14 results about "Al2o3 nanoparticles" patented technology

The invention discloses a dynamic self-repairing PI-based nano protective coating for a crease-free folding screen. The dynamic self-repairing PI-based nano protective coating is prepared from a polyimide matrix, a dynamic cross-linking agent, self-repairing microcapsules, a surface-modified nano inorganic filler and a surface energy regulator, the polyimide matrix is obtained by polymerizing aromatic dianhydride and a diamine monomer containing a flexible chain segment, and the flexible chain segment comprises an ether bond or a methylene chain segment; the shell material of the self-repairing microcapsule is polyurea or polyurethane, and the core material of the self-repairing microcapsule is a polyimide repairing agent; the surface modified nano inorganic filler is SiO2 or Al2O3 nano particles subjected to surface grafting modification by a silane coupling agent. The preparation method has the beneficial effects that the coating prepared by the preparation method simultaneously realizes the basic performances of high hardness, high toughness, high light transmittance and strong adhesion, has the efficient grading self-repairing capability aiming at damages of different scales, and finally passes more than one hundred thousand times of extreme bending fatigue tests; the problems of balance of multi-performance requirements, single repair mechanism and low efficiency in the prior art are solved.

This invention discloses a method for refining primary silicon in Al-Si alloys through synergistic modification with nano-ceramics based on laser additive manufacturing. The method involves uniformly mixing Al-Si alloy powder with TiB2 and Al2O3 nano-ceramics using a ball mill under inert gas protection to obtain a ceramic-reinforced nano-Al-Si alloy composite powder. This nano-ceramic-modified Al-Si alloy powder is then melted and solidified layer by layer using a laser powder bed melting and forming equipment to create the desired target part. In this method, during the solidification of the nano-ceramic-reinforced Al-Si alloy melt, Al2O3 nanoparticles, due to their similarity to the Si crystal structure and the existence of a good interfacial coherence relationship, act as heterogeneous nucleation sites for primary silicon, increasing the nucleation rate and refining the size of primary silicon. TiB2 nanoparticles, distributed at the solid-liquid interface, can to a certain extent prevent the diffusion and aggregation of Si atoms into Si-Si atom clusters, thereby inhibiting the growth of the primary silicon phase, promoting the regularization of the primary silicon morphology and refining its size, and effectively reducing matrix grain size, significantly improving the mechanical properties of the Al-Si alloy.

The invention relates to the field of solid-state electrolytes, in particular to a sintering aid for a solid-state electrolyte and the solid-state electrolyte containing the sintering aid. The solid electrolyte is an LLTO solid electrolyte, and the sintering aid comprises the following components: a Li4Ti5O12 nano material, modified or unmodified Al2O3 nano particles and at least one fluoride; moreover, based on the total mass of the sintering aid, the mass percentage contents of the Li4Ti5O12 nano material, the modified Al2O3 nano particles and the fluoride are respectively selected from 60%-65%, 30%-35% and 5%-10%. The ionic conductivity of the LLTO solid electrolyte prepared by the sintering aid provided by the invention is remarkably improved.

This invention discloses the application of arc-fed wire feeding technology in the preparation of aero-engine turbine disk materials, belonging to the field of aero-engine turbine disk manufacturing technology. It involves using GH4169 high-temperature alloy as the base wire, electroplating TiC nanoparticles and Al2O3 nanoparticles to form a coating layer, producing a composite wire. An ultrasonic-assisted arc-fed wire feeding additive manufacturing process is then performed, with the ultrasonic action area covering the molten pool along the liquid / solid two-phase region. When the deposition layer temperature drops to a set temperature, alternating vertical and horizontal forging is performed in a multi-directional micro-forging process. Finally, heat treatment is conducted to obtain the aero-engine turbine disk material. This invention successfully solves the technical problems of coarse microstructure, numerous defects, and unstable performance in traditional additive manufacturing of aero-engine turbine disk materials through the synergistic effect of ultrasonic-assisted arc-fed wire feeding additive manufacturing, nanoparticle composite reinforcement, and synchronous multi-directional micro-forging.

The invention discloses a mechanoluminescence optical fiber and a preparation method and application thereof, and belongs to the field of rare earth. The mechanoluminescence optical fiber comprises a polydimethylsiloxane condensate, and core fluorescent powder, Al2O3 nanoparticles and long afterglow fluorescent powder which are uniformly distributed in the polydimethylsiloxane condensate, the core fluorescent powder is ZnS fluorescent powder doped with Cu < 2 + >; and the long-afterglow fluorescent powder is SrAl2O4 fluorescent powder doped with Eu < 2 + > and Dy < 2 + >. According to the mechanoluminescence optical fiber disclosed by the invention, through the synergistic effect of the added specific long-afterglow fluorescent powder and the core fluorescent powder, the mechanoluminescence optical fiber has excellent luminous intensity and long-afterglow performance.

