2004 Progress Report: Plasma Polymerization: A Novel, Environmentally-Compatible Process for Surface Engineering of MetalsEPA Grant Number: R829579
Title: Plasma Polymerization: A Novel, Environmentally-Compatible Process for Surface Engineering of Metals
Investigators: Boerio, F. James , Bengu, B. , Gupta, M.
Institution: University of Cincinnati
EPA Project Officer: Richards, April
Project Period: March 11, 2002 through March 10, 2006
Project Period Covered by this Report: March 11, 2004 through March 10, 2005
Project Amount: $300,000
RFA: Technology for a Sustainable Environment (2001) RFA Text | Recipients Lists
Research Category: Nanotechnology , Sustainability , Pollution Prevention/Sustainable Development
The main objective of this research is to develop environmentally compatible, all-plasma processes for surface engineering of metals prior to adhesive bonding. Plasma processes for etching or cleaning of metal substrates such as aluminum and for the subsequent deposition of plasma-polymerized primer films have been investigated. The mechanisms by which typical epoxy adhesive systems interact with plasma-polymerized primer films also have been investigated. Although most of this research involves plasma processes carried out at pressures below atmospheric pressure, the use of air plasmas at atmospheric pressure for surface engineering of metal substrates also is being explored.
Plasma-polymerized silica-like films can be effectively applied as primers to metals such as aluminum prior to adhesive bonding or coating operations. Plasma-etching is an effective method for preparing metals for deposition of plasma-polymerized primers; however, magnesium that is present in the oxide layers of some aluminum alloys must be removed from the surface before deposition of the primers to form durable bonds to those alloys. Atmospheric-pressure air plasmas can be used effectively to etch the surfaces of metals and to deposit plasma-polymerized primers onto the clean surfaces. Epoxy adhesives cured with dicyandiamide interact with metal substrates such as aluminum mostly by end-on coordination of the lone pair of electrons on the nitrile group of dicyandiamide to metal atoms. The same adhesive systems, however, interact with silica-like substrates mostly by hydrogen bonding and/or formation of covalent bonds through ring-opening of epoxide groups.
Plasma processing is an effective method for surface engineering of metals prior to adhesive bonding or coating operations. The technique is compatible with the environment. Atmospheric-pressure air plasmas are especially attractive because they do not require vacuum systems, can be applied to large objects with complex shapes, especially when combined with robotic controls, and can be adapted easily for continuous processing.
No future activities were reports by the investigators.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
|Other project views:||All 9 publications||1 publications in selected types||All 1 journal articles|
||Bengu B, Boerio FJ. Interaction of epoxy/dicyandiamide adhesives with metal substrates. The Journal of Adhesion 2006;82(12):1133-1155.||