A kind of method of the composite being prepared coated with silver on surface by catechol-polyamines
Technical field
The invention belongs to prepare conducing composite material field, be specifically related to a kind of at the variously-shaped and material list of performance
The method of face reduction silver, particularly relates to prepare base by catechol-polyamines is surface-functionalized under conditions of reducing agent exists
The method of body/silver composite material.
Background technology
Metal-powder is the important source material of electronics industry, national defense industry.Owing to the density of metal is very big, with metal fine powder it is
The material of main conductive medium is difficult to avoid the generation of signs of degradation during storing and using, and this is by shadow to a great extent
Ring the use of product.Other metals of metallic cover or nonmetal basal body be a kind of core be polymer ceramic etc. nonmetal or
Other metals, surface are the core-shell type composite powder of metal, and it can give the special electricity of matrix, magnetic, optical property and antioxygen
Change and ageing-resistant performance, also can improve the wettability of powder and metal.This patent will relate specifically to one can be at most of non-gold
Belong to material and metal material surface carries out the most modified method, mainly with glass microballoon, aluminium powder as example.
Glass microballoon has that density is little and the feature of uniform particle sizes, and density is much smaller than metal-powder.But common glass
Microballon is insulator, it is impossible to as the packing material of conductive material.Use low-density electro-conductive glass microballon as conductive material
Can effectively overcome the settlement issues of conducting medium.Glass microballoon chemical nickel plating on surface, copper, silver and composite coating can be used as electromagnetism
Shielding material and the conductive filler of absorbing material.Due to its surface hydrophobicity, untreated glass microballoon surface and other materials
The bonding stability on surface and adhesion are poor, need to be further processed so that it is surface can form even compact
Silver layer.
Aluminum, due to light specific gravity, the advantage such as ductility is good, metallic luster is good and cheap, is widely used in electricity
The fields such as son, aviation and electric slurry.But aluminium powder surface activity is big, extremely unstable, easy and air generation redox reaction,
So that the advantage losing itself.Therefore, in the application, it must be carried out surface process so that the aluminium powder after process had both kept this
The density of body is light, and the advantage that metallic luster is good has good electric conductivity simultaneously.Silver is noble metal, close with the color of aluminum,
And its excellent conductivity, if being coated with the silver of one layer of uniform and thin on aluminium powder, while keeping aluminium powder intrinsic advantage, give aluminum
The electric conductivity that powder is good, has been greatly reduced cost simultaneously, and products obtained therefrom can be used for the field such as electromagnetic shielding, electrocondution slurry.
In the past few decades, scientists various methods metallized to matrix surface are explored and have been studied,
Wherein method includes mechanical mixing, Sol-gel method etc..These methods have different defects for powder surface modification, such as
Mechanical mixing mixing is uneven, Sol-gel method crystal grain when reducing metal oxide is easily grown up.Select the most in the invention
By the method for chemical plating.
At present, there are some researches show that dopamine can help the metallization of material as a kind of active substance.Dopamine can
To show to stick in multiple polymers, and adhesive property is excellent, and process is simple.This kind of method comes from shellfish
The protein material of secretion can be bonded in the wet structure of object effectively, and the principle of this phenomenon is ground by existing scientist
Study carefully.Result of study shows, the dihydroxyphenylalanine (DOPA) in the protein material secreted by shellfish rises wherein
To Main Function, and prove that dopamine can be good in various organic or inorganic matrix surfaces bonding, adhesive property and matrix without
Close, and the further grafting of metal or other monomers can be carried out at matrix surface as effective platform.In patent CN
By depositing dopamine on glass microballoon surface in 101812678 B, subsequently at its surface reduction silver, prepare silvered glass micro-
Pearl.But, dopamine, as medical agent, synthesizes and extracts difficulty, expensive.Needed for the method, the response time is longer, many
Bar amine realizes preferably cladding and needs 24h on glass microballoon surface, and the silver-plated glass beads electrical conductivity prepared is relatively low, only 2.0-
2.5×10-3S/m.These shortcomings significantly limit the method and the most extensively apply and large-scale production.
