Chemistry at interfaces: Electropositive metals on polymer surfaces

Abstract

This paper presents a study of chemical interactions between polymer surfaces and metal atoms deposited from the vapor phase. Such interactions may play an important role in interfacial metal-polymer adhesion. The chemical nature of the interface formed when an electropositive metal (chromium or cesium) is deposited onto the surface of PMDA-ODA polyimide has been investigated using chemical model studies coupled with photoelectron spectroscopic techniques. X-ray photoelectron spectroscopy, synchrotron-radiation-excited core-level photoemlssion, and near-edge X-ray absorption spectroscopy were used to analyze changes in polymer surfaces during deposition of chromium and cesium. Chemical model studies using cyclic voltammetry and UV-vislble spectroscopy were performed using several simpler polymers or monomeric model compounds which contained structural subunits of the polyimide. Results of these experiments ^Copyright 1988 by International Business Machines Corporation. Copying in printed form for private use is permitted without payment of royalty provided that (1) each reproduction is done without alteration and (2) the Journal reference and IBM copyright notice are included on the irst page. The title and abstract, but no other portions, of this paper may be copied or distributed royalty free without further permission by computer-based and other information-service systems. Permission to republish any other portion of this paper must be obtained from the Editor.show that chromium (and other electropositive metals studied so far) initially reacts rapidly with the carbonyl groups of polyimide, causing reduction of the dianhydride portion of the polymer, with concomitant chromium oxidation. Continued deposition of chromium onto the reacted polymer surface results in the formation of chromium carbide, oxide, and nitride species, indicating a disruption of the polymer chemical structure.

Electrochemical and Surface Analytical Approach to Passive Film on 200 Series Stainless Steels Formed in Sulfuric Acid

“…After curve fitting N 1s spectra reveals its presence in two forms (Fig. 4(b)), the major peak at BE of 400.2 eV suggests for NO or NH 23,24) and another peak at BE of 399.3 eV for CrN/Cr 2 N. 25) Considering potential-pH equilibrium diagram for N-H 2 O system 26) it is noticed that NH 4 ϩ ions are stable at lower potential and NO 3 Ϫ ions are at higher potential. Hence, in the present study for the given potential (100 mV SCE ) and pH (0.5), NO is more likely to form.…”

Adhesion at copper- polyamide 11- copper and aluminum-poly amide 11-aluminum laminate interfaces: influence of metal surface oxidation

“…Aluminum, having a higher affinity to oxygen than copper, can orient carbonyl groups in polymers such as poly(ethyleneterephthalate) [17,18] or polyamide [24][25][26]. Furthermore, the electrochemical potentials of PA 11 and Al favor the electron transfer from the metal to the polymer.…”

“…This, as suggested previously, is considered to be the initial step of polymer-metal interaction [4]. Possibly, aluminum reacts with the carbonyl group, opening the C=O double bond, to form a complex involving a -C-O-A1 sequence [24][25][26].…”

An Auger study on the interaction of Cu and Cr films with polyimide

“…It is difficult to determine the reactivity of Cr with oxygen by the AES analysis. XPS studies have shown the presence of chemical bonding states between Cr and 0 in the very carefully controlled interfaces formed under UHV conditions [22,23]. An XPS study on the peeled surface may be necessary to resolve the nature of the bonding state of Cr to polyimide in the interface formed under realistic processing conditions.…”