In these experiments, we described the interaction between two immiscible vapors, while condensing on a cooler surface, by the analysis of their occupation factor and the mean radius size of the droplets for each substance. Vapor condensation occurs when air with the condensing vapor is in contact with a surface at a temperature below the dew point (also called Breath Figure [D. Beysens, C. R. Phys. 7 (2006) 1082, and references therein]). We perform the experiments with different ratio between the condensing vapors, which in our case are water and HMDSO.

The main findings were that the coating used is suitable to reproduce classical water BF. However, the HMDSO BF (without water vapor) occurred in our experimental conditions without the (free) growth regime. Nevertheless, when the two vapors are mixed, we observe anomalous growth rates for the HMDSO, although water droplets follow very slightly modified growth. This deviation could be related to the appearance of mixed water-HMDSO clusters. In the experiments of condensation of HMDSO on a previously formed water BF, we observed that the clusters of HMDSO and water only are produced when the BF of water has had an initial occupation factor greater than a threshold value.

• • J. Guadarrama-Cetina et al. Phys. Rev. E 87 (2013), 054401.

  • J. Guadarrama-Cetina, Ph.D. thesis. Universidad de Navarra (2013).

We thank an anonymous reviewer for his or her remarks, R. Narhe for suggesting the experiment, and D. Beysens and R. Narhe for fruitful discussions. This work was partly supported by the Spanish MEC (Grant No. FIS2011-24642) and by Departamento de Educación (Gobierno de Navarra). J.G.C. acknowledges financial support from the "Asociación de Amigos de la Universidad de Navarra." .

Initial stage of mixed condensation. The region of inhibited condensation sorrounding the drops can be observed: