TY - JOUR

T1 - Effects of Aggregate Charge and Subphase Ionic Strength on the Properties of Spread Polyelectrolyte/Surfactant Films at the Air/Water Interface under Static and Dynamic Conditions

AU - Tummino, Andrea

AU - Toscano, J.

AU - Sebastiani, F.

AU - Носков, Борис Анатольевич

AU - Varga, Imre

AU - Campbell, Richard

N1 - Funding Information: We thank the Institut Laue-Langevin for allocations of neutron beam time on FIGARO (DOIs: 10.5291/ILL-DATA.9-10-1433 and 10.5291/ILL-DATA.9-12-461) as well as the Partnership for Soft Condensed Matter for access to the ellipsometer and Brewster angle microscope. This research has received funding from the People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme FP7/2007-2013/under REA grant agreement no. 290251 and from the Hungarian National Research, Development and Innovation Office (NKFIH K116629), which is gratefully acknowledged. This publication is the partial result of the Research & Development Operational Programme for the project “Modernization and Improvement of Technical Infrastructure for Research and Development of J. Selye University in the Fields of Nanotechnology and Intelligent Space”, ITMS 26210120042, cofunded by the European Regional Development Fund. B.A.N. is grateful to St. Petersburg State University for the grant no. 2.40.532.2017.

PY - 2018/2/13

Y1 - 2018/2/13

N2 - We demonstrate the ability to tune the formation of extended structures in films of poly(sodium styrenesulfonate)/dodecyltrimethylammonium bromide at the air/water interface through control over the charge/structure of aggregates as well as the ionic strength of the subphase. Our methodology to prepare loaded polyelectrolyte/surfactant films from self-assembled liquid crystalline aggregates exploits their fast dissociation and Marangoni spreading of material upon contact with an aqueous subphase. This process is proposed as a potential new route to prepare cheap biocompatible films for transfer applications. We show that films spread on water from swollen aggregates of low/negative charge have 1:1 charge binding and can be compressed only to a monolayer, beyond which material is lost to the bulk. For films spread on water from compact aggregates of positive charge, however, extended structures of the two components are created upon spreading or upon compression of the film beyond a monolayer. The application of ellipsometry, Brewster angle microscopy, and neutron reflectometry as well as measurements of surface pressure isotherms allow us to reason that formation of extended structures is activated by aggregates embedded in the film. The situation upon spreading on 0.1 M NaCl is different as there is a high concentration of small ions that stabilize loops of the polyelectrolyte upon film compression, yet extended structures of both components are only transient. Analogy of the controlled formation of extended structures in fluid monolayers is made to reservoir dynamics in lung surfactant. The work opens up the possibility to control such film dynamics in related systems through the rational design of particles in the future.

AB - We demonstrate the ability to tune the formation of extended structures in films of poly(sodium styrenesulfonate)/dodecyltrimethylammonium bromide at the air/water interface through control over the charge/structure of aggregates as well as the ionic strength of the subphase. Our methodology to prepare loaded polyelectrolyte/surfactant films from self-assembled liquid crystalline aggregates exploits their fast dissociation and Marangoni spreading of material upon contact with an aqueous subphase. This process is proposed as a potential new route to prepare cheap biocompatible films for transfer applications. We show that films spread on water from swollen aggregates of low/negative charge have 1:1 charge binding and can be compressed only to a monolayer, beyond which material is lost to the bulk. For films spread on water from compact aggregates of positive charge, however, extended structures of the two components are created upon spreading or upon compression of the film beyond a monolayer. The application of ellipsometry, Brewster angle microscopy, and neutron reflectometry as well as measurements of surface pressure isotherms allow us to reason that formation of extended structures is activated by aggregates embedded in the film. The situation upon spreading on 0.1 M NaCl is different as there is a high concentration of small ions that stabilize loops of the polyelectrolyte upon film compression, yet extended structures of both components are only transient. Analogy of the controlled formation of extended structures in fluid monolayers is made to reservoir dynamics in lung surfactant. The work opens up the possibility to control such film dynamics in related systems through the rational design of particles in the future.

KW - AIR-WATER-INTERFACE

KW - BREWSTER-ANGLE MICROSCOPY

KW - SODIUM DODECYL-SULFATE

KW - FLUID INTERFACES

KW - SURFACE-TENSION

KW - CATIONIC SURFACTANTS

KW - NEUTRON REFLECTION

KW - ADSORPTION LAYERS

KW - AQUEOUS-SOLUTIONS

KW - POLYMER

UR - http://www.scopus.com/inward/record.url?scp=85041959354&partnerID=8YFLogxK

UR - http://www.mendeley.com/research/effects-aggregate-charge-subphase-ionic-strength-properties-spread-polyelectrolytesurfactant-films-a

U2 - 10.1021/acs.langmuir.7b03960

DO - 10.1021/acs.langmuir.7b03960

M3 - Article

VL - 34

SP - 2312

EP - 2323

JO - Langmuir

JF - Langmuir

SN - 0743-7463

IS - 6

ER -