Piezoelectric Enhancement in P(VDF-TrFE) Copolymer Films via Controlled and Template-Induced Epitaxy.

The surge in wearable electronics and Internet of Things technologies necessitates the development of both flexible sensors and a sustainable, efficient, and compact power source. The latter further challenges conventional batteries due to environmental pollution and compatibility issues. Addressing this gap, piezoelectric energy harvesters emerge as one kind of promising alternative to convert mechanical energy from ambient sources to electrical energy to charge those low-energy-consumption electronic devices. Despite slightly lower piezoelectric performance compared with those inorganic materials, piezoelectric polymers, notably poly(vinylidene fluoride-co-trifluoroethylene) P(VDF-TrFE), offer compelling properties for both flexible mechanical energy harvesting and self-powered strain/stress sensing, though their piezoelectric performance is expected to be further enhanced via varieties of modulation strategies of microstructures. Herein, we reported the controlled epitaxy process of micrometer-thick copolymer films with the cooperation of friction-transferred poly(tetrafluoroethylene) templates and precise modulation of the annealing conditions. Epitaxial P(VDF-TrFE) films present averaged d33 piezoelectric coefficient of -58.2 pC/N between 50 Hz and 1 kHz with good electromechanical and thermal stability. Owing to the nature of anisotropic crystallization, the epitaxial films exhibit an anisotropic transverse piezoelectric property. Epitaxial films were further utilized for mechanical energy harvesting and monitoring of human pulsation and respiration. This study provided a feasible route for the development of high-performance flexible piezoelectric devices to meet the requirement of flexible electronics.

Direct Defluorination and Amination of Polytetrafluoroethylene and Other Fluoropolymers by Lithium Alkylamides.

Polytetrafluoroethylene (PTFE) and, by extension, fluoropolymers are ubiquitous in science, life, and the environment as perfluoroalkyl pollutants (PFAS). In all cases, it is difficult to transform these materials due to their chemical inertness. Herein, we report a direct amination process of PTFE and some fluoropolymers such as polyvinylidene fluoride (PVDF) and Nafion by lithium alkylamide salts. Synthesizing these reactants extemporaneously between lithium metal and an aliphatic primary di- or triamine that also serves as a solvent leads to the rapid nucleophilic substitution of fluoride by an alkylamide moiety when in contact with the fluoropolymer. Moreover, lithium alkylamides dissolved in suitable solvents other than amines can react with fluoropolymers. This highly efficient one-pot process opens the way for further surface or bulk modification if needed, providing an easy, inexpensive, and fast experiment protocol on large scales.

Adhesion of Candida albicans on PTFE membranes used in guided bone regeneration.

OBJECTIVES: Guided bone regeneration (GBR) is a core procedure used to regenerate bone defects. The aim of the study was to investigate the adherence of Candida albicans on six commercially available polytetrafluoroethylene (PTFE) membranes used in GBR procedures and the subsequent clinical consequences. MATERIALS AND METHODS: Six commercially available PTFE membranes were tested. Two of the membranes had a textured surface and the other four a plane, nontextured one. C. albicans (ATCC 24433) was cultured for 24 h, and its cell surface hydrophobicity was assessed using a modified method. C. albicans adhesion to membrane discs was studied by scanning electron microscopy (SEM) and real-time polymerase chain reaction (PCR). RESULTS: C. albicans was found to be hydrophobic (77.25%). SEM analysis showed that C. albicans adherence to all membranes examined was characterized by patchy, scattered, and small clustered patterns except for one nontextured membrane with a most rough surface in which a thick biofilm was observed. Real-time PCR quantification revealed significantly greater adhesion of C. albicans cells to PTFE membranes than the control membrane (p ≤ .001) with the membranes having a textured surface exhibiting the highest count of 2680 × 104 cells/ml compared to the count of 707 × 104 cells/mL on those with a nontextured one (p ≤ .001). One membrane with nontextured surface, but with most rough surface was found to exhibit the highest count of 3010 × 104 cells/ml (p ≤ .05). CONCLUSION: The results of this study indicate that C. albicans adhesion on membranes' surfaces depends on the degree of surface roughness and/or on the presence of a texture. Textured PTFE membranes and/or membranes high roughness showed significantly more adhered C. albicans cells. These findings can impact the surgeon's choice of GBR membrane and postoperative maintenance.

