Freeze drying preparation method for nano-rare earth oxide powder

Abstract

The invention discloses a freeze drying preparation method for nano-rare earth oxide powder. The method comprises the following steps: dissolving one or two of dispersants, namely polyethylene glycoland fatty alcohol-polyoxyethylene ether, in water, dissolving soluble rare earth nitrate in water, and carrying out ultrasonic treatment so as to realize adequate dispersion and dissolving; atomizingthe solution into liquid nitrogen for pre-freezing or carrying out pre-freezing at -20 DEG C for over 4 hours; after the temperature of a freeze dryer is decreased to -50 DEG C, introducing the pre-frozen solution into the freezer dryer, starting a vacuum pump to maintain the vacuum degree to be below 20Pa, and carrying out freeze drying for 8-36 hours; and after the freeze drying, grinding composite powder, putting the composite powder into a furnace, and calcining the composite powder in air to remove the dispersing agent, so as to obtain the superfine nano-rare earth oxide powder. The preparation method is a physical method, does not relate to chemical reaction and is low in pollution, and the process is simple and convenient.

Description

technical field

[0001] The invention provides a freeze-drying preparation method of nano rare earth oxide powder, which belongs to the technical field of powder preparation engineering. Background technique

[0002] Rare earth oxides have many unique spectral properties and physical and chemical properties, and have been widely used in petroleum, chemical industry, metallurgy, textile, ceramics, glass, permanent magnet materials and other fields. Rare earth oxides are widely used in functional materials such as luminescent materials, magnetic materials, superconductors, high-performance ceramics, ultraviolet absorbers, and precision polishing materials. With the continuous advancement of science and technology, the value of rare earth oxides will increase. Ultrafine rare earth oxide powder is an important part of rare earth nanomaterials. Due to its special physical and chemical properties, its performance has made a huge leap in optical, electrical, magnetic, mechanical an...

Examples

Embodiment 1

[0027] (1) Dissolve 0.1 g of polyethylene glycol PEG in 100 mL of deionized water, then dissolve 2 g of yttrium nitrate in it, and finally add the solution to 200 ml with deionized water (the concentration of yttrium nitrate is 0.01 g / mL), Ultrasonic treatment (ultrasonic treatment power 100W, ultrasonic time 1h) to fully dissolve and disperse.

[0028] (2) Spray the solution into liquid nitrogen to prefreeze.

[0029] (3) After the temperature of the lyophilizer reaches the freezing temperature of -60°C and stabilizes, put the pre-frozen solution into the lyophilizer, turn on the vacuum pump and keep the vacuum below 20 Pa, and freeze-dry for 36 hours.

[0030] (4) Grinding the freeze-dried powder and calcining it in air at 500° C. for 1 h to remove the dispersant, and finally obtain ultrafine nanometer yttrium oxide powder. XRD such as figure 1 As shown, the phase is pure yttrium oxide. At the same time, the average grain size of the ultrafine nanometer yttrium oxide powd...

Embodiment 2

[0033] (1) Dissolve 2 g of polyethylene glycol PEG in 100 mL of deionized water, then dissolve 20 g of yttrium nitrate in it, and finally add the solution to 200 ml with deionized water (the concentration of yttrium nitrate is 0.1 g / mL). Ultrasonic treatment (ultrasonic treatment power 300W, ultrasonic time 0.3h) to fully dissolve and disperse.

[0034] (2) Spray the solution into liquid nitrogen to prefreeze.

[0035] (3) After the temperature of the lyophilizer reaches the freezing temperature of -50°C and stabilizes, put the pre-frozen solution into the lyophilizer, turn on the vacuum pump and keep the vacuum below 20 Pa, and freeze-dry for 24 hours.

[0036] (4) Grinding the freeze-dried powder and calcining it in air at 500° C. for 1 h to remove the dispersant, and finally obtain ultrafine nanometer yttrium oxide powder. The average grain size of ultra-fine nanometer yttrium oxide powder is 35.4nm, and the surface morphology is as follows: Figure 4 shown. The powder o...

Embodiment 3

[0038] (1) First dissolve 0.02g fatty alcohol polyoxyethylene ether AE in 100mL deionized water, then dissolve 10g scandium nitrate in it, and finally add the solution to 200ml with deionized water (the concentration of scandium nitrate is 0.05g / mL ), using ultrasonic treatment (ultrasonic treatment power 200W, ultrasonic time 0.5h) to make it fully dissolved and dispersed.

[0039] (2) Spray the solution into liquid nitrogen to prefreeze.

