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 that impact material performance. Here, we study these questions 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 stability 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 min after foam production. Taken together, mass spectrometry and SANS present a structural and compositional picture of SDS/HPMC foams and an approach amenable to systematic study for foams, gathering mechanistic insights and providing formulation guidance for rational foam design.

中文翻译：

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表面活性剂/聚合物泡沫的多尺度微观结构，组成和稳定性

包含聚合物添加剂是改善泡沫稳定性的已知策略，但是关于泡沫中掺入的聚合物量以及影响材料性能的结构变化仍存在疑问。在这里，我们结合流动相匹配的QTOF质谱和小角度中子散射（SANS）测量，在十二烷基硫酸钠（SDS）/羟丙基甲基纤维素（HPMC）泡沫中研究这些问题。质谱结果表明，通过测量HPMC与SDS的比率，可以在排水过程中将聚合物掺入并保留在泡沫中。结果证实了在我们的测量时间内与母液和稳定性相匹配的比率。SANS测量利用精确的对比度匹配来揭示胶束结构的详细描述（尺寸，形状，和聚集数）以及泡沫膜的厚度。HPMC的存在导致薄膜更厚，这与泡沫生产后的最初15–20分钟内泡沫稳定性增加有关。质谱和SANS共同呈现了SDS / HPMC泡沫的结构和组成图，以及一种适合于泡沫的系统研究，收集力学见解并为合理的泡沫设计提供配方指导的方法。