Toward Defect-Free Nanoimprinting.

Nanoimprinting large-area structures, especially high-density features like meta lenses, poses challenges in achieving defect-free nanopatterns. Conventional high-resolution molds for nanoimprinting are often expensive, typically constructed from inorganic materials such as silicon, nickel (Ni), or quartz. Unfortunately, replicated nanostructures frequently suffer from breakage or a lack of definition during demolding due to the high adhesion and friction at the polymer-mold interface. Moreover, mold degradation after a limited number of imprinting cycles, attributed to contamination and damaged features, is a common issue. In this study, a disruptive approach is presented to address these challenges by successfully developing an anti-sticking nanocomposite mold. This nanocomposite mold is created through the co-deposition of nickel atoms and low surface tension polytetrafluoroethylene (PTFE) nanoparticles via electroforming. The incorporation of PTFE enhances the ease of polymer release from the mold. The resulting Ni-PTFE nanocomposite mold exhibits exceptional lubrication properties and a significantly reduced surface energy. This robust nanocomposite mold proves effective in imprinting fine, densely packed nanostructures down to 100 nm using thermal nanoimprinting for at least 20 cycles. Additionally, UV nanoimprint lithography (UV-NIL) is successfully performed with this nanocomposite mold. This work introduces a novel and cost-effective approach to reusable high-resolution molds, ensuring defect-reduction production in nanoimprinting.

Prophylactic splenic artery embolization using n-butyl-2-cyanoacrylate and coils prior to endoscopic necrosectomy in a patient with necrotizing pancreatitis: A case report.

We present a case of prophylactic endovascular embolization in a 51-year-old man with necrotizing pancreatitis (NP) before undergoing endoscopic necrosectomy (EN). Contrast-enhanced CT imaging revealed the presence of a walled-off necrosis (WON) surrounding the pancreas, with the splenic artery coursing through the cavity. The splenic artery was embolized using n-butyl-2-cyanoacrylate (NBCA) and coils to mitigate the risk of massive bleeding in EN. A newly developed polytetrafluoroethylene (PTFE)-coated microcatheter was used to inject NBCA, enabling embolization of a long segment of the splenic artery without adhering to the vessel wall. Coils were placed distal and proximal to the embolized segment to optimize control. Over 5 sessions of EN, no massive bleeding was encountered. This report demonstrates the benefits of utilizing PTFE-coated microcatheters for enhanced safety and maneuverability during embolization with NBCA. Furthermore, it highlights the importance of prophylactic embolization during EN for managing NP.

Microscopic Chemical Reaction Mechanism and Kinetic Model of Al/PTFE.

In order to study the microscopic reaction mechanism and kinetic model of Al/PTFE, a reactive force field (ReaxFF) was used to simulate the interface model of the Al/PTFE system with different oxide layer thicknesses (0 Å, 5 Å, 10 Å), and the thermochemical behavior of Al/PTFE at different heating rates was analyzed by simultaneous thermal analysis (TG-DSC). The results show that the thickness of the oxide layer has a significant effect on the reaction process of Al/PTFE. In the system with an oxide layer thickness of 5 Å, the compactness of the oxide layer changes due to thermal rearrangement, resulting in the diffusion of reactants (fluorine-containing substances) through the oxide layer into the Al core. The reaction mainly occurs between the oxide layer and the Al core. For the 10 Å oxide layer, the reaction only exists outside the interface of the oxide layer. With the movement of the oxygen ions in the oxide layer and the Al atoms in the Al core, the oxide layer moves to the Al core, which makes the reaction continue. By analyzing the reaction process of Al/PTFE, the mechanism function of Al/PTFE was obtained by combining the shrinkage volume model (R3 model) and the three-dimensional diffusion (D3 model). In addition, the activation energy of Al/PTFE was 258.8 kJ/mol and the pre-exponential factor was 2.495 × 1015 min-1. The research results have important theoretical significance and reference value for the in-depth understanding of the microscopic chemical reaction mechanism and the quantitative study of macroscopic energy release of Al/PTFE reactive materials.

