CN102151528A - High purity nano material and preparation method thereof - Google Patents

Abstract

The invention discloses a high purity nano material and a preparation method thereof. The method is characterized by comprising the following steps of; (1) subjecting cation exchange fiber or ion exchange resin to acid-base pretreatment and washing with deionized water to cause electric conductivity to be less than 100 muS/cm; (2) adding precursor salt ion solution having certain concentration to fiber/resin solution, slightly stirring to perform ion pre-exchange to convert fiber/resin; (3) adding urea having certain concentration to a converted fiber/resin system, uniformly stirring and then performing hydrothermal treatment under certain temperature and time; and (4) separating the product from fiber by ultrasonic treatment, filtering, centrifuging, drying and calcining. The method of the invention realizes the low temperature double-control synthesis of nano materials with different appearances; impurity ions in the system are enriched on fiber/resin through exchange reaction, without washing the product. The entire synthesis process is energy-saving and environmentally-friendly, and carves out a new way for the synthesis of high purity nano material.

Description

A kind of high-purity nm material and preparation method thereof

Technical field

The present invention relates to a kind of high-purity nm material and preparation method thereof.

Background technology

Nano material has special nature, the dispersivity of nano material height and a large amount of interfaces provide the short-range diffusion approach for atom, caused high diffusivity, it is to creep, superplasticity has appreciable impact, and solid solubility enhancing, sintering temperature reduction, chemism increase, the corrosion resistance of limit solid solution are strengthened.Character such as the power that therefore nano material showed, heat, sound, light, electromagnetism often are different from the character that this material shows when the coarse-grain state.Toughness that compare with the conventional crystal material, nano material has high strength---hardness, high diffusibility, high-ductility---, low-density, low elastic modulus, high resistance, high specific heat, high thermal expansion coefficient, lower thermal conductivity, strong soft magnet performance.These properties make nano material can be widely used in fields such as strong mechanical performance environment, photo-thermal absorption, nonlinear optics, magnetic recording, special conductor, molecular sieve, ultra micro composite, catalyst, heat exchange material, sensing element, sintering aid, lubricant.

Existing how tame manufacturer is in succession with nanometer powder and nano-component industrialization American-European-Japanese, synthesizes in nanometer, many-sides such as nanodevice Precision Machining, nanometer biotechnology, nanometer basic theory are in rank first.Some nano material development companies have also been founded by China under the international environment influence, China has more than 20 tame research institutions of more than 50 university and more than 300 enterprise to be engaged in research in nanotechnology at present, set up more than 10 nanometer technology production line, company more than 100 with the nanometer technology registration is individual, mainly produces primary product such as superfine nano powder, biochemical nano powder.

Through decades the research of nanometer technology being explored, scientist can handle single atom in the laboratory now, and nanometer technology has had rapid development.The application study of nanometer technology is just at field high speed developments such as semiconductor chip, cancer diagnosis, optics new material and biomolecule trackings.

Though nanometer technology is seen experimental study and the small-scale production stage of still being at present on the whole, from viewpoint of history: nowadays a country that payes attention to micron science and technology the seventies in last century has all become developed country.The current country that payes attention to the development nanometer technology becomes advanced country in 21 century probably.Nanometer technology is stern challenge to us, is again rare opportunity, must the renewed attention nanometer technology and nanometer basis Study on Theory, and for China realizes that in 21 century economic liftoff establishes solid foundation.The change that whole human society will produce essence because of the development and the commercialization of nanometer technology.

At present, the preparation method of nano-powder is varied, integrate and mainly contain liquid phase method, solid phase method and vapor phase method, and liquid phase method becomes the prefered method of preparation of industrialization because the reaction condition gentleness is easy to advantages such as control.In the process of preparation superfine powder, each stage all can cause the formation of growing up of particle and aggregate.Compare with other preparation methods, hydro-thermal method provides physics that can't obtain and chemical environment for the reaction and the crystallization of various predecessors under condition of normal pressure.Dissolving and crystallization process have been experienced in the formation of powder.Can also not take high temperature sintering to handle in the preparation process, avoid the powder hard aggregation that may form, the powder purity height, the good dispersion that make, and pollute little, less energy consumption.

