NanoFTIR for nanomaterial

Multimodal analytics of nanocomposites

Metal-organic frameworks (MOFs) consist of metal ions coordinated with organic ligands to form nanocrystals. MOF with its tunable pore size and electrophilicity has great potential in the application of energy storage, gas capture, and chemical separation. However, the nanoscale properties of single MOF crystals remained unexplored until recently. In this research, we leverage nanoFTIR, the scattering-type scanning near-field optical microscopy (s-SNOM) combined with FTIR, to study MOF nanoparticles in polymer thin film systems. We also aim to work on understanding the material degradation of perovskite using various material characterization techniques.

nano-FTIR is based in on a s-SNOM setup comprising an asymmetric interferometer where the AFM tip and the sample are located in one of the interferometer arms. Broadband source (e.g. laser, synchrotron, etc.) illuminates the AFM tip. Tip-scattered light is recombined with the reference beam at the detector. The detector signal is recorded as a function of reference mirror position, creating an (asymmetric) interferogram. Fourier transformation of this interferogram returns the local amplitude and phase spectra, which relate to the sample reflectivity and absorption. Adopted from neaSPEC.com.

In the AFM mode, it shows there is nanocomposite aggregate underneath the PVDF polymer. Conventional FTIR will not be able to identify nano-objects on this scale. By nanoFTIR, we see that the characteristic peaks of ZIF71 at 1470 and 1530 cm^-1 are present at the red point, and the 1470 peak is present at the orange point, and no ZIF71 characteristics are shown at the blue point.