报告题目:Gaining Insights into Functional Polymer Materials at 50 nm Spatial Resolution Using an AFM Probe as Infrared Absorption Sensor
报告人:Jiping Ye
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摘要:Atomic Force Microscopy (AFM) and infrared (IR) spectroscopy have been combined in a single instrument (nano-IR) capable of producing 50 nm spatial resolution IR spectra and absorption images. [1,2] This new capability enables the spectroscopic characterization of polymer materials at resolutions of over two orders of magnitude better than conventional IR. A tunable IR laser generating pulses of the order of 10 ns was used for excitation of the sample. Short duration thermomechanical waves, due to infrared absorption and resulting thermal expansion, were studied by monitoring the resulting excitation of the contact resonance modes of the AFM cantilever.
In this study, we have applied this nano-IR technology to direct visualization of interfacial functional groups and their distributions, compositional distribution and phase separation structure, crystalline structures of microdomains, and local molecular orientation. We will discuss results from the following three samples. i) Multilayer barrier films PET/PE where to visualize hidden binder and adhesion process; ii) Multi-component blends of PC/ABS where to understand phase separation and chemical state and also why 40/60 ABS/PC blend has a good impact resistance; iii) PVDF binder film for LIB electrode where to identify the polymer backbone conformation; iv) Fluorinated proton exchange membrane of fuel cell where to visualize the relationship between free water and bound water distributions; v) Films of P(HB-co-HHx), which were melted and annealed to generate crystalline microdomains of different sizes, where to monitor the development of polymer crystalline structures at varying distances from a nucleation site; vi) Spin-coated PVDF Film and electrospinning nanodiameter fibers where to visualize local molecular orientation by polarization measurements.