  The formation of smart emulsions or foams whose stability can be controlled
on-demand by switching external parameters is of great interest for basic
research and applications. An emerging group of smart stabilizers are
microgels, which are nano- and micro-sized, three-dimensional polymer networks
that are swollen by a good solvent. In the last decades, the influence of
various external stimuli on the two-dimensional phase behavior of microgels at
air- and oil-water interfaces has been studied. However, the impact of the
top-phase itself has been barely considered. Here, we present data that
directly address the influence of the top-phase on the microgel properties at
interfaces. The dimensions of pNIPAM microgels are measured after deposition
from two interfaces, i.e., air- and decane-water. While the total in-plane size
of the microgel increases with increasing interfacial tension, the portions or
fractions of the microgels situated in the aqueous phase are not affected. We
correlate the area microgels occupy to the surface tensions of the interfaces,
which allows to estimate an elastic modulus. In comparison to nanoindentation
measurements, we observe a larger elastic modulus for the microgels. By
combining compression, deposition, and visualization, we show that the
two-dimensional phase behavior of the microgel monolayers is not altered,
although the microgels have a larger total in-plane size at higher interfacial
tension. A peer reviewed and extended version of this preprint and the
electronic supplementary information can be found under S.~Bochenek, A.~Scotti,
W.~Richtering, \textit{Soft Matter}, 2020, DOI: 10.1039/d0sm01774d.
