CN1187153C

CN1187153C - Method for making silver nano wire using aerogel as template

Info

Publication number: CN1187153C
Application number: CNB021512779A
Authority: CN
Inventors: 陈龙武; 甘礼华; 成俊杰
Original assignee: Tongji University
Current assignee: Tongji University
Priority date: 2002-12-16
Filing date: 2002-12-16
Publication date: 2005-02-02
Anticipated expiration: 2022-12-16
Also published as: CN1422719A

Abstract

The present invention provides a method for preparing silver nanometer wires by using aerogel as templates, which relates to the preparation technology for silver nanometer wires. The present invention is characterized in that first, the inorganic oxide aerogel with the pore diameter of 10 to 100 nm, the porosity factor of higher than 90% and the pore diameter centralized in 30 nm as the templates; then, the inorganic oxide aerogel is ground into sheets with the thickness of 1 to 3 nm by abrasive paper; the sheets are washed by purified water and are baked; subsequently, after soaked for 30 to 40 minutes in a dextrose water solution, the sheets are taken out and are wiped dry by filter paper; next, the sheets are soaked for 30 to 40 minutes in a silver amino solution with the concentration of 3% to 5%, after taken out of the silver amino solution, the sheets are cleaned by the purified water and is wiped dry, and silver liquid attached to the surface is removed; finally, the templates formed by the existing silver nanometer wires are arranged in a sodium hydroxide solution with the concentration of 2 to 5 mol*1<-1> to be soaked until the templates are totally dissolved; obtained black powder is the silver nanometer wires. The present invention has simple process. Compared with a conventional porous template process, the present invention has high efficiency (which is improved by more than 10 to 100 times), and can be used for making ultralong silver nanometer wires.

Description

With the aeroge is the method that template prepares nano silver wire

Technical field

The present invention relates to the technology of preparing of nano silver wire.

Background technology

Nano wire is a kind of urstoff based on nanometer (1/1000000000th meter) yardstick, by the method for physics and chemistry, the nanostructured system of arranging the line array that assembles according to certain rules.This structural system had both had the characteristic of nanoparticle, be quantum size effect, small-size effect, skin effect etc., has the new effect that the nanostructured combination causes again, as characteristics such as quantum coupling effect and cooperative effects, and be easy to change by outfield (as light, electricity, magnetic etc.), realize control to its performance.Therefore, it is the basis of design ultramicro-quantum structure devices of new generation, and is manifesting great application prospect as the line of syringe needle, nano-device and the super large integrated circuit of PSTM, the microelectrode of chemical sensor, the aspects such as super reinforcing agent of composite.Nano silver wire is a kind of of numerous nano wires.This nano silver wire is specially adapted to make the connecting line of nanometer micro-electrode and nano-device.

For this reason, simple and efficient and produce the basic unit of nanostructured in a large number for how, promptly the method for nano wire is one of focus in the nanosecond science and technology research.The template synthetic method is occupied in all multi-methods of preparation nano wire at present

Extremely important status (' A General Template-Based Method for Preparation ofNanomaterials ' Hulteen J C, Martin C R.J.Mater.Chem., 7 (7): 1075-1087 (1997)).The template synthetic method is to be template with the thick film with nano aperture, Applied Electrochemistry, gaseous phase deposition, and methods such as chemical polymerization, sol-gel add hole with related substance, form nano wire.This shows that the selected of template with nano aperture is the prerequisite of synthesis of nano structure elementary cell.In order to obtain to have the thick film of nano aperture, expert both domestic and external adopts several different methods to seek the preparation method by multiple channel.They or adopt the monocrystalline silicon piece of single-sided polishing, by meticulous electrochemical treatments such as vacuum evaporation, acquisition has silica template (' is that template prepares aligned carbon nanotube with the porous silicon ' Xu Dongsheng of nano aperture, Guo Guolin, Gui Linlin etc. are published in Chinese science (B collects), 2000 the 4th phase 289-293 pages or leaves); Perhaps adopt high-purity aluminium foil, the electrochemical treatments such as vacuum evaporation synthetic or meticulous by the chemical method of complexity obtains porous alumina formwork (' Self Origanized Formation of Hexagonal Pore Arrays in Alumina ' Jessensky O.Appl.Phy.Lett., 72 (10): 1173 (1998)); (Pan Shanlin etc. are published in Science Bulletin for ' research for preparing height-oriented carbon nano pipe array film with porous alumina formwork ' Wang Chengwei, Li Mengke, 2000 the 45th volume the 3rd phase 493-497 pages or leaves); (' Formation of a Titanium DioxideNanotube Array ' Hoyer P..Langmuir, 12:1411-1413 (1996)).Yet, the sort of method no matter, preparation all quite is not easy, and its hole density also is restricted.And the height of hole density directly has influence on the preparation efficiency of nano wire.Therefore, up to now, still constantly exploring how to obtain high-quality template quickly and easily both at home and abroad, and be that the basis prepares nano wire with this template.

Summary of the invention

The objective of the invention is to be not easy to obtain at template in the preparation of present nano wire, hole density and hole length such as are restricted at problem, seek a kind of brand-new template, and produce the technology of nano silver wire with this template.

In order to achieve the above object, the present invention is performed such.Find that through studying for a long period of time aeroge is a kind of by the mutual coalescent solid mass with porous network structure that forms of nano particle.It has following characteristics: A. and has bigger nanoscale hole, and hole can make very evenly, and length is unrestricted again; B. the yardstick of hole can be regulated by the change of preparation condition; C. the wetability of hole surface can be regulated; D. the porosity of aeroge reaches as high as 99.8%.And the existing ripe method of the preparation of aeroge, obtain than being easier to.For this reason, the inventor through test many times, has found the technology of producing nano silver wire by electroless deposition processes with the template of aeroge as the preparation nano wire.

