PNNL

Abstract

Environmental films form when airborne particulate and molecular species adsorb on solid surfaces. Recent studies have characterized these films but overlook how collection methods and host-surface character (orientation, chemical functionality, or height) change the deposition process. In this work, environmental films are collected at a rural location on gold and silicon surfaces (water contact angles of ca. 57° and 5 µm) particles have similar elemental compositions. Minor differences are observed at smaller particulate sizes (~5 µm) which include with carbon rich particles mostly attributed to pollen or biotic activity. A final difference between the two films is that there are different values for total dissolved solids (TDS) and pH. Chemical analysis shows the presence of nitrate and sulfate as well as heterogeneous cation pools on the surfaces. Results of this study can be applied to environmental films and indoor films to help inform models for the adsorption of particulate and organic species.