Abstract
Understanding the stability of chemical interactions at the polymer/metal oxide interface under humid conditions is vital to understand the long-term durability of hybrid systems. Therefore, the interface of ultrathin PMMA films on native aluminum oxide, deposited by reactive adsorption, was studied. The characterization of the interface of the coated substrates was performed using ambient pressure X-ray photoelectron spectroscopy (APXPS), Fourier transform infrared spectroscopy in the Kretschmann geometry (ATR-FTIR Kretschmann) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The formation of hydrogen bonds and carboxylate ionic bonds at the interface are observed. The formed ionic bond is stable up to 5 Torr water vapour pressure as shown by APXPS. However, when the coated samples are exposed to an excess of aqueous electrolyte, an increase in the amount of carboxylate bonds at the interface, as a result of hydrolysis of the methoxy group, is observed by ATR-FTIR Kretschmann. These observations, supported by ToF-SIMS spectra, lead to the proposal of an adsorption mechanism of PMMA on aluminum oxide, which shows the formation of methanol at the interface and the effect of water molecules on the different interfacial interactions.
Highlights
One of the main goals in interface engineering is the achievement of high adhesion strengths at polymer/metal interfaces, especially in humid or aggressive conditions[1]
An interface spectrum is obtained of the interface between the adsorbed polymer and the hydroxide surface, while the deposition process is occurring
We showed that ATR-Fourier transform infrared spectroscopy (FTIR) Kretschmann, ToF-SIMS and ambient pressure X-ray photoelectron spectroscopy (APXPS) can be used to identify chemical interactions locally at the hybrid interface
Summary
One of the main goals in interface engineering is the achievement of high adhesion strengths at polymer/metal interfaces, especially in humid or aggressive conditions[1]. To investigate the interface region in an adequate way, one has to use appropriate analysis techniques and methodologies that allows access to this region in order to probe and extract useful information. This is rather challenging, as conventional hybrid systems are composed of a thick (μm) polymer layer on one side coupled with a thick metal substrate on the other side. The work shown here is part of ongoing research, where the initial effects of water on interfacial interactions of different acrylic polymers are investigated. APXPS has been validated as an in situ probe for the effect of water on the interfacial chemistry using carboxylic polymers. PMMA has an ester functional group, a methyl methacrylate, which leads to a large difference in macroscopic properties with respect to PAA, such as a high resistance to water
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
