Martin-Fabiani et al SANS macroRAFT latexes-Revised.pdf (3.42 MB)
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In situ monitoring of latex film formation by small-angle neutron scattering: Evolving distributions of hydrophilic stabilizers in drying colloidal films

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journal contribution
posted on 02.04.2019, 10:30 by Ignacio Martin-Fabiani, David K. Makepeace, Philip G. Richardson, Jennifer Lesage de la Haye, Diego Alba Venero, Sarah E. Rogers, Franck D’Agosto, Muriel Lansalot, Joseph L. Keddie
The distribution of hydrophilic species, such as surfactants, in latex films is of critical importance for the performance of adhesives, coatings and inks, among others. However, the evolution of this distribution during the film formation process and in the resulting dried films remains insufficiently elucidated. Here, we present in situ (wet) and ex situ (dry) SANS experiments that follow the film formation of two types of latex particles, which differ in their stabilizer: either a covalently bonded poly(methacrylic acid) (PMAA) segment or a physically adsorbed surfactant (sodium dodecyl sulfate, SDS). By fitting the experimental SANS data and combining with gravimetry experiments, we have ascertained the hydrophilic species distribution within the drying film and followed its evolution by correlating the size and shape of stabilizer clusters with the drying time. The evolution of the SDS distribution over drying time is being driven by a reduction in the interfacial free energy. However, the PMAA-based stabilizer macromolecules are restricted by their covalent bonding to core polymer chains and hence form high surface-area disc-like phases at the common boundary between particles and PMAA micelles. Contrary to an idealized view of film formation, the PMAA does not remain in the walls of a continuous honeycomb structure. The results presented here shed new light on the nanoscale distribution of hydrophilic species in drying and ageing latex films. We provide valuable insights into the influence of the stabilizer mobility on the final structure of latex films.

Funding

This work was funded by the European Union Seventh Framework Programme BARRIER-PLUS project (FP7-SME-2012-2, No. 304758).

History

School

  • Aeronautical, Automotive, Chemical and Materials Engineering

Department

  • Materials

Published in

Langmuir

Volume

35

Issue

10

Pages

3822 - 3831

Citation

MARTIN-FABIANI, I. ... et al., 2019. In situ monitoring of latex film formation by small-angle neutron scattering: Evolving distributions of hydrophilic stabilizers in drying colloidal films. Langmuir, 35(10), pp. 3822 - 3831.

Publisher

© American Chemical Society (ACS)

Version

AM (Accepted Manuscript)

Publisher statement

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Langmuir, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.langmuir.8b04251

Publication date

2019-02-19

ISSN

0743-7463

eISSN

1520-5827

Language

en