The invention discloses an alpha-Al2O3 nano-particle high-precision particle size grading method based on a four-layer non-equidistant density gradient solution and a collaborative sedimentation mechanism, which comprises the following steps: S1, carrying out surface dispersion treatment on alpha-Al2O3 nano-particles to form a uniform particle suspension with the mass fraction of 0.1-0.2 wt%; and S2, constructing four layers of non-equidistant density gradient liquid: sequentially and slowly injecting solvents with different densities into the centrifugal tube from bottom to top. According to the method, a four-layer non-equidistant density gradient liquid system is constructed, and a multi-stage differential sedimentation interface is formed in the centrifugation process, so that alpha-Al2O3 nanoparticles in different particle size sections obtain a relatively clear migration path, the mixing crossing probability of particles with approximate particle sizes at the interface is reduced, and the definition of a hierarchical structure is improved.

The invention discloses a preparation method of a textile with a passive radiation cooling function, and a composite fiber membrane with a radiation cooling effect is prepared by utilizing an absolute methanol solution of PA6 and a DMF (Dimethyl Formamide) solution containing TPU (Thermoplastic Polyurethane) and Al2O3 through an electrostatic spinning technology. The fiber membrane is composed of a TPU / Al2O3 layer and a PA6 layer, scattering of sunlight in the fiber layer is enhanced through the micro-nano-level fiber scale, Al2O3 nanoparticles are evenly dispersed in TPU fibers, the reflectivity of the composite fiber membrane to ultraviolet-visible light is enhanced, the effect of protecting the human skin is achieved, functional groups in TPU can enhance infrared radiation of an atmospheric transparent window, and the functional groups in TPU can enhance the infrared radiation of the atmospheric transparent window. And the temperature is reduced. PA6 is used as an infrared transparent material, infrared radiation of human skin can be enhanced, and the radiation refrigeration effect of the composite fiber membrane is further enhanced.

The invention discloses an intelligent cable bridge with an active heat dissipation function, and the cable bridge comprises a cable trough frame, a plurality of cooling pipes are fixedly arranged on the inner wall of the bottom of the cable trough frame, the interior of each cooling pipe is filled with a phase-change material, the phase-change materials are acetone and Al2O3 nanoparticles, the side surface of the cable trough frame is provided with rectangular air inlets, and the rectangular air inlets are communicated with the cooling pipes. Two sliding rails are fixedly installed on the side wall of the cable groove frame and located on the two sides of the rectangular air inlet hole. The conical heat conduction groove collects cable heat to drive the piezoelectric film to generate power, electric energy is stored and then supplies power to the semiconductor cooler, the cooling fan and the electromagnet, and zero external energy heat dissipation is achieved. The acetone and Al2O3 nano-particle composite phase change material improves the heat capacity and the response speed, and cross overheating is avoided in combination with the spaced cable trough. The electromagnet linkage baffle automatically opens and closes the air inlet hole along with the temperature, gravity reset sealing is achieved, semiconductor refrigeration waste heat is returned to the power generation end, and the energy efficiency is improved.

The invention discloses a morphology response difference-based alpha-Al2O3 nanoparticle differential centrifugal separation method, which comprises the following steps: S1, dispersing alpha-Al2O3 nanoparticles in absolute ethyl alcohol at a concentration of 0.55 wt%, and continuously dispersing the particles by using an ultrasonic device; s2, carrying out high-speed centrifugation on the obtained suspension liquid under the condition of 10000-15000 rpm, discarding lower-layer precipitates, and reserving supernate; s3, performing ultrasonic dispersion on the supernate again under the same condition as that in the step S1; s4, carrying out medium-speed centrifugation on the dispersed system at a speed of 4000-7000 rpm, and collecting the lower layer precipitate; and S5, repeating the combined process of the steps S2-S4 for 2-3 rounds, combining all precipitates obtained in the medium-speed centrifugation stage, and drying to obtain the target alpha-Al2O3 nanoparticles. The particles obtained by the method show higher polishing rate and lower surface roughness and defect density in CMP (Chemical Mechanical Polishing), and the density and grain uniformity are improved in ceramic sintering; meanwhile, the method is clear in process, adjustable in parameter and high in equipment universality, and has remarkable industrial amplification and engineering application potential.

