TW201442943A - Method and micro device to rapidly manufacture nano metal wire - Google Patents

Abstract

This invention is a method and a micro device to rapidly manufacture nano metal wire. The method is primarily to introduce a reaction solution exclusive for nano metal wire into an electro-thermo microfluidic reaction device, and following the rapid heating reaction, nano metal wire can be produced. The device comprises multiple staggered and overlapped micro channel units and micro heating units. This invention has the benefits of increasing chemical synthesis reaction rate, reducing energy consumption, and achieving rapid and mass production.

Description

Method for rapidly manufacturing nano metal wire and micro device thereof

The invention relates to a method for rapidly manufacturing a nanowire and a micro device thereof, and relates to a method and a related reaction device for rapidly manufacturing a nanowire, in particular a nanowire.

One-dimensional nano metal materials, such as nano gold, tin, silver, platinum nanowires, etc., are often used for wire materials because of their good electrical conductivity. Since the surface effect, quantum effect, etc. are more obvious in the microscopic state, the one-dimensional nano metal material is quite suitable for various nanoelectronic components using the above effects, or can be further applied to the superconducting thick film circuit, Electrodes, low temperature conductive coatings and electromagnetic wave absorbing materials. Among the nano metal materials, since silver is the best conductive metal material, the application of nano silver wire is most favored.

As far as the general material growth mechanism is concerned, the natural growth structure of the face-centered cubic lattice structure material (FCC) is mostly a cubic crystal growth uniform structure, so it is desirable to synthesize a structural appearance material having an asymmetrical shape. The synthesis of cubic stacked crystal structure is easy, but in terms of engineering practicality, the one-dimensional nanowire with structural shape of asymmetrical type has considerable application value in engineering, especially with high axial length ratio. One-dimensional metal materials are indispensable for conduction or heat conduction because of their It has a higher contact probability than spherical silver, and the high axial length ratio of the silver wire can make the subsequent purification step more convenient. In other words, the reaction precipitate can be easily separated from the process without any complicated process. It can be purified. Recently, many researches on the fabrication of metal materials related to one-dimensional structures have been proposed at home and abroad. The one-dimensional structure synthesis process of face-centered cubic materials has been proposed, including hard stencil method and solution phase process. The method used to synthesize structured nano-silver is the polyol method in the solution phase process. Because the reducing ability of the polyol is mainly affected by the reaction temperature, the nucleation of the metal can be controlled by temperature adjustment. During the growth process, nano particles with various types of structures are synthesized. Most importantly, in order to control the type structure of the final product, a so-called "capping agent" is usually added to the process liquid phase to control the crystal growth direction. Since the coating agent produces different reaction strengths on different crystal faces of the metal crystal, an asymmetric coating is generated. The growth of the metal is caused by asymmetry in the formation process, wherein PVP (polyvinyl pyrrolidone) is the most commonly used coating material in the one-dimensional silver wire process, and not only the PVP has a nitrogen atom on its monomeric pyrrolidone functional machine. Oxygen atoms can help the entire PVP polymer long chain to adsorb on the silver surface, and PVP has a series of faces that tend to adsorb on the growing silver wire, which can passivate the continuous growth of the particles on the surface. Among the many crystal faces, only the face series is PVP. The weaker crystal plane is adsorbed, so the crystal growth rate on the surface is much higher than that of other crystal planes, and the one-dimensional silver line can be formed by the asymmetric growth mechanism, so the adsorption of PVP Behavior is the key to affect the asymmetric growth of silver. The typical polyol phase synthesis method dissolves the silver precursor in the liquid polyol (such as ethylene glycol) in the presence of PVP, by controlling some reaction parameters. Such as the molar ratio of PVP and silver precursors, temperature, reaction time and addition of reactants Order, etc., to generate the shape and shape of the particles to achieve the desired control.

There are also quite mature achievements in the research of Taiwan's one-dimensional nano-silver line, but most of them are scholars in the field of materialization, and scholars in the field of heat flow and energy are rare. The most representative one should be the Department of Chemistry of Tsinghua University. Prof. Zhou Gengsheng and Professor Dong Tengyuan, Dean of the School of Science, National Sun Yat-Sen University, and the Institute of Materials Engineering of the Institute of Industrial Science and Technology, Professor Zhou Gengsheng published a series of research results on the stable growth and application process technology of nano-wires in solution phase process as early as 2006. In addition, Professor Dong Tengyuan, Dean of the School of Science at National Sun Yat-Sen University, has made outstanding research results in the fabrication of one-dimensional metal wire by hard stencil method, especially in the use of photoreaction characteristics of TiO ₂ to produce nanowires by catalytic reaction. Related research, as well as the alumina porous membrane electroless plating growth method has made outstanding achievements in the production of nanowires, which have been able to produce silver, gold and nickel wires with uniform wire diameter and high slender ratio; In recent years, the research institute has invested a considerable amount of manpower and material costs to develop nanowires, and the results are quite good. The results of the photonics exhibition show that the direction and main force of the development of wire rods are concentrated on the related applications of display materials. There is not much ink on the basic physical properties and mass production mechanism, and the practical use of the energy field is not specifically concerned. The process still follows the traditional chemical synthesis process. How to apply other tools and cross-domain technology for rapid production is not involved at all. From the practical commercial application and production of nanowires, there is still a distance on the practical level.

From the research results of the above-mentioned one-dimensional nanowires at home and abroad, the existing one-dimensional nanowire manufacturing is mostly synthesized by the traditional chemical material process, the process steps are complicated, the synthesis reaction speed is slow, and the academic and basic research is still It is feasible, and it is necessary to design a special reactor with a large volume and process energy consumption to carry out the process, so that it is possible to achieve rapid mass production. The effect is that the manufacture of one-dimensional nanowires with a special machine for the introduction of micro-system components will be very promising, which will effectively increase the chemical synthesis reaction rate, reduce the process energy consumption, and achieve rapid mass production.

In view of this, the inventor has been able to use the case to meet the actual demand for rapid manufacturing of nanowires.

In order to improve the shortcomings of the prior art for producing nanowires, the main object of the present invention is to provide a new method and a novel device, which mainly introduces a reaction solution for preparing a nanowire into an electrothermal microfluidic reactor. After the rapid heating reaction, the purpose of generating a nanowire is obtained.

The reaction solution comprises A, B liquid, and the liquid A composition is an appropriate amount of PVP (molecular weight 40,000) dissolved in anhydrous ethylene glycol (purity 99.5%) and added with silver nitrate; B liquid is sodium salt aqueous solution Provides the driving energy required for the ion exchange reaction. First, the liquid A is heated above room temperature (40 ° C), and then mixed with the B liquid and heated to maintain the growth reaction of the nano silver wire at 210 ° C for two hours, then cooled to room temperature and then washed with deionized water. Separated to purify the nano silver wire.

The reason why the electrothermal microfluidic reaction device is used in this case is that the fluid movement at a small scale has characteristics such as relatively high flow velocity, high interface surface-to-volume ratio, high surface tension, and short diffusion distance. Therefore, the application of microfluidic properties combined with chemical reactions or physical effects on various chemical synthesis reaction processes and R&D designs will enable Achieve high efficiency, high speed, low energy consumption and other advantages and objectives; rapid mixing, heating, cooling and reaction are one of the most important mechanisms in the design of microfluidic reactors, the higher the degree of mixing, temperature rise and fall, will be The reaction rate is greatly increased, and the time and energy required for the operation of the microfluidic device are rapidly reduced. Therefore, the main research and development of the microfluidic reaction device is focused on improving the mixing and heat transfer efficiency.

In addition, in the micro-device that rapidly manufactures nano-wires, it is very important to carry out the process of stable heating to make the nano-silver line grow. It is not common to use a micro-heating device that needs to be heated for a long time. This is because Generally, the micro-heating device can provide extremely rapid temperature-increasing heating effect, and the most widely used biomedical wafers are not designed to heat the medical tissue for a long time, so the micro-channel length required for the heating process is Very short, however, the fixed high temperature (210 ° C) reaction time required for the nanowire to grow in a conventional chemical reaction flask must take up to 20 minutes, although the microchannel and microheater can greatly accelerate the Nai The temperature rise reaction speed of the rice silver wire process solution, but the total length of the flow channel at a flow rate of 200 μ m/sec must also be designed to a spectrum of 24 cm, so although the rapidly warming micro-heating device has been commonly used in bioreactive wafers and senses. In the design of the test wafer, the design of the micro-device for rapidly manufacturing the nano-wires will still adopt the so-called multi-wafer stacking combination. Long micro-channel design of constant temperature heating.

The micro device for rapidly manufacturing a nanowire includes a micro flow channel unit and a micro heating unit having a plurality of interleaved stacks.

The micro flow channel unit is formed with a serpentine microchannel formed on one side of the microchannel, and two ports are respectively disposed at opposite ends of the microchannel, wherein a port can penetrate the microchannel unit The other side.