Sustainable H2O2 production in a floating dual-cathode electro-Fenton system for efficient decontamination of organic pollutants.

Electrochemical advanced oxidation processes (EAOPs) based on natural air diffusion electrode (NADE) promise efficient and affordable advanced oxidation water purification, but the sustainable operation of such reaction systems remains challenging due to severe cathode electrowetting. Herein, a novel floating cathode (FC) composed of a stable hydrophobic three-phase interface was established by designing a flexible catalytic layer of FC. This innovative electrode configuration could effectively prolong the service life of the cathode by mitigating the interference of H2 bubbles from the hydrogen evolution reaction (HER), and the H2O2 production rate reached 37.59 mg h-1·cm-2 and realize a long-term stable operation for 10 h. Additionally, an FC/carbon felt (CF) dual-cathode electro-Fenton system was constructed for in situ sulfamethoxazole (SMX) degradation. Efficient H2O2 production on FC and Fe(III) reduction on CF were synchronously achieved, attaining excellent degradation efficiency for both SMX (ca. 100%) with 2.5 mg L-1 of Fe(Ⅱ) injection. For real wastewater, the COD removal of the FC/CF dual-cathode electro-Fenton system was stabilized at exceeding 75%. The practical application potential of the FC/CF dual-cathode electro-Fenton system was also demonstrated for the treatment of actual landfill leachate in continuous flow mode. This work provides a valuable path for constructing a sustainable dual-cathode electro-Fenton system for actual wastewater treatment.

Influence of the PET-PTFE Separator Pore Structure on the Performance of Lithium Metal Batteries.

The separator is a crucial component in lithium batteries, as it physically separates the cathode and the anode while allowing ion transfer through the internal channel. The pore structure of the separator significantly influences the performance of lithium batteries, particularly lithium metal batteries. In this study, we investigate the use of a Janus separator composed of poly(ethylene terephthalate) (PET)-polytetrafluoroethylene (PTFE) fibers in lithium metal batteries. This paper presents a comprehensive analysis of the impact of this asymmetric material on the cycling performance of the battery alongside an investigation into the influence of two different substrates on lithium-ion deposition behavior. The research findings indicate that when the rigid PET side faces the lithium metal anode and the soft PTFE side faces the cathode, it significantly extends the cycling lifespan of lithium metal batteries, with an impressive 82.6% capacity retention over 2000 cycles. Furthermore, this study demonstrates the versatility of this separator type in lithium metal batteries by assembling the lithium metal electrode with high cathode-loading capacities (4 mA h/cm2). In conclusion, the results suggest that the design of asymmetric separators can serve as an effective engineering strategy with substantial potential for enhancing the lifespan of lithium metal batteries.

Unveiling the Role of PTFE Surface Coverage on Controlling Gas Diffusion Layer Water Content.

