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When fabricating polymeric membranes using the non‐solvent induced phase separation (NIPS) technique, the characteristics and performance of the resulting membranes are significantly influenced by the additives incorporated into the casting solution. In this study, polychlorotrifluoroethylene (PCTFE) microfiltration (MF) membranes were fabricated using different pore‐formers including organic solvents, inorganic salts, and polymers. PCTFE was used as an attractive polymer for the first time in the liquid filtration process. This is due to its favorable properties for MF membranes such as ease of processing, high mechanical robustness, and fouling‐resistance. Dimethylformamide (DMF), ethanol, NaCl, ammonium bicarbonate, and polyethylene glycol (PEG) were incorporated at 1–4 wt% concentration as pore‐forming agents into the PCTFE solution. The prepared membranes were characterized by scanning electron microscopy (SEM), water contact angle measurement, and their filtration performance was assessed by pure water permeability (PWP) measurement and separation of milk fat in a cross‐flow membrane module. From the results, the overall porosity, surface porosity, mean pore size, hydrophilicity, PWP, steady flux, and fat rejection were in the following order for the modified membranes: PCTFE/DMF > PCTFE/PEG > PCTFE/ethanol > PCTFE/ammonium bicarbonate > PCTFE/NaCl. Among modified membranes, the highest fat rejection (95.8%) was obtained for the 1 wt% DMF‐containing casting solution. The fat rejection of this membrane was slightly less than the neat PCTFE membrane (97.5%), but its steady permeate flux was more than twice that of the pure sample. Additionally, the anti‐fouling and mechanical characteristics of the membranes were also investigated to assess the suitability of PCTFE polymers for the MF process. Highlights: MF process was conducted using novel PCTFE flat‐sheet membranes.The PCTFE membrane was prepared with different pore‐formers.Using different concentrations of pore‐formers affected the membrane structure.Using pore‐formers affected the PCTFE membrane performance. [ABSTRACT FROM AUTHOR]

One of the decisive factors that determines the effectiveness of using carbon nanotubes (CNTs) for reinforcing polymer matrices is their uniform distribution in the matrix. It is shown that the percolation threshold in the polychlorotrifluoroethylene (PCTFE)–CNTs system, determined by electrical conductivity data, shifts to lower values with a more uniform distribution of CNTs, while the electrical conductivity increases and correlates with the structure and strength characteristics. Preliminary deagglomeration of CNTs was carried out using ultrasonic treatment in a dispersion of graphene nanoplatelets (GNPs). Three water systems with a CNTs content of 0.5, 0.25, and 0.125 wt.% were dispersed. The GNPs content was 0.1 mass fractions to 1 mass fractions of CNTs for all systems. The dependences of the real (εʹ) and imaginary (εʺ) components of the complex dielectric constant, electrical conductivity (σ) and relative bending strength limit on the volume content of CNTs (ϕ) were found, which have a percolation character. Percolation indices were determined for the dependences σ = f (ϕ), which for the specified concentrations were: flow thresholds (ϕc) − 0.0047, 0.0032, 0.00097 and critical indices (t) − 2.01, 1.78, 1.75, respectively. The most uniform distribution of CNTs, which was achieved at the minimum content of CNTs during dispersion (0.125 wt.% CNTs), corresponds to the maximum value of σ, the lowest percolation threshold, which correlates with the maximum bending strength limit. [ABSTRACT FROM AUTHOR]

The interaction of graphene with fragments of polychlorotrifluoroethylene (PCTFE) has been studied by quantum chemistry methods. Within the frameworks of the density functional theory with B3LYP exchangecorrelation functional, 6-31G(d,p) basis set and the Grimme dispersion correction, and the second order MøllerPlesset perturbation theory (MP2), the values of the interaction energy of graphene with polychlorotrifluoroethylene oligomers were calculated and the most probable structures of their intermolecular complexes were optimized. As a graphene model, graphene-like planes (GLP) of different sizes were chosen, namely: С40Н16, С54Н18 and С96Н24. Oligomers of polychlorotrifluoroethylene and graphene-like planes in the formed nanocomposites are located closer to each other than individual polymer links. When comparing the results of calculations by the B3LYP-D3/6-31G(d,p) and MP2/6-31G(d,p) methods, both in the case of interactions of polychlorotrifluoroethylene oligomers with each other and intermolecular complexes of polychlorotrifluoroethylene oligomers and graphene-like planes, it has been found that the second order MøllerPlesset method is characterized by a larger intermolecular distance and a lower energy of intermolecular interactions compared to the method of the density functional theory with the Grimme dispersion correction, which is explained by the fact that the MP2 method does not fully take into account the relatively small components of dispersion interactions. Analysis of the calculation results using quantum chemistry methods shows that the addition of graphene-like planes to the polychlorotrifluoroethylene polymer leads to an increase in the intermolecular interaction energy, regardless of the calculation method used and the sizes of polychlorotrifluoroethylene oligomers and graphene-like planes. This may indicate greater strength and thermal stability of the nanocomposite based on graphene-like planes with polychlorotrifluoroethylene oligomers. The zero value of the Gibbs free energy ΔGreact for the interaction of two dimers with each other is characteristic at 270 K, and the similar value of the interaction of the PCTFE dimer with GLP is at a much higher temperature (420 K). This fact reflects the growth in thermostability of nanocomposites as compared to the polymer itself. [ABSTRACT FROM AUTHOR]

