1270results about How to "Good monodispersity" patented technology

The present invention provides new compositions containing colloidal nanocrystals with high photoluminescence quantum yields, new synthetic methods for the preparation of highly luminescent colloidal nanocrystals, as well as methods to control the photoluminescent properties of colloidal nanocrystals. The new synthetic methods disclosed herein allow photoemission brightness (quantum yield) to be correlated with certain adjustable nanocrystal growth parameters associated with a given synthetic scheme.

There is provided a method of preparing carbon supported, ternary alloy composition core-shell PtVFe nanoparticles for use as fuel cell electrocatalysts. These catalysts have been found particularly useful for oxygen reduction reactions. The alloy nanoparticles can be assembled on carbon supports which then may undergo subsequent activation and / or calcination treatments. The method, combined with new synthetic feed and processing conditions, provides core-shell PtVFe alloy nanoparticles of 1–3 nm size. The catalyst-produced high monodispersity, controlled composition are highly dispersed, and have a uniform distribution. Finally, the correlation of the preparation and treatment parameters to the ORR catalytic activities of the prepared nanoparticles is described. The catalysts exhibit ORR in the range of 2 to 4 times more than a standard Pt / carbon catalyst.

An inorganic nanowire having an organic scaffold substantially removed from the inorganic nanowire, the inorganic nanowire consisting essentially of fused inorganic nanoparticles substantially free of the organic scaffold, and methods of making same. For example, a virus-based scaffold for the synthesis of single crystal ZnS, CdS and free-standing L10 CoPt and FePt nanowires can be used, with the means of modifying substrate specificity through standard biological methods. Peptides can be selected through an evolutionary screening process that exhibit control of composition, size, and phase during nanoparticle nucleation have been expressed on the highly ordered filamentous capsid of the M13 bacteriophage. The incorporation of specific, nucleating peptides into the generic scaffold of the M13 coat structure can provide a viable template for the directed synthesis of a variety of materials including semiconducting and magnetic materials. Removal of the viral template via annealing can promote oriented aggregation-based crystal growth, forming individual crystalline nanowires. The unique ability to interchange substrate specific peptides into the linear self-assembled filamentous construct of the M13 virus introduces a material tunability not seen in previous synthetic routes. Therefore, this system provides a genetic tool kit for growing and organizing nanowires from various materials including semiconducting and magnetic materials.

There is described a method for forming an emulsion (1) containing at least one dispersed phase (3) and a continuous phase (2) in a fluidic microsystem (100), said method comprising the steps: forming flows (4, 5) of different liquids which flow towards a dispersion region (10), and forming the emulsion (1) from the liquids in the dispersion region (10), wherein the flows (4, 5) run through a common channel (20) to the dispersion region (10) and the flows (4, 5) are arranged next to one another relative to a first reference direction, and wherein the emulsion (1) is produced as the liquids flow through a cross-sectional widening (11) provided in the dispersion region (10), at which the cross section of the channel (20) widens in a second reference direction different from the first reference direction. A fluidic microsystem for forming an emulsion (1) containing a continuous phase (2) and at least one dispersed phase (3) is also described. A fusion of droplets in electric fields is also described.

The invention discloses a magnetic luminescent composite nano-particle Fe3O4 / CdTe / SiO2 and a preparation method thereof. The method for preparing the magnetic luminescent composite nano-particle Fe3O4 / CdTe / SiO2 comprises the steps of: firstly preparing hydrophobic monodisperse Fe3O4 nano-particles by adopting a chemical oil-phase high-temperature method, and modifying the surfaces of the hydrophobic Fe3O4 nano-particles to ensure that the hydrophobic Fe3O4 nano-particles are dispersed in a water phase; preparing luminescent CdTe quantum dots of which the surfaces are provided with carboxyl groups, and precipitating the luminescent CdTe quantum dots on the surfaces of the magnetic Fe3O4 nano-particles through the co-precipitation; then utilizing ligand exchange to modify a silane coupling agent on the surfaces of the luminescent CdTe quantum dots; and finally forming an outermost SiO2 coating layer through silane or silicon ester hydrolysis. The diameter of the magnetic luminescent composite nano-particle Fe3O4 / CdTe / SiO2 is between 30 and 50nm; the magnetic luminescent composite nano-particle Fe3O4 / CdTe / SiO2has double functions of magnetism and fluorescence at the same time, has strong and durable fluorescence intensity after labeling rat bone marrow-derived mesenchymal stem cells, and apparently reduces cellular magnetic resonance signals. The particle has broad application prospect in the fields such as biological labeling, bioseparation and the like.

