Agglomerating nanoparticles
A method of agglomerating nanoparticles to form larger agglomerates is shown. The nanoparticles are mixed with a resin to form a first mixture ( 803 ) of agglomerates, having sizes over a range that includes agglomerates considered to be too large, suspended in the resin. A bead milling cylinder ( 802 ) produces a second mixture ( 808 ) with fewer large agglomerates. A filter ( 1001 ) removes the remaining large agglomerates. The resulting mill base is cut with a solvent before deployment.
1. A method of agglomerating nanoparticles to form larger agglomerates, comprising the steps of:
mixing said nanoparticles with a resin to form a first mixture of agglomerates suspended in said resin, said first mixture comprising agglomerates having a largest dimension which is greater than a predetermined specified dimension;
bead milling said first mixture to produce a second mixture with a reduced number of agglomerates having said largest dimension greater than said predetermined specified dimension; and
filtering said second mixture to produce a third mixture of agglomerates suspended in said resin, wherein substantially none of said agglomerates have a largest dimension greater than said predetermined specified dimension; wherein said first mixture comprises a percentage by weight of nanoparticles to resin of substantially three percent.
2. The method of claim 1 , wherein said nanoparticles have said largest dimension of less than one hundred nanometers.
3. The method of claim 1 , wherein said nanoparticles are substantially spherical.
4. The method of claim 1 , wherein said nanoparticles are acicular.
5. The method of claim 1 , wherein said particles are particles of antimony doped tin oxide.
6. The method of claim 1 , wherein said resin is an undiluted lacquer.
7. The method of claim 6 , wherein said lacquer is solvent-based.
8. The method of claim 1 , wherein said predetermined specified dimension is ten micrometers.
9. The method of claim 1 , wherein said mixing step is performed by a speed mixer operating at a rotational speed of up to one thousand six hundred revolutions per minute.
10. The method of claim 1 , wherein said bead milling step provides a mixing power that is controlled to minimize reducing the largest dimension of agglomerates to a largest dimension of below five micrometers.
11. The method of claim 1 , wherein said filtering step utilizes a filter with openings having a largest dimension of ten micrometers.