Summary of the invention
It is an object of the invention to solve deficiency present in the existing composite technology preparing coated with silver on surface, and carry
Confession is a kind of prepares the method that Surface coating has the composite of silver by catechol-polyamines surface modification.Provided by the present invention
Method is easy and simple to handle, the shortest, low cost, covering property and the electric conductivity of prepared composite are good.
After the present invention is by being deposited on matrix surface by catechol-polyamines in the basic conditions, will be with poly-(adjacent benzene two
Phenol-polyamines) surface-functionalized matrix is placed in silver plating solution, adds reducing agent glucose solution, prepare covering property good,
There is the matrix/silver composite material of electric conductivity, specifically comprise the following steps that
1) by matrix in ethanol solution after ultrasonic cleansing, being placed on catechol concentration is 5~25mM/L, and pH is
In the catechol of 7.0~10.0-many amine aqueous solutions, stir not higher than 24h with the stir speed (S.S.) of 30~100 turns/min, obtain table
Face deposition has the matrix of poly-(catechol-polyamines).Preferably catechol concentration be 10mM/L, pH be 8.5, mixing time is
4h;
2), when silver nitrate solution ammonia water titration to the precipitation that mass concentration is 5~40g/L just being disappeared, preparation obtains
Silver plating solution.Preferred concentration is 10g/L;
3) by step 1) in the surface deposition of preparation have the matrix of poly-(catechol-polyamines) to be placed in step 2) silver prepared
In plating solution, every 4g matrix adds 0.01g polyethylene of dispersing agent ketopyrrolidine (PVP), stirs 20 minutes;
4) stirring under conditions of to step 3) silver plating solution in add mass concentration be 5~80g/L glucose solution,
The volume of used glucose solution is identical with the volume of silver nitrate solution, reacts 1~60 minute under room temperature, obtains surface and covers
There is the matrix of silvery white silver layer.Preferably concentration of glucose is 20g/L, and the response time is 60 minutes.
It doesn't matter with the concentration of silver plating solution in the selection of glucose concentration, but is silver plating solution concentration at concentration of glucose
Twice time reduction effect best.
Described polyamines is diethylenetriamine, triethylene tetramine, TEPA, five hexamine or six ethylene seven amine.Excellent
Select TEPA.
Described catechol is 1:3~3:1 with the mol ratio of polyamines, and preferred molar ratio is 1:1.
Wherein, step 1) described in method the matrix of all forms is all suitable for, include but not limited to spherical microballon,
Lamellar, fiber, microgranule, powder etc., it is simultaneously suitable for all material kind, including metal, inorganic non-metallic, polymer, is combined
Material etc..The preferred silicon dioxide microsphere of matrix.
The principle of the present invention is: the nitrogen-containing group in polyamines can play the effect of reduction silver ion, and catechol
Phenolic hydroxyl group can fix the silver particles that reduction generates.Meanwhile, by chemically treated matrix/silver composite material, there is good bag
Covering performance and electric conductivity, this has been primarily due to reducing agent additional, promotes the reduction process of silver, simultaneously catechol-many
The existence of amine is accelerated and has consolidated the Argent grain growth at matrix surface.Owing to catechol-polyamines is at polymeric matrix table
Face be deposited as physical process, unrelated with the surface topography of inorganic matter matrix and chemical composition in whole method, be applicable to each
Plant form and the inorganic matter matrix of composition.
With existing prepare Conductive inorganic nonmetallic materials technology compared with, the inventive method has the advantages that
1) present invention is easy and simple to handle, and the shortest (the preferably basic 5h of total reaction time), (cost of material is dopamine to low cost
1/50).
2) the matrix surface silver layer even compact prepared by the present invention, (electrical conductivity is 1.0 to have good electric conductivity
1.5×105And covering property S/m).