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Copyright of Plastics Science & Technology / Suliao Ke-Ji is the property of Plastics Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Polychlorotrifluoroethylene (PCTFE) is a promising candidate for cryogenic storage and transportation materials in clean energy industry. But, how to improve its toughness without scarification other performance is still challenging. In this study, the immiscible PA11 is introduced into PCTFE matrix as toughening agent based on a strategy of enhanced interfacial effect. As the incorporation of PA11 increased from 0 to 20 wt%, the toughness of the PCTFE/PA11 shows a trend of first increasing and then decreasing, which reaches the optimal performance with 5 wt% PA11. The elongation at break and impact strength are respectively increased by ~3 and ~1.9 times without obvious reduction of other mechanical performance. Meanwhile, PA11 could enhance the primary nucleation and crystallization ability of PCTFE. With further detailed information of microstructures and Fourier infrared spectra, a multieffect synergistic toughening mechanism based on rigid particle and intermolecular interaction has been elucidated. Furthermore, the toughening of PA11 on PCTFE at ultra‐low temperature of −196°C is confirmed. [ABSTRACT FROM AUTHOR]

Polychlorotrifluoroethylene (PCTFE) is one of the earliest developed and commercialized fluoropolymers and has been used in high-frequency communication, anti-corrosion, and medical packaging fields. However, relatively poor processability and mechanical performances resulting from high molecular regularity and crystallinity limited its broader applications. Herein, the pristine PCTFE was physically modified by blending with its pyrolysis products (FCO). It was demonstrated that the addition of FCO accelerated the molecular relaxation and retarded the crystallization process of PCTFE, leading to the distinct improvement of processability and mechanical performances. When 10% FCO was loaded, the equilibrium torque was decreased by 20%; the elongation at break and impact strength were enhanced by 3.6 and 10.6 times in comparison to those of PCTFE. Additionally, because of the good compatibility of the components, the blend also maintained ultralow dielectric constant/loss, good transparency, and high water-vapor barrier performances. Accordingly, this work paved an effective route to prepare high-performance PCTFE materials, which may play an important role in high-frequency communication field.

The chemical composition of the surfaces of γ-irradiated polytetrafluoroethylene and polychlorotrifluoroethylene plates has been studied by X-ray photoelectron spectroscopy (XPS). In the chemical composition of irradiated polytetrafluoroethylene, the concentration of fluorine decreased and the concentrations of carbon and oxygen increased as a result of the degradation of the main polymer chain with the formation of low-molecular-weight compounds and the oxidation of free radicals stabilized on the surface of the irradiated polymer. The chemical composition of the polychlorotrifluoroethylene surface revealed by analyzing the XPS spectrum noticeably changed after γ-irradiation with a decrease in the concentration of carbon and an increase in the concentrations of fluorine, oxygen, and chlorine. [ABSTRACT FROM AUTHOR]

The action of accelerated 1–4-MeV protons on polychlorotrifluoroethylene in vacuum was accompanied by a preferential rupture of the main polymer chain with the release of more than 30 gaseous products, most of which were tetrafluoroethylene and chlorine- and fluorine-containing compounds. As a result of proton bombardment, the concentration of carbon on the polymer surface decreased and the concentrations of fluorine and chlorine increased. It has been shown that the incorporation of chlorine atoms into the structure of a perfluoropolymer changes the mechanism of its proton bombardment and helps to protect its macromolecule from the reaction of fluorine abstraction by accelerated protons with the formation of hydrogen fluoride. It has been found that irradiation with accelerated protons leads to changes in surface energy characteristics. [ABSTRACT FROM AUTHOR]