Summary of the invention

Proposition of the present invention is intended to adopt a kind of low-temperature hydro-thermal synthesis based on the double elements DIFFUSION CONTROLLED, synthetic high-purity nm material powder.

Technical solution of the present invention is achieved in that

(1) with the method for cation exchange fibre or ion exchange resin employing acid-base pretreatment, spends deionised water and make electrical conductivity＜100 μ S/cm;

(2) certain density precursor salt solion is added in the fiber/resin solution, gentle agitation is carried out the pre-exchange of ion, and fiber/resin is made the transition;

(3) the finite concentration urea liquid is added in back fiber/resin system transition, hydrothermal treatment consists is carried out in the back that stirs under uniform temperature, time conditions;

(4) with product ultrasonic make with fiber separation, filtration, centrifugal, drying after, roasting.

Described preparation technology's optimal processing parameter is: the pre-exchange degree of metal ion on described fiber/resin is 80%, 90 ℃ of synthesis temperatures, generated time 8～24h, baking temperature are 80 ℃, drying time 24h.

Compared with prior art, the invention has the advantages that:

(1) this method is reflected at by ion-exchange surface and has removed impurity in the building-up process simultaneously, has removed water-washing process from.

(2) need not to add surfactant in the building-up process, can obtain high degree of dispersion, do not have and reunite, highly purified nano material powder.

(3) the renewable recycling of used fiber/resin.Compare with the traditional water thermal synthesis method, this experiment just can reach identical granularity and the purity of Geng Gao at a lower temperature, is a kind of energy-conservation eco-friendly new method.

Description of drawings

Fig. 1: fresh ion-exchange fibre scanning electron microscope sem figure;

Fig. 2: the spherical basic carbonate cerium of fiber surface scanning electron microscope sem figure;

Fig. 3: fiber surface sheet basic carbonate cerium scanning electron microscope sem figure;

Fig. 4: the bar-shaped basic carbonate cerium of fiber surface scanning electron microscope sem figure;

Fig. 5: the X-ray diffraction XRD figure of nano-cerium oxide sample behind 400 ℃ of roasting 4h.

The specific embodiment

As Fig. 1～shown in Figure 5.A kind of new method for preparing nano material is characterized in that it being a kind of low-temperature hydro-thermal synthesis based on the double elements DIFFUSION CONTROLLED.The metal group of this nano material becomes one or more the transition metal that comprises in iron, cobalt, ruthenium, rhodium, palladium, osmium, iridium, platinum, copper, silver, the gold, and one or more thuliums in lanthanide series such as lanthanum, cerium, praseodymium, neodymium etc., synthetic product is its corresponding carbonate, subcarbonate and oxide thereof.Its technical process mainly may further comprise the steps:

(1) with the method for cation exchange fibre or ion exchange resin employing acid-base pretreatment, spends deionised water and make electrical conductivity＜100 μ S/cm;

(2) certain density precursor salt solion is added in the fiber/resin solution, gentle agitation is carried out the pre-exchange of ion, and fiber/resin is made the transition;

(3) the finite concentration urea liquid is added in back fiber/resin system transition, hydrothermal treatment consists is carried out in the back that stirs under uniform temperature, time conditions;

(4) with product is ultrasonic make product and fiber separation, filtration, centrifugal, drying after, roasting.

Be described further below in conjunction with embodiment.

Embodiment 1

The pre-exchange of cation exchange fibre: under the room temperature condition, get preliminary treatment (GB/T5476-1996) strong acidic ion-exchange fiber 2.0g excessively in the 250ml beaker, add 0.01mol/L cerous nitrate solution 40ml, be supplemented to 100ml with deionized water, stir 3h at 200r/min condition lower magnetic force, deionized water is washed to out water conductivity＜100 μ S/cm then, leaches the back in 80 ℃ of dry 24h.