The micro-flow channel unit is fabricated by directly cutting a PDMS microfluidic structural component by using a metal mold, and the metal mold manufacturing method is to abandon the conventional enamel-based process to use a 50 μm copper metal-surface electric wood board as a substrate. One way is to directly attach SU8 dry film negative photoresist up to 100 μm thick to copper metal surface bakelite, and then use UV light with film mask to expose and develop with NaCO3 solution to make 40 μm high. The structural photoresist of m is then combined with a magnetically controlled plasma sputtering machine to sputter a highly bonded titanium metal material to form a conductive corrosion-resistant layer, and directly insert the resisted substrate into the nickel sulfonate. Electroforming in the electroforming tank can obtain a nickel-based micro-metal mold, which is finished by drafting to obtain a finished product. The other method is based on the general traditional chemical etching process, but the resist used to increase the dimensional accuracy of the finished product is made of wet photoresist, and the exposure film is exposed by ultraviolet light with a film mask. After development cleaning, a 50 μm copper metal surface bakelite substrate is placed in a sulfuric acid + nitric acid solution or directly etched with a ferric chloride solution to achieve a single layer of 50 μm thick microstructured fluid components; Processing speed, processing quality and environmental considerations can be used to directly form a single-layer microstructure by directly engraving a metal panel with a laser micromachining machine without using an chemical etching method that is prone to overcutting conditions, so that it can also be made into a required component. After processing and chemical etching, the burrs can be processed to form components with complex shapes and composite materials. All the processes can be operated under normal atmospheric conditions, and the fabricated components are about ten to several hundred micrometers, which is equivalent. Easy to operate.

The micro heating unit has electrodes disposed on the upper and lower ends of one side, and one or more heating wires are juxtaposed between the two electrodes; and the micro heating unit is provided with one or two mouth.

The micro heating unit is prepared by surface cleaning a ruthenium wafer substrate having excellent heat transfer properties with a low concentration NaOH aqueous solution, and then pre-coating an OmniCoat adhesive layer by spin coating, and then performing a thermal compression bonding process. A 100 μm -SU8 negative photoresist film is attached, and then the shape of the electrode and the heating wire are defined by ultraviolet light exposure. After development, the bottom portion of the Omni Coat portion of the photoresist is removed, and the metal chromium layer is sputtered. The polishing process is finally applied to the Ti/W heating electrode by DC sputtering, and the SU8 is peeled off and the electrode is finally mounted.

Further, the microfluidic unit and the microheating unit having the electrode structure are placed in O ₂ /RF Plasma for treatment, and after one minute of activation, the direct compression is pressed (about 4-5 kg of weight is pressed), and placed. The ceramic hot plate is allowed to stand at 60 ° C for 30 minutes and then cooled to complete the tight package bonding. The entire process is short, inexpensive and all procedures are completely unnecessary in the clean room. Finally, a plurality of packaged micro flow channel units and a micro heating unit are stacked, and a plate body is respectively disposed on the outermost sides, and the two plates are locked and combined by the combination components, thereby completing the miniature of the case. Device.

Each of the plates is provided with a through hole, and the through hole can communicate with a corresponding port of the micro flow channel.

1‧‧‧Electrothermal microfluidic reactor

2‧‧‧Microchannel unit

21‧‧‧microchannel

22‧‧‧Port

23‧‧‧Port

3‧‧‧Micro heating unit

31‧‧‧heat wire

32‧‧‧ electrodes

33‧‧‧ wearing a mouth

The first picture is a three-dimensional combined appearance of the micro device of this case.

The second picture is an exploded view of the micro device of this case.

The third figure is a partial stereoscopic exploded enlarged view of the micro device of the present invention.

The fourth picture is a schematic diagram of the action of the micro device of this case.

Here is an example to illustrate the rapid manufacture of nanowires in this case. Method and its micro device details.

The method for rapidly manufacturing a nanowire of the invention mainly comprises introducing a reaction solution for preparing a nanowire into an electrothermal microfluidic reaction device, and after rapid heating reaction, a nanowire can be obtained.

The reaction solution comprises A, B liquid, and the liquid A composition is an appropriate amount of PVP (molecular weight 40,000) dissolved in anhydrous ethylene glycol (purity 99.5%) and added with silver nitrate; B liquid is sodium salt aqueous solution Provides the driving energy required for the ion exchange reaction.

As shown in the first, second and third figures, the electrothermal microfluidic reaction device 1 comprises a plurality of micro-channel units 2 and a micro-heating unit 3 which are alternately stacked.

The micro flow channel unit 2 is formed with a serpentine microchannel 21 formed on one side thereof, and two ports 22 and 23 are respectively disposed at opposite ends of the micro channel 21, wherein a port 23 can penetrate through To the other side of the microchannel unit 2.

The micro heating unit 3 is provided with an electrode 32 disposed on the upper and lower ends of one side, and one or more heating wires 31 are juxtaposed between the two electrodes 32; and the micro heating unit 3 is disposed on the micro heating unit 3 One or more openings 33.

