Patents by Inventor Koon G. Neoh

Koon G. Neoh has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Recovery of precious metals from acid solutions by N-containing electroactive polymers
    Patent number: 5411573
    Abstract: The present invention is directed to a process for reducing the oxidation state of a metal by contacting an acidic solution of the metal with an electroactive polymer, and accumulating and recovering the metal. More particularly, the invention is directed to a method for recovering precious metals like gold, platinum, palladium, and gold-platinum alloys from acidic solution by contacting the solution with an electroactive polymer like polyaniline or polypyrrole.
    Type: Grant
    Filed: October 22, 1993
    Date of Patent: May 2, 1995
    Assignee: National University of Singapore
    Inventors: En-Tang Kang, Yen P. Ting, Koon G. Neoh, Kuang L. Tan
  • Chemical synthesis of stable and electroactive polypyrrole and related polyheterocyclic compounds
    Patent number: 4956444
    Abstract: A simple chemical process for the simultaneous polymerization and oxidation of pyrrole, N-substituted pyrroles, and other heterocycles having five or six member rings by halogenic or organic electron acceptors. The polypyrrole-acceptor charge transfer complexes so produced are of high purity and are stable in the atmosphere, in the presence of moisture and at elevated temperatures. The conductivities of the complexes are controllable between 30 ohm.sup.-1 cm.sup.-1 and 10.sup.-3 ohm-1 cm-1, depending on the type of acceptor used and the process conditions.
    Type: Grant
    Filed: April 9, 1987
    Date of Patent: September 11, 1990
    Assignee: National University of Singapore
    Inventors: En-Tang Kang, Thiam C. Tan, Koon G. Neoh