Polychlorotrifluoroethylene (PCTFE) has the outstanding water-vapor barrier performances among thermoplastics, and is with excellent transparency, high cryogenic toughness, and ultralow dielectric constant/loss. It plays an important role in high-performance packaging, electric circuit constructions, anti-corrosion coatings, cryogenic sealing, and so forth. Nevertheless, due to its borderline thermal stability and sensitivity to shearing effect, the melt-processing of PCTFE is rather difficult. Herein, a solvent-assisted method, which contained fabrication, coating, drying, and sintering of PCTFE suspension, was proposed for the fabrication of PCTFE films. The influence of processing parameters, including particle shape, drying temperature, and sintering time on the film-forming process was investigated. The as-prepared PCTFE films exhibited exceptional mechanical properties, with a tensile strength and failure strain of ∼42 MPa and ∼108 %, respectively. The water vapor transmission rate, light transmittance, and haze reached ∼0.02 g/(m2·24 h), ∼91 %, and ∼3 %, respectively. Finally, the potential film-forming mechanism was explained by the densification of PCTFE particles via capillary force, neck formation and particles coalescence driven by surface tension and viscous flow, and co-crystallization across the initial particle interfaces. In summary, the solvent-assisted method opened a new pathway for the processing of PCTFE films and is conducive to broadening their application fields. [Display omitted] • PCTFE film is prepared via solvent-assisted method. • The capillary force drives PCTFE particles into a compact particle network. • A higher drying temperature leads to a denser particle network. • Surface tension and viscous flow drive PCTFE particles into a complete film. • PCTFE film exhibits exceptional performances. [ABSTRACT FROM AUTHOR]

Abstract Poly (ethylene chlorotrifluoroethylene) (ECTFE) membrane presents interesting properties for microfiltration (MF) and membrane distillation (MD). In this paper, ECTFE is prepared via thermally induced phase separation (TIPS) process using acetyl tributyl citrate (ATBC) as an environmentally friendly diluent. Phase diagram of the ECTFE/ATBC system is measured, and the effects of ECTFE concentration and quenching bath temperature on the membrane structure, properties and performance are investigated, by characterizing with scanning electron microscope (SEM), pure water flux, contact angle, mechanical properties, mean pore size and porosity. The results show that the ECTFE membranes prepared with ATBC as diluent possessed spherulite structure, high hydrophobicity and liquid entry pressure of water (LEP w), promising permeate flux, salt rejection and mechanical strength in vacuum membrane distillation (VMD). The permeate flux reached to 22.3 L/(m2.h) with salt rejection rate of 99.9%. These results indicated that ECTFE membranes prepared with green diluent ATBC is an interesting candidate for VMD operation. Graphical abstract Unlabelled Image Highlights • ECTFE membrane prepared with a green diluent via TIPS method. • ECTFE/ATBC binary equilibrium phase diagram obtained for the first time. • The prepared ECTFE membrane showed high hydrophobicity. • The prepared ECTFE membrane possessed high performance in VMD. [ABSTRACT FROM AUTHOR]

Abstract A glucose/oxygen biofuel cell (BFC) that can operate continuously under oxygen-free conditions is described. The oxygen-deficit limitations of metabolite/oxygen enzymatic BFCs have been addressed by using an oxygen-rich cathode binder material, polychlorotrifluoroethylene (PCTFE), which provides an internal oxygen supply for the BFC reduction reaction. This oxygen-rich cathode component mitigates the potential power loss in oxygen-free medium or during external oxygen fluctuations through internal supply of oxygen, while the bioanode employs glucose oxidase-mediated reactions. The internal oxygen supply leads to a prolonged energy-harvesting in oxygen-free solutions, e.g. , maintaining over 90% and 70% of its initial power during 10- and 24-h operations, respectively, in the absence of oxygen. The new strategy holds considerable promise for energy-harvesting and self-powered biosensing applications in oxygen-deficient conditions. Highlights • A glucose/O 2 biofuel cell operating continuously under oxygen-free conditions. • An O 2 -rich cathode binder material, providing internal oxygen supply for the BFC reduction reaction. • Energy-harvesting and self-powered applications in O 2 -fluctuating conditions. [ABSTRACT FROM AUTHOR]

Semi-crystalline polymers poly(vinylidene fluoride) and PVDF-based copolymer were common membrane materials which have found broad application. In an attempt to illuminate the relation between phase inversion and the polymer crystalline polymorphism, the effect of LiCl on PVDF polymorphs, membrane morphology, pore structure, hydrophobicity, thermal property, and permeability were investigated for Poly(vinylidene fluoride-co-chlorotrifluoroethylene) (PVDF-CTFE) membrane prepared by non-solvent induced phase inversion method. Both thermodynamic and kinetic effect were observed, and LiCl was found to favor the crystallization process. The phase inversion route and rate were significantly influenced by LiCl, result in the increase of the content of β-phase, membrane crystallinity, thermo-resistance, overall pore size, and pore interconnectivity when increase LiCl content. The surface pore size and porosity increased firstly when LiCl content was lower than 5%, but significantly decreased with more LiCl. Meanwhile, the pore interconnectivity was highly recommend for membrane evaluation as porosity was found delivering partial information. Membrane M5 presents optimal performance with a permeate flux of 21.85 kg/m 2 h and the permeate conductivity was lower than 15 µS/cm at a temperature difference of 30 °C. This work demonstrates the relation between phase inversion and the crystalline structure and illuminate its effect on the final membrane. It provides a novel method for membrane mechanism research and membrane evaluation which can be instructive for PVDF membrane research and application. [ABSTRACT FROM AUTHOR]

