Entropy of aqueous surfaces. Application to polymeric Langmuir films

Louise Deschênes; Johannes Lyklema; François St-Germain

doi:10.1016/j.cis.2017.04.004

Entropy of aqueous surfaces. Application to polymeric Langmuir films

Adv Colloid Interface Sci. 2017 Sep:247:149-162. doi: 10.1016/j.cis.2017.04.004. Epub 2017 Apr 9.

Authors

Louise Deschênes¹, Johannes Lyklema², François St-Germain³

Affiliations

¹ Saint-Hyacinthe Research and Development Centre, Agriculture and Agri-Food Canada, 3600 Casavant Blvd. West, QC J2S 8E3, Canada. Electronic address: louise.deschenes@agr.gc.ca.
² Department of Physical Chemistry and Soft Matter, Wageningen University and Research, Helix Building Stippeneng 4, 6708 WE, Wageningen, Netherlands.
³ Saint-Hyacinthe Research and Development Centre, Agriculture and Agri-Food Canada, 3600 Casavant Blvd. West, QC J2S 8E3, Canada.

PMID: 28501099
DOI: 10.1016/j.cis.2017.04.004

Abstract

Measuring surface (excess) entropies provides a bounty of valuable structural information that is hard to obtain otherwise. In the paper these quantities are defined and procedures of measurements discussed. Mostly they involve measurements at different temperatures. A review is given for interfaces with aqueous solutions in the absence of polymers. This review illustrates how, sometimes unanticipated, pieces of information are obtained, for example with cloud seeding and a possible explanation of the Jones-Ray effect. As a novel extension the procedure is applied to deposited, or Langmuir, monolayers of poly(ethylene oxide)-poly(propylene oxide) block copolymers. It will be shown how the various phase transitions and associated configurations of these polymers can be recognized and monitored.

Keywords: Jones-Ray effect; Langmuir monolayers; PEO; PPO; Surface entropy; Surface tension.

Publication types

Review