24 results about "Ostwald ripening" patented technology

The invention belongs to the technical field of perovskite solar cells, and particularly relates to a preparation method for improving the quality of a perovskite thin film by using a local high-temperature field, and the method comprises the steps: 1, forming a perovskite precursor thin film on an electron transmission layer; step 2, when the precursor film is in an intermediate phase or an incompletely crystallized state, placing the precursor film below a heating plate with a microstructure array, keeping a gap between a convex part of the microstructure array and the surface of the precursor film, and forming a periodically distributed local high-temperature field on the surface of the precursor film; step 3, maintaining the local high-temperature field to act for a period of time, so that the local area of the precursor film is preferentially crystallized; and 4, removing the heating plate, and uniformly annealing the precursor film. According to the method, a local high-temperature field is applied to induce a hot spot region to preferentially nucleate, abnormal growth and Ostwald ripening of crystal grains are inhibited, and the large-area uniform perovskite thin film with narrow crystal grain size distribution, low defect density and a flat film surface is obtained, so that the efficiency and consistency of a device are improved.

The invention discloses a large-area scintillator and a preparation method thereof, and belongs to the technical field of large-area scintillator preparation. The method comprises the following steps: uniformly mixing Cs3Cu2I5 powder with a solvent capable of dissolving the Cs3Cu2I5 powder to form slurry, preparing a large-area scintillator film with controllable area and thickness through a blade coating method, enabling scintillator grains to undergo dissolution and recrystallization processes through a vacuum annealing process, and preparing the large-area scintillator film on the basis of Ostwald curing effect. The small crystal grains are adsorbed to the surface of the larger crystal grains to form larger crystal grains, and gaps among the crystal grains are filled; as the internal defects of the crystal grains are reduced, the light scattering is reduced, the light transmittance of the scintillator is improved, and finally, large-area high-resolution imaging is realized; according to the method, the light transmittance of the scintillator film is improved from 5% of a Cs3Cu2I5: 2Me scintillator film to 20% or above of a Cs3Cu2I5: DMSO scintillator film through regulation and control of a solvent, the high resolution of 16 lp mm <-1 >-18 lp mm <-1 > is kept, and an excellent imaging effect on a real object is achieved.

The invention discloses a preparation method of small-size monodisperse silver nanoparticles, and belongs to the technical field of nano materials. According to the method, silver salt serves as a precursor, step-by-step temperature control reaction is carried out in a coexistence system of an alkaline reducing agent and a polyanionic steric hindrance stabilizer, and small-size monodisperse growth of silver nanoparticles is achieved. According to the step-by-step temperature control strategy, the Ostwald ripening and agglomeration growth of the particles are effectively inhibited by accurately regulating and controlling nucleation and growth kinetics and based on an electric double layer-steric hindrance synergistic stabilization mechanism, so that the small size and monodispersity of the silver nanoparticles are synchronously realized. The average particle size of the obtained silver nanoparticles is as low as 9 nm, the particle size distribution range is narrow, and the particles are monodisperse. The prepared silver nanoparticles are suitable for high-performance conductive ink and have wide application prospects in the field of flexible printing electronics.

The invention relates to the technical field of alloy materials, in particular to an alloy material for a high-strength pressure-resistant drill rod and a preparation method of the alloy material. The material is prepared from matrix alloy powder and modified composite precursor powder through ball-milling mixing and hot isostatic pressing, wherein the modified composite precursor is prepared by taking graphene oxide as a carrier through a dual confinement strategy of vanadium acetylacetonate interlayer intercalation in-situ nitridation and secondary chelation of vanadium ions on a polydopamine interface, so that Ostwald ripening of a precipitated phase at a high temperature is effectively inhibited, and the interface bonding force is greatly enhanced. The yield strength attenuation rate of the obtained material at the high temperature of 180 DEG C is lower than 2.8%, the strength and toughness are synergistically improved, and the material is particularly suitable for manufacturing drill rods in the high-temperature and high-pressure environments of deep wells and ultra-deep wells.

The CO2 bubble nucleation and ripening process in-situ observation device and method based on nano CT belongs to the technical field of porous medium in-situ imaging. The device comprises a nano CT scanning device, a high temperature and high pressure reaction kettle, a CO2-saline pre-equilibrium and injection unit, a pressure control unit, a temperature control unit, a pipeline bundling and rotating adaptation unit, a synchronous data acquisition unit and an image analysis unit. During the experiment, the CO2 saturated liquid or residual CO2 occurrence state is established, then the bubble nucleation is induced by pressure reduction or fluid displacement, and the time sequence CT scanning is carried out under the condition of no flow or controllable seepage, so as to obtain the parameters such as bubble volume, interface area, curvature, connectivity and ripening type. The application can be used for quantitatively revealing the CO2 bubble nucleation, Ostwald ripening, dissolution and stable residence mechanism under the temperature and pressure conditions of the reservoir.

The invention discloses a positive electrode active material and a preparation method and application thereof, the positive electrode active material provided by the invention is a disordered single-crystal nickel-manganese spinel positive electrode material, and the proportion of Mn < 3 + > in transition metal elements in the disordered single-crystal nickel-manganese spinel positive electrode material is 3-8 mol%. According to the invention, the content of Mn < 3 + > in the nickel-manganese spinel positive electrode material is regulated and controlled, and the characteristics of stable single crystal structure, few surface side reactions and excellent electron and ion conductivity of Mn < 3 + > are fully combined. The disordered nickel-manganese spinel single-crystal positive electrode material is prepared by adopting a short-time high-temperature sintering and high-cooling-rate process, the formation of a single crystal is ensured by short-time high-temperature sintering, and meanwhile, the Ostwald ripening phenomenon of particles is avoided; the high cooling rate can promote generation of Mn < 3 + >, the conductivity of the positive electrode material is enhanced, and the prepared positive electrode active material has good electrochemical performance.

The application provides monodisperse spherical micro-nano silver powder and a preparation method thereof, and belongs to the technical field of metal powder preparation. The application uses silver nitrate solution as a silver source, polyvinylpyrrolidone as a dispersant, and ascorbic acid as a reducing agent to prepare micro-nano silver powder with narrow particle size distribution and high sphericity at low temperature. The kinetics of hydrolysis and reduction nucleation is effectively slowed down at low temperature, the thermal motion of polyvinylpyrrolidone molecular chains is weakened, the polyvinylpyrrolidone molecular chains can be more orderly and stably adsorbed on specific crystal faces of silver crystal nuclei, the anisotropic growth of crystal nuclei is inhibited, and the low-temperature Ostwald ripening between particles is effectively prevented, so that the uniformity of particle size is ensured; at low temperature, the reduction capacity of ascorbic acid is moderated. The'mild reduction' and 'ordered guidance' are perfectly matched, and a good balance between reaction kinetics and thermodynamics is achieved. The prepared silver powder has excellent morphology, super-high sphericity and good monodispersity, and can be applied to high-end electronic paste.

The application discloses monodisperse smooth spherical silver powder, a preparation method and application thereof, wherein the silver powder has a particle size distribution parameter D100 of less than or equal to 4.0 microns, a sphericity ratio range of 0.85 to 1.15, and a specific surface area range of 0.60 to 0.75 m 2 / g. In view of the trend of narrow line width of the metalized printing of the crystalline silicon solar cell, the silver powder as the conductive phase of the silver paste needs to have a smaller D100 value and higher monodispersity. The application realizes high sphericity of the silver particles by constructing high supersaturation, inhibits agglomeration by combining two types of surface adsorbents with adsorption effect, and then adjusts the D100 value and optimizes the smoothness of the surface by Ostwald ripening process, so as to obtain the silver powder with excellent monodispersity, small D100 value, high sphericity and smooth surface, which effectively meets the high-precision requirement of the narrow line width printing of the photovoltaic cell, and is suitable for the field of high-performance conductive paste preparation.