The invention relates to a method for improving the stability of a perovskite solar cell, and belongs to the technical field of perovskite solar cell preparation, and the internal structure of the perovskite solar cell comprises a substrate, a conductive layer, a hole transport layer, a perovskite absorption layer, an electron transport layer and a back electrode layer from bottom to top. An interface layer is further arranged between the hole transport layer and the perovskite layer, a nano-particle layer is further arranged between the hole transport layer and the interface layer, and the method comprises the following steps: firstly preparing the nano-particle layer on the hole transport layer, and then preparing the interface layer on the nano-particle layer; wherein the preparation material of the hole transport layer is NiOx, and the preparation material of the nanoparticle layer is any one of Al2O3 nanoparticles, SnO2 nanoparticles, SiO2 nanoparticles and MgO nanoparticles. According to the perovskite solar cell, the nanoparticle layer is arranged between the hole transport layer and the interface layer, so that the binding force between the interface layer and the hole transport layer is improved, and the stability of the perovskite solar cell is improved.

This invention discloses a differential centrifugation method for separating α-Al₂O₃ nanoparticles based on morphological response differences, comprising the following steps: S1: Dispersing α-Al₂O₃ nanoparticles at a concentration of 0.55 wt% in anhydrous ethanol, and continuously dispersing the particles using an ultrasonic device; S2: Centrifuging the resulting suspension at 10,000–15,000 rpm, discarding the lower precipitate, and retaining the supernatant; S3: Dispersing the supernatant again using ultrasonication under the same conditions as in step S1; S4: Centrifuging the dispersed system at 4,000–7,000 rpm at a medium speed, and collecting the lower precipitate; S5: Repeating the combined process of steps S2–S4 2–3 times, merging all precipitates obtained in the medium-speed centrifugation stage, and obtaining the target α-Al₂O₃ nanoparticles after drying. The particles obtained by this method exhibit higher polishing rates, lower surface roughness, and lower defect density in CMP, which improves density and grain uniformity in ceramic sintering. At the same time, the method has a clear process, adjustable parameters, and strong equipment versatility, and has significant potential for industrial scale-up and engineering applications.

This invention discloses a high-boiling-point stable nano-heat exchange fluid and its preparation method. The heat exchange fluid uses a binary mixed base liquid composed of pure water and a polyol selected from ethylene glycol, 1,2-propanediol, and 1,2-butanediol. After adding a surfactant to the binary mixed base liquid, a nanoparticle system mainly composed of Al2O3 nanoparticles is introduced, followed by dispersion and homogenization treatment to obtain the stable nano-heat exchange fluid. The nanoparticle system may further include MWCNT nanoparticles and SiO2 nanoparticles to form composite nanoparticles, balancing enhanced thermal conductivity and dispersion stability. Compared with existing heat exchange working fluids, this invention improves the liquid-phase stable operating range, thermal conductivity, and adaptability to cyclic heat exchange by synergistically controlling the base liquid composition and the nanoparticle system. It is suitable for closed-loop high-temperature heat exchange, industrial waste heat recovery, and thermal management of electronic devices.

The invention relates to a polyimide composite gradient structure lithium battery diaphragm which is characterized by comprising a base layer, a middle layer and a surface layer which are sequentially arranged, the base layer is a polyimide nanofiber net, the diameter of polyimide nanofibers is 50-200nm, the porosity of the base layer is 70-85%, and the thickness of the base layer is 15-30mu m; the middle layer is a composite coating of a hydrophilic polymer and Al2O3 nano-particles, the surface of at least one side of the base layer is coated with the middle layer, the thickness of the middle layer ranges from 2 micrometers to 4 micrometers, the average particle size of the Al2O3 nano-particles ranges from 50 nm to 100 nm, and the Al2O3 nano-particles account for 30%-50% of the total mass of the middle layer; the surface layer is a porous layer containing SiO2 micron particles and covers the surface of the middle layer, the thickness of the surface layer is 3-6 microns, the average particle size of the SiO2 micron particles is 1-3 microns, the porosity of the surface layer is increased in a gradient mode from the side close to the middle layer to the outer side, and the gradient change rate is 10-15% / micron. According to the scheme, the lithium battery diaphragm with synergic improvement of temperature resistance, liquid absorption rate and ion conduction performance is realized.

The invention belongs to the technical field of semiconductor material preparation and new energy, and particularly discloses flexible water photovoltaic fabric based on MXene and Al2O3 and a preparation method of the flexible water photovoltaic fabric. The flexible water photovoltaic fabric based on MXene and Al2O3 comprises a flexible cotton cloth substrate, a flexible water photovoltaic fabric layer and a flexible water photovoltaic fabric layer, the functional coating is loaded on the surface of the cotton cloth fiber and in interwoven pores; the functional coating is of a graded composite structure containing Al2O3 nano particles and MXene nano sheets; wherein the Al2O3 nanoparticles are used as a water evaporation induced charge generation source; the MXene nanosheets are mutually lapped to form a three-dimensional conductive network, and the three-dimensional conductive network is used for rapidly extracting and conducting charges generated at the interface of the Al2O3 nanoparticles. The flexible water photovoltaic fabric prepared by the invention has excellent flexibility and better current output performance.