Tracking polymer diffusion in a wet latex film with fluorescence resonance energy transfer

• Published in: Review of scientific instruments 2007-08, Vol.78 (8), p.084101-084101
• Main Authors: Haley, Jeffrey C, Liu, Yuanqin, Winnik, Mitchell A, Demmer, David, Haslett, Tom, Lau, Willie
• Format: Article
• Language: English
• Subjects: Computer-Aided Design; Diffusion; Equipment Design; Equipment Failure Analysis; Fluorescence Resonance Energy Transfer - methods; Latex - chemistry; Materials Testing - instrumentation; Materials Testing - methods; Membranes, Artificial; Reproducibility of Results; Sensitivity and Specificity; Specimen Handling - instrumentation; Specimen Handling - methods; Wettability
• ISSN: 0034-6748; 1089-7623
• DOI: 10.1063/1.2766844

We describe an instrument to measure the polymer interdiffusion between donor-labeled and acceptor-labeled latex polymers in a partially wet latex film with fluorescence resonance energy transfer (FRET). It is possible to temporarily arrest the drying process of a wet latex film by sealing the film in an airtight chamber. In our approach, we measure donor fluorescence decays from 0.5 mm diameter spots at various positions across an arrested latex film with time-correlated single photon counting. We interpret the resulting decays with a Monte Carlo simulation of the FRET process and extract information about the extent of polymer diffusion as a function of position on the film. These results enable us to determine the extent of polymer interdiffusion as a function of distance from the wet-dry edge in the latex film. To highlight this device's ability to capture the rapid early stages of latex interdiffusion, we report results from an acrylate copolymer latex.