The application discloses a vanadium salt hetero-support and a preparation method and application thereof, and belongs to the field of material preparation and catalysis technology. The vanadium oxide-vanadium carbide hetero-support is prepared by a precursor method, vanadium salt is uniformly mixed with an organic carbon source, stirring and dissolving are conducted, drying and filtering are conducted, and a vanadium oxide-vanadium carbide hetero-support precursor is obtained, and the precursor is calcined in an argon or nitrogen atmosphere to obtain the vanadium salt hetero-support. The raw material used is low in price, the process is simple, no flammable and explosive gas is generated in the calcination process, the safety factor is high, the target product is generated by one-step calcination, impurities are not easily introduced, and the repeatability is high. The method is based on the theory of strong and weak metal carrier interaction, and a two-component vanadium salt hetero-support is used as a catalyst base, the catalyst sintering problem caused by Ostwald ripening, particle aggregation and migration is overcome, and thus a catalyst with good stability and good catalytic performance is obtained.

The application discloses a compound essential oil emulsion based on in-situ self-assembly of biopolymer interface and a preparation method thereof. In the preparation method, whey protein isolate, sodium caseinate and stevioside at the oil-water interface are driven by non-covalent supramolecular interaction to self-assemble into two-phase wettable complexes, spontaneously adsorbed at the interface to form a mixed adsorption layer, and generate a complex interface film with stable viscoelasticity and interface relaxation phenomenon, thereby effectively improving the stability of the nano-emulsion system. In addition, without adding Ostwald ripening inhibitors, by compounding thyme essential oil and relatively non-polar rosemary essential oil, the two complement each other, and a compound essential oil emulsion with high stability and broad-spectrum antibacterial property is obtained. The application can not only provide a natural and green food-grade emulsifier for the food industry, but also provide a new solution for controlling bacterial and fungal contamination during the storage of fresh products, dairy products, meat products and the like.

The invention discloses a preparation method of a primary small-particle high-voltage lithium ion battery positive electrode material, and relates to a preparation method of a lithium ion battery positive electrode material. In order to solve the problems of large primary particle size and poor electrochemical performance of the existing lithium ion battery positive electrode material high-voltage lithium nickel manganese oxide, the positive electrode material disclosed by the invention is prepared by forming second-phase inert particles in situ in the preparation process, and then calcining and lithium-matching calcining. The introduction of the second-phase inert particles during calcination inhibits the Ostwald ripening process, so that the particle size of primary particles in the material is significantly reduced, the overgrowth of particles in the conventional synthesis process is avoided, the specific surface area is optimized, and the diffusion path of lithium ions is shortened. The lithium nickel manganese oxide / lithium metal battery assembled by the positive electrode material has a capacity retention ratio of 88.2% after 1000 cycles at 25 DEG C and 5 C, has a discharge specific capacity of 95.9 mAh g <-1 > at a discharge rate of 20 C, and can be used in the field of high-voltage lithium ion batteries.

This invention relates to a composition comprising a compound of formula (I) and an agrochemical active ingredient selected from ADEPI DY N TM (pydiflumetofen), oxathiapiprolin, sedaxane and azoxystrobin; R 1O[C(R 2)(H )C( R3 )(H)O]nX (I), where R1 is C6-12 alkyl or is C6-12 alkenyl; n is from 5 to 50; independently, each [C{R2)(H)C(R3)(H)O] unit has both R2 and R3 being hydrogen or has one of R2 and R3 being hydrogen and the other being phenyl; provided that at least one [C(R2){H)C(R3)(H)O] unit has one of R2 and R3 being hydrogen and the other being phenyl; and X is hydrogen or is selected from C1-4 alkyl; and to use of a compound of formula (I) to reduce particle growth (such as nucleation, crystal growth or Ostwald ripening) of an agrochemical active ingredient.

