Are Indoor Surfaces Dropping Acid or Dropping the Base? Insights into Water Films and pH for Model and Authentic Indoor Samples

摘要

Indoor surfaces are complex environments that play an important role in driving gas and particle phase chemistry. These surfaces can have heterogeneous uptake, condensed phase reactions, and emitted reaction products altering the composition of indoor environments. Despite their important role, indoor surfaces remain a mystery due to their complex and difficult to probe nature. A fundamental question that is not well understood is the acidity or basicity of indoor environments and the impact that may have on indoor gas and particle chemistry. This presentation will discuss initial results aimed at probing the properties, composition, and pH of water films on common indoor materials and model systems through systematic studies with Raman microspectroscopy, atomic force microscopy with photothermal infrared spectroscopy, and other characterization methods. These initial results offer an early glimpse into these complex systems and their role in indoor atmospheric chemistry.