Drying of Soft Colloidal Films

arXiv (Cornell University)

Abstract

Thin films made of deformable micro- and nano-units, such as biological membranes, polymer interfaces, and particle-laden liquid surfaces, exhibit a complex behavior during drying, with consequences for various applications like wound healing, coating technologies, and additive manufacturing. Studying the drying dynamics and structural changes of soft colloidal films thus holds the potential to yield valuable insights to achieve improvements for applications. In this study, we employ interfacial monolayers of core-shell microgels with varying degrees of softness as model systems and investigate their drying behavior on differently modified solid substrates (hydrophobic vs. hydrophilic). By leveraging on video microscopy, particle tracking, and thin film interference, we shed light on the interplay between microgel adhesion to solid surfaces and the immersion capillary forces that arise in the thin liquid film. We discovered that a dried replica of the interfacial microstructure can be more accurately achieved on a hydrophobic substrate relative to a hydrophilic one, particularly when employing softer colloids as opposed to harder counterparts. These observations are qualitatively supported by experiments with a thin film pressure balance which allows mimicking and controlling the drying process and by computer simulations with coarse-grained models.

Authors 10

1. Keumkyung Kuk

   Heinrich Heine University Düsseldorf

   Affiliation as printed

   Institut für Physikalische Chemie I: Kolloide und Nanooptik , Heinrich-Heine-Universität Düsseldorf , Universitätsstr. 1 , 40225 Düsseldorf , Germany

2. Julian Ringling

   Heinrich Heine University Düsseldorf

   Affiliation as printed

   Institut für Physikalische Chemie I: Kolloide und Nanooptik , Heinrich-Heine-Universität Düsseldorf , Universitätsstr. 1 , 40225 Düsseldorf , Germany

3. Kevin Gräff
4. Sebastian Hänsch
5. Virginia Carrasco-Fadanelli
6. Andrey A. Rudov Aachen DWI - Leibniz Institute for Interactive Materials

   Lomonosov Moscow State University · DWI – Leibniz Institute for Interactive Materials · Moscow State University

   Affiliation as printed

   DWI-Leibniz Institute for Interactive Materials , 52056 Aachen , Germany

   Physics Department , Lomonosov Moscow State University , Moscow 119991 , Russian Federation

7. Igor I. Potemkin Aachen DWI - Leibniz Institute for Interactive Materials

   Lomonosov Moscow State University · DWI – Leibniz Institute for Interactive Materials · Moscow State University

   Affiliation as printed

   DWI-Leibniz Institute for Interactive Materials , 52056 Aachen , Germany

   Physics Department , Lomonosov Moscow State University , Moscow 119991 , Russian Federation

8. Regine von Klitzing

   Technische Universität Darmstadt

   Affiliation as printed

   Institute for Condensed Matter Physics , Soft Matter at Interfaces , Technische Universität Darmstadt , Hochschulstr. 8 , 64289 Darmstadt , Germany

9. Ivo Buttinoni

   Heinrich Heine University Düsseldorf

   Affiliation as printed

   Institut für Experimentelle Physik der kondensierten Materie , Heinrich-Heine-Universität Düsseldorf , Universitätsstr. 1 , 40225 Düsseldorf , Germany

10. Matthias Karg

    Heinrich Heine University Düsseldorf

    Affiliation as printed

    Institut für Physikalische Chemie I: Kolloide und Nanooptik , Heinrich-Heine-Universität Düsseldorf , Universitätsstr. 1 , 40225 Düsseldorf , Germany