This invention discloses a method for reducing the fluorescence half-width at half-maximum (HWHM) of core-shell indium phosphide quantum dots (IPDs) and its product, belonging to the field of luminescent materials technology. In this invention, aluminum isopropoxide is added to the nucleation step of the IPDs to passivate surface defects, suppress the formation of defect states, and inhibit Ostwald ripening during nucleation, resulting in a more uniform nucleus size distribution. The method of this invention has the advantages of simple process, convenient synthesis, and ease of large-scale production; the prepared IPDs exhibit narrower HWHM, higher quantum yield, and environmental friendliness, making them suitable for widespread application.

This invention provides a wide-bandgap perovskite thin film, its preparation method, and its application, belonging to the field of photovoltaic materials and devices technology. This invention introduces Rb... + This alters the coordination environment of lead ions in the precursor solution, improving the micelle stability formed by lead ions and solvent. This prevents lead ions from immediately reacting with iodide ions and precipitating during coating, thus delaying crystallization and allowing more time for the film to form a uniform mesophase. Simultaneously, Rb... + The introduction of [a specific substance] alters the solute environment of the precursor solution, resulting in fewer lead ions in the solute during the supersaturation process. This changes the instantaneous supersaturation, which is the core driving force for crystallization. The higher the supersaturation, the more crystal nuclei will burst forth in the solution. The change in instantaneous supersaturation can suppress disordered rapid nucleation and promote the growth of a small number of crystal nuclei through Ostwald ripening / preferred orientation during the annealing stage, resulting in a thin film with large grains and low grain boundary density.

The present disclosure relates to the field of gas sensing technology, in particular to a synergistic metal-polyphenol network nanocomposite material, a preparation method and application thereof. The method uses WO3, SnO2, In2O3 or ZnO as a nanometer oxide matrix, constructs a "metal-polyphenol network" by using plant polyphenols with "molecular glue" amphiphilic properties, customizes the loading of single-layer or multi-layer "metal-polyphenol network" on the surface of the matrix, reduces metal ions in situ to metal nanoparticles and uniformly anchors them on the surface of the matrix to form an intermediate; finally, the polyphenol is carbonized by heat treatment in an inert atmosphere to form an ultrathin carbon layer, obtaining a carbon-coated synergistic metal-polyphenol network nanocomposite material. The method realizes the uniform dispersion and stable anchoring of active metals, effectively inhibits particle agglomeration caused by Ostwald ripening, is green and environmentally friendly in the synthesis process, and can also optimize the sensing performance of the material in a targeted manner. When the material is used to prepare a hydrogen sensor, it exhibits high sensitivity, high selectivity and high durability.

The invention discloses a rapid preparation method of twin-structure nanoparticles and the twin-structure nanoparticles, and relates to the technical field of nanoparticle preparation, and the rapid preparation method comprises the following steps: adding a metal salt or metal nanoparticles as a metal source and a conductive carrier into a solvent, and carrying out ultrasonic dispersion to obtain precursor slurry; the obtained precursor slurry is subjected to forced air drying overnight until the solvent is completely volatilized, loose precursor powder loaded with a metal source is obtained, and the precursor powder is formed into a precursor; clamping the precursor between two electrodes to form a conductive path, applying pulse current under the protection of vacuum or inert gas, performing rapid thermal shock treatment, and rapidly cooling to room temperature after power failure to complete the continuous process of through-flow heating and power failure cooling; according to the method, the metal nanoparticles which are uniform in size and good in dispersity and internally contain clear twin boundaries can be prepared within the second-level time scale; energy consumption and process complexity are reduced, particle growth and Ostwald ripening are inhibited, and catalytic activity and stability are improved.