Halogenated polymers have emerged as interesting materials for membrane gas separation. Herein, we demonstrate that a combination of F and Cl substituents in polymers provide unexpectedly superior He/gas separation properties, as exemplified by polychlorotrifluoroethylene (PCTFE). PCTFE exhibits a He permeability of 26 Barrers at 35 °C and pure gas selectivity of He/H 2 , He/CO 2 , and He/CH 4 of 6.2, 53, and 1100, respectively. These selectivity values are among the highest reported for polymers, and the separation performance is very close to the Robeson's upper bounds. The effect of crystallinity in PCTFE on gas transport properties is discussed, and the gas transport properties in PCTFE are compared with other polyethylene (PE) analogues such as PE, polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), and polytetrafluoroethylene (PTFE). The effect of F and Cl substituents on gas solubility is also elucidated using a variety of hydrocarbons and halogenated liquids. The F substituents lead to unexpectedly high He solubility and exhibit unfavorable interactions with H 2 and CH 4 , while the Cl substituents increase solubility parameter and size-sieving ability, both of which contribute to the superior He/gas separation properties (particularly He/H 2 and He/CH 4 ). The understanding of the role of F and Cl substituents of polymers in gas transport properties can be useful in designing high performance polymers for membrane gas separation. [ABSTRACT FROM AUTHOR]

Contact mechanical seal is a normal technology applied on middle axis of liquid rocket turbo pump, and the kinetic and static seal rings contact low temperature rocket propellant. Copper-graphite (Cu/C) composite as an excellent self-lubrication material was widely used in aerospace industry, this study took Cu/C as ball and bearing steel as disk to investigate the tribology properties, and distilled water were used to simulate the lox tribology performances. This study prepared polytrifluorochloroethylene (PCTFE) micro-particles which were coated on the oxide surfaces of bearing steel disk at temperature of 150 °C. The tribology results showed that the oxide surfaces treated with micro PCTFE particles have lower fiction coefficient and lower wear rate than original disk in water, and the wear morphology revealed that the treated surfaces obviously had less Cu/C composite transfer film than original disk. Meanwhile SEM, EDS, XRD, XPS and light microscope etc revealed that PCTFE micro-particles could associate with the oxide surfaces and caused higher water contact angle, due to the properties of the fluorine-containing composite may cause the good lubrication effect in water. Thus this technology shows great potential to enhance tribological performances for aerospace industry on a large scale. [ABSTRACT FROM AUTHOR]

The poly (methyl methacrylate) (PMMA) polymer blend films were prepared by solution casting method with varying PolyChloroTriFluoroEthylene (PCTFE) concentrations (1–5 wt %). The crystallinity, bonding behavior and disorder in the films were investigated with X-ray diffraction (XRD), Fourier transform infrared (FTIR), UV–visible and ellipsometry techniques, while surface morphology was studied using Atomic force microscopy (AFM). The nanocrystalline nature of PMMA is seen to be preserved in the blends although there are clear indications of bond modifications. The addition of PCTFE results in the improvement of overall crystallinity of the films via the interaction among PMMA and degraded PCTFE molecules when the films are casted from diluted solutions. In agreement, corresponding disorder in terms of Urbach energy shows a decreasing trend upon inclusion of more and more PCTFE molecules. Micro-Raman spectra are dominated by fluorescence background, which is proposed as arising from degraded PCTFE. Supporting this, FTIR spectra also shows modifications in bonding as a function of PCTFE percentage, but this bond modification is not enough to produce refractive index variation in the sample, which is dominated by the host PMMA contribution for all the PCTFE concentrations. The study suggests the useful range of PCTFE concentration in which PMMA host properties can be modified for optimizing optical and structural properties without much degradation of PCTFE. [ABSTRACT FROM AUTHOR]

Three topological blocks (low- and high-temperature amorphous and crystalline) have been detected for the first time in polychlorotrifluoroethylene with a pseudo-network structure. The molecular weight of the polymer decreases and the crystalline and high-temperature amorphous fractions degrade with an increase in γ-radiation dose. Thermal annealing at 493 K leads to amorphization of the polymer, as well as its radiolysis. However, slow recrystallization of the thermally annealed polymer has been observed during storage at 300 K. [ABSTRACT FROM AUTHOR]

Desalination by membrane distillation (MD) have found rapid growth and diversified applications in recent decade, associated with it was the demand for hydrophobic membranes. Poly (vinylidene fluoride- co -chlorotrifluoroethylene) (PVDF-CTFE) was used for hydrophobic membrane preparation with LiCl additive by non-solvent induced phase inversion (NIPS), the effect of polymer concentration was investigated in terms of membrane morphology, pore structure, hydrophobicity, thermal property, and membrane distillation (MD) performance to evaluation its potential in MD desalination. It was found that the solid-liquid demixing process showed more influence with increasing polymer content due to the delayed phase inversion process, which was responsible for the suppressed macrovoids, reduced pore size, higher hydrophobicity and pore interconnectivity. The melting temperature and crystallinity also increased due to the crystallization during membrane formation. M3 with 12% polymer content presents the best MD performance (permeate flux of 20.65 kg/m 2 ·h with a salt rejection higher than 99.95%). Ethanol and sodium hydroxide (NaOH) solution were applied as the second immersion bath to post-treat the nascent membranes. Pore enlargement effect was found for both post-treated membranes. However, the dehalogenation process was the most important mechanism for NaOH, while the obstruction of partial shrinkage was the mechanism of ethanol solution. In a word, PVDF-CTFE hydrophobic membrane show potential in MD desalination, especially when a second solution bath is used for membrane modification as the flux enhancement without the sacrifice of salt rejection. [ABSTRACT FROM AUTHOR]

The hypothesis of the study was that linear chained polymers have a natural chance to stabilize as a helix. Ten linear chained polymers, poly(ethylene glycol), polyethyleneimine, poly(lactic acid), poly(N-vinyl-pyrrolidone), poly(trans-1-butenylene), poly(1-chloro-trans-1-butenylene), poly(1-methyltrans-1-butenylene), poly(1,4,4-trifluoro-trans-1-butenylene), polyacrylonitrile, polychlorotrifluoroethylene, were investigated. The structure of polymers was drawn and then optimized at Hartree-Fock, 6-31G* level of theory. The helix parameter was extracted from the optimized geometries using a home-made program. Seven out of ten polymers are likely to have a helical structure; the polymers with oxygen shown the highest residual error. The helix coefficient and rotation step per monomer were also calculated. The top three polymers according to rotation step per monomer behaved same as the one according to the helix coefficient. The top three non-increasing order was: polychlorotrifluoroethylene-Cl, polyacrylonitrile-N, and poly(lactic acid)-C-methyl. The smallest rotation step per monomer was associated with the smallest value of the helix coefficient (this being linearly related to rotation step per monomer). The highest helix radius was identified for poly(1-chloro-trans-1-butenylene), followed by poly(1-methyl-trans-1-butenylene) and poly(1,4,4-trifluoro-trans-1-butenylene). [ABSTRACT FROM AUTHOR]

In this paper, the tribological performances of polychlorotrifluoroethylene and polyimide compared with those of 0Cr18Ni9 steel at temperatures as low as − 120 °C were investigated, including varying speed and load. The results demonstrated that the coefficient of friction and wear rate of polychlorotrifluoroethylene were lower and more stable than those of polyimide. The excellent self-cleaning performance of polychlorotrifluoroethylene kept its interface smooth and reduced the coefficient of friction and wear rate. The study demonstrated the superior integrity and sealing performance of polychlorotrifluoroethylene in cryogenic environments, and proved its suitability as a valve component at low temperatures. • The wear rate of PI is not sensitive to decreasing temperature. • The wear rate of PCTFE decreases with decreasing temperature. • The COF of PI increases with decreasing temperature. • PCTFE self-cleaning property ensures a smooth interface and a low COF and wear rate. • PCTFE has better wear and tribological properties than PI at low temperatures. [ABSTRACT FROM AUTHOR]

Polychlorotrifluoroethylene (PCTFE) particles were co-deposited with nickel–tungsten (Ni–W) coatings through electro-deposition process. The nanocomposite coatings have been prepared in four different concentrations (0, 4, 8 and 20 g/l). Corrosion performance of the coatings was examined using potentiodynamic polarization and Electrochemical Impedance Spectroscopy (EIS). Surface morphology and composition of the composite coatings were characterized by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDAX) measurements and X-ray Diffraction (XRD) analysis. The tribological properties of a surface have been investigated in ambient condition by Atomic Force Microscopy (AFM). Results show that, there is a significant shift in corrosion potential towards the noble direction, decrease in corrosion current density, and increase in charge transfer resistance and decrease in double-layer capacitance values with the incorporation of PCTFE particles in the Ni–W matrix. Higher PCTFE contents, however, negatively affected the corrosion behavior of the coatings. Co-deposition of the PCTFE particles into the Ni–W coating changed the structure and morphology of the deposited coating and decreased the nodules and crystalline size. By increasing the PCTFE concentration of coatings, microhardness decreased and the elastic behavior of coating, increased. The coatings with 4 and 8 g l − 1 PCTFE shows the low friction force in comparison with other samples. [ABSTRACT FROM AUTHOR]

Four common types of additives for polymer membrane preparation including organic macromolecule and micromolecule additives, inorganic salts and acids, and the strong non-solvent H 2 O were used to prepare poly (vinylidene fluoride-co-chlorotrifluoroethylene) (PVDF-CTFE) hydrophobic flat-sheet membranes. Membrane properties including morphology, porosity, hydrophobicity, pore size and pore distribution were investigated, and the permeability was evaluated via direct contact membrane distillation (DCMD) of 3.5 g/L NaCl solution in a DCMD configuration. Both inorganic and organic micromolecule additives were found to slightly influence membrane hydrophobicity. Polyethylene glycol (PEG), organic acids, LiCl, MgCl 2 , and LiCl/H 2 O mixtures were proved to be effective additives to PVDF-CTFE membranes due to their pore-controlling effects and the capacity to improve the properties and performance of the resultant membranes. The occurrence of a pre-gelation process showed that when organic and inorganic micromolecules were added to PVDF-CTFE solution, the resultant membranes presented a high interconnectivity structure. The membrane prepared with dibutyl phthalate (DBP) showed a nonporous surface and symmetrical cross-section. When H 2 O and LiCl/H 2 O mixtures were also used as additives, they were beneficial for solid–liquid demixing, especially when LiCl/H 2 O mixed additives were used. The membrane prepared with 5% LiCl + 2% H 2 O achieved a flux of 24.53 kg/(m 2 ·hr) with 99.98% salt rejection. This study is expected to offer a reference not only for PVDF-CTFE membrane preparation but also for other polymer membranes. [ABSTRACT FROM AUTHOR]

To improve the practicality and safety of a novel explosive dihydroxylamm onium 5,5′-bis (tetrazole)-1,1′-diolate (TKX-50), polyvinylidene difluoride (PVDF) and polychlorotrifluoroe-thylene (PCTFE) were respectively added to the TKX-50, forming the polymer-bonded explosives (PBX). Interfacial and mechanical properties of PBX were investigated through molecular dynamics (MD) method, desensitizing mechanisms of fluorine-polymers for TKX-50 were researched by compression and bulk shear simulations. Results show that the binding energies ( E) between polymers (PVDF or PCTFE) and TKX-50 surfaces all rank in order of (011) > (100) > (010), shorter interatomic distance and the resulted higher potentials lead to higher E on TKX-50/PVDF interfaces than that on PCTFE/TKX-50 interfaces. Compared with TKX-50, the ductility of PBX is improved due to the isotropic mechanical property and flexibility of fluorine-polymers especially the PCTFE. Desensitizing effect of fluorine-polymers for TKX-50 is found under loading condition, which is attributed to the enhanced compressibility and buffer capacity against external pressure in compression, as well as the improved lubricity to reduce the sliding potentials in bulk shear process. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A series of plate impact experiments have been performed to probe the shock behavior of polychlorotrifluoroethylene (PCTFE), in terms of its optical and mechanical response. Interfacial velocity measurements using interferometric techniques have shown differences between measured and actual velocities, and been used to determine changes in refractive index due to shock-induced density increases. These have further been used to determine an optical correction factor, and allow the possibility of PCTFE being used as an optical window in future shock loading experiments. The shear strength of shock loaded PCTFE has also been shown to be near-constant behind the shock front, in common with other fluorinated polymers, although the strength variation with impact stress is greater than other similar materials. It has been suggested that the presence of a larger chlorine atom replacing a fluorine allows for a degree of tacticity between polymer chains, with local variations of charge density along the chain (due to the presence of the chlorine atom) also having an effect. [ABSTRACT FROM AUTHOR]