The invention discloses a preparation method for a composite cathode material of a lithium ion battery by means of spray drying pyrolysis treatment. The preparation method includes the steps: dissolving a first type of binder organic carbon source into solvent of a proper quantity, adding a silicon source, a second type of binder and a dispersing agent, dispersing uniformly, adding graphite, dispersing for a certain time, subjecting uniformly dispersed suspension to spray drying, and using the first type of binder organic carbon source to bond the silicon source, the graphite and the second type of binder particles into spherical or spherical-like forms to obtain a composite precursor; and transferring the precursor into a shielding atmosphere for sintering, heating the second type of binder to a certain temperature to be melted into a liquid crystal state, bonding the particle silicon source and the graphite into cores, subjecting the organic carbon source to pyrolysis at the high temperature to form a coating, and furnace cooling to obtain the carbon-silicon composite cathode material of the lithium ion battery. The preparation method is simple, easy in implementation and high in practicality. The carbon-silicon composite prepared by the method has the advantages of high reversible capacity, designable capacity, high circulating performance and high-current discharging performance, high tap density and the like.

The present invention discloses a graphene quantum dot preparation method, belongs to the technical field of nanometer material preparation, and particularly relates to a graphene quantum dot preparation method. The technical scheme comprises that: a carbon material being subjected to deep oxidation is cut into graphene oxide nano-sheets, C=C bonds and C-C bonds of the graphene oxide are broken to prepare green fluorescence graphene oxide quantum dots, and a reduction or high temperature annealing method is further adopted to prepare the blue fluorescence graphene quantum dots. According to the present invention, the operations are simple, the raw materials are easy to obtain, and the prepared graphene quantum dots have characteristics of excellent monodispersity, good water solubility and strong fluorescence, and have potential application prospects in the fields of supercapacitors, lithium batteries, biological imaging, solar cells, field-effect transistors, OLEDs and the like.

The invention relates to a mono-dispersed spherical mesoporous silicon dioxide nanomaterial, which is characterized in that: the nanomaterial has a spherical structure of which the particle diameter is 80-200 nanometers; the relative standard deviation of the particle diameter is not more than 8 percent; the specific surface area of the material is 1,057-1,379 m<2> / g; the pore volume is 0.74-0.89 cm<3> / g; the mesoporous pore diameter is 2.4-2.6 nanometers; and the nanometer material has a pore canal structure formed radially from the center of a sphere to an outer surface. The mono-dispersed spherical mesoporous silicon dioxide nanomaterial is prepared by hydrolyzing and condensing by taking a cationic surfactant as a template, tetraethyl orthosilicate as a silicon source and alcohol as a cosolvent under alkaline condition. The method has the advantages of simple equipment, easiness of operation, short preparation period, high repeatability, high yield, low cost and environment friendliness. The prepared silicon dioxide material is of spherical nanoparticles which have controllable particle diameters, uniform particle diameter distribution, high mono-dispersity, narrow pore diameter distribution and ordered mesoporous pore canal structures.

The invention relates to a multi-core core-shell-structure silicon carbon composite negative pole material and a preparation method thereof. The preparation method comprises the following steps: 1. preparation method of high-dispersivity multi-core porous spheres; 2. preparation of high-dispersivity asphalt suspension; and 3. preparation of multi-core core-shell-structure silicon carbon composite negative pole material: adding the porous spheres prepared in the step 1 into the high-dispersivity asphalt suspension prepared in the step 2, carrying out ultrasonic dispersion, heating and drying by distillation while intensely stirring to remove the solvent, transferring the powder particles into a protective atmosphere, and holding at low temperature so that the asphalt liquid enters the inside of the porous spheres to enhance the binding strength between the silicon source and the conducting carbon mesh, carry out secondary coating on the silicon source, overcome the defects in the coating in the step 1 and enhance the capacity performance of the silicon; and carrying out high-heat treatment. The invention is simple and easy to implement, and has the advantage of high practicality. The prepared silicon carbon composite material has the advantages of high reversible capacity, designable capacity, favorable cycle performance, favorable heavy-current discharge capacity, high tap density and the like.

