Search Results (49)

In the production process of the heavy oil industry, efficiently demulsifying water-in-heavy oil (W/HO) emulsions can effectively prevent the negative effects of emulsion corrosion on equipment, increase costs, reduce oil quality, and pollute the environment. Herein, polyether demulsifier complexes (PDC) were obtained by compounding fatty alcohol nonionic polyether (FAP) with perfluoropolyether (PFPEA, [CF₃O(CF₂CF₂O)_nCF₃]) through a simple physical blending method. The experimental results demonstrate that PDC exhibited outstanding demulsification performance for W/HO emulsions across varying temperatures: At 60 °C and 400 ppm dosage, PDC achieved complete dehydration (100%) within just 2 min, showing significantly faster demulsification kinetics compared to FAP and PFPEA. Even at the reduced temperature of 40 °C, PDC maintained effective demulsification capability, achieving complete phase separation within 6 min. These findings collectively establish PDC’s superior demulsification efficiency for W/HO emulsions, with particularly remarkable performance under challenging low-temperature conditions. Research on the demulsification mechanism indicates that PDC achieves efficient demulsification performance due to the synergistic effect the synergistic effect of FAP and PFPEA to effectively destroy the non-covalent bonds (hydrogen and π–π stacking) of interfacially active asphaltenes (IAA) at the oil–water interface, thereby achieving demulsification of W/HO emulsion. PDC with outstanding demulsification ability exhibits significant potential for practical applications in heavy crude oil–water emulsion treatment, and this work can provide insights for developing new composite demulsifiers for petroleum production. Full article

A spiral microfluidic chip (SMC) and multi-spiral microfluidic chip (MSMC) for lipid nanoparticle (LNP) production were fabricated using a CO₂ laser engraving method, using perfluoropolyether (PFPE) and poly(ethylene glycol) diacrylate as photopolymerizable base materials. The SMC includes a spiral microchannel that enables rapid fluid mixing, thereby facilitating the production of small and uniform LNPs with a size of 72.82 ± 24.14 nm and a PDI of 0.111 ± 0.011. The MSMC integrates multiple parallel SMC structures, which enables high-throughput LNP production without compromising quality and achieves a maximum production capacity of 960 mL per hour. The LNP fabrication technology using SMC and MSMC has potential applications in the pharmaceutical field due to the ease of chip fabrication, the simplicity and cost-effectiveness of the process, and the ability to produce high-quality LNPs. Full article

High-energy boron-based fuel aluminum-diboride (AlB₂) has attracted much attention in the field of solid propellants. However, the low reactivity of AlB₂ hindered its further application. In this study, highly reactive AlB₂@hydroxyl-terminated perfluoropolyether alcohol (AlB₂@HTPFA) composites with a core–shell structure were prepared by coating AlB₂ with functionalized fluoropolymers by using a facile one-step in situ polymerization method. AlB₂@HTPFA composites with varying polymer contents (0, 5, 10, and 15 wt%) were obtained. The in situ polymerization strategy enables precise control over the polymer coating thickness and interfacial interactions, which is critical for optimizing the reactivity and thermal stability of composites. The morphology and structure were characterized, and the microcore–shell structure of AlB₂@HTPFA was obtained. Compared with raw AlB₂, the combustion efficiency of coated fuel increased by 4.1%, 5.6%, and 7.5%, respectively, with varying polymer contents. Meanwhile, the reactivity of AlB₂@HTPFA (5 wt%) was 0.65 MPa/s, which is ~1.5 times that of AlB₂. Additionally, the ignition and combustion characteristics of AlB₂@HTPFA were investigated by laser ignition experiments with potassium perchlorate (KP) as an oxidant. The results revealed that AlB₂@HTPFA/KP composites showed a greatly reduced combustion duration compared to uncoated AlB₂. The ignition and combustion enhancement mechanism of AlB₂@HTPFA was proposed. During the ignition process, the existence of HTPFA can result in a pre-ignition reaction, thus raising its reaction activity. This work provided a promising candidate for high-energy fuel that can be used in energetic materials. Full article

Microfluidic devices are greatly affected by the materials used. The materials used in previous studies had problems in various aspects, such as processing, adsorption, and price. This study will investigate the materials needed to overcome such problems. Various microfluidic devices based on the perfluorinated compound perfluoropolyether (PFPE) were fabricated and mixed with hydrophilic and amphiphilic monomers, including poly(ethylene glycol) diacrylate, polyethylene glycol monomethacrylate, poly(ethylene glycol) methyl ether methacrylate, acrylic acid, and 2-hydroxyethyl methacrylate. A PFPE-based sheet with a repeating structure of hydrophobic and hydrophilic groups was fabricated. Thus, the hydrophilicity of highly hydrophobic PFPE was enhanced. The fluidic channel was engraved on a PFPE-based sheet using laser cutting and a fabricated microfluidic device. The channels of microfluidic devices are micro-scale (100 µm~300 µm). The lipid nanoparticles and droplets generated through the microfluidic device demonstrated uniform particles continuously. Full article

Lithium titanate oxide cells are gaining attention in electric vehicle applications due to their ability to support high-current charging and their enhanced thermal stability. However, despite these advantages, safety concerns, particularly thermal runaway, pose significant challenges during abuse conditions such as overcharging. In this study, we investigated the effectiveness of various dielectric fluids in mitigating thermal runaway during overcharge abuse tests of cylindrical LTO cells with a capacity of 10 Ah. The experimental campaign focused on overcharging fully charged cells (starting at 100% State of Charge) at a current of 40A (4C). The tests were conducted under two conditions: the first benchmark test involved a cell exposed to air, while the subsequent tests involved cells submerged in different dielectric fluids. These fluids included two perfluoropolyether fluorinated fluids (PFPEs) with boiling points of 170 °C and 270 °C, respectively, a synthetic ester, and a silicone oil. The results were analyzed to determine the fluids’ ability to delay possible thermal runaway and prevent catastrophic failures. The findings demonstrate that some dielectric fluids can delay thermal runaway, with one fluid showing superior performance with respect to the others in preventing fire during thermal runaway. The top-performing fluid was further evaluated in a simulated battery pack environment, confirming its ability to mitigate thermal runaway risks. These results provide important insights for improving the safety of battery systems in electric vehicles. Full article

Within electrical contacts, poor electrical conductivity of lubricants can lead to triboelectric charging, causing electrostatic currents and thermal effects, which accelerate lubrication failure. This study aimed to address these challenges by producing and testing three greases with different base oils: ionic liquid ([Oley][Oleic]), synthetic oil (PAO4), and vegetable oil-based synthetic ester (trimethylolpropane oleate). Each grease was prepared with polytetrafluoroethylene powder as the thickener. The greases were tested using a custom-made tribometer, integrated with a grounded electrical current system, with friction tests conducted with up to a 2 A electrical current flow at a constant voltage supply of 4.5 V. Under triboelectric friction testing, [Oley][Oleic] grease outperformed a commercial perfluoropolyether grease by 27.7% in friction and 16.3% in wear. This grease also showed better performance than formulated lithium grease with extreme pressure additives. The study demonstrates that greases with low interfacial resistance can retain their lubrication capacity under triboelectric conditions. These results indicate that [Oley][Oleic] grease, with its ionic liquid base oil, offers a promising solution for applications involving electrical contacts. This study highlights the potential of using advanced base oils and thickeners to enhance the performance and sustainability of lubricants in demanding environments. Full article

As part of a publicly funded cooperation project, novel high-performance lubricants (oils, greases, assembly pastes) based on ionic liquids and with the addition of specific micro- or nanoparticles are to be developed, which are adapted in their formulation for use in applications where their negligible vapor pressure plays an important role. These lubricants are urgently needed for applications in cleanrooms and high vacuum (e.g., pharmaceuticals, aerospace, chip manufacturing), especially when the frequently used perfluoropolyethers (PFPE) are no longer available due to a potential restriction of per- and polyfluoroalkyl substances (PFAS) due to European chemical legislation. Until now, there has been a lack of suitable laboratory testing technology to develop such innovative lubricants for extreme niche applications economically. There is a large gap in the tribological test chain between model testing, for example in the so-called spiral orbit tribometer (SOT) or ball-on-disk test in a high-frequency, linear-oscillation test machine (SRV-Tribometer from German “Schwing-Reib-Verschleiß-Tribometer”), and overall component testing at major space agencies (ESA—European Space Agency, NASA—National Aeronautics and Space Administration) or their service providers like the European Space Tribology Laboratory (ESTL) in Manchester. A further aim of the project was therefore to develop an application-orientated and economical testing methodology and testing technology for the scientifically precise evaluation and verifiability of the effect of ionic liquids on tribological systems in cleanrooms and under high vacuum conditions. The newly developed test rig is the focus of this publication. It forms the basis for all further investigations. Full article

This work investigated material extrusion additive manufacturing (MatEx AM) of specialized fluoroelastomer (FKM) compounds for applications in rubber seals and gaskets. The influence of a commercially available perfluoropolyether (PFPE) plasticizer on the printability of a control FKM rubber compound was studied using a custom-designed ram material extruder, Additive Ram Material Extruder (ARME), for printing fully compounded thermoset elastomers. The plasticizer’s effectiveness was assessed based on its ability to address challenges such as high compound viscosity and post-print shrinkage, as well as its impact on interlayer adhesion. The addition of the PFPE plasticizer significantly reduced the FKM compound’s viscosity (by 70%) and post-print shrinkage (by 65%). While the addition of the plasticizer decreased the tensile strength of the control compound, specimens printed with the plasticized FKM retained 34% of the tensile strength of compression-molded samples, compared to only 23% for the unplasticized compound. Finally, the feasibility of seals and gaskets manufacturing using both conventional and unconventional additive manufacturing (AM) approaches was explored. A hybrid method combining AM and soft tooling for compression molding emerged as the optimal method for seal and gasket fabrication. Full article

A perfluoropolyether (PFPE)-based microfluidic device with cross-junction microchannels was fabricated with the purpose of producing uniform droplets. The microchannels were developed using CO₂ laser engraving. PFPE was chosen as the main material because of its excellent solvent resistance. Polyethylene glycol diacrylate (PEGDA) was mixed with PFPE to improve the hydrophilic properties of the inner surface of the microchannels. The microchannels of the polydimethylsiloxane microfluidic device had a blackened and rough surface after laser engraving. By contrast, the inner surface of the microchannels of the PFPE-PEGDA microfluidic device exhibited a smooth surface. The lower power and faster speed of the laser engraving resulted in the development of microchannels with smaller dimensions, less than 30 μm in depth. The PFPE and PFPE-PEGDA microfluidic devices were used to produce uniform water and oil droplets, respectively. We believe that such a PFPE-based microfluidic device with CO₂-laser-engraved microchannels can be used as a microfluidic platform for applications in various fields, such as biological and chemical analysis, extraction, and synthesis. Full article

Benzoyl peroxide (BPO) and niacinamide (Niac) are commonly used alone or in combination with other molecules in the treatment of acne. BPO and Niac in the same product could exert complementary and synergistic effects improving efficacy in acne. Furthermore, Niac could reduce some side effects of BPO, such as skin irritation and erythema. A film-forming cream product containing BPO 4% and Niac 4%, vehiculated in a mixture of polyvinyl alcohol (PVA) and perfluoropolyether (PFPE) has been recently developed (B-N cream). A 28-day, assessor-blinded pilot trial was conducted to evaluate the clinical efficacy, skin tolerability, sebum production, skin redness, and skin microbiome modulation of B-N cream in subjects with mild to moderate acne of the face. Twenty-two adult men and women with mild-to-moderate acne of the face participated in this trial, after their written informed consent. B-N cream was applied once daily in the evening. The use of B-N cream was associated with a statistically significant decrease in acne lesions after treatment in comparison with baseline (non-inflammatory lesions: −40%; inflammatory lesions: −43% and total lesions: −41%). The use of the cream was not associated with a skin barrier function alteration. The skin redness score (−11%) and the sebum production (−42%) were significantly reduced after treatment. The use of B-N cream determined a reduction in the relative abundance of the Actinobacteria phylum (Corynebacterium and Propionibacterium, from 56% to 47%) and a significant increase in the abundance of Bacteroidetes phylum (from 3% to 5.2%). In addition, the product was well tolerated. In conclusion, this film-forming, medical device cream was effective in subjects with mild-to-moderate acne, reducing acne lesions and sebum production without altering skin barrier function, offering good skin tolerability. Furthermore, this product exerts positive skin microbiome modulation effects. Full article

With decreasing clearance between the protrusion of a slider and a disk interface, there is a higher likelihood of contact occurring during shock or vibration experienced by hard disk drives (HDDs), which may induce lubricant depletion. Based on the molecular dynamics (MD) model of perfluoropolyether lubricant with a coarse-grained beads spring approach, we compared the slider configurations’ influence on the lubricant transfer volume quantitatively. By further investigating the parameters of the cylindrical asperities, including the width and depth, as well as considering the asperity amounts of the slider, we successfully observed the lubricant depletion process during slider and disk contact. The results demonstrate that the penetration depth was reduced as the asperity amount increased, mainly owing to the increased contact area between the surfaces. The decreasing depth of the asperity and the increasing width of the asperity helped to reduce the depletion volume. In addition, the utilization of a cylindrical slider configuration can contribute to a reduction in lubricant depletion resulting from contact between the head and disk. Full article

A novel polymeric microcapsule was designed and synthesized using perfluoropolyether silane (PFPE-silane) as a superhydrophobic core material and ethyl cellulose (EC) as a shell material. The effects of the stirring rate and the core-to-shell ratio on the synthesized microcapsules were investigated. The physicochemical properties of the polymeric microcapsules were evaluated using scanning electron microscopy, fourier transform infrared spectroscopy, thermogravimetric analysis, laser particle size analysis, and wettability analysis. The results showed that when the stirring rate was 650 rpm and the core-to-shell ratio was 1:1, well-distributed and uniformly dispersed microcapsules could be obtained. The results also indicated that the prepared polymeric microcapsules were spherical particles with micropores on the surface, and they had an average particle size of 165.71 μm. The EC shells could effectively prevent the thermal decomposition of PFPE-silane during cement hydration, and the PFPE-silane also exhibited excellent hydrophobicity. The specially designed structure of this polymeric microcapsule suggests its potential for enhancing the corrosion resistance of reinforced concrete structures. Full article

This paper reports the synthesis of a novel quaternary surfactant containing a hydroxyethyl group (PFPE-C) and the surface properties of its aqueous solution (investigated by comparisons with two structurally similar chemicals, dodecyl-(2-hydroxyethyl)-dimethylammonium chloride (DHDAC) and PFPE-A). The minimum surface tension (${\gamma }_{CMC}$) and critical micelle concentration (CMC) of the PFPE-C aqueous solution were 17.35 mN/m and 0.024 mmol/L, respectively. This study confirms that surfactants containing hydroxyethyl groups efficiently reduce the surface tension of aqueous solutions, and fluorocarbon surfactants exhibit better surface activity than ordinary hydrocarbon surfactants with similar structures. The micellization, aggregation, air-water interfacial adsorption, and wettability of PFPE-C aqueous solutions have been systematically investigated. Highly concentrated PFPE-C aqueous solutions exhibit good wettability on PTFE and paraffin films. Moreover, the aggregates of PFPE-C in the aqueous solution were clearly seen as vesicles on Cryo-TEM micrographs. Primary biodegradation results indicate that 19% of PFPC-C can be degraded within one week. Full article

Slippery coatings, such as the slippery liquid-infused porous surface (SLIPS), have gained significant attention for their potential applications in anti-icing and anti-fouling. However, they lack durability when subjected to mechanical impact. In this study, we have developed a robust slippery coating by blending polyurethane acrylate (PUA) with methyltriethoxysilane (MTES) and perfluoropolyether (PFPE) in the solvent of butyl acetate. The resulting mixture is homogeneous and allows for uniform coating on various substrates using a drop coating process followed by drying at 160 °C for 3 h. The cured coating exhibits excellent water repellency (contact angle of ~108° and sliding angle of ~8°), high transparency (average visible transmittance of ~90%), exceptional adherence to the substrate (5B rating according to ASTMD 3359), and remarkable hardness (4H on the pencil hardness scale). Moreover, the coating is quite flexible and can be folded without affecting its wettability. The robustness of the coating is evident in its ability to maintain a sliding angle below 25° even when subjected to abrasion, water jetting, high temperature, and UV irradiation. Due to its excellent nonwetting properties, the coating can be employed in anti-icing, anti-graffiti, and anti-sticking applications. It effectively reduces ice adhesion on aluminum substrates from approximately 217 kPa to 12 kPa. Even after 20 cycles of icing and de-icing, there is only a slight increase in ice adhesion, stabilizing at 40 kPa. The coating can resist graffiti for up to 400 cycles of writing with an oily marker pen and erasing with a tissue. Additionally, the coating allows for easy removal of 3M tape thereon without leaving any residue. Full article

Aqueous polyurethane is an environmentally friendly, low-cost, high-performance resin with good abrasion resistance and strong adhesion. Cationic aqueous polyurethane is limited in cathodic electrophoretic coatings due to its complicated preparation process and its poor stability and single performance after emulsification and dispersion. The introduction of perfluoropolyether alcohol (PFPE-OH) and light curing technology can effectively improve the stability of aqueous polyurethane emulsions, and thus enhance the functionality of coating films. In this paper, a new UV-curable fluorinated polyurethane-based cathodic electrophoretic coating was prepared using cationic polyurethane as a precursor, introducing PFPE-OH capping, and grafting hydroxyethyl methacrylate (HEMA). The results showed that the presence of perfluoropolyether alcohol in the structure affected the variation of the moisture content of the paint film after flash evaporation. Based on the emulsion particle size and morphology tests, it can be assumed that the fluorinated cationic polyurethane emulsion is a core–shell structure with hydrophobic ends encapsulated in the polymer and hydrophilic ends on the outer surface. After abrasion testing and baking, the fluorine atoms of the coating were found to increase from 8.89% to 27.34%. The static contact angle of the coating to water was 104.6 ± 3°, and the water droplets rolled off without traces, indicating that the coating is hydrophobic. The coating has excellent thermal stability and tensile properties. The coating also passed the tests of impact resistance, flexibility, adhesion, and resistance to chemical corrosion in extreme environments. This study provides a new idea for the construction of a new and efficient cathodic electrophoretic coating system, and also provides more areas for the promotion of cationic polyurethane to practical applications. Full article