Cross-sectional chemical nanoimaging of composite polymer nanoparticles by infrared nanospectroscopy

CIC nanoGUNE Seminars

Speaker

Monika Goikoetxea, Post-doctoral Researcher, Nanooptics

When

2022/10/10
11:00

Place

nanoGUNE seminar room, Tolosa Hiribidea 76, Donostia - San Sebastian

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**Cross-sectional chemical nanoimaging of composite polymer nanoparticles by infrared nanospectroscopy** Monika Goikoetxea Post-doctoral Researcher, Nanooptics, CIC nanoGUNE Multicomponent waterborne polymer nanoparticles are key ingredients in many technological and industrial products, such as in coatings, adhesives and cosmetics. The final performance properties of the composite particles depend on their morphology and chemical composition, which in turn are the result of complex kinetic and thermodynamic processes that occur during the polymerization. For that reason, chemical and structural characterization of the final polymer nanoparticles is critically important to understand the polymerization and to improve the synthesis. However, despite of all efforts devoted to the development of characterization techniques, the precise determination of the morphology and particularly of the local chemical composition of the waterborne composite polymer particles has remained elusive so far, especially when dealing with complex morphologies. The current challenges and limitations may be overcome by exploiting the high chemical sensitivity together with resolution of emerging infrared nanospectroscopy techniques. Here we introduce Infrared scattering-type scanning near-field optical microscopy (IR s-SNOM) and nanoscale Fourier transform infrared (nano-FTIR) spectroscopy to study multicomponent nanostructured polymer particles and demonstrate its excellent sensitivity to local chemical composition via hyperspectral infrared nanoimaging and subsequent chemometric analysis. To that end, we developed a method for preparing thin particle slices without any embedding material, thus avoiding chemical contamination. In particular, we studied particles composed by acrylic and fluoroacrylate monomers, finding an unexpected composition for each of the phases that form the complex core- shell-shell morphology, which provides unprecedented chemical insights beyond conventional electron microscopy analysis of the same particles.