A low cost electrospray device for capturing nanoparticles in a vacuum system

Abstract

The application discloses a low-cost electrospray device for capturing nanoparticles in a vacuum system, which comprises a micro-injection pump, a stainless steel capillary, a high-voltage direct-current power supply and a vacuum cavity. The micro-injection pump is used to slowly extrude a syringe to provide a stable flow rate of a nanoparticle solution for the device. A conductive wire is connected to the liquid through a PEEK tee connector to charge the liquid. The vacuum cavity is located behind the electrospray and has a pressure lower than the atmospheric pressure. The charged liquid is attracted by a grounded metal ring after flowing out of the stainless steel capillary, breaks through the surface tension and forms a uniform spray to pass through the middle of the grounded metal ring. The electrospray is sucked into the vacuum cavity due to the pressure difference. A quadrupole rod is arranged in the vacuum cavity to guide and store the nanoparticles. The device can form a stable and continuous nanoparticle electrospray by providing a lower voltage, so as to realize the loading of the nanoparticles in the vacuum.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vacuum suspension, in particular to a low-cost electrospray device for capturing nanoparticles in a vacuum system. BACKGROUND

[0002] The ability to manipulate and measure the translation, rotation, and free dynamics of suspended nanoscale objects in vacuum with high precision provides a new experimental platform for fundamental and applied research. For example, the high acceleration and force sensitivity of suspended objects drive the development of sensors and the exploration of new physics, and the damping and noise can be minimized in ultra-high vacuum, paving the way for quantum-limited sensing and detection, and exploring macroscopic quantum physics in large-mass systems that have not been explored so far.

[0003] One of the main challenges in capturing nanoparticles is to control the entry of nanoparticles into the vacuum. The most commonly used loading technique is to spray with an atomizer, which relies on air damping, requires loading under atmosphere, and has a large amount of atomization, which is very easy to contaminate the vacuum system.

[0004] Compared with the atomizer, the loading method of the electrospray has many advantages, such as increasing the charge-to-mass ratio of the nanoparticles, facilitating their control, reducing the amount of atomization, and avoiding contamination of the vacuum system.

[0005] The principle of the electrospray device is that the droplet at the end of the capillary is polarized under the action of high voltage, and when the electric charge is high enough, it will break through the surface tension of the liquid and be sprayed out. The droplet continuously evaporates during the spraying process, increasing the charge-to-mass ratio of the droplet, and when it increases to a certain extent, it will further break through the surface tension and further split to form smaller droplets, thereby forming an electrospray.

[0006] There are two types of existing electrospray devices. The first type uses a stainless steel capillary as a nozzle, but due to process limitations, its inner diameter is difficult to make very small, which causes the nozzle to produce larger droplets. Therefore, a higher voltage is required to produce a spray, which will make the use process more dangerous and the purchase of a high-voltage power supply more costly. The second type uses a quartz capillary as a nozzle, which can achieve a smaller inner diameter. The inner diameter used in electrospray is usually 25-75 μm, and the nozzle part can be stretched by heating to produce a smaller aperture, thereby making the droplets at the nozzle smaller. This has the advantage of using a lower voltage, but since the aperture is very small, nanoparticles can easily cause the device to be blocked, and the equipment for stretching the quartz tube also requires a high cost. SUMMARY

[0007] The application aims to provide a low-cost electrospray device for capturing nanoparticles in a vacuum system to solve the problems of the prior art.

[0008] To achieve the above object, the application provides the following solution: the application provides a low-cost electrospray device for capturing nanoparticles in a vacuum system, comprising

[0009] a micro-injection pump connected to one end of a quartz capillary through a capillary hose, and the other end of the quartz capillary is connected to one end of a PEEK tee connector through a PEEK hand-tight joint.

[0010] a stainless steel capillary screwed into the other end of the PEEK tee connector through a PEEK hand-tight joint; and

[0011] a high-voltage direct-current power supply connected to a conductive wire, the conductive wire is screwed into the middle end of the PEEK tee connector through a PEEK hand-tight joint, and the end of the conductive wire is located in the inner cavity of the PEEK tee connector and contacts the nanoparticle solution in the cavity,

[0012] a vacuum cavity, a ground metal ring is arranged on the outside of the stainless steel capillary, and a PEEK tube is arranged at the connecting port of the vacuum cavity, the PEEK tube is arranged opposite to the ground metal ring, and the air pressure in the vacuum cavity is 10 3 ~ 10 4 Pa, and the electrospray is sucked into the vacuum cavity due to the pressure difference.

[0013] Preferably, the capillary hose is a polytetrafluoroethylene capillary hose, the micro-injection pump extrudes the syringe at a speed of 0.5 ml / h, the inner diameter of the capillary hose is 0.3 mm, and the outer diameter is 0.8 mm.

[0014] Preferably, the other end of the quartz capillary is sleeved in a capillary sleeve, and the capillary sleeve is sleeved in the PEEK hand-tight joint; the outer diameter of the quartz capillary is 0.36 mm, the inner diameter is 0.05 mm, and the length is 3-20 cm.

[0015] Preferably, the stainless steel capillary is sleeved in a capillary sleeve, and the capillary sleeve is sleeved in the PEEK hand-tight joint, and then the PEEK hand-tight joint is screwed into the other end of the PEEK tee connector; the outer diameter of the stainless steel capillary is 0.3 mm, the inner diameter is 0.1 mm, and the length is 3-20 cm.

[0016] Preferably, the conductive wire is sleeved in a capillary sleeve, the capillary sleeve is sleeved in a PEEK hand screw joint, and the PEEK hand screw joint is screwed into the middle end interface of the PEEK tee connector; the voltage range of the high-voltage direct-current power supply is 0-2000V.

[0017] Preferably, the solvent of the nanoparticle solution in the inner cavity of the PEEK tee connector is alcohol.

[0018] Preferably, the diameter of the conductive wire is 0.2mm; the outer diameter of the PEEK tube is 1mm, the inner diameter is 0.25mm, and the length is 10cm.

[0019] Preferably, the grounding metal ring is placed 1mm away from the outlet of the stainless steel capillary tube, the distance between the PEEK tube and the grounding metal tube is 0.5-2cm; and the vacuum degree in the vacuum cavity is maintained by a mechanical pump.

[0020] Preferably, the inner side of the three interface ends of the PEEK tee connector is respectively provided with an internal thread, and the PEEK hand screw joint is provided with a corresponding external thread, so that the quartz capillary tube, the stainless steel capillary tube and the conductive wire can be respectively fixed by the hand screw joint.

[0021] The present application has the following beneficial technical effects compared with the prior art:

[0022] The low-cost electrospray device for capturing nanoparticles in a vacuum system in the present application comprises a micro-injection pump, a stainless steel capillary tube, a high-voltage direct-current power supply and a vacuum cavity. The micro-injection pump slowly extrudes a syringe to provide a stable flow rate of nanoparticle solution for the device. The conductive wire contacts the liquid through the PEEK tee connector to charge the liquid. The vacuum cavity is located behind the electrospray and has a pressure lower than atmospheric pressure. The charged liquid is attracted by the grounding metal ring after flowing out of the stainless steel capillary tube, breaks through the surface tension, and forms a uniform spray that passes through the middle of the grounding metal ring. The electrospray is sucked into the vacuum cavity due to the pressure difference, and the vacuum cavity has a quadrupole rod for guiding and storing nanoparticles. The device can form a stable and continuous nanoparticle electrospray by providing a lower voltage, thereby achieving the loading of vacuum nanoparticles. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0024] Figure 1The overall structure schematic diagram of a low-cost electrospray device for capturing nanoparticles in a vacuum system;

[0025] 1, high-voltage direct-current power supply; 2, microsyringe pump; 3, capillary hose; 4, quartz capillary; 5, conductive metal wire; 6, PEEK tee connector; 7, PEEK hand joint; 8, PEEK hand joint; 9, PEEK hand joint; 10, stainless steel capillary; 11, grounding metal ring; 12, PEEK capillary; 13, vacuum cavity. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0027] The purpose of the present application is to provide a low-cost electrospray device for capturing nanoparticles in a vacuum system to solve the problems existing in the prior art, which has a simple structure, low cost, and can load nanoparticles into a vacuum using only a lower voltage power supply.