3) matrix/silver composite material prepared by the present invention, has higher adhesion strength between silver layer and matrix.
4) pattern and the composition of inorganic matter matrix are not limited by the present invention, and the attachment of silver does not interferes with the physics of inorganic matter
Mechanical performance and hot property.
Accompanying drawing explanation
Fig. 1, x-ray photoelectron power spectrum (XPS) the wide range figure of embodiment 1 microsphere, wherein (a) pure silicon dioxide microsphere, (b)
Silicon dioxide microsphere i.e. silicon dioxide/poly-(catechol-four ethylene that poly-(catechol-TEPA) is surface-functionalized
Five amine) core-shell microspheres and (c) surface reduction have the silicon dioxide microsphere i.e. silicon dioxide/poly-(catechol-tetrem of silver
Alkene five amine)/silver core-shell microspheres.
Fig. 2, X-ray diffraction power spectrum (XRD) spectrogram of embodiment 1 microsphere, wherein (a) pure silicon dioxide microsphere, (b) dioxy
SiClx/poly-(catechol-TEPA) core-shell microspheres and (c) silicon dioxide/poly-(catechol-four ethylene five
Amine)/silver core-shell microspheres.
Fig. 3, scanning electron microscope (SEM) image of embodiment 1, wherein (a) pure silicon dioxide microsphere, (b) titanium dioxide
Silicon/poly-(catechol-TEPA) core-shell microspheres and (c) silicon dioxide/poly-(catechol-four ethylene five
Amine)/silver core-shell microspheres.
Scanning electron microscope (SEM) image of Fig. 4, comparative example 9 and embodiment 1 microballon, wherein (a) is comparative example more than 9
The silicon dioxide/silver core shell-type complex microsphere that bar amine surface is modified, (b) is that catechol in embodiment 1-TEPA is modified
After silicon dioxide/silver core shell-type complex microsphere.
The aluminum that (a) of gained blank aluminium powder in Fig. 5, embodiment 10, (b) catechol-TEPA are surface-functionalized
Powder i.e. aluminum/poly-(catechol-TEPA) core-shell microspheres and (c) surface reduction have the aluminium powder i.e. aluminum of silver/poly-
The XPS wide range figure of (catechol-TEPA)/silver core-shell microspheres.
The different amplification in the face absolutely of quenching of the silicone rubber that in Fig. 6, embodiment 11, the silver-plated glass beads of gained is filled
A SEM photograph that () 400 times and (b) is 1000 times.
Detailed description of the invention
Below in conjunction with embodiment, the present invention will be further described, but the present invention is not limited to following example.
Embodiment 1
1) configuration concentration is the catechol-TEPA aqueous solution of 10mM/L, and catechol rubs with TEPA
Your ratio is 1:1, and with after Tris-HCl buffer regulation PH to 8.5, is soaked wherein by the glass microballoon that 4g cleans with ethanol, with
The stir speed (S.S.) of 60 turns/min stirs 4 hours, and deposition is had the glass of poly-(catechol-TEPA) micro-by stirring after terminating
Pearl filters out, and is washed with deionized water clean, vacuum drying;
2) configuration concentration is the silver nitrate solution of 10g/L, just disappears to precipitation by ammonia water titration, obtains silver plating solution;
3) will be by step 1) in poly-(catechol-TEPA) surface-functionalized after glass microballoon stirring bar
Be immersed in step 2 under part) in the 100ml silver plating solution that obtains, this silver plating solution adds 0.01g polyethylene of dispersing agent pyrrolidine
Ketone (PVP), to improve glass microballoon dispersive property in the solution, stirs 20 minutes;
4) glucose solution that 100ml mass concentration is 20g/L is added step 3) silver plating solution in, react 60 minutes
After, available Surface coating has the glass microballoon of silver particles.
After measured, this glass microballoon (silicon dioxide)/galactic nucleus shell-type compounded microbeads can conduct electricity, electrical conductivity 1.0 1.5 ×
105Between S/m.
In the present embodiment, the atomic percent of pure silicon dioxide and silicon dioxide/silver core shell-type complex microsphere surface-element contains
Amount ratio is shown in Table 1.
Pure silicon dioxide microsphere XPS wide range figure and XRD spectra are shown in Fig. 1 (a) and Fig. 2 (a), silicon dioxide/dopamine respectively
The XPS wide range figure of core-shell microspheres and XRD spectra are shown in Fig. 1 (b) and Fig. 2 (b) respectively, silicon dioxide/poly-(catechol-
TEPA)/silver XPS wide range the figure of core-shell microspheres and XRD spectra be shown in Fig. 1 (c) and Fig. 2 (c) respectively;Scanning electron
Microscope (SEM) image is shown in Fig. 3, wherein (a) pure silicon dioxide microsphere, (b) silicon dioxide/poly-(catechol-four ethylene five
Amine) core-shell microspheres and (c) silicon dioxide/poly-(catechol-TEPA)/silver core-shell microspheres.
It is seen in fig. 1, that at Fig. 1 (b) silicon dioxide/poly-(catechol-TEPA) core-shell microspheres
XPS wide range figure occurs in that the nitrogen element not having in Fig. 1 (a) pure silicon dioxide, illustrates that poly-(catechol-TEPA) sinks
Amass on silicon dioxide microsphere surface.It is combined at Fig. 1 (c) silicon dioxide/poly-(catechol-TEPA)/galactic nucleus shell-type
The XPS wide range figure of microsphere occurs in that silver peak, illustrates to deposited silver particles on silicon dioxide microsphere surface.As can be seen from Figure 2,
At Fig. 2 (a) pure silicon dioxide and the XRD of Fig. 2 (b) silicon dioxide/poly-(catechol-TEPA) core-shell microspheres
Spectrogram does not have silver-colored peak, and at Fig. 2 (c) silicon dioxide/poly-(catechol-TEPA)/silver core-shell microspheres
XRD spectra in have the silver-colored peak of four kinds of different crystalline lattice structures to occur, it was demonstrated that have silver particles on silicon dioxide microsphere surface.From Fig. 3
Can be seen that Fig. 3 (a) pure silicon dioxide, Fig. 3 (b) silicon dioxide/poly-(catechol-TEPA) core-shell microspheres
With the change of the surface topography of Fig. 3 (c) silicon dioxide/poly-(catechol-TEPA)/silver core-shell microspheres, with
Time can be seen that the silver layer on the silicon dioxide/silver core shell-type complex microsphere surface prepared with chemical reduction method is fine and close continuously, tool
Standby good electric conductivity.
Embodiment 2
Process is with embodiment 1, by step 4) in the response time change 30min, 40min, 50min, 90min and 120min into can
Obtain Surface coating and have the glass microballoon of silver particles.
After measured, this silicon dioxide/silver core shell-type compounded microbeads can conduct electricity, and electrical conductivity is 1.0 1.5 × 105S/m it
Between.
Embodiment 3
Process is with embodiment 1, by step 1) in the concentration of catechol-TEPA change into 5mM/L, 15mM/L,
20mM/L and 25mM/L, available Surface coating has the glass microballoon of silver particles.
After measured, this silicon dioxide/silver core shell-type compounded microbeads can conduct electricity, and electrical conductivity is 1.0 1.5 × 105S/m it
Between.
Embodiment 4
Process is with embodiment 1, by step 1) in mixing time change 2 hours, 8 hours, 12 hours and 24 hours into, available
Surface coating has the glass microballoon of silver particles.
After measured, this silicon dioxide/silver core shell-type compounded microbeads can conduct electricity, and electrical conductivity is 1.0 1.5 × 105S/m it
Between.
