Selective Retardation of Perfume Oil Evaporation from Oil-in-Water Emulsions Stabilized by Either Surfactant or Nanoparticles

Abstract

We have used dynamic headspace analysis to investigate the evaporation rates of perfume oils from stirred oil-in-water emulsions into a flowing gas stream. We compare the behavior of an oil of low water solubility (limonene) and one of high water solubility (benzyl acetate). It is shown how the evaporation of an oil of low water solubility is selectively retarded and how the retardation effect depends on the oil volume fraction in the emulsion. We compare how the evaporation retardation depends on the nature of the adsorbed film stabilizing the emulsion. Surfactant films are less effective than adsorbed films of nanoparticles, and the retardation can be further enhanced by compression of the adsorbed nanoparticle films by preshrinking the emulsion drops.

Volatile fluorinated nanoemulsions: A chemical route to controlled delivery of inhalation Anesthesia

“…below the detection limit of 0.1% v/v). Water evaporation from concentrated o/w emulsions is known to concentrate and compress the oil droplets [17], and drying from emulsions is widely used in the coatings industry for film forming applications. The presence of concentrated surface mesophases has also been shown to retard evaporation [18].…”

“…Thus, the release profile targeted in aim (ii) can be obtained [19]. In fact, the range of concentrations accessible with changing stirring rate are such that a single formulation could be used to provide constant delivery of anesthetic at different levels from 0.5 to 4% v/v [17,19].…”

“…It is acknowledged in the literature that modeling of evaporation from systems under flow presents significant challenges, due to unknown parameters of interest for a given system [17,20]. These difficulties notwithstanding, extensive work from groups at Hull University have provided various theoretical descriptions that can assist in understanding the observed behavior.…”

“…(1)) (P = equilibrium vapor pressure, z relates to the flow of the carrier gas in the stagnant vapor layer) [10,17]. The height of the stagnant layer depends in a complex manner on the flow of gas across the surface, but generally as flow (F) increases h v decreases and evaporation increases (Eq.…”

“…(1)). Therefore, according to the theoretical framework of Binks et al [12,17], evaporation rate is expected to be dependent on the thickness of the water layer separating the droplets from the air/emulsion interface, h w , which also relates to the spatial arrangement of the droplets via s.…”