title: Measurement of thickness and composition of a solvent film on a bubble.
abstract: Solvent-coated air bubbles in the air-assisted solvent extraction (AASX) process achieve the dual role of high solvent specific surface area and ease of phase separation. The properties and thickness of the solvent film control the process. As an approach to the study, the layer interferometry (in the UV-vis region) and FT-IR spectroscopy were used to measure the time dependent thickness and chemical composition, respectively, of a film formed by blowing an air bubble in kerosene-based solvents. The film was stabilized by the presence of 1.5 ppm silicone oil, as employed in AASX. The film appears to comprise two layers; an outer layer of almost constant thickness and an inner layer which decreased in thickness with time. The latter is considered relevant to AASX. Generally, the initial thickness was approximately 3 microm which decreased over several minutes to a final rupture thickness of 500 nm. The initial thickness is of the order determined indirectly. The chemical composition of the layer did not change with time.
authors.affiliation: Department of Mining, Metals & Materials Engineering, McGill University, 3610 University, Montreal, QC, H3A 2B2, Canada.
authors.forename: H M
authors.initials: HM
authors.lastname: Tarkan
authors.forename: S
authors.initials: S
authors.lastname: Gélinas
authors.forename: J A
authors.initials: JA
authors.lastname: Finch
mesh_terms: D000388:Air; D007648:Kerosene; D012827:Silicone Oils; D012997:Solvents / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D007648:Kerosene; D012827:Silicone Oils; D012997:Solvents