Embodiment 5
Process is with embodiment 1, by step 2) in silver nitrate concentration change 5g/L, 20g/L, 30g/L and 40g/L into, accordingly
Glucose concentration is 10g/L, 40g/L, 60g/L and 80g/L, and available Surface coating has the glass microballoon of silver particles.
After measured, this silicon dioxide/silver core shell-type compounded microbeads can conduct electricity, and electrical conductivity is 1.0 1.5 × 105S/m it
Between.
Embodiment 6
Process is with embodiment 1, by step 1) in the PH of catechol-TEPA solution be adjusted to 7 respectively, 7.5,8,
9,9.5 and 10, available Surface coating has the glass microballoon of silver particles.
After measured, this silicon dioxide/silver core shell-type compounded microbeads can conduct electricity, and electrical conductivity is 1.0 1.5 × 105S/m it
Between.
Embodiment 7
Process is with embodiment 1, by step 1) in TEPA change diethylenetriamine, triethylene tetramine, five ethylene six into
Amine and six ethylene seven amine, available Surface coating has the glass microballoon of silver particles.
After measured, this silicon dioxide/silver core shell-type compounded microbeads can conduct electricity, and electrical conductivity is 1.0 1.5 × 105S/m it
Between.
Embodiment 8
Process is with embodiment 1, by step 1) in the mol ratio of catechol and TEPA change into 1:2,1:3,2:1 and
3:1, available Surface coating has the glass microballoon of silver particles.
Comparative example 9
1) configuration concentration is the aqueous dopamine solution of 10mM/L, and with after Tris-HCl buffer regulation PH to 8.5, by 4g
The glass microballoon cleaned with ethanol soaks wherein, stirs 24 hours with the stir speed (S.S.) of 60 turns/min, and stirring will deposition after terminating
The glass microballoon having poly-dopamine filters out, and is washed with deionized water clean, vacuum drying;
2) configuration concentration is the silver nitrate solution of 10g/L, just disappears to precipitation by ammonia water titration, obtains silver plating solution;
3) by by step 1) in poly-dopamine surface-functionalized after glass microballoon under conditions of stirring, be immersed in step
2), in the 100ml silver plating solution obtained in, this silver plating solution adds 0.01g polyethylene of dispersing agent ketopyrrolidine (PVP) to improve
Glass microballoon dispersive property in the solution, stirs 20 minutes;
4) glucose solution that 100ml mass concentration is 20g/L is added step 3) silver plating solution in, react 60 minutes
After, available Surface coating has the glass microballoon of silver particles.
In comparative example 9, products obtained therefrom is shown in the silicon dioxide/silver core shell-type complex microsphere surface-element of gained in embodiment 1
Table 2.From Table 2, it can be seen that the silver element content after the surface-functionalized glass microballoon of poly-dopamine is silver-plated is relatively low, element silicon
Content is higher.The silver layer of the glass microballoon surface deposition that this poly-dopamine of explanation is surface-functionalized is relatively thin, and content is less, causes it
Electrical conductivity is relatively low.
Its scanning electron microscope image with embodiment 1 products obtained therefrom is shown in Fig. 4, before carrying out reduction silver by chemical deposition
Put, compared for the silver layer (Fig. 4 (a)) of the surface-functionalized glass microballoon surface deposition of poly-dopamine and poly-(adjacent benzene two
Phenol-TEPA) difference of surface topography of silver layer (Fig. 4 (b)) of surface-functionalized rear glass microballoon surface deposition, explanation
By chemical reduction method under similarity condition, the silver layer of the glass microballoon surface deposition that poly-dopamine is surface-functionalized is the thinnest
Pine, silver layer is imperfect, and poly-(catechol-TEPA) surface-functionalized after glass microballoon surface deposition silver layer even
Continuous densification, the most completely, it was demonstrated that during reduction silver, the effect of catechol-TEPA is better than dopamine.
This is because TEPA has substantial amounts of-NH3Group, its faint reproducibility can be by the silver ion reduction in solution
Become silver particles, it is provided that the core needed for silver particles growth, the silver layer making deposition is compact and complete.