[0040] (3) After the temperature of the lyophilizer reaches the freezing temperature of -50°C and stabilizes, put the pre-frozen solution into the lyophilizer, turn on the vacuum pump and keep the vacuum below 20 Pa, and freeze-dry for 24 hours.

[0041] (4) Grinding the freeze-dried powder and calcining it in air at 800° C. for 0.5 h to remove the dispersant, and finally obtain ultrafine nano scandium oxide powder. The average grain size of ultra-fine nano scandium oxide powder is 75.4nm. The powder obtained by the freeze-drying method ...

technical field

[0001] The invention provides a freeze-drying preparation method of nano rare earth oxide powder, which belongs to the technical field of powder preparation engineering. Background technique

[0002] Rare earth oxides have many unique spectral properties and physical and chemical properties, and have been widely used in petroleum, chemical industry, metallurgy, textile, ceramics, glass, permanent magnet materials and other fields. Rare earth oxides are widely used in functional materials such as luminescent materials, magnetic materials, superconductors, high-performance ceramics, ultraviolet absorbers, and precision polishing materials. With the continuous advancement of science and technology, the value of rare earth oxides will increase. Ultrafine rare earth oxide powder is an important part of rare earth nanomaterials. Due to its special physical and chemical properties, its performance has made a huge leap in optical, electrical, magnetic, mechanical an...

Examples

Embodiment 1

[0027] (1) Dissolve 0.1 g of polyethylene glycol PEG in 100 mL of deionized water, then dissolve 2 g of yttrium nitrate in it, and finally add the solution to 200 ml with deionized water (the concentration of yttrium nitrate is 0.01 g / mL), Ultrasonic treatment (ultrasonic treatment power 100W, ultrasonic time 1h) to fully dissolve and disperse.

[0028] (2) Spray the solution into liquid nitrogen to prefreeze.

[0029] (3) After the temperature of the lyophilizer reaches the freezing temperature of -60°C and stabilizes, put the pre-frozen solution into the lyophilizer, turn on the vacuum pump and keep the vacuum below 20 Pa, and freeze-dry for 36 hours.

[0030] (4) Grinding the freeze-dried powder and calcining it in air at 500° C. for 1 h to remove the dispersant, and finally obtain ultrafine nanometer yttrium oxide powder. XRD such as figure 1 As shown, the phase is pure yttrium oxide. At the same time, the average grain size of the ultrafine nanometer yttrium oxide powd...

Embodiment 2

[0033] (1) Dissolve 2 g of polyethylene glycol PEG in 100 mL of deionized water, then dissolve 20 g of yttrium nitrate in it, and finally add the solution to 200 ml with deionized water (the concentration of yttrium nitrate is 0.1 g / mL). Ultrasonic treatment (ultrasonic treatment power 300W, ultrasonic time 0.3h) to fully dissolve and disperse.

[0034] (2) Spray the solution into liquid nitrogen to prefreeze.

[0035] (3) After the temperature of the lyophilizer reaches the freezing temperature of -50°C and stabilizes, put the pre-frozen solution into the lyophilizer, turn on the vacuum pump and keep the vacuum below 20 Pa, and freeze-dry for 24 hours.

[0036] (4) Grinding the freeze-dried powder and calcining it in air at 500° C. for 1 h to remove the dispersant, and finally obtain ultrafine nanometer yttrium oxide powder. The average grain size of ultra-fine nanometer yttrium oxide powder is 35.4nm, and the surface morphology is as follows: Figure 4 shown. The powder o...

Embodiment 3

[0038] (1) First dissolve 0.02g fatty alcohol polyoxyethylene ether AE in 100mL deionized water, then dissolve 10g scandium nitrate in it, and finally add the solution to 200ml with deionized water (the concentration of scandium nitrate is 0.05g / mL ), using ultrasonic treatment (ultrasonic treatment power 200W, ultrasonic time 0.5h) to make it fully dissolved and dispersed.

[0039] (2) Spray the solution into liquid nitrogen to prefreeze.

[0040] (3) After the temperature of the lyophilizer reaches the freezing temperature of -50°C and stabilizes, put the pre-frozen solution into the lyophilizer, turn on the vacuum pump and keep the vacuum below 20 Pa, and freeze-dry for 24 hours.

[0041] (4) Grinding the freeze-dried powder and calcining it in air at 800° C. for 0.5 h to remove the dispersant, and finally obtain ultrafine nano scandium oxide powder. The average grain size of ultra-fine nano scandium oxide powder is 75.4nm. The powder obtained by the freeze-drying method ...

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