The application relates to the technical field of semiconductor materials, and discloses a large-grain cesium tin iodine perovskite film based on vacuum pretreatment low-temperature annealing and a preparation method thereof, a hole transport layer is spin-coated on an ITO surface, a CsSnI3 precursor solution is spin-coated on the hole transport layer after annealing treatment, and then the CsSnI3 precursor solution is placed in a vacuum chamber for vacuum storage for a preset time; and the perovskite film after vacuum storage is subjected to annealing treatment under an inert atmosphere and at a second temperature less than 60 DEG C. Through the vacuum pretreatment mode, the solvent in the just-coated perovskite film is volatilized, the supersaturation is controlled to reach an optimal value, and the crystallization rate is improved; meanwhile, the low-temperature lower than 60 DEG C is used to slow down the solvent volatilization rate and the perovskite crystallization rate, sufficient time is left for the Ostwald ripening to be prolonged, and the perovskite grain growth is promoted; the method is simple in operation, low in energy consumption, and can prepare a large-grain high-quality CsSnI3 perovskite film.

The invention discloses a wear-resistant transparent aluminum oxide composite material and a preparation method thereof, and belongs to the technical field of aluminum oxide.The preparation method comprises the steps that firstly, epoxypropane serves as a proton trapping agent, aluminum, zirconium and zinc metal salts are subjected to hydrolytic polymerization in an ethanol water solution, gel is formed and combined with nano titanium dioxide, and the gel is impregnated and aged through isopropanol; the preparation method comprises the following steps: inducing to form a hollow structure by using an Ostwald curing mechanism to obtain alumina-based composite precursor xerogel, converting the alumina-based composite precursor xerogel through stepped heating sintering to obtain composite powder, and finally carrying out synergistic modification on the surface of the composite powder by using stearic acid and lanthanum nitrate hexahydrate to obtain the composite powder. And coating polymethyl methacrylate through in-situ free radical polymerization to prepare the aluminum oxide composite material with high wear resistance, high light transmittance and strong ultraviolet resistance.

The application relates to the fields of agricultural biotechnology and pesticide preparation technology, and discloses a preparation method and application of 2,4-di-tert-butyl phenol nanoemulsion, which comprises the following steps: 2,4-di-tert-butyl phenol is dissolved in ethyl acetate to form an oil phase mixture; the obtained oil phase mixture is mixed with Tween 80 under magnetic stirring, stirring is performed until the mixture is fully mixed, an oil phase-emulsifier system is obtained after internal gas is removed through ultrasonic treatment, then the oil phase-emulsifier system is slowly added into 8 times the volume of deionized water under magnetic stirring at 45 DEG C, and mutual dissolution of the water phase and the oil phase is promoted through ultrasonic treatment for 40 min to obtain a pre-emulsion. The obtained pre-emulsion is emulsified through a high-pressure homogenizer, 20000 psi, and circulation is performed for 8 times to obtain the nanoemulsion. The nanoemulsion prepared by the application has a nanoscale particle size, the system presents good kinetic stability, is not prone to delamination, precipitation or Ostwald ripening, and shows high storage stability.

The invention relates to a continuous lithium precipitation method for battery-grade lithium carbonate, and belongs to the technical field of battery materials. According to the method, the scheme that an online high-dispersion mixing technology and a specific fine grain inhibitor are combined for use is innovatively provided, the fine grain inhibitor has a unique comb-shaped molecular structure and can be rapidly adsorbed to the surface of a new crystal nucleus at the moment of high-dispersion mixing, and the fine grain inhibitor can be rapidly adsorbed to the surface of the new crystal nucleus through the anchoring effect and the steric hindrance effect. Explosive nucleation and disordered growth of fine grains are effectively inhibited, and a solute is guided to orderly deposit towards a dominant crystal nucleus through an Ostwald ripening process. The method successfully realizes the unification of efficient mixing and high-quality crystallization, can continuously and stably produce battery-grade lithium carbonate which is uniform in granularity, regular in morphology, high in purity and easy to filter and wash, and fundamentally breaks through the technical bottlenecks of low efficiency of a traditional intermittent process and poor quality of an existing continuous process.

