Patent ID: 7736485
Filing Date: 2010-06-15
Classification: B82Y,C01B,C01F,C01G,C01P,C09C,C25B,H01B,Y10T

Abstract:
1. A method of producing magnesium hydroxide nanoplatelets, comprising the steps of: providing an electrolyzer comprising an anode compartment, a cathode compartment, and a center compartment situated between the anode compartment and the cathode compartment, and separated from the anode compartment and the cathode compartment by ion selective membranes; adding a solution of electrolyte at a pH of about 8 to the anode compartment; adding a solution of up to about 50 wt. % sodium hydroxide at a pH of 8 or higher to the cathode compartment; adding a solution of a second electrolyte to the center compartment, wherein the solution has from about 30,000 ppm chloride ion to about 200,000 ppm chloride ion; operating the cathode compartment at an amperage of 3.75 amps per square inch or less, whereby hydroxide ion is generated in the cathode compartment and migrates through its ion selective membrane into the center compartment, and whereby sodium ion is generated in the anode compartment and migrates through its ion selective membrane into the center compartment; thereafter adding to the center compartment a solution of soluble magnesium ion and a third electrolyte, the solution having from about 300 ppm to 100,000 ppm magnesium ions and from about 5000 ppm to about 200,000 ppm anions, whereby the soluble magnesium ion reacts with hydroxide ion to yield magnesium hydroxide nanoplatelets, wherein a residence time in the center compartment of the magnesium hydroxide nanoplatelets is from about 0.1 minutes to about 10 minutes; removing residual water from the magnesium hydroxide nanoplatelets, whereby dried magnesium hydroxide nanoplatelets are obtained; and applying heat to one side of the dried magnesium hydroxide nanoplatelets, whereby magnesium hydroxide is converted to magnesium oxide through a portion of a thickness of the nanoplatelets, causing them to roll into nanotubes, whereby magnesium (hydr)oxide nanotubes are obtained.