Spectroscopy technique for detecting water saturation front in polymer

  1. Hello all,

    I am a grad student in materials science. As part of a research project, I need to measure/detect the velocity of a water saturation front moving through polymers (a few materials, most fluoro/perfluoropolymers).
    The ultimate goal of the project is to determine the permeability of polymer seals operating at temperature and pressure as a function of time. In order to do so, I will subject the polymer samples (o-rings of ~5cm diameter, ~.5cm thickness) to these conditions in an aging cell (a "pressure vessel") for a few days. After a certain time, I would try to characterize how far into the sample water has diffused by sectioning the sample and using some kind of characterization technique.
    If water cannot be easily detected, I also have the option of exposing the samples to CO2 and trying to detect that, although water would be preferred.
    I have enough funding to use any of the shared facilities here at Stanford but not enough to buy any expensive machines.
    Can you think of any characterization technique that could detect water or CO2 in a polymer matrix?

    Here are my ideas so far:
    Water (and CO2) are IR and Raman active. I can section samples and do FTIR and Raman spectroscopy but the signals are weak for water and these don't usually have any spatial resolution. I can section the sample into different lengths into the sample to detect whether each section has water or not. I also heard that we have a micro Raman instrument with spatial resolution.
    I am mostly worried that since these 2 techniques only analyze the surface of materials, all the water (or CO2) will desorb from the surface before I can detect anything.

    Any input is appreciated.


  2. jcsd
  3. Greg Bernhardt

    Staff: Admin


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