TREATED MAGNETIZABLE PARTICLES AND METHODS OF MAKING AND USING THE SAME
Magnetizable particles treated with a silane precursor comprising a hydrophobic group.
1 . A method comprising:
treating magnetizable particles with a silane precursor comprising a hydrophobic group.
2 . A method as set forth in claim 1 wherein the silane precursor comprises octyltriethoxysilane.
3 . A method as set forth in claim 1 wherein the hydrophobic group is —CH 3 (CH 2 ) 7 .
4 . A method as set forth in claim 1 wherein the particles each comprise iron.
5 . A method comprising:
applying a magnetic field to magnetorheological fluid comprising magnetizable particles and a silicate coating thereon comprising hydrophobic group to cause the viscosity of the fluid to increase.
6 . A method as set forth in claim 5 wherein the fluid further comprises a carrier present in about 5 to about 50 weight percent of the fluid.
7 . A method as set forth in claim 6 wherein the carrier comprises water.
8 . A method as set forth in claim 6 wherein the carrier comprises an alcohol.
9 . A method as set forth in claim 6 wherein the carrier comprises hydrocarbon oil.
10 . A method as set forth in claim 6 wherein the particles are present in about 50 to about 95 weight percent of the fluid.
11 . A method as set forth in claim 5 wherein the silicate coating comprises SiOCH 3 (CH 2 ) 7 groups.
12 . A method as set forth in claim 11 wherein the magnetizable particles comprise iron powder.
13 . A method comprising:
hydrolyzing a silane;
mixing magnetizable particles, the hydrolyzed silane and a solvent together for a sufficient time to produce coated particles comprising the magnetizable particles coated with a hydrophobic protective coating;
condensing any hydroxyl groups on the coating;
separating the coated particles from the solvent.
14 . A method as set forth in claim 13 wherein the silane comprises an octyl group.
15 . A method as set forth in claim 13 wherein the silane comprises octyltriethoxysilane.
16 . A method as set forth in claim 13 further comprising adding the coated particles to a carrier vehicle to form a magnetoreological fluid and applying a magnetic field to the magnetoreological fluid.
17 . A product comprising:
a magnetorheological fluid comprising magnetizable particles and a silicate coating thereon comprising hydrophobic group.
18 . A product as set forth in claim 17 wherein the fluid further comprises a carrier present in about 5 to about 50 weight percent of the fluid.
19 . A product as set forth in claim 17 wherein the coating is present in about 0.01 to about 0.1 weight percent of the particle with the coating thereon.
20 . A product as set forth in claim 17 wherein the silicate coating comprises SiOCH 3 (CH 2 ) 7 groups.