Refractometric discrimination of void-space filling and swellingduring vapour sorption in polymer films

Cross, G.H.; Ren, Y.T.; Swann, M.J.

Abstract

Thin polymeric films have been deposited as upper cladding layers on a new integrated optical interferometer fabricated from layers of silicon oxynitride on a silicon wafer. The evanescent field of the probing waveguide mode transduces refractive index changes in the polymer layer into the measured phase changes in the device. Real-time measurement of index change and its sign is obtained. Upon exposure to humid air, we record water sorption by films of poly(vinyl pyrollidone) by a rapid positive index change for void-space filling followed by a slow negative index change for swelling. Sorption of water vapor into a thin film of the viscous liquid polymer polyethylenimine shows only swelling mode behaviour and a simple constitutive model can be applied to give the fractional water occupied volume.

Citation

Cross, G., Ren, Y., & Swann, M. (2000). Refractometric discrimination of void-space filling and swellingduring vapour sorption in polymer films. Analyst, 125(12), 2173-2175. https://doi.org/10.1039/b007847f

• Journal Article Type: Article
• Publication Date: Jan 1, 2000
• Deposit Date: May 8, 2013
• Journal: Analyst
• Print ISSN: 0003-2654
• Electronic ISSN: 1364-5528
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 125
• Issue: 12
• Pages: 2173-2175
• DOI: https://doi.org/10.1039/b007847f
• Public URL: https://durham-repository.worktribe.com/output/1581920