Gravimetric and density profiling using the combination of surface acoustic waves and neutron reflectivity

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• 作者：Daniel T.W. Toolan^a ; Robert Barker^b ; ¹ ; Tim Gough^c ; Paul D. Topham^d ; Jonathan R. Howse^a ; ; Andrew Glidle^e ; ^{andrew.glidle@gla.ac.uk" class="auth_mail" title="E-mail the corresponding author}
• 关键词：NR ; Neutron Reflectivity ; QCM ; Quartz Crystal Microbalance ; ATR-FTIR ; Attenuated Total Reflection Fourier Transform Infra-Red ; RAIRS ; Reflectance Absorbance Infra-Red Spectroscopy ; XPS ; X-ray Photoelectron Spectroscopy ; Nb ; neutron scattering length density ; SAW ; Surface Acoustic Wave ; IDTs ; Interdigitated Transducer electrodes ; PMMA ; poly methyl methacrylate ; VNA ; Vector Network Analyser ; PECVD ; plasma-enhanced chemical vapour deposition ; d-PS ; deuterated polystyrene
• 刊名：Journal of Colloid and Interface Science
• 出版年：2017
• 出版时间：1 February 2017
• 年：2017
• 卷：487
• 期：Complete
• 页码：465-474
• 全文大小：1403 K

文摘

A new approach is described herein, where neutron reflectivity measurements that probe changes in the density profile of thin films as they absorb material from the gas phase have been combined with a Love wave based gravimetric assay that measures the mass of absorbed material. This combination of techniques not only determines the spatial distribution of absorbed molecules, but also reveals the amount of void space within the thin film (a quantity that can be difficult to assess using neutron reflectivity measurements alone). The uptake of organic solvent vapours into spun cast films of polystyrene has been used as a model system with a view to this method having the potential for extension to the study of other systems. These could include, for example, humidity sensors, hydrogel swelling, biomolecule adsorption or transformations of electroactive and chemically reactive thin films. This is the first ever demonstration of combined neutron reflectivity and Love wave-based gravimetry and the experimental caveats, limitations and scope of the method are explored and discussed in detail.