[0028] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0029] As shown in Figure 1 The present application provides a low-cost electrospray device for capturing nanoparticles in a vacuum system. The microsyringe pump 2 is connected to one end of the quartz capillary 4 through the capillary hose 3 made of polytetrafluoroethylene material. The other end of the quartz capillary 4 is sleeved in the capillary sleeve, and the capillary sleeve is sleeved in the PEEK hand joint 7. Then the PEEK hand joint 7 is screwed into one end of the PEEK tee connector 6. Since the PEEK material has a certain deformation ability, the parts will be sealed during the screwing process.

[0030] The stainless steel capillary 10 is sleeved in the capillary sleeve, and the capillary sleeve is sleeved in the PEEK hand joint 9. Then the PEEK hand joint 9 is screwed into the last end of the PEEK tee connector 6.

[0031] The high-voltage direct-current power supply 1 is connected to the conductive metal wire 5, which is sleeved in the capillary sleeve, and the capillary sleeve is sleeved in the PEEK hand joint 8. Then the PEEK hand joint 8 is screwed into the middle end of the PEEK tee connector 6.

[0032] The PEEK tee connector 6 has an internal cavity. The conductive metal wire 5 will come into contact with the nanoparticle solution inside the cavity. To use a lower voltage, alcohol, which has a lower surface tension than water, is used as the solvent for the nanoparticle solution. The grounding metal ring 11 is concentrically placed 1 mm from the outlet of the stainless steel capillary tube 10. A PEEK tube 12 is fixed to one side of the vacuum chamber 13. The PEEK tube 12 is placed opposite the grounding metal ring 11, and the distance between the PEEK tube 12 and the grounding metal ring 11 is 0.5-2 cm. During the loading of nanoparticles, the air pressure inside the vacuum chamber 13 is 10. 3 ~10 4 Pa, the vacuum level is maintained by a mechanical pump, and the electrospray will be drawn into the vacuum chamber 13 due to the pressure difference.

[0033] In one embodiment, the high-voltage DC power supply 1 is in contact with the solution through the conductive metal wire 5, forming a high-voltage power supply section. The voltage range of the high-voltage DC power supply 1 is 0 to 2000V; preferably, the power supply voltage range of the high-voltage DC power supply 1 is +1300V to +1600V.

[0034] In one embodiment, the microinjection pump 2 squeezes the syringe at a rate of 0.5 ml / h, providing a continuous and stable liquid flow rate.

[0035] In one embodiment, the capillary tube 3 has an inner diameter of 0.3 mm and an outer diameter of 0.8 mm; the quartz capillary tube 4 has an outer diameter of 0.36 mm, an inner diameter of 0.05 mm, and a length of 10 cm.

[0036] In one embodiment, the conductive metal wire 5 has a diameter of 0.2 mm.

[0037] In one embodiment, the stainless steel capillary 10 has an outer diameter of 0.3 mm, an inner diameter of 0.1 mm, and a length of 10 cm.

[0038] In one embodiment, the PEEK tube 12 has an outer diameter of 1 mm, an inner diameter of 0.25 mm, and a length of 10 cm.

[0039] The PEEK tee connector 6 has a central cavity, and its three ports are threaded. The PEEK hand-tightening connector has corresponding threads, which can be used to fix the quartz capillary 4, the stainless steel capillary 10, and the conductive metal wire 5 respectively. During operation, the air pressure in the vacuum chamber 13 is maintained by a mechanical pump. The solvent for the nanoparticle solution is alcohol with low surface tension to further reduce the Rayleigh limit so that a lower voltage can be used.

[0040] The low-cost electrospray device for capturing nanoparticles in a vacuum system in the present application uses a micro-injection pump 2 to slowly extrude a syringe to provide a stable flow rate of nanoparticle solution for the device, a conductive metal wire 5 contacts the liquid through a PEEK tee connector 6 to charge the liquid, the gas pressure in the vacuum chamber 13 is lower than atmospheric pressure, located behind the electrospray, the charged liquid flows out of the stainless steel capillary 10 and is attracted by the grounded metal ring 11, breaks through the surface tension, and forms a uniform spray that passes through the middle of the grounded metal ring 11, the electrospray is sucked into the vacuum chamber 13 by the pressure difference, and the vacuum chamber 13 has a quadrupole rod for guiding and storing nanoparticles. Through the device, a stable and continuous nanoparticle electrospray can be formed by providing only a lower voltage, thereby realizing the loading of vacuum nanoparticles. The device does not need to stretch the quartz tube nozzle, only a cheap stainless steel capillary 10 and a voltage of 1300V or more are needed to realize the electrospray of nanoparticles, thereby loading the charged nanoparticles into the vacuum system, greatly reducing the cost of electrospray.

