The EPA (Ellipsometric Porosimeter Atmospheric pressure) is designed to allow fast film characterization at ambient pressure and temperature. To make mesopore size investigation simple, cheap, and non toxic, we performed EP measurements using a pulsed air flow with controlled partial pressure of water. This system allows a fast partial pressure equilibration at each point of the isotherm (a complete adsorption-desorption cycle can be obtained within 30 min time)


The EPA setup is made of a spectroscopic ellipsometer on which is fixed a cell of environment control containing the film to analyze. In laboratories, gas volumetry analyses are usually time-consuming, mainly because of long pressure equilibration time within the analysis chamber. In the experimental setup of these experiments, we replaced the pressure equilibration system by a continuous flux of air containing a fixed partial pressure of adsorbate directly in contact with the mesoporous film to analyze.

EPA gives access to:

  • Pore size Distribution from 1.5nm to 60 nm diam
  • Average pore size
  • Porosity
  • Cumulative surface area
  • Thickness – refractive index – absorption coefficients
  • Young Modulus