Curvature can inhibit evaporation inside micropores

We observe evaporation in micropores using X-ray microscopy and optical microscopy. Micropores can induce low or negative pressure inside fluids in micropores. We calculate internal pressure changes by curvature between air and fluids, particularly by controlling cavity size and ambient pressure. We explain how curvature inhibits evaporation inside micropores by competition between negative Laplace pressure (hydrodynamics) and modified vaporization pressure (thermodynamics). From our observations, small micropore size, high ambient pressure, and high relative humidity are favorable for evaporation inhibition from micropores. This finding would be crucial in understanding microscale and nanoscale phenomena regarding evaporation.