A micro flow channel unit 2 and a micro heating unit 3 are placed in O ₂ /RF Plasma for treatment, and after one minute of activation, they are directly pressed and pressed (about 4-5 kg weight pressed) and placed on a ceramic heating plate. After 30 minutes of standing at 60 ° C, cooling is completed to complete the tight package bonding. Finally, a plurality of package-bonded micro-channel unit 2 and micro-heating unit 3 are stacked, and a plate body 11 is respectively disposed on the outermost sides, and the two plates 11 are locked by the combination elements 12 and 13. In combination, the electrothermal microfluidic reaction device 1 of the present invention is completed. Each of the plates 11 is provided with a through opening 111, and the through opening 111 can communicate with one of the corresponding ports 22 or 23 of the micro flow path 21.

In the implementation, the liquid A of the reaction solution is heated above room temperature (40 ° C), and then mixed with the liquid B and heated, and the reaction solution is input from the opening 111 of the electrothermal microfluidic reaction device 1 through the inflow microchannel. 21 and proceed, continue to maintain the micro-heating unit 3 at about 210 ° C, carry out growth reaction for two hours, and then output from the other end of the mouth 111, then cooled to room temperature and then washed with deionized water, separation to purify the nano silver line. Because the nano-silver wire requires a fixed high temperature (210 ° C) reaction time for the growth reaction process, it takes up to 20 minutes. With the device of the present invention, the temperature rising reaction rate of the nano silver wire process solution can be greatly accelerated.

In summary, the method for rapidly manufacturing nanowires and the micro device thereof provide an ideal and fast nano silver wire preparation technology, which has the advantages of increasing the chemical synthesis reaction rate, reducing the process energy consumption, and achieving rapid mass production. advantage. The technical content of this case is in full compliance with the requirements for the invention patent. The case was indeed exploited in the industry and was not seen in the publication or publicly used before the application, and is not a technology known to the public. Furthermore, this case effectively solves the long-standing problems in the prior art and achieves the long-term needs of relevant users and consumers. It is proved that the new model cannot be easily completed. The case is rich in "industry useability", "novelty" and "progressiveness" as stipulated in the Patent Law. The patents are submitted in accordance with the law, and the bureau is required to investigate in detail and approve the patent as soon as possible to protect the wisdom of the applicant. Property rights, encourage innovation .

The present invention has been described by way of example only, and it is to be understood by those skilled in the art. The preferred embodiment of the present invention is only one of the ways in which the present invention can be implemented in a specific manner, but is not limited thereto, and should be defined in the scope of the appended patent application.

1‧‧‧Microdevice

2‧‧‧Microchannel unit

3‧‧‧Micro heating unit

Claims (6)

A method for rapidly manufacturing a nanowire is to introduce a reaction solution for preparing a nanowire into a electrothermal microfluidic reaction device having a serpentine microchannel and capable of heating, and after being heated, a naphthalene can be produced. Rice metal wire. The method for rapidly manufacturing a nanowire according to claim 1, wherein the reaction solution comprises A and B liquids, and the liquid A is composed of an appropriate amount of PVP dissolved in anhydrous ethylene glycol and dissolved in silver nitrate. Among them; liquid B is an aqueous solution of sodium salt. A method of rapidly producing a nanowire according to claim 2, wherein the PVP has a molecular weight of 40,000. A method of rapidly producing a nanowire according to claim 2 or 3, wherein the anhydrous ethylene glycol has a purity of 99.5%. The method of rapidly manufacturing a nanowire according to claim 1, wherein the electrothermal microfluidic reaction device comprises a plurality of interlaced microchannel units and a micro heating unit; wherein the microchannel unit a serrated microchannel is formed on one side of the recess, and two ports are respectively disposed at opposite ends of the microchannel, wherein one port can penetrate to the other side of the microchannel unit; the micro heating unit, An electrode is disposed on one of the upper side and the lower end edge, and one or more heating wires are juxtaposed between the two electrodes; and the micro heating unit is provided with one or more through holes; The flow channel unit and the micro heating unit are stacked, and a plate body is respectively disposed on the outermost sides, and the two plates are locked and combined by the combination component. An electrothermal microfluidic reaction device comprising: a plurality of interlaced microfluidic cells and a microheating unit; wherein the microfluidics a channel unit, wherein one side is formed with a serpentine microchannel, and two opposite ports are respectively disposed at two opposite ends of the microchannel, wherein one port can penetrate to the other side of the microchannel unit; a heating unit, wherein one side is provided with two electrodes in a separated relationship, and one or more heating wires are juxtaposed between the two electrodes; and the micro heating unit is provided with one or more through holes; The micro-channel unit and the micro-heating unit are disposed outside the micro-heating unit, and are combined and locked by the combination component; the plates include a through hole, and the opening can communicate with one of the corresponding ports of the micro flow channel.