Embodiment 2

The preparation of spherical basic carbonate cerium: get by embodiment 1 and pre-pay the cerium type strong acidic ion-exchange fiber of finishing changing, add in the 20ml 1.0mol/L urea liquid and be supplemented to 70ml, ultrasonic 3h under the room temperature, change in the 100ml hydrothermal reaction kettle, keep 24h in 90 ℃ of baking ovens, filter after reducing to room temperature, be washed to neutrality, in 80 ℃ of dry 24h.

Embodiment 3

The pre-exchange of cation exchange fibre: under the room temperature condition, get preliminary treatment (GB/T5476-1996) strong acidic ion-exchange fiber 2.0g excessively in the 250ml beaker, add 0.05mol/L cerous nitrate solution 40ml, be supplemented to 100ml with deionized water, stir 3h at 200r/min condition lower magnetic force, deionized water is washed to out water conductivity＜100 μ S/cm then, leaches the back in 80 ℃ of dry 24h.

Embodiment 4

The preparation of sheet basic carbonate cerium: get by embodiment 3 and pre-pay the cerium type strong acidic ion-exchange fiber 2.0g that finishes changing, add in the 20ml 1.0mol/L urea liquid and be supplemented to 70ml, ultrasonic 3h under the room temperature, relay in the 100ml hydrothermal reaction kettle, keep 8h in 90 ℃ of baking ovens, filter after reducing to room temperature, be washed to neutrality, in 80 ℃ of dry 24h.

The preparation of bar-shaped basic carbonate cerium: get by embodiment 3 and pre-pay the cerium type strong acidic ion-exchange fiber 2.0g that finishes changing, add in the 20ml 1mol/L urea liquid and be supplemented to 70ml, ultrasonic 3h under the room temperature, relay in the 100ml hydrothermal reaction kettle, keep 16h in 90 ℃ of baking ovens, filter after reducing to room temperature, be washed to neutrality, in 80 ℃ of dry 24h.

Embodiment 5

The preparation of nano-cerium oxide: get by embodiment 3 and pre-pay the cerium type strong acidic ion-exchange fiber 2.0g that finishes changing, add in the 20ml 1mol/L urea liquid and be supplemented to 70ml, ultrasonic 3h under the room temperature, relay in the 100ml hydrothermal reaction kettle, keep 16h in 90 ℃ of baking ovens, filter after reducing to room temperature, be washed to neutrality, in 80 ℃ of dry 24h, 400 ℃ of roasting 4h.

Claims (3)

1. high-purity nm material, it is characterized in that: the metal group of this nano material become comprise in iron, cobalt, ruthenium, rhodium, palladium, osmium, iridium, platinum, copper, silver, the gold one or more transition metal and one or more thuliums in lanthanide series such as lanthanum, cerium, praseodymium, neodymium etc., synthetic product is its corresponding carbonate, subcarbonate and oxide thereof.

2. high-purity nm preparation methods according to claim 1 is characterized in that: may further comprise the steps:

(1) with the method for cation exchange fibre or ion exchange resin employing acid-base pretreatment, spends deionised water and make electrical conductivity＜100 μ S/cm;

(2) certain density precursor salt solion is added in the fiber/resin solution, gentle agitation is carried out the pre-exchange of ion, and fiber/resin is made the transition;

(3) the finite concentration urea liquid is added in back fiber/resin system transition, hydrothermal treatment consists is carried out in the back that stirs under uniform temperature, time conditions;

(4) with product ultrasonic make with fiber separation, filtration, centrifugal, drying after, roasting.

3. according to the described preparation of nanomaterials of claim 2, the optimal processing parameter that it is characterized in that described preparation method is: the pre-exchange degree of metal ion on fiber/resin is 80%, 90 ℃ of synthesis temperatures, generated time 8-24h, baking temperature is 80 ℃, drying time 24h.

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