Gas diffusion layers (GDLs) are usually coated with a hydrophobic agent to achieve a delicate balance between liquid and gas phases to maximize mass transport. Yet, most GDL numerical models to date have assumed an average contact angle for all materials, thereby eliminating the possibility of studying the role of the polytetrafluoroethylene (PTFE) content. This study introduces two mixed wettability algorithms to predict the mixed wetting behavior of GDLs composed of multiple materials. The algorithms employ contact angle and distance to solid materials to determine the critical capillary pressure for each pore voxel. The application of the algorithms to the estimation of capillary pressure vs saturation curves for two GDLs, namely, a micro-computed tomography (µ-CT) reconstructed SGL 39BA GDL and a stochastically reconstructed Toray 120C GDL, showed that, in agreement with experimental data, the addition of PTFE resulted in a decrease in saturation at a given capillary pressure. For Toray-120C, the mixed wettability model was capable of reproducing experimentally observed features in the intrusion curve at low saturation that could not be reproduced with a single wettability model, providing a clear link between PTFE coverage and intrusion at low saturation. Numerical results also predicted an increased breakthrough pressure and a decrease in saturation with increasing PTFE, in agreement with experimental observations. The decreased saturation at breakthrough improves gas transport through the layer while maintaining the layer's ability to remove water. Diffusivity simulations confirm the increase in diffusivity at breakthrough with increasing PTFE, thereby providing a rationale for the addition of PTFE, as well as for the optimal amount. This study emphasizes the importance of multimaterial wetting models and calls for more detailed investigations into PTFE and ionomer distributions in GDLs and catalyst layers, respectively.

Is transvaginal mesh surgery with polytetrafluoroethylene mesh ORIHIME® feasible for anterior pelvic organ prolapse?-Randomized comparative study between ORIHIME® and Polyform™.

OBJECTIVE: Transvaginal mesh surgery for pelvic organ prolapse has been widely performed in Japan, but polypropylene mesh has not been used in Japan since the ban on TVM using polypropylene mesh in the United States. Currently, polytetrafluoroethylene mesh ORIHIME® is the only mesh available for TVM in Japan. Although polytetrafluoroethylene is a safe material, its low coefficient of friction and insufficient adhesion to the surrounding tissue make it difficult to maintain the mesh position when it is used in the transvaginal mesh surgery. The aim of this study was to evaluate the feasibility of TVM-A2 using ORIHIME®. METHODS: One hundred cases of TVM-A2 were included in the study. The patients were randomly assigned to two groups: the ORIHIME® group (Group O) and the PolyformTM group (Group P). With 50 patients in each group, the complications and recurrences up to the fourth year were compared. Surgeries were performed using the TVM-A2 method. Statistical analysis was performed using EZR. RESULTS: There were no significant differences in baseline parameters between the two groups. We observed no perioperative complications, and saw one case of postoperative abscess formation in Group O, which resolved successfully after incision and drainage. The 4-year recurrence rate was significantly higher in Group O. CONCLUSION: As the recurrence rate was significantly higher in Group O, we conclude that TVM-A2 using ORIHIME® which is the same procedure as TVM-A2 using polypropylene mesh is not feasible in repairing the pelvic organ prolapse.

A Novel Approach of Electrocatalytic Deamination From Aromatic Amide to Diarylimide on Ni-PTFE Modified Electrode.

A hydrophobic Ni-PTFE modified electrode has been prepared by constant current and cathodic electroplating with a nickel sheet as substrate in a PTFE suspension. Then the Ni-PTFE modified electrode was used for electroreduction from aromatic amide to diarylimide. The electrochemical characterizations such as cyclic voltammogram, EIS, polarization curves, and electrode stability have been carried out by electrochemical workstation. The structure of the electroreduction product diarylimide was characterized by 1H NMR, FT-IR, MS(Mass Spectrum), and EA(Elemental Analyzer). Based on the hydrophobicity of the electrode, an approach suggested that the phenyl ketone radical may be formed by electroreductive deamination at the cathode. With the construction of C-N bond by the radical coupling, the electrocatalytic reduction may be comprised of a one-electron process including an ECC (Electrochemical-Chemical-Chemical) process. The electroreduction of aromatic amide to diarylimide may be controlled by both charge migration and concentration polarization. Electrocatalytic reduction of aromatic amides on Ni-PTFE modified electrodes is all well conversion ratio.

Rubber-like PTFE Thin Coatings Deposited by Pulsed Electron Beam Deposition (PED) Method.

