The mass transfer of gas through foam films is a prototype of various industrial and biological processes. The aim of this paper is to give a perspective and critical overview of studies carried out to date on the mass transfer of gas through foam films. Contemporary experimental data are summarized, and a comprehensive overview of the theoretical models used to explain the observed effects is given. A detailed description of the processes that occur when a gas molecule passes through each layer that forms a foam film is shown. The permeability of the film-building surfactant monolayers plays an important role for the whole permeability process. It can be successfully described by the models used to explain the permeability of surfactant monolayers on aqueous sub-phase. For this reason, the present paper briefly discusses the surfactant-induced resistance to mass transfer of gases through gas-liquid interface. One part of the paper discusses the experimental and theoretical aspects of the foam film permeability in a train of foam films in a matrix or a cylinder. This special case is important to explain the gas transfer in porous media or in foams. Finally, this paper will highlight the gaps and challenges and sketch possible directions for future research.
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http://dx.doi.org/10.1016/j.cis.2007.08.002 | DOI Listing |
J Contam Hydrol
January 2025
Department of Civil and Environmental Engineering, Colorado School of Mines, 1500 Illinois St, Golden, CO 80401, USA. Electronic address:
Soil samples collected from an aqueous film-forming foam (AFFF)-impacted sandy soil formation at two depth intervals above the water table were used in bench-scale column experiments to evaluate the release of poly- and perfluoroalkyl substances (PFASs) under different degrees of water saturation. Artificial rainwater was applied to the soils under constant and variably saturated conditions. Results from constant saturation experiments suggest that retention of PFAS mass at air-water interfaces was evident in the deep soil (f < 0.
View Article and Find Full Text PDFLangmuir
January 2025
School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, PR China.
Aqueous film-forming foam (AFFF) is a targeted product for liquid fuel fires and has the benefits of a long storage period and high fire extinguishing efficiency. However, because of the toxicity and bioaccumulation of the core raw material's long-chain fluorocarbon surfactant, traditional AFFF is being phased out. For this reason, three efficient AFFFs (F-1, F-2, and F-3; more details in Table 2) were designed using anionic surfactants (PBAF) with branched C perfluorinated chains, hexadecyltrimethylammonium bromide (CTAB), and dodecyl dimethyl betaine (BS-12) as core materials.
View Article and Find Full Text PDFFood Chem X
January 2025
College of Food Science, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, 163319, China.
The objective of this study was to substitute partially fat with pea protein isolate (PP)/rutin (Ru) complexes to produce a healthy and stable low-fat whipped cream. Ru enhanced the foam properties of PP. The Ru binding equivalent was the best at a mass ratio of PP/Ru of 64:4, the PP/Ru complexes particle size was the smallest.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
Jilin Provincial Science and Technology Innovation Centre of Optical Materials and Chemistry, School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, Changchun 130022, China. Electronic address:
The materials currently available for information encryption often suffer from low transparency, poor mechanical strength, and a reliance on single decryption conditions, which limits their security and hence application potential. To address these challenges, we developed a transparent, mechanically robust polymer film inspired by the camouflage and communication strategies of the glass squid. In this film, 2,5-dihydroxyterephthalic acid (DHTA) and zinc acetate dihydrate are integrated into a crosslinked polyvinyl alcohol-glutaraldehyde (PVA-GA) matrix to achieve bidirectional irreversible fluorescence and sequential decryption.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
Department of Civil and Environmental Engineering, Clarkson University, Potsdam, New York 13699, United States.
The nonthermal destruction of aqueous film-forming foam (AFFF) stockpiles, one of the major culprits responsible for water and soil contamination by per- and polyfluoroalkyl substances (PFAS), is extremely challenging because of the coexistence of mixed recalcitrant PFAS and complicated organic matrices at extremely high concentrations. To date, the complete defluorination of undiluted AFFF at ambient conditions has not been demonstrated. This study reports a novel piezoelectric ball milling approach for treating AFFF with a total organic fluorine concentration of 9080 mg/L and total organic carbon of 234 g/L.
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