ABSTRACT Different thermal processing methods were used to fabricate the crystalline properties of poly(vinylidene fluoride- co-chlorotrifluoroethylene) [P(VDF- co-CTFE)] films. We observed that the crystallinity and crystal grain size of the various samples decreased with the quenching temperature. Compared to that of the annealed P(VDF- co-CTFE) sample, a higher dielectric constant of 13.9 at a frequency of 100 Hz was obtained in the film with liquid nitrogen quenching because the increasing small crystalline regions were susceptible to the excitation of external electric field. Meanwhile, the breakdown electric strength of the low-temperature-quenched film increased to 530 MV/m when the depth of shallow electronic energy level decreased, as depicted by Fröhlich collective electron approximated electric breakdown theory. Moreover, when we introduced the leakage current density curves, the effect of the space charges on the electric displacement was proven. As a result, the discharged energy density of the liquid-nitrogen-quenched P(VDF- co-CTFE) film was enhanced to 15.32 J/cm3 at an electric field of 530 MV/m; this provided an effective way in addition to chemical modification to achieve a high energy storage ability in this poly(vinylidene fluoride)-based fluoropolymer. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42794. [ABSTRACT FROM AUTHOR]

A fundamental understanding of theversatile and tunable nanostructuration effect of two phosphoniumionic liquids (ILs), denoted octadecyltriphenylphosphonium iodide(IL-C18) and tributyl(methyl)phosphonium methylsulfate (IL-108),on a semicrystalline fluorinated copolymer poly(vinylidene fluoride-co-chlorotrifluoroethylene) (P(VDF-CTFE)) was elaborated.This research suggests that the nanostructuration mechanism is verydependent on the diffusion and interacting abilities of ILs in matrix,which are determined by the chemical structures of ILs. Both ILs appearto diffuse and regularly assemble in the rigid amorphous fraction(RAF) of P(VDF-CTFE) between crystalline lamellae thanks to the “template”confinement effect of 2D structure. The assembled structure showsa gradually regular 1D to 2D geometric evolution with increasing theILs amount revealed by Porod exponents in SANS analyses. Simultaneously,these regularly assembled ILs in the RAF also act as “template”to efficiently induce a complete transition of nonpolar α-phaseto polar γ- and/or β-phase with only a tiny amount ofILs (from 2 wt %) (by XRD and FTIR). Moreover, the crystallizationdisplays a depression behavior with reduced Tc, Tm, crystallinity (by DSC),and crystallite size (by SANS) due to the existence of ILs in theRAF seen as obstacle for the regular chain-folding and the dipolarinteraction with P(VDF-CTFE). We propose that the synergistic influenceof mutual “templates” endues phosphonium ILs a versatilenanostructuration on the fluorinated matrix. Moreover, this versatilenanostructuration effect can be easily tuned by tailoring the chemicalstructures of ILs. The difference in the chemical structures of ILsendows them different diffusion rates upon crystallization from solutionfor preparing resulting blend films and strengths of dipolar interactionwith P(VDF-CTFE), consequently affecting their dispersion state inthe matrix to reside in the RAF with different extents and interactingabilities (confirmed by DEA and DMA). Thus, IL-108 with faster migrationrate and stronger dipolar interaction than IL-C18 (due to the smallersteric hindrance and extra polar groups in the cation/anion combinationof the IL structure) locates in the RAF much more to induce more trans-configuration (β-phase), more homogeneous dispersionmorphology, and higher depression of crystallization. [ABSTRACT FROM AUTHOR]

The dependence of the real ε' and imaginary ε" constituents of complex dielectric permittivity of polychlorotrifluoroethylene–carbon nanotubes (CNT) systems in the content range 0.0025-0.05 (volume fraction) before and after noncontact dispergation treatment have been investigated. It has been shown that the values ε' and ε" are 1.5 times higher in the region of ultra-high frequencies for the composites containing CNT treated by noncontact dispergation in comparison with non-treated materials whereas the percolation threshold is 3 times lower in the region of low frequencies. [ABSTRACT FROM AUTHOR]

Kel-F 81 (PCTFE/Polychlorotrifluoroethylene) polymer targets were subjected to ramp loadings generated by a ceramic flyer accelerated into the targets by a gas gun in the plate impact configuration. This approach used a ceramic graded areal density flyer in conjunction with a ceramic buffer plate to induce a ramp loading in the target. The flyer was comprised of a rapid prototyped alumina ceramic. The loading was observed with embedded electromagnetic particle velocity gauges (PV gauges) with the results compared with ANSYS Autodyn™ hydrocode simulations. Experimental results show that ramp loadings of varying duration and magnitude were induced into the target. These loadings can be described as shockless compressions leading to shocked states within the material. In addition, numerical simulations provided further insight into the loading approach – with good agreement found with experimental data, opening the potential to design more complex loading systems in future. [ABSTRACT FROM AUTHOR]