Concrete technology is that in the following order several steps carries out:

At first carry out choosing of template:

Choose the aperture at 10-80nm, porosity is greater than 90% inorganic oxide aeroge Al ₂O ₃, SiO ₂Template as synthesis of silver nano-wire.In order to make the good uniformity of made nano silver wire, it is narrow preferably to select to distribute as the aperture of the aeroge of the template of making nano silver wire, with concentrate in the 30nm for well.

Carry out the processing of template then:

With sand paper aeroge is polished into laminarly, the thickness of thin slice is at 1-3mm, and is clean with purified rinse water, and with oven dry or the way that dries up, it is stand-by to remove moisture.

Then be producing of nano silver wire:

A. soak in reducing solution earlier, reducing solution is the D/W of 10%-50%, soak time 30-40 minute.

B. template is taken out from reducing solution, dry with filter paper, soak in silver liquid ammonia, the concentration of silver is 3%-5% in the silver liquid ammonia.Soak time 30-40 minute.

C. take out, clean with pure water, with filter paper wiping aeroge surface, remove the silvering solution of surface attachment, this moment, existing nano silver wire formed in the aeroge hole.

Be the removal of template at last:

The template that existing nano silver wire forms is put into the sodium hydroxide solution immersion, and the concentration of sodium hydroxide solution is 2-5mol1 ^-1, soak till template is all dissolved.Remaining black powder is a nano silver wire of the present invention.

The present invention has following advantage:

1. because the preparation process of aeroge is much more simple and convenient than the preparation of porous silica template commonly used at present, alumina formwork, therefore producing of whole nano silver wire of the present invention is become and be more prone to.

2. can reach 99.8% because the porosity of aeroge is the highest, compare with present conventional foraminous die plate, its hole density can improve 10-100 doubly, even can be higher.So of the present invention is that template obtains nano silver wire by electroless deposition processes with the aeroge, efficient is improved more than 10-100 times.

3. because the aeroge block can be done very greatly, so the hole length of aeroge template is unrestricted in principle, the method that with the aeroge is template prepares nano silver wire therefore of the present invention can be made the nano wire of overlength.

The specific embodiment

Embodiment 1

At first, the SiO that selects for use sol-gel and supercritical drying drying method to make ₂Aeroge is as the template of preparation nano silver wire, and the aperture of this aeroge concentrates between the 10-30nm, and pore-size distribution is quite narrow, so the nano silver wire that makes is very even.Then, this aeroge is polished into the thick thin slice of 2mm, after commercially available pure water cleans, oven dry.

Then, above-mentioned cleaning and the template of having removed moisture be placed in 10% D/W soaked 30 minutes, take out and dry, immersed again in the silver liquid ammonia of argentiferous 3% 30 minutes, make silver liquid ammonia at SiO with filter paper ₂React in the aeroge template hole, generate nano silver wire.

At last, taking out, clean with commercially available pure water, wipe the silver liquid ammonia of surface attachment with filter paper, is 2moll with its immersion concentration again ^-1Sodium hydroxide solution, make SiO ₂The dissolving of aeroge template is cleaned repeatedly with pure water at last, and containing diameter in the black powder that obtains is nano level wire silver, i.e. nano silver wire.

Embodiment 2

At first, the Al that selects for use sol-gel and supercritical drying drying method to make ₂O ₃Aeroge is as the template of preparation nano silver wire, and the aperture of this aeroge concentrates between the quite narrow 60-80nm of distribution, and porosity is greater than 90%.Then, this aeroge is polished into the thick thin slice of 1mm, after commercially available distilled water cleans, oven dry.

Then, above-mentioned cleaning and the template of having removed moisture be immersed in soak 40 minutes in 50% the D/W after, take out and dry with filter paper, immerse again in the silver liquid ammonia of argentiferous 5%, after 40 minutes, make silver liquid ammonia and glucose at Al ₂O ₃React in the aeroge template hole, generate nano silver wire.

At last, taking out, clean with commercially available distilled water, wipe the silver liquid ammonia of surface attachment with filter paper, is 5moll with its immersion concentration again ^-1Sodium hydroxide solution, make Al ₂O ₃The dissolving of aeroge template is cleaned repeatedly with distilled water at last, and resulting black powder is a nano silver wire.

Claims

1. be the method that template prepares nano silver wire with the aeroge, it is characterized in that: be to use Al ₂O ₃, SiO ₂Aeroge obtains nano silver wire as template by electroless deposition processes, and concrete technology is pressed routine steps in order and carried out:

At first choose the aperture at 10-80nm, porosity is greater than 90%, and the aperture concentrates on inorganic oxide aeroge within the quite narrow 30nm of distribution as template;

With sand paper aeroge is polished into the thin slice of thickness at 1-3mm then, thin slice is clean with purified rinse water, dries or dries up;

Then elder generation soaked 30-40 minute in the reducing solution of the D/W of 10%-50%; Then template being taken out from reducing solution, dry with filter paper, is to soak 30-40 minute in the silver liquid ammonia of 3%-5% in concentration again; Take out, clean with pure water, with filter paper wiping aeroge surface, remove the silvering solution of surface attachment, this moment, existing nano silver wire formed in the aeroge hole;

At last, the template of existing nano silver wire formation being put into concentration is 2-5moll ^-1Sodium hydroxide solution soaks, and till template was all dissolved, remaining black powder was a nano silver wire of the present invention.