The invention relates to a hollow material with a composite structure of SiO2 / TiO2 and a preparation method and application thereof. By applying hydrothermal reaction, glucose solution is carbonized at 160 to 200 DEG C to obtain carbon nanometer spheres with a particle size of 200nm to 1um; the carbon nanometer spheres are used as hard templates; hydrolysis of ethyl orthosilicate and tetrabutyl titanate are used for wrapping the SiO2 and TiO2 on the surfaces of the carbon spheres; the obtained product is annealed for an hour at the temperature of 450 to 500 DEG C; the carbon spheres are removed, and the hollow structure of silicon dioxide / titanium dioxide is obtained; then the obtained product is prepared into membranes with different layers by applying a czochralski method and a spin coating method respectively. The method is reasonable in design and simple in technology; besides, the hollow structure has even size-distribution and controllable particle size; the hollow silicon dioxide can remarkably improve the transmission rate of the membranes; the composite membranes are widely applied to fields such as windshields, various lenses and agricultural greenhouses.

Monodisperse colored spherical particles each having two separated color regions of two hues, that is, two-colored spherical particles, useful, for example, for displays of characters, graphics, images and the like, the two hues being for reverse display in terms of electricity and magnetism from the viewpoint of good suitability for display are provided. In the production process and the apparatus for producing the colored spherical polymer particles, microchannels are utilized including a first microchannel through which a colored continuous phase comprising a color dye / pigment dispersed in a fluid dispersing medium containing a polymerizable resin component and having colored phases of different hues is transferred, and a second microchannel through which a spheroidizing disperse phase flows. The process and apparatus spheroidizes the discharged colored continuous phase having two hues and cures the polymerizable resin component in the colored continuous phase, whereby colored spherical polymer particles are formed.

The invention relates to a method for preparing series of high-purity silver nanometer materials. The method comprises the following steps: using a halogen-containing metal salt adjuvant to treat polyalcohol, a macromolecule surface active agent, the halogen-containing metal salt adjuvant and salts of silver ions in three steps, and then preparing the nanometer materials by performing a hybrid reaction at a high temperature. The nanometer materials prepared by the using the method have the advantages of uniform appearance, high purity, excellent monodispersity, lower cost, and simple reaction device. By using the method, the appearance is controllable, the size controlling scope is wide, and the large-scale synthesis of silver nanometer materials can be realized. The method has an industrialization prospect.

A process for preparing nano-class metal particles by dual-pouring method features that under the existance of protector and regulator, the metallic salt is reduced by reducing agent to obtain one ormore (30-100 nm) metallic particles. Its advantages are high dispersity, easy control of diameter, high output rate up to 95%, and preparing the particles of more metals by a single equipment.

The invention relates to a hollow porous spherical platinum-silver alloy nano-material and a preparation method for the same. The nano-material is of a spherical structure with a porous shell and an internal cavity, the diameter of the spherical structure ranges from 5 nanometers to 500 nanometers, the inner diameter of the cavity ranges from 1 nanometer to 400 nanometers, the thickness of a porewall ranges from 1 nanometer to 50 nanometers, and the pore diameter ranges from 1 nanometer to 20 nanometers. Polyatomic alcohol, inorganic silver salt precursor, inorganic platinum salt precursor and polyvinylpyrrolidone are used as reaction raw materials, inorganic salt containing halogen ions and copper-containing inorganic salt are used as auxiliaries, and the hollow porous spherical platinum-silver alloy nano-material is synthesized by means of reaction. The preparation method is simple in process, convenient in operation, fine in repeatability and low in cost, and the obtained hollow porous spherical platinum-silver alloy nano-material can be used for the fields of chemical and electrochemical catalysis, chemical sensors, biomolecular sensors, information storage, fuel cells, solarcells and the like. Particularly, the hollow porous structure of the nano-material can be effectively applied to slow drug release and target-oriented drug delivery treatment.

The invention discloses a preparation method and a use of poly(lactic-co-glycolic acid) (PLGA) microspheres as nucleic acid vaccine vectors. A result of an animal immunization experiment shows that the PLGA microspheres can be utilized as gene vaccine vectors. Principles of the PLGA microspheres comprise that 1, the PLGA microspheres have core-shell structures; surface polymers comprise polymine, PLGA, glucose, chitosan, polylysine, FeCl3 and FeCl2; and through static electricity, dewatering interaction and hydrogen bond-nucleic acid vaccine interaction, a nucleic acid vaccine is concentrated to form a compact nucleic acid vaccine so that nucleic acid vaccine degradation is reduced in vivo; 2, the PLGA microspheres have magnetism and thus after immunization injection, in a strong magnetic field, the distribution of the PLGA microspheres in muscular tissue is improved and the defect of limited contact between the PLGA microspheres and target cells is overcome; and 3, through long-term strong magnetic field induction, a magnetic PLGA microsphere / nucleic acid vaccine complex can enter into the skin; and because of rich antigen presenting cells in the skin, a strong and fast immune response can be induced.

The invention belongs to the technology field of nanometer materials preparation, particularly relates to a preparation method of monodisperse polystyrene microspheres capable of controlling the particle size of the polystyrene microspheres within a certain range by changing the use amount of a stabilizer. The invention prepares polystyrene microspheres with simply purified styrene as a monomer, potassium persulfate as an initiator, water as a reaction medium and polyvinylpyrrolidone as a stabilizer by using soap-free emulsion polymerization. The preparation method uses electromagnetic stirring instead of electric stirring; and has the advantages of relatively low requirements for the uniformity of stirring speed, no need of surfactant, simple process, and low cost. The obtained polystyrene microspheres have good monodispersity, and the particle size thereof can be controlled within the range of 250-1,400nm by changing the use amount of the stabilizer. The monodispersed polystyrene microspheres have important application value as a module or template in construction of photonic crystals, inorganic / organic nanometer composite materials and hollow micrometer / nanometer spheres.

The invention discloses a sandwich-like hollow structure metallic oxide @ noble metal nanoparticles @ metallic oxide catalyst as well as a preparation method and the use of the sandwich-like hollow structure metallic oxide @ noble metal nanoparticle @ metallic oxide catalyst. The method combines a sol-gel method and a hydrothermal method, and comprises the steps of preparing a spherical SO2 template with uniform size by the sol-gel method; then, coating a metallic oxide shell layer on the surface of the spherical SO2 template, adsorbing noble metal nanoparticles to the surface of the shell layer by electrostatic action, and further coating another metallic oxide shell layer on the surface of the spherical SO2 template by the sol-gel method; finally, carrying out crystallization on the amorphous metallic oxide shell layers and removing the SO2 template by adopting the hydrothermal method to obtain the sandwich-like hollow structure catalyst. The existing 'high-temperature calcination and alkali etching' method is replaced by the hydrothermal method; the method has the characteristics of being simple in operation, high in yield and good in monodispersity; the prepared sandwich-like hollow structure material is excellent in activity and stability in a catalytic reaction.

The invention relates to a preparation method of a monodispersed vaterite type calcium carbonate microsphere, which comprises the following steps of: (1) preparing a calcium salt aqueous solution with the concentration of 30-150mmol / L, and then, adjusting the pH value of the calcium salt aqueous solution to 8.5-10; (2) preparing a carbonate or hydrocarbonate aqueous solution with the concentration of 30-150mmol / L, and then, adjusting the pH value of the carbonate or hydrocarbonate aqueous solution to 8.5-10; (3) preparing a functional hyperbranched polyglycerol aqueous solution with the concentration of 20-400mg / L, and then, adjusting the pH value of the functional hyperbranched polyglycerol aqueous solution to 8.5-10; (4) mixing and uniformly stirring the carbonate or hydrocarbonate aqueous solution, the calcium salt aqueous solution and the functional hyperbranched polyglycerol aqueous solution at the temperature of 10-35 DEG C, and aging for 1-12h; and (5) centrifuging or filtering the mixed solution, cleaning a sediment, and drying to obtain the monodispersed vaterite type calcium carbonate microsphere. The monodispersed vaterite type calcium carbonate microsphere prepared by using the preparation method provided by the invention has the advantages of uniform particle size, stable crystal form and industrial application value.

