Reduction In Electrical Resistance Research Articles

Electromechanical response of smart ultra-high-performance concrete under uniaxial load: Experimental investigation and electric field analysis

This study explores the electromechanical response of smart ultra-high-performance concrete (S-UHPC) under uniaxial tension and compression using both attached and embedded electrodes with direct current. Within the linear elastic region, the response of S-UHPC was influenced by the type of electrode due to the deformation of the silver paste used in the attached electrodes. Furthermore, although the electromechanical response of S-UHPC beyond the linear elastic region showed minimal variation between different electrode types, their self-sensing capabilities were significantly affected by the choice of electrode. Under uniaxial tension, the electrical resistivity of S-UHPC decreased marginally up to the limit of proportionality and then more substantially beyond it, primarily owing to the formation of matrix cracks. This reduction in electrical resistivity associated with crack formation was corroborated through electrical field analysis performed using COMSOL MultiphysicsⓇ. A key finding was that the decrease in electrical resistivity (from 0.1788 to 0.0286 kΩ·cm, -84.0 %) in the tensile strain-hardening region could be attributed to an increase in electrical current density within steel fibers; specifically, the current density increased from 0.2417 to 0.7047 A/mm2 as the number of matrix cracks increased from zero to seven.

Electrodeposition modification of heterogeneous cation exchange membrane using expanded polystyrene waste: Enhanced electrochemical properties and electrodialytic performance

In this study, surface modification of a cation exchange membrane based on polyvinyl chloride was accomplished via electrochemical deposition of post-sulfonated waste-expanded polystyrene aiming to enhance its electrochemical properties and electrodialytic performance. The membrane was synthesized by the phase inversion method, modified with different concentrations of polyelectrolyte, characterized by FTIR and SEM analyses, and applied for electrodialytic desalination of NaCl solution. Deposition of sulfonated polystyrene with polyelectrolyte concentration of 2 g/l, current of 8 mA/cm2, and period time of 30 min caused a reduction in electrical resistance up to 52 %. Furthermore, the sodium ionic flux through electrodialytic desalination was improved by 58 % as a result of the promotion of the electrochemical properties of the membrane.

Blended Copper and Nano-Silver Screen-Printed Circuits on FTO-Coated Glass

Using a mixture of micro-copper and nano-silver in the production of screen-printed circuits has the potential to reduce material costs and cost variability. The fundamental premise of this study involved dispersing silver nanoparticles among the larger copper microparticles at selected ratios and subsequently sintering in order to establish their resultant electrical and physical performance. Commercial materials were mixed, printed, and sintered at two thermal regimes on fluorine-doped tin oxide (FTO)-coated glass substrate. The inclusion of 25% silver provided an appreciable reduction in electrical resistance from 4.21 Ω to 0.93 Ω, with further silver additions having less impact. The thermal regime used for sintering had a secondary impact on the final electrical performance. The addition of silver reduced the adhesion to the FTO substrate, with reduced film integrity. The results show that blending inks offers the advantage of enhancing material conductivity while simultaneously reducing costs, making it a compelling area for exploration and advancement in the field of electronics manufacturing.

Mechanisms of methanol detection in graphene oxide and conductive polymer active layers for gas sensing devices

The admixture of PEDOT:PSS with Graphene Oxide (GO) in precise proportions achieves a substantial reduction in electrical resistivity, thereby augmenting its suitability as an electrode in organic devices. This study explores the electrical and morphological attributes of commercial PEDOT:PSS and chemically synthesized aqueous PEDOT ink when both are combined with GO. The investigation extends to the application of these conductive inks as active layers in flexible methanol sensing devices. Notably, a resistivity minimum is observed in the case of GO:PEDOT:PSS 78%, while the highest response to methanol is attained with GO:PEDOT:PSS 68%. To establish a theoretical underpinning for these findings, and to understand the interaction between gas/vapors with nanostructured materials, a model rooted in Kirchhoff’s Circuit approach is developed, with the aim of elucidating the factors behind the resistivity minimum and response maximum at distinct specific mass ratios between PEDOT and GO. Calculating the equivalent resistivity and response of the systems, the positions of minimum and maximum points are in agreement with the experimental data. Furthermore, the influence of PSS in the samples is examined, unveiling diverse interaction mechanisms between methanol molecