Multiscale Microstructure, Composition, and Stability of Surfactant/Polymer Foams
Stefania Perticaroli, Jana Herzberger, Yiping Sun, Jonathan D. Nickels, Ryan Murphy, Kathleen Weigandt, Paula J. Ray
Foam stability is a critical part of product performance and consumer experience in materials as diverse as beer or detergents. Inclusion of polymer additives is a known strategy to improve foam stability, but questions persist about the amount of polymer incorporated in the foam and the resulting structural changes which impact material performance. Here, we study this question in sodium dodecyl sulfate (SDS) / hydroxypropyl methylcellulose (HPMC) foams using a combination of Flow Injection QTOF mass spectrometry and Small Angle Neutron Scattering (SANS) measurements leveraging contrast matching. Mass spectrometry results demonstrate polymer incorporation and retention in the foam during drainage by measuring the HPMC to SDS ratio. The results confirm a ratio matching the parent solution and stable over the time of our measurements. The SANS measurements leverage precise contrast matching to reveal detailed descriptions of the micellar structure (size, shape, and aggregation number); along with the foam film thickness. The presence of HPMC leads to thicker films, correlating with increased foam stability over the first 15-20 minutes after foam production. Taken together, mass spectrometry and SANS present a structural and compositional picture of SDS/HPMC foams which is amenable to systematic study to gather mechanistic insights and provide formulation guidance to optimize rational foam design.
, Herzberger, J.
, Sun, Y.
, Nickels, J.
, Murphy, R.
, Weigandt, K.
and Ray, P.
Multiscale Microstructure, Composition, and Stability of Surfactant/Polymer Foams, Langmuir
(Accessed July 3, 2022)