PTFE coatings were manufactured using the pulsed electron beam deposition (PED) technique and deposited on Si substrates. The deposition was carried out at constant parameters: temperature 24 °C, discharge voltages 12 kV, and 5000 electron pulses with a pulse frequency of 5 Hz. Nitrogen was used as the background gas. The gas pressure varied from 3 to 11 mTorr. The coating adhesion was evaluated using micro scratch testing and the residual scratch morphology was characterized by atomic force microscopy. Detailed studies of the chemical and physical structure were conducted using infrared spectroscopy and X-ray diffraction. These analyses were then correlated with the mechanical response of the coatings observed during the scratch tests. Drawing upon a review of the literature concerning energetic beam interactions with PTFE material, hypotheses were posed to explain why only specific conditions of the PED process yielded PTFE coatings with rubber-like properties.

Fluorinated Polydopamine Shell Decorated Fillers in Polytetrafluoroethylene Composite for Achieving Highly Reduced Coefficient of Thermal Expansion.

The noticeable difference in the coefficient of thermal expansion (CTE) for polytetrafluoroethylene (PTFE) coatings and copper substrates is a major challenge for thermal debonding of the copper-clad laminate (CCL) in high-frequency communications. Theoretically, ceramic fillers with low CTEs in the coating can effectively reduce the gap, and there remains a trade-off between the dispersibility of fillers and the interfacial interactions with the polymeric matrix. Here, we propose a novel approach to prepare a pentafluorobenzoyl chloride (PFBC)-modified polydopamine (PDA) shell on silica particles by using amidation. Such modified particles perform excellent dispersion and exhibit diminished interfacial gaps in the PTFE matrix, which highly reduces CTE to 77 ppm/°C, accounting for only 48.1% of the neat coating. Moreover, the composite exhibits enhanced mechanical strength and toughness, and consequently suppresses thermal debonding in CCL under high-temperature conditions. Therefore, results present a promising potential for its use in the next-generation CCL of high-frequency communication devices.

Per- and polyfluoroalkyls used as cosmetic ingredients - Qualitative study of 765 cosmetic products.

Per- and polyfluoroalkyl substances (PFAS) form a vast family comprising more than 4700 synthetic compounds. Their molecules contain a terminal functional group and a hydrophobic carbon tail (alkyl group) at which the hydrogen atoms are totally (in the case of perfluorinated compounds) or partially (in the case of polyfluorinated compounds) replaced by fluorine atoms. Due to the very specific properties of their structure, they have been used in a vast range of applications over the last 70 years. These substances are considered to be of concern for the environment. Their effects on human health are still poorly understood because studies are still too rare, but the cutaneous route could be a significant pathway of penetration. In this context, we made a qualitative study to assess the presence of PFAS in various cosmetics such as hygiene products, skin care products, make-up and perfumes. Among the 765 products studied, we found 11 different PFAS. Polytetrafluoroethylene (PTFE) and perfluorodecalin, present in 25.9% and 22.2% of products containing it, respectively, were the most frequent. Although the presence of this type of ingredient seems to be limited in Europe, make-up appears to be the type of product most likely to contain PFAS.

Research on the destroy characteristics of PTFE/Cu composite liner to explosive reactive armor.

The jet generated through PTFE based inert material liner has the characteristics of low energy, low density, and large aspect ratio, which can effectively achieve the "penetration without explosion" of explosive reactive armor. PTFE/Cu composite material liner with various densities is prepared, to research the roles of preparation procedure and density in the destroy effect of jet on reactive armor. Through numerical simulation research, it was found that there was no reaction at all in the explosive layer penetrated by the jet generated by the sinter liner molded, while the explosive layer penetrated by the jet generated through the hot-pressing sintering and extrusion molding liner experienced local reactions on the jet impact channel, and the overall explosive layer did not undergo any reaction. Through experimental verification, it has been proven that all three types of jets have achieved "penetration without explosion" on explosive reactive armor.