[0041] It should be noted that for those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, the scope of the present application is defined by the appended claims rather than the above description, therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application, and any reference signs in the claims should not be considered as limiting the claims.

[0042] The principles and implementation modes of the present application are described by applying specific examples in the present application, the above embodiment descriptions are only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, there will be changes in specific implementation modes and application scope. In conclusion, the content of the present description should not be understood as a limitation of the present application.

Claims

1. A low cost electrospray device for capturing nanoparticles by a vacuum system, characterized in that: Comprising a micro-injection pump connected to one end of a quartz capillary tube through a capillary tube, the other end of the quartz capillary tube is connected to one end of a PEEK tee connector through a PEEK hand screw joint; and a stainless steel capillary tube screwed into the other end of the PEEK tee connector through a PEEK hand screw joint; and a high-voltage direct current power supply connected to a conductive wire, the conductive wire is screwed into the middle end of the PEEK tee connector through a PEEK hand screw joint, the end of the conductive wire is located in the inner cavity of the PEEK tee connector and contacts the nanoparticle solution in the cavity, the solvent of the nanoparticle solution in the PEEK tee connector cavity is alcohol; Vacuum cavity, the outside of the stainless steel capillary is spaced with grounding metal ring, the connecting port of the vacuum cavity is provided with PEEK tube, the PEEK tube is placed opposite to the grounding metal ring, the air pressure in the vacuum cavity is 10 3 ~10 4 Pa, electrospray is inhaled into the vacuum cavity by pressure difference; the grounding metal ring is placed 1mm from the outlet of the stainless steel capillary, the distance between the PEEK tube and the grounding metal tube is 0.5-2cm; the vacuum degree in the vacuum cavity is maintained by mechanical pump; the quadrupole rod for guiding and storing nanoparticles is arranged in the vacuum cavity; the PEEK tee connector has a cavity in the middle, the inner side of the three interface ends of the PEEK tee connector is respectively provided with internal thread, the PEEK hand screw joint is provided with corresponding external thread, the quartz capillary, the stainless steel capillary and the conductive metal wire can be respectively fixed by the hand screw joint.

2. A low cost electrospray device for vacuum system nanoparticle capture according to claim 1, characterized in that: The capillary tube uses a polytetrafluoroethylene capillary tube; the micro-injection pump extrudes the syringe at a speed of 0.5 milliliters per hour, the inner diameter of the capillary tube is 0.3 millimeters, and the outer diameter is 0.8 millimeters.

3. The low cost electrospray device for vacuum system nanoparticle capture of claim 1, wherein: The other end of the quartz capillary tube is sleeved in a capillary sleeve, and the capillary sleeve is sleeved in the PEEK hand screw joint; the outer diameter of the quartz capillary tube is 0.36 millimeters, the inner diameter is 0.05 millimeters, and the length is 3-20 centimeters.

4. The low cost electrospray device for vacuum system nanoparticle capture of claim 1, wherein: The stainless steel capillary tube is sleeved in a capillary sleeve, and the capillary sleeve is sleeved in the PEEK hand screw joint, and then the PEEK hand screw joint is screwed into the other end of the PEEK tee connector; the outer diameter of the stainless steel capillary tube is 0.3 millimeters, the inner diameter is 0.1 millimeters, and the length is 3-20 centimeters.

5. The low cost electrospray device for vacuum system nanoparticle capture of claim 1, wherein: The conductive wire is sleeved in a capillary sleeve, and the capillary sleeve is sleeved in the PEEK hand screw joint, and then the PEEK hand screw joint is screwed into the middle end of the PEEK tee connector; the voltage range of the high-voltage direct current power supply is 0-2000V.

6. The low cost electrospray device for vacuum system nanoparticle capture of claim 1, wherein: The diameter of the conductive wire is 0.2 millimeters; the outer diameter of the PEEK tube is 1 millimeter, the inner diameter is 0.25 millimeter, and the length is 10 centimeters.

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