The invention relates to the technical field of agricultural biotechnology and pesticide preparations, and discloses a preparation method and application of a 2, 4-di-tert-butylphenol nanoemulsion, the method comprises the following steps: dissolving 2, 4-di-tert-butylphenol in ethyl acetate to form an oil phase mixture; under magnetic stirring, the obtained oil phase mixture and Tween 80 are mixed and stirred to be fully mixed, internal gas is removed through ultrasound, an oil phase-emulsifier system is obtained, then the oil phase-emulsifier system is slowly added into deionized water with the volume 8 times that of the oil phase-emulsifier system under magnetic stirring at 45 DEG C, ultrasonic treatment is conducted for 40 min, mutual dissolution of the water phase and the oil phase is promoted, and the pre-emulsion is obtained. The obtained pre-emulsion is emulsified by a high-pressure homogenizer at 20000 psi, and is circulated for 8 times to obtain the nano-emulsion. The nano-emulsion prepared by the invention has a nano-scale particle size, the system presents good dynamic stability, layering, precipitation or Ostwald ripening are not easy to occur, and the storage stability is relatively high.

The invention provides a hollow photoactive Cu / Zn-MOFs catalyst as well as a preparation method and application thereof, and relates to the technical field of photocatalytic materials. According to the invention, through an improved Ostwald ripening method, copper metal particles are anchored on the surface of Zn-TPBD, and the Cu / Zn-MOFs composite material with a clear structure and a hollow structure is successfully prepared. Cu / Zn-MOFs have the advantages of wide absorption range, high charge separation efficiency, strong O2 adsorption / activation capability, good recycling property, light / heat stability, low cost, easy obtaining and the like, and the Cu / Zn-MOFs prepared by the method can be used as a catalyst in photocatalytic aerobic dehydrogenation reaction to realize 99% conversion rate of quinoline; meanwhile, the photocatalyst shows high-efficiency photocatalytic activity on oxidative dehydrogenation reaction of polysubstituted quinoline derivatives, and the stability of the structure and the catalytic efficiency can still be kept after multiple times of cyclic catalytic use. The Cu / Zn-MOFs catalyst prepared by the preparation method disclosed by the invention provides favorable conditions for realizing efficient and green synthesis of quinoline derivatives.

The invention discloses an electrocatalysis-based SRB bacterium rapid determination sensing material and a preparation method and application thereof. The preparation method comprises the following steps: adding polyvinylpyrrolidone and polyethylene glycol into a copper nitrate salt solution, and carrying out ultrasonic treatment until powder is completely dissolved; under magnetic stirring, rapidly injecting hydrazine hydrate into the mixed solution, and reacting at normal temperature for a period of time to obtain Cu2O nanoparticles; and adding a HAuCl4 solution into the Cu2O nanoparticle dispersion liquid, continuously stirring, and carrying out in-situ replacement to obtain the Cu2O coated Au hollow nanostructure loaded with Au nanoparticles. The hollow and open conductive metal-metal oxide heterogeneous nanostructure is synthesized through an Ostwald curing process, and the hollow and open conductive metal-metal oxide heterogeneous nanostructure is used as a rapid detection sensing platform for sulfate reducing bacteria based on electrocatalysis and has a wide research prospect in the aspect of rapid detection of microorganisms.

The application discloses a heat treatment method for laser additive manufacturing of aluminum alloy, which takes into account the performance and stress relief of the aluminum alloy. Based on the fact that the mechanical strength of AlSi10Mg alloy significantly decreases after stress relief annealing, the optimal solid solution temperature is determined through multiple DSC tests. Based on the characteristics of the supersaturated solid solution matrix of laser additive manufacturing, the solid solution time is further optimized. Secondly, based on the Ostwald ripening and LSW coarsening theory, the aging temperature and time are optimized and determined, so that a large number of nano-sized Si particles are precipitated in the further supersaturated Al matrix after solid solution, and the optimal nano-particle size and volume fraction are obtained, thereby improving the mechanical strength of the alloy to make up for the loss of mechanical properties caused by stress relief annealing. Compared with the traditional similar T6 heat treatment process system, the optimal heat treatment temperature and time are further optimized and determined, so that the mechanical strength reaches the initial deposition state level, and the effect is unique and significant.