The invention discloses a water phase preparation method of a spherical silver nanoparticle with adjustable size, which comprises the following steps of: 10, preparing a silver seed solution : 101, mixing deionized water with a sodium citrate solution, and obtaining a stabilizer solution after stirring; 102, heating the stabilizer solution to the temperature of water bath, adding an AgNO3 solution, and then adding a NaHB4 solution; and 103, utilizing the deionized water to obtain a constant volume after cooling at room temperature, and obtaining the silver seed solution; 20, preparing the spherical silver nanoparticle: 201, adding deionized water to a flask, then adding sodium citrate solution to obtain a reducer solution, and heating the reducer solution to a boiling state; 202, adding the silver seed solution to the reducer solution, and then adding the AgNO3 solution; and 203, cooling at room temperature to obtain the spherical silver nanoparticle. The preparation method can be used for preparing the spherical silver nanoparticle with favorable monodispersity, and the size of the spherical silver nanoparticle can be adjusted.

The invention relates to a noble metal nanocatalyst loaded on a dendritic macromolecule functionalized graphene and a preparation method thereof. The nanocatalyst is composed of graphene, silane coupling agents, dendritic macromolecules and noble metal nanoclusters, wherein the dendritic macromolecules are amino-terminated polyamide-amine (PAMAM) dendritic macromolecules, and the noble metal nanoclusters comprise palladium, platinum, gold, silver, ruthenium, iridium, osmium and related alloys. Aminos are introduced onto the surfaces of exfoliated graphene by the silane coupling agents, then different generations of the dendritic macromolecules are covalently introduced, and further the nanoclusters of noble metals and the related alloys are loaded by using the above-obtained materials as templates. The loaded noble metal nanocatalyst is not easy to agglomerate or to fall off during catalytic processes, and has high catalytic activity. The loaded noble metal nanoclusters has the characteristics of tunable size and controllable shape, and the structure and composition of the noble metal alloys can be controlled accurately. The method is simple in process and short in period, and can easily realize industrial production.

The invention relates to a mesoporous nano silicon ball compound targeting drug delivery system as well as a preparation method and application thereof. The preparation method of the mesoporous nano silicon ball compound targeting drug delivery system comprises the following steps: 1) preparing amino-functionalized drug loading mesoporous silicon dioxide microspheres; 2) preparing hyaluronic acid-hydrosulphonyl polypeptide-adriamycin (HA-RGD-DOX); 3) preparing mesoporous microsphere-hyaluronic acid-hydrosulphonyl polypeptide-adriamycin--paclitaxel (MSNs-HA-RGD-DOX_PTX); and 4) preparing fluorescent marker modified mesoporous microsphere-hyaluronic acid-hydrosulphonyl polypeptide-adriamycin--paclitaxel compound (MSNs-HA-RGD-DOX-PTX). The mesoporous nano silicon ball compound targeting drug delivery system has the beneficial effects that firstly multi-targeting synergistic drug delivery is realized, multiple tumour cells and tissues can be killed, and reversal drug resistance is good; secondly, blood stability is excellent; thirdly, invisibility, drug release degree and controlled release properties are good; fourthly, in vivo tracing function is good; and fifthly, the mesoporous nano silicon ball compound targeting drug delivery system has good general applicability.

The invention relates to a preparation method for hollow nano metal, which comprises the following steps: a), reducing agent is dissolved into deionized water firstly, then is mixed with organic solvent and surface active agent, and stirring is performed for preparing microemulsion; b), water inside a system is evaporated through azeotropic distillation till the solution is clear and colorless, and at the moment, and the reducing agent is coated with the surface active agent and exist in the system in a state of monodispersed nano particles; c), metallic compound is added into the system after getting complexing through complexant, and metal is obtained through the reduction of the metallic compound on the surface of the reducing agent; and d), centrifugal separation is performed on the system after reduction reaction, precipitation is taken, and the hollow nano metal can be obtained through centrifugation after water washing. A micro-emulsion method is utilized for preparing the hollow nano metal in an assisting manner, and since the reducing agent is used as a hard template, the size and the appearance of the hollow nano metal can be effectively controlled. The prepared hollow nano metal has excellent monodispersity and is uniform in size.