In this paper, organic electroluminescence fluoropolymer film devices, i.e., organic light-emitting diodes (OLEDs) comprising polychlorotrifluoroethylene (PCTFE) films treated by an atmospheric-pressure nonthermal plasma (NTP) graft-polymerization process, are investigated. PCTFE films can provide a long lifetime for OLEDs because of their excellent gas barrier properties; however, they are difficult to laminate, owing to low adhesiveness. The surfaces of PCTFE films are treated by an atmospheric-pressure NTP-graft-polymerization process to improve their adhesiveness, and then, indium tin oxide and a luminous layer are deposited on the treated PCTFE films. As a result, OLEDs comprising PCTFE films are successfully demonstrated. [ABSTRACT FROM AUTHOR]

In order to synthesize the polymer composite system of the PCTFE-CuS/ZnS, the nanodispersed ZnS was synthesized by hydrothermal method afterwards heterostructures of CuS/ZnS were obtained using ion-substitution mechanism. The concentration dependence of the real and the imaginary components of the complex dielectric permeability and electrical conductivity of synthesized samples were investigated. Obtained composites have high values of the dielectric permeability at high frequencies and conductivity at low frequencies. At 50 % (molar) substitution of Zn ions by Cu the percolation threshold was determined at the volumetric content of CuS about 0.06. [ABSTRACT FROM AUTHOR]

Fire events involving halogenated materials, such as plastics and electronics, produce complex mixtures that include unidentified toxic and environmentally persistent contaminants. Ultrahigh-resolution mass spectrometry and mass defect filtering can facilitate compound identification within these complex mixtures. In this study, thermal decomposition products of polychlorotrifluoroethylene (PCTFE, [-CClF-CF2-] n), a common commercial polymer, were analyzed by Fourier transform ion cyclotron resonance mass spectrometry. Using the mass defect plot as a guide, novel PCTFE thermal decomposition products were identified, including 29 perhalogenated carboxylic acid (PXCA, X = Cl,F) congener classes and 21 chlorine/fluorine substituted polycyclic aromatic hydrocarbon (X-PAH, X = Cl,F) congener classes. This study showcases the complexity of fluoropolymer thermal decomposition and the potential of mass defect filtering to characterize complex environmental samples. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Electrical properties of synthesized nanostructured materials based on nanocrystalline tin dioxide modified with copper iodide and polychlorotrifl uoroethylene were studied. It was shown that the complex dielectric permittivity in the microwave range and the low-frequency electrical conductivity of the polymeric composites depend on the copper iodide concentration on the surface of tin dioxide and reach the maximum values at a volume fraction of CuI of about 0.5. The percolation thresholds were determined for the three-component system. Their values increase from 0.04 to 0.05 vol. fraction as the content of copper iodide in the CuI/SnO system is raised from 0.04 to 0.6 vol. fraction. [ABSTRACT FROM AUTHOR]

Frequency dispersion of complex dielectric permittivity and conductivity of polychlorotrifluoroethylene-copper oxide system in the temperature range of 293-353 K have been studied. It has been found that the electrical conductivity of composites is described by ω0.8 power law in the 10-1-106 Hz frequency range that corresponds to the hopping mechanism of charge transfer. Two areas of relaxation frequencies with the activation energies of 0.39 and 0.51 eV were determined in the composites. [ABSTRACT FROM AUTHOR]

We have studied the α-decays of Po into Pb and of Po into Pb tagged by the coincidence with the preceding β-decays from Bi and Bi, respectively. The Rn, Th, and Rn sources used were sealed inside quartz vials and inserted in the Counting Test Facility at the underground Gran Sasso National Laboratory in Italy. We find that the mean lifetime of Po is (236.00 ± 0.42(stat) ± 0.15(syst)) μs and that of Po is (425.1 ± 0.9(stat) ± 1.2(syst)) ns. Our results, obtained from data with signal-to-background ratio larger than 1000, reduce the overall uncertainties and are compatible with previous measurements. [ABSTRACT FROM AUTHOR]

Hydrophobic nanosilica or nanofluoric particles were mixed with fluoropolyurethane resin to fabricate superhydrophobic coatings that have contact angles higher than 145°. These coatings were prepared from the simple mixing of nanoparticles in fluoropolymer and were cured at room temperature. Different fractions of nanosilica, nanofluoric particles, and the combination of them were used to find the best formulations of superhydrophobic coatings. Contact angle, contact angle hysteresis, sliding angle, hardness, and UV durability tests were conducted to find the effectiveness of these coatings. The results showed that only fluoropolyurethane coatings containing nanosilica or the combination of it and fluoric particles were superhydrophobic. Also, the hardness of coatings was increased by raising nanoparticle concentrations. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]