2025 • Science Advances

Condensation of water vapor in confined geometries, known as capillary condensation, is a fundamental phe-nomenon with far-reaching implications. While hydrophilic pores enable liquid formation from undersaturatedvapor without energy input, the condensate typically remains confined, limiting practical utility. Here, we explorethe use of amphiphilic nanoporous polymer-infiltrated nanoparticle films that condense and release liquid waterunder isothermal and undersaturated conditions. By tuning the polymer fraction and nanoparticle size, we opti-mize condensation and droplet formation. As vapor pressure increases, voids fill with condensate, which sub-sequently exudes onto the surface as microscopic droplets. This behavior, enabled by a balance of polymerhydrophobicity and capillarity, reveals how amphiphilic nanostructures can drive accessible water collection. Ourfindings provide design insights for materials supporting energy-efficient water harvesting and heat manage-ment without external input.
Baekmin Q. Kim, Zachariah Vicars, Máté Füredi, Lilia F. Escobedo, R. Bharath Venkatesh, Stefan Guldin, Amish J. Patel, Daeyeon Lee