Embodiment 10
1) configuration concentration is the catechol-TEPA aqueous solution of 10mM/L, and catechol rubs with TEPA
Your ratio is 1:1, and with after Tris-HCl buffer regulation PH to 8.5, soaks wherein, the aluminium powder that 4g cleans with ethanol with 60
Turn/stir speed (S.S.) of min stirs 24 hours, deposition is had the aluminium powder mistake of poly-(catechol-TEPA) by stirring after terminating
Leach, be washed with deionized water clean, vacuum drying;
2) configuration concentration is the silver nitrate solution of 10g/L, just disappears to precipitation by ammonia water titration, obtains silver plating solution;
3) will be by step 1) in poly-(catechol-TEPA) surface-functionalized after aluminium powder stirring under conditions of
Be immersed in step 2) in the 100ml silver plating solution that obtains, this silver plating solution adds 0.01g polyethylene of dispersing agent ketopyrrolidine
(PVP) to improve aluminium powder dispersive property in the solution, stir 20 minutes;
4) glucose solution that 100ml mass concentration is 20g/L is added step 3) silver plating solution in, react 60 minutes
After, available Surface coating has the aluminium powder of silver particles.
After measured, this aluminum/galactic nucleus shell-type composite can conduct electricity, and electrical conductivity is 1.0 1.5 × 105Between S/m.
Fig. 5 is the blank aluminium powder of gained in embodiment 10, aluminum/poly-(catechol-TEPA) core-shell type composite wood
Material and the XPS wide range figure of aluminum/poly-(catechol-TEPA)/galactic nucleus shell-type composite.Due to Fig. 5 (b) aluminum/
The XPS spectrum figure of poly-(catechol-TEPA) occurs in that the nitrogen element not having in pure aluminium powder spectrogram, illustrates at aluminium powder table
Face deposition has poly-(catechol-TEPA), in the XPS spectrum of Fig. 5 (c) aluminum/poly-(catechol-TEPA)/silver
Figure occurs in that silver peak, it was demonstrated that deposited silver particles on aluminium powder surface.
Embodiment 11
The silver-plated glass beads 125g of preparation, methyl vinyl silicone rubber 50g, vulcanizing agent double 2,5 in embodiment 1 are added
In mill the most mixing, use vulcanizing press under the conditions of 175 DEG C × 10Mpa × 15min, elastomeric compound is carried out one section of sulfur
Changing, electric drying oven with forced convection carries out post vulcanization under conditions of 190 DEG C × 3.5hr, prepares the silicon that silver-plated glass beads is filled
Rubber.
Fig. 6 is the SEM photograph of the different amplification in face absolutely of quenching of the silicone rubber that silver-plated glass beads is filled.From Fig. 6
A, it can be seen that silver-plated glass beads is evenly distributed in silicone rubber in (), contact with each other formation conductive path.From the Fig. 6 amplified
It can be seen that silver-plated glass beads still keeps the most complete without coming off through mixing, sulfuration rear surface silver layer in (b), maintain
Good electric conductivity.
The contrast of the mechanical property of the silicone rubber that table 3 is filled for silver-plated glass beads and electrical property and company standard.From table
In it can be seen that the mechanical property of silicone rubber filled of the silver-plated glass beads of preparation and electrical property all meet enterprise requirements.
In table 1 embodiment 1, pure silicon dioxide and silicon dioxide/poly-(catechol-TEPA)/galactic nucleus shell-type are multiple
Close the relative atomic percent of microsphere surface element
The silicon dioxide of gained/poly-dopamine/silver and the silicon dioxide of gained in embodiment 1/poly-(neighbour in table 2 comparative example 9
Benzodiazepines-TEPA)/silver core-shell microspheres surface-element relative atomic percent
The mechanical property of the silicone rubber that table 3 silver-plated glass beads is filled and electrical property