Hypothesis: Numerous hydrocarbon and fluorine-based hydrophobic surfaces have been widely applied in various engineering and bioengineering fields. It is hypothesized that the hydrophobic interactions of hydrocarbon and fluorinated surfaces in aqueous media would show some differences.
Experiments: The hydrophobic interactions of hydrocarbon and fluorinated surfaces with air bubbles in aqueous solutions have been systematically and quantitatively measured using a bubble probe atomic force microscopy (AFM) technique. Ethanol was introduced to water for modulating the solution polarity. The experimental force profiles were analyzed using a theoretical model combining the Reynolds lubrication theory and augmented Young-Laplace equation by including disjoining pressure arisen from the Derjarguin-Landau-Verwey-Overbeek (DLVO) and non-DLVO interactions (i.e., hydrophobic interactions).
Findings: The experiment results show that the hydrophobic interactions were firstly weakened and then strengthened by increasing ethanol content in the aqueous media, mainly due to the variation in interfacial hydrogen bonding network. The fluorinated surface exhibited less sensitivity to ethanol than hydrocarbon surface, which is attributed to the presence of ordered interfacial water layer. Our work reveals the different hydrophobic effects of hydrocarbon and fluorinated surfaces, with useful implications on modulating the interfacial interactions of relevant materials in various engineering and bioengineering applications.
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http://dx.doi.org/10.1016/j.jcis.2022.12.084 | DOI Listing |
Zhong Nan Da Xue Xue Bao Yi Xue Ban
July 2024
Department of Endocrinology &Metabolism, West China Hospital, Sichuan University, Chengdu 610041.
Cushing's disease is a rare endocrine disorder characterized by hypercortisolism. Chronic elevated cortisol levels can lead to dysfunction or complications in multiple organs of systems, including cardiovascular, glucose, and bone metabolism, severely impacting patients' quality of life and posing life-threatening risks. Surgery is the first-line treatment for Cushing's disease.
View Article and Find Full Text PDFScience
January 2025
State Key Laboratory of Coordination Chemistry, MOE Key Laboratory of High-Performance Polymer Materials & Technology, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, China.
We explored the potential for membrane materials to reduce energy and carbon requirements for the separation of aliphatic hydrocarbon feedstocks and products. We developed a series of fluorine-rich poly(arylene amine) polymer membranes that feature rigid polymer backbones with segregated perfluoroalkyl side chains. This combination imbues the polymers with resistance to dilation induced by hydrocarbon immersion without the loss of solution-based membrane fabrication techniques.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Environmental Science & Engineering, Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA 02134.
Wastewater receives per- and polyfluoroalkyl substances (PFAS) from diverse consumer and industrial sources, and discharges are known to be a concern for drinking water quality. The PFAS family includes thousands of potential chemical structures containing organofluorine moieties. Exposures to a few well-studied PFAS, mainly perfluoroalkyl acids (PFAA), have been associated with increased risk of many adverse health outcomes, prompting federal drinking water regulations for six compounds in 2024.
View Article and Find Full Text PDFMembranes (Basel)
December 2024
PSI Center for Energy and Environmental Sciences, 5232 Villigen PSI, Switzerland.
The impeding ban on per- and polyfluoroalkyl substances (PFAS) prompted researchers to focus on hydrocarbon-based materials as constituents of next-generation proton exchange membranes (PEMs) for polymer electrolyte fuel cells (PEFCs). Here, we report on the fuel cell performance and durability of fluorine-lean PEMs prepared by the post-sulfonation of co-grafted α-methylstyrene (AMS) and 2-methylene glutaronitrile (MGN) monomers into preirradiated 12 µm polyvinylidene fluoride (PVDF) base film. The membranes were subjected to two distinctly different accelerated stress test (AST) protocols performed at open-circuit voltage (OCV): the US Department of Energy-similar chemical AST (90 °C, 30% relative humidity (RH), H/air, 1 bar), developed originally for perfluoroalkylsulfonic acid (PFSA) membranes, and the high relative humidity AST (80 °C, 100% RH, H/O, 2.
View Article and Find Full Text PDFBiomimetics (Basel)
December 2024
Department of Chemistry, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel.
Developing a durable multifunctional superhydrophobic coating on polymeric films that can be industrially scalable is a challenge in the field of surface engineering. This article presents a novel method for a scalable technology using a simple single-step fabrication of a superhydrophobic coating on polymeric films that exhibits excellent water-repelling and UV-blocking properties, along with impressive wear resistance and chemical robustness. A mixture of titanium precursors, tetraethylorthosilicate (TEOS), hydrophobic silanes and silica nano/micro-particles is polymerized directly on a corona-treated polymeric film which reacts with the surface via siloxane chemistry.
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