Method for the fabrication of corrosion resistant electrodes

Patent metadata

Field	Value
Publication number	US-2016231273-A1
Application number	US-201615130762-A
Country	US
Kind code	A1
Filing date	Apr 15, 2016
Priority date	Jan 31, 2013
Publication date	Aug 11, 2016
Grant date	—

Abstract

An electrode for use in instruments capable of measuring the electrophoretic mobility of particles in solution is disclosed. The electrode is comprised of an inexpensive support member, generally made of titanium, onto a flat surface of which has been connected, generally by microwelding, a flat electrically conductive but chemically inert foil member, preferably platinum. A uniform texture can be generated on the exposed surfaces of the electrode by various means including tumbling the electrode with an abrasive. An oxide layer can be generated on the support member by soaking the composite electrode in an appropriate medium, protecting the exposed surface of the support member from fluid contact with the sample solution, while the foil member, unaffected by the oxidation process, is able to contact the sample solution.

First claim

1 . A method for the fabrication of an electrode for use in an electrophoretic mobility detector comprising the steps of
A. providing an electrically conductive support member comprising at least one planar surface; B. providing a flat, chemically inert, electrically conductive foil member; C. welding said foil member to said conductive support member about the perimeter of said foil member, forming, thereby, a composite electrode; and D. etching the exposed surface of said electrically conductive foil member of said composite electrode so as to achieve a uniform, non-smooth surface there upon.

2 . The method of claim 1 wherein said welding is performed by an electron beam.

3 . The method of claim 1 wherein said electrically conductive foil member is comprised of platinum.

4 . The method of claim 3 wherein said platinum foil member is disc shaped.

5 . The method of claim 4 comprising the further step of milling an o-ring groove about a perimeter of the support member where said perimeter of said support member is chosen such that it does not intersect the planar surface to which the foil member is attached.

6 . The method of claim 3 wherein said platinum foil member is 100±5 μm thick, permitting thereby the foil member to be cleaned with mild abrasives without damage.

7 . The method of claim 1 wherein said etching of said exposed surface of said electrically conductive foil member is achieved by mechanically tumbling said composite electrode with an abrasive.

8 . The method of claim 1 wherein said etching of said exposed surface of said electrically conductive foil member is achieved by the application thereto of hydrofluoric acid.

9 . The method of claim 1 wherein said etching of said exposed surface of said electrically conductive foil member is achieved by ion beam etching.

10 . The method of claim 1 comprising the further steps of
a. selecting said support member to be composed of a material or materials whose surface, when exposed to a strong oxidizer, causes an oxide layer to grow thereupon; and
b. selecting said conductive foil member to be composed of a material or materials whose surface, when exposed to a strong oxidizer, resists an oxide layer forming thereupon.

11 . The method of claim 10 comprising the further step of causing an oxide layer to be formed upon the exposed surface of said support member by means of exposing said composite electrode to an oxidation agent.

12 . The method of claim 11 wherein said oxidizing agent is a solution comprised of hydrogen peroxide and water.

13 . The method of claim 12 wherein said solution is composed 30% hydrogen peroxide and 70% water.

14 . The method of claim 10 comprising the further step of passing an electrical current through said composite electrode while said composite electrode is bathed in a salt solution causing, thereby, an oxide layer to form upon said support member of said composite electrode.

Assignees

• Wyatt Tech Corp

Inventors

• Trainoff Steven P

Classifications

• C25D9/06

  by anodic processes · CPC title

• B23K2103/18

  Dissimilar materials · CPC title

• G01N27/44765 Primary

  of the counter-flow type · CPC title

• B23K15/0093

  characterised by the properties of the materials to be welded · CPC title

• G01N27/44704

  Details; Accessories · CPC title