The invention discloses a novel method for reducing and preparing functionalized nano-silver based on polyphenol. The preparation process is as follows: 1), stock solutions of all reaction liquids are prepared, and the stock solutions comprise a silver-bearing predecessor stock solution, a polyphenol compound stock solution and an alkaline stock solution; 2), a polyphenol compound solution is prepared: a certain amount of the polyphenol compound stock solution is taken and added into ultrapure water, and the stock solution and the ultrapure water are mixed uniformly; 3), the pH value and the temperature of the polyphenol compound solution are adjusted: a proper amount of the alkaline stock solution is taken and added into the polyphenol compound solution prepared in the step 2), the pH value of the mixed solution is adjusted, the mixed solution is placed and kept out of the sun, and the temperature of the mixed solution is adjusted; and 4), a nano-silver solution is generated: a certain amount of the silver-bearing predecessor stock solution is added into the mixed solution with adjusted pH value and temperature in the step 3) and is kept out of the sun, and reaction is performed for a certain time. The operation method is simple, the synthesis speed is high, the cost is low, the biocompatibility is high, the method is pollution-free, the sizes of the synthesized nano-silver particles are small, the monodispersity is good, and the nano-silver also has the performance of a polyphenol compound.

The invention relates to a method for manufacturing series silver nano-sheets in a batch. The method includes dividing polyhydric alcohol, dimethyl formamide, high-polymer surfactant, metal salt adjuvant containing halogen and metal silver salt into three batches to be treated by the aid of the metal salt adjuvant containing the halogen; then uniformly mixing the materials; and obtaining the series silver nano-sheets by means of heating reaction. The silver nano-sheets are uniform in shape, high in purity, fine in monodispersity and low in cost, a reaction device is simple, large-scale preparation of the silver nano-sheets can be realized, and the method has an industrial prospect.

The invention provides a preparation method of perovskite quantum dots. The preparation method comprises steps as follows: A), Cs2CO3, oleic acid and octadecene are mixed and subjected to a heating reaction under the condition of protective atmosphere, and a cesium oleate precursor solution is obtained; B), lead halide and octadecene are mixed and subjected to heating and heat preservation under the condition of protective atmosphere, after an oleic acid and oleylamine mixed solution is added and heated to 170-190 DEG C, an obtained mixed solution is mixed and reacts with the cesium oleate precursor solution, and the perovskite quantum dots are obtained, wherein the lead halide is selected from one or more of lead chloride, lead bromide and lead iodide. According to the preparation method, the coordination effect of surface ligands of the perovskite quantum dots of different halide ions directly synthesized at a higher temperature is more remarkable, so that stability and fluorescence quantum efficiency of the synthesized perovskite quantum dots are both guaranteed.

The present invention provides novel calibration devices for use with fluorescent nanocrystal labels. Methods of preparing and using the calibration devices are also provided. Monodispersed populations of nanocrystals are deposited on surfaces. The monodispersed populations are obtained by dissolving the nanocrystals in a polar solvent.

The invention discloses a process for preparing high purity nano cerium dioxide, which comprises using cerium salts as cerium source, using carbonates, oxalates or oxalic acid as precipitating reagent, charging surface active agent, carrying out chemical precipitation reaction under the mechanical stirring action, obtaining precursors, finally subjecting the precursors to filtration, scouring, dispersing, drying and sintering in Muffle type furnaces.

A method of synthesizing highly monodispersed Au nanoparticles having diameters in the range of 30-90 nm. Seed nanoparticles in a controlled concentration are combined with a precursor, also in a controlled concentration, a reducing and capping agent (e.g., sodium acrylate) in aqueous solution. Under controlled conditions of pH, temperature, and time, highly monodispersed nanoparticles having diameters in the range of 30-100 nm are produced. A relative size standard deviation of the size distribution of the resulting nanoparticles is as low as 2%.

The invention discloses the preparation method of low cost cadmium selenide (CdSe) / cadmium sulphide (CdS) / zinc sulphide (ZnS) quantum point. The invention is characterized in that ethide xanthic acid cadmium and ethide xanthic acid zinc are adopted to be respectively dissolved in the mixed solvent of oleic amine and oleic acid, as well as cadmium stearate and zinc stearate; as the front dirking liquid of clads CdS and ZnS of a SdSe quantum point, the invention is slowly dropped into the mixed liquor of octadecene and octadecylamine dissolved with CdSe quantum point, so as to obtain CdSe / CdS / ZnS quantum points. The invention has the advantages that the price of the raw material is cheap, the toxicity is low, the operation is simple, and the mass synthesis is proper.