Particles and inks and films using them
View Patent ↗Particles and particle films are provided. In certain examples, particles produced from a single phase process may be used to provide industrial scale synthesis of particles for use in devices such as printed wiring boards.
1. A method of producing hexadecylamine capped silver particles in a single phase solution, the method comprising:
mixing silver or a silver salt with a hexadecylamine capping agent in a single phase solution comprising ethylene glycol, ethanol and toluene, and maintaining the single phase solution;
adding a borohydride reducing agent to the single phase solution; and
isolating hexadecylamine capped silver particles from the single phase solution.
2. The method of claim 1 further comprising removing the hexadecylamine capping agent from the hexadecylamine capped silver particles to provide uncapped silver particles.
3. The method of claim 2 further comprising dispersing the uncapped silver particles in a solvent.
4. The method of claim 3 further comprising mixing the dispersed uncapped silver particles with an additional metal to provide an alloy.
5. The method of claim 4 in which the additional metal is one or more metals selected from the group consisting of gold, palladium, platinum, copper, and tin.
6. The method of claim 3 further comprising disposing the dispersed uncapped silver particles on a substrate.
7. The method of claim 6 in which the disposing step comprises spin coating, inkjet printing, paste printing or combinations thereof.
8. The method of claim 2 in which the step of removing the capping agent comprises dispersing the hexadecylamine capped silver particles in a solvent and heating the dispersed hexadecylamine capped silver particles.
9. The method of claim 1 in which the hexadecylamine capped silver particles are nanoparticles.
10. The method of claim 1 comprising configuring the hexadecylamine capping agent to be about 18% by weight based on the total weight of the hexadecylamine capped silver particles.
11. The method of claim 1 , wherein the borohydride reducing agent is selected from the group consisting of: sodium borohydride, sodium cyanoborohydride, potassium borohydride and sodium triacetoxyborohydride.
12. A method of producing a printed wiring board comprising:
producing hexadecylamine capped silver particles from a process comprising:
mixing silver or a silver salt with a hexadecylamine capping agent in a single phase solution comprising ethylene glycol, ethanol and toluene, and maintaining the single phase solution; and
adding a borohydride reducing agent to the single phase solution to produce the hexadecylamine capped silver particles;
isolating the hexadecylamine capped silver particles from the single phase solution;
dispersing the hexadecylamine capped silver particles in a carrier;
disposing the dispersed hexadecylamine capped silver particles on a substrate; and
heating the substrate.
13. The method of claim 12 further comprising disposing the dispersed hexadecylamine capped silver particles on a substrate in a selected pattern to provide the printed wiring board.
14. The method of claim 12 , wherein the borohydride reducing agent is selected from the group consisting of: sodium borohydride, sodium cyanoborohydride, potassium borohydride and sodium triacetoxyborohydride.