CN102753720A - Production of nanoparticles - Google Patents

Abstract

Composite nanoparticles can be produced by a processing apparatus comprising a source of charged, moving nanoparticles (10) or a first material and a first size, apparatus for imposing a like potential in a region (42) lying in the path of the nanoparticles, and a physical vapour deposition (PVD) source (40) of a second material directed toward the region, thereby to produce nanoparticles of a second and greater size being a composite of the first and second materials. The apparatus for imposing a like potential can comprise one or more conductive rings (28) surrounding the path of the nanoparticles, each at a successively lower potential. The physical vapour deposition source can be one or more of a sputter target, or an evaporative source, or another PVD source. There can be a plurality of physical vapour deposition sources, thereby allowing a larger region in which the shell is deposited. All of the physical vapour deposition sources can deposit the same material, for a uniform shell. Alternatively, different sources could allow for multiple shells or alloy shells.

Description

The manufacturing of nanoparticle

Technical field

The present invention relates to the manufacturing of nanoparticle.

Background technology

Nanoparticle can be made through many methods, comprises vacuum-deposition method.The deposition process of standard requires material in Vakuumkammer, to evaporate, and is deposited in the substrate then.In order to make nanoparticle, can make to be evaporated material and to remain under the gas phase to allow the nanoparticle nucleation.

Summary of the invention

The present invention solves the problem of making composite nanoparticle.Because o lot of reasons needs nanoparticle to comprise by shell or the outer inner core that surrounds.This is because under some situations, the surface of nanoparticle is an action face, and the expectation material that is used for this surface very expensive (such as platinum), therefore only on effective outside of nanoparticle, uses the expensive material maybe be more to one's profit.Under other situation, can conduction or semiconductive material be deposited on the non-conductive core, have the nanoparticle of the quantum/characteristic electron of expectation with formation.In biosystem, can make composite nanoparticle with different qualities, said different qualities is showed by core and shell.For example, the surface has the nanoparticle that tumor marker and core have strong effect antitumour drug (such as iron) possibly have better effect, and this is because have only medicine to be sent to tumour, thereby the dosage that is provided is higher than the dosage that provides under other situation.

Distinct issues are the manufacturing of this particle.Suppose that nanoparticle maybe be by at least 50,000 atom composition, then making nanoparticle is not simple working.

Therefore the present invention provides a kind of device of processing nanoparticle; It comprises the source of a nanoparticle charging, that move; Said nanoparticle has first material and first size, in the zone in the path of nanoparticle, apply the device of same potential and towards said zone and have the physical vapour deposition source (PVD) of second material, has the second bigger size and is the nanoparticle of the synthetics of first and second materials so that make.

This device moves in the following manner: make charged nanoparticle run into identical electromotive force, promptly with the identical electromotive force of symbol of the electric charge of nanoparticle.When nanoparticle gets into should the zone time, nanoparticle will slow down, thereby will in this zone, spend the longer time.Then, can produce the steam of expectation shell material towards one or more PVD source in this zone, this steam will be deposited on and move on the slower nanoparticle, thereby increase the size of nanoparticle and produce the core/shell structure of expectation.

The device that applies same potential can comprise around one or more conducting rings in the path of nanoparticle.For example a plurality of conducting rings that have the electromotive force that reduces continuously respectively are set, can make same potential be decreased to minimum from maximum along the direct of travel of the nanoparticle that moves through path along nanoparticle.This can realize in the following manner: each conducting ring is connected to adjacent ring via resistance component, first conducting ring is connected serially to voltage of supply and with last conducting ring ground connection.In this way, near nanoparticle at first get into high same potential zone and obviously slow down.Then, nanoparticle progresses into lower same potential district, and quickens along potential gradient, leaves this structure up to nanoparticle much at one speed with its entering the time.

Usually, the nanoparticle in moving is electronegative, and the electromotive force that is therefore applied is for negative.

The physical vapour deposition source can be one or more sputtering targets or evaporation source, perhaps other PVD source.Can have a plurality of physical vapour depositions source, thereby make the zone of deposit shell bigger.In order to obtain the shell of homogeneous, all physical vapour deposition sources can the deposit identical materials.As selection, homology can compound shell of deposit or alloy shell.

Description of drawings

Below, with reference to following accompanying drawing, mode is explained embodiments of the invention by way of example,

Wherein:

Fig. 1 is the sectional view that is used to make the device of composite nanoparticle;

Fig. 2 illustrates in greater detail conducting ring; And

Fig. 3 shows the variation of electromotive force with respect to distance.

Embodiment

With reference to figure 1, disclosed the device that is used to make composite nanoparticle.This device is made up of the device 10 that is used to make nanoparticle that is positioned at left-hand side shown in Figure 1.The final core that forms resulting composite nanoparticle of these nanoparticles.Cover 12 has the outlet 14 that is positioned at its low order end, and comprises low-pressure gas 16.This cover 12 is included in the Vakuumkammer 18, so low-pressure gas 16 has higher air pressure with respect to surrounding space.As a result, low-pressure gas 16 will be overflowed via outlet 14, thereby form the air-flow shown in the arrow 20.In order to keep and the supply of additional low-pressure gas 16, correspondingly the high order end at cover 12 is provided with gas inlet 22.

Be provided with sputtering deposit device 24 at cover in 12, this sputtering deposit device 24 is actually general routine.Sputtering target 26 is provided for making the material of nanoparticle core.Sputtering target 26 is splashed to material in the low-pressure gas 16 towards outlet 14 usually.Be entrained in the air-flow 20 by sputtering particle, and by sputtering particle keep during outlet 14 mobile since low-pressure gas 16 and repeatedly each other magnetic hit.After for some time; These magnetic hit making the mode of being described with the front by sputtering particle be agglomerated into nanoparticle; For example in document GB2430202A, describe, the document includes this paper by reference in and the technician can come to understand fully the present invention with reference to said document.

The nanoparticle that is obtained still is entrained in the air-flow 20, thereby leaves cover 12 through hole 14.In the exit, the series connection conducting ring 28 that nanoparticle is opened through the axially spaced-apart that schematically shows among Fig. 2.Each ring 28 is kept by the separator 30 (Fig. 1) that a ring is connected to next ring with being separated.Separator 30 all has resistance (Fig. 2), and the first ring 28a is connected to higher negative voltage, and last ring 28i ground connection.As a result, electric current via the resistive isolation part from a circulation to next ring, thereby make and on each separator, have pressure drop.Therefore; The group effect of series connection conducting ring is to form voltage profile as shown in Figure 3; The nanoparticle that moves from left to right wherein as shown in Figure 1 runs into rapid increase voltage 32 (at the first ring 28a place) at first, and roughly mild slope 34, this voltage edge reduces gradually then.In fact, each ring has the electromotive force between voltage of supply and ground voltage, and this electromotive force is by the determining positions along a string resistive isolation part 30a-30i.

Of above GB243020A, electronegative usually by the nanoparticle that device 10 is made.Here it is encircles the reason that is connected to higher negative voltage with first.If use the replacement nanoparticle manufacturing system that produces the positively charged nanoparticle, otherwise then can the first ring 28a be connected to higher positive potential.The effect of the potential barrier 32 that forms thus is that the nanoparticle of arrival is slowed down.The voltage of the first ring 28a is set for and is made this deceleration-operation be not enough to catch fully (or repulsion) nanoparticle, thereby nanoparticle passes the first ring 28a reluctantly with low voltage.Then, nanoparticle runs into the electromotive force 34 of continuous decay, thereby nanoparticle is quickened towards last conducting ring 28i.

Last ring 28i ground connection, the electromotive force when the electromotive force here starts with nanoparticle is consistent.Thereby the retarded motion that runs at the first ring 28a place has by chance been offset in the accelerated motion in the ring 28.Yet the then slow again resume speed of initial deceleration motion is intended to make nanoparticle to remain in the zone of conducting ring.The variation electromotive force that is produced by ring forms " stagnant area " in the zone of these rings.

Two other sputter deposition systems are set in the both sides of stagnant area.In a side the first sputtering deposit device 36 is set, and the second sputter deposition system (not shown) gets into via the port in the vacuum system 38.These sputter deposition systems are provided with second target 40 with differing materials, and this material will be used for forming the shell of nanoparticle.Two sputter deposition systems 36 are towards the stagnant area, and materials evaporated is sprayed to the stagnant area between the conducting ring 28.Therefore, when the stagnant area, make nanoparticle and the second material cloud coalescence that forms thus, thereby the nanoparticle that is obtained have different cores and shell structure.At last, nanoparticle is leaving via mouth 42 through after the last ring 28i, and can conventional mode be collected.

In order to make nanoparticle have the shell of homogeneous, two sputter deposition systems 36 can be provided with identical target 40.As selection, material different can be set, so that can be according to specifying or each sputter deposition system forms compound shell and/or alloy shell with respect to the relative position of stagnant area.The one group of sputtering target that is placed on the same position place along the stagnant area will form the alloy shell, and the sputtering target that separates along the stagnant area can form the successive shell.

Should be appreciated that, without departing from the present invention, can much be out of shape the foregoing description.

Claims (13)

1. nanoparticle processing unit (plant); It comprises the source of a nanoparticle charging, that move; Said nanoparticle has first material and first size, in the zone in the path of said nanoparticle, apply the device of same potential and towards said zone and have the physical vapour deposition source of second material, has the second bigger size and is the nanoparticle of the synthetics of first and second materials so that make.

2. device according to claim 1, the wherein said device that applies same potential comprise the one or more conducting rings around said nanoparticle path.

3. device according to claim 1 and 2, the direct of travel of the nanoparticle during move on wherein said same potential edge reduces to minimum from maximum.

4. according to the described device of the claim 3 that depends on claim 2, wherein there are a plurality of conducting rings with the electromotive force that reduces continuously in the path along nanoparticle.

5. device according to claim 4, wherein each conducting ring is connected to adjacent ring through resistance component.

6. device according to claim 5, wherein first conducting ring is connected to voltage source.

7. device according to claim 6, wherein last conducting ring ground connection.

8. according to each described device in the claim 1 to 7, nanoparticle is electronegative in wherein said the moving, and the said electromotive force that is applied in is for negative.

9. according to each described device in the claim 1 to 8, wherein said physical vapour deposition source is a sputtering target.

10. according to each described device in the claim 1 to 8, wherein said physical vapour deposition source is an evaporation source.

11., wherein have a plurality of physical vapour depositions source according to each described device in the claim 1 to 10.

12. device according to claim 11, wherein all physical vapour deposition source deposit identical materials.

13. one kind substantially with reference to accompanying drawing said and/or as nanoparticle processing unit (plant) shown in the drawings.

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