Eugene B Napadensky

US Patent:

7307127, Dec 11, 2007

Filed:

Apr 6, 2004

Appl. No.:

10/828521

Inventors:

Eugene Napadensky - Newark DE, US
Yossef A. Elabd - Baltimore MD, US
Dawn M. Crawford - Bel Air MD, US
James M. Sloan - Bel Air MD, US

Assignee:

United States of America as represented by the Secretary of the Army - Washington DC

International Classification:

C08F 8/36

US Classification:

525353, 525343, 525348, 525189, 5253335, 525344, 521 28, 521 33

Abstract:

A block copolymer composition AB is provided that has pendent groups —RZ extending from the A copolymer on at least 70 mol % of the A monomers, where R and Z are each an ionic species. The composition is included in a semipermeable membrane for use in a direct methanol fuel cell. Also described are articles of protective apparel comprising the composition which advantageously has barrier properties as well as superior water vapor transport properties.

US Patent:

6579948, Jun 17, 2003

Filed:

Nov 22, 2000

Appl. No.:

09/716967

Inventors:

Nora C. Beck Tan - Perryville MD
Dawn M. Crawford - Bel Air MD
James M. Sloan - Bel Air MD
Eugene Napadensky - Newark DE

Assignee:

The United States of America as represented by the Secretary of the Army - Washington DC

International Classification:

C08F 838

US Classification:

5253335, 4283084, 4283088, 525344

Abstract:

A semipermeable membrane that is capable of remaining flexible at a temperature of at least -60Â C. is selective to liquid penetrants depending on the size and polarity of the penetrants, and more specifically, the membrane has sufficient selectivity so as to be capable of allowing water to diffuse therethrough at a higher rate than virtually all organic liquids having a molecular weight higher than that of methanol. The semipermeable membrane, which is produced from an unsulfonated block copolymer having polystyrene and polyisobutylene segments, includes a sulfonated block copolymer including poly (styrene-co-styrene sulfonic acid) segments and polyisobutylene segments. Prior to modification by sulfonation, the unsulfonated polystyrene and polyisobutylene block copolymer includes polystyrene monomer in an amount of from 5% to 90% by weight of the total unsulfonated block copolymer. After modification, from 1 to 70 mole % of the polystyrene monomer in the unsulfonated polystyrene and polyisobutylene block copolymer is converted to styrene sulfonic acid in the sulfonated block copolymer. By virtue of the semipermeable membranes excellent transport and mechanical properties, and ease of processing, the various embodiments of the membrane advantageously find numerous uses, including in chemical and/or biological protective apparel, as an ion-conducting membrane for use in a fuel cell, and in medical equipment and apparel.