method thereof, and belongs to the technical field of materials. According to the invention, the polyamide acid hydrogel is prepared under the action of the auxiliary agent and the surfactant in an aqueous solution system; the method then includes introducing metal ions to coordinate and crosslink the polyamic acid hydrogel to prepare coordination crosslinking type polyamic acid hydrogel; then carrying out freeze drying and thermal imidization to obtain coordination cross-linking type polyimide aerogel;the method has the advantages of being simple, efficient, low in equipment requirement, wide in application range and environmentally friendly; the problem that traditional polyimide high-performanceaerogel is difficult to prepare can be effectively avoided, and the obtained aerogel can be used for gas adsorption, organic matter adsorption, heat insulation materials and the like and has high potential application value in the fields of air pollution treatment, water pollution treatment, heat insulation structural materials and the like.

The invention belongs to the technical field of catalysts, and provides a method for preparing a starch carbon-based Fenton-like catalyst based on an EDTA chelation technology, the method comprises the following steps: firstly, cross-linking starch and disodium ethylene diamine tetraacetate EDTA-2Na by using a cross-linking agent to form a high polymer; uniformly chelating a large amount of metal ions on a high polymer by using ammonia nitrogen and carboxyl oxygen functional groups with extremely strong coordination ability in disodium ethylene diamine tetraacetate, so that the metal loading capacity of the catalyst is improved, and the prepared Fenton-like catalyst is high in skeleton strength, high in catalytic efficiency and low in metal ion dissolution rate; meanwhile, incomplete carbonization is generated by utilizing low-temperature hydrothermal carbonization so that tar and volatile gas are prevented from being generated, and the yield is as high as 50%. Results of the embodiment show that when the starch carbon-based Fenton-like catalyst prepared by the preparation method is used for degrading rhodamine B, the degradation efficiency can reach 98.9% within 10 minutes, and after five times of circulation, the degradation rate of rhodamine B can still reach 96.5% within 15 minutes.