Numerical Simulation Study on Impact Initiation on Shielded Charge Using Hypervelocity Composite-Structure Reactive Fragments.

In order to study the impact initiation process and mechanism of hypervelocity PTFE/Al composite structure reactive fragments on a shielded charge, first, an existing PTFE/Al reactive fragment hypervelocity collision experiment was numerically simulated using the SPH algorithm in ANSYS/AUTODYN 17.0 software. Then, the Lee-Tarver model was verified to describe the detonation reaction behavior and explosion damage effect of reactive materials. A numerical simulation analysis of the impact of two kinds of ultra-high-speed PTFE/Al composite-structure reactive fragments on a shielded charge was carried out using the SPH algorithm. These were steel-coated PTFE/Al and steel-semi-coated PTFE/Al fragments, and they were compared with the impact of steel fragments. The results indicate that the threshold velocities of the impact initiation of the two composite-structure reactive fragments on the shielded charge were both 2.6 km/s, while the threshold velocity of the steel fragment was 2.7 km/s. Under the threshold velocity condition, the two composite-structure reactive fragments increase the time and intensity of the compressed shock wave pulse in the explosive due to the impact energy release effect of the reactive materials, causing the shielded charge to detonate under the continuous long-term pulse loads. However, the mechanism of the steel fragment on the shielded charge belongs to the shock-detonation transition. The research results can provide scientific references for the design of hypervelocity reactive fragments and the study of their damage mechanism.

Hydrophilic Modification of Polytetrafluoroethylene (PTFE) Capillary Membranes with Chemical Resistance by Constructing Three-Dimensional Hydrophilic Networks.

Polytetrafluoroethylene (PTFE) capillary membranes, known for the great chemical resistance and thermal stability, are commonly used in membrane separation technologies. However, the strong hydrophobic property of PTFE limits its application in water filtration. This study introduces a method whereby acrylamide (AM), N, N-methylene bisacrylamide (MBA), and vinyltriethoxysilane (VTES) undergo free radical copolymerization, followed by the hydrolysis-condensation of silane bonds, resulting in the formation of hydrophilic three-dimensional networks physically intertwined with the PTFE capillary membranes. The modified PTFE capillary membranes prepared through this method exhibit excellent hydrophilic properties, whose water contact angles are decreased by 24.3-61.2%, and increasing pure water flux from 0 to 1732.7-2666.0 L/m2·h. The enhancement in hydrophilicity of the modified PTFE capillary membranes is attributed to the introduction of hydrophilic groups such as amide bonds and siloxane bonds, along with an increase in surface roughness. Moreover, the modified PTFE capillary membranes exhibit chemical resistance, maintaining the hydrophilicity even after immersion in strong acidic (3 wt% HCl), alkaline (3 wt% NaOH), and oxidative (3 wt% NaClO) solutions for 2 weeks. In conclusion, this promising method yields modified PTFE capillary membranes with great hydrophilicity and chemical resistance, presenting substantial potential for applications in the field of water filtration.

Crosslinking and fluorination reinforced PTFE nanofibrous membrane with excellent amphiphobic performance for low-scaling membrane distillations.

Membrane distillation (MD) has emerged as a promising technology for desalination and concentration of hypersaline brine. However, the efficient preparation of a structurally stable and salinity-resistant membrane remains a significant challenge. In this study, an amphiphobic polytetrafluoroethylene nanofibrous membrane (PTFE NFM) with exceptional resistance to scaling has been developed, using an energy-efficient method. This innovative approach avoids the high-temperature sintering treatment, only involving electrospinning with PTFE/PVA emulsion and subsequent low-temperature crosslinking and fluorination. The impact of the PVA and PTFE contents, as well as the crosslinking and subsequent fluorination on the morphology and MD performance of the NFM, were systematically investigated. The optimized PTFE NFM displayed robust amphiphobicity, boasting a water contact angle of 155.2º and an oil contact angle of 132.7º. Moreover, the PTFE NFM exhibited stable steam flux of 52.1 L·m-2·h-1 and 26.7 L·m-2·h-1 when fed with 3.5 wt % and 25.0 wt % NaCl solutions, respectively, and an excellent salt rejection performance (99.99 %, ΔT = 60 °C) in a continuous operation for 24 h, showing exceptional anti-scaling performance. It also exhibited stable anti-wetting and anti-fouling properties against surfactants (sodium dodecyl sulfate) and hydrophobic contaminants (diesel oil). These results underscore the significant potential of the PTFE nanofibrous membrane for practical applications in desalination, especially in hypersaline or polluted aqueous environments.

UV-C side-emitting optical fiber-based disinfection: a promising approach for infection control in tight channels.

The growth of pathogenic bacteria in moist and wet surfaces and tubing of medically relevant devices results in serious infections in immunocompromised patients. In this study, we investigated and demonstrated the successful implementation of a UV-C side-emitting optical fiber in disinfecting medically relevant pathogenic bacteria (Pseudomonas aeruginosa and Methicillin-resistant Staphylococcus aureus [MRSA]) within tight channels of polytetrafluoroethylene (PTFE). PTFE is a commonly used material both in point-of-use (POU) water treatment technologies and medical devices (dental unit water line [DUWL], endoscope). For a 1-m-long PTFE channel, up to ≥6 log inactivation was achieved using a 1-m-long UV side-emitting optical fiber (SEOF) with continuous 16-h exposure of low UV-C radiation ranging from ~0.23 to ~29.30 µW/cm2. Furthermore, a linear model was used to calculate the inhibition zone constant (k`), which enables us to establish a correlation between UV dosage and the extent of inactivated surface area (cm2) for surface-bound Escherichia coli on a nutrient-rich medium. The k` value for an irradiance ranging from ~150 to ~271.50 µW/cm2 was calculated to be 0.564 ± 0.6 cm·cm2/mJ. This study demonstrated the efficacy of SEOFs for disinfection of medically relevant microorganisms present in medically and domestically relevant tight channels. The impact of the results in this study extends to the optimization of operational efficiency in pre-existing UV surface disinfection setups that currently operate at UV dosages exceeding the optimal levels.IMPORTANCEGermicidal UV radiation has gained global recognition for its effectiveness in water and surface disinfection. Recently, various works have illustrated the benefit of using UV-C side-emitting optical fibers (SEOFs) for the disinfection of tight polytetrafluoroethylene (PTFE) channels. This study now demonstrates its impact for disinfection of medically relevant organisms and introduces critical design calculations needed for its implementation. The flexible geometry and controlled emission of light in these UV-SEOFs make them ideal for light distribution in tight channels. Moreover, the results presented in this manuscript provide a novel framework that can be employed in various applications, addressing microbial contamination and the disinfection of tight channels.

Recent Progress in Cellulose Hydrophobization by Gaseous Plasma Treatments.

Cellulose is an abundant natural polymer and is thus promising for enforcing biobased plastics. A broader application of cellulose fibers as a filler in polymer composites is limited because of their hydrophilicity and hygroscopicity. The recent scientific literature on plasma methods for the hydrophobization of cellulose materials is reviewed and critically evaluated. All authors focused on the application of plasmas sustained in fluorine or silicon-containing gases, particularly tetrafluoromethane, and hexamethyldisiloxane. The cellulose materials should be pre-treated with another plasma (typically oxygen) for better adhesion of the silicon-containing hydrophobic coating. In contrast, deposition of fluorine-containing coatings does not require pre-treatment, which is explained by mild etching of the cellulose upon treatment with F atoms and ions. The discrepancy between the results reported by different authors is explained by details in the gas phase and surface kinetics, including the heating of samples due to exothermic surface reactions, desorption of water vapor, competition between etching and deposition, the influence of plasma radiation, and formation of dusty plasma. Scientific and technological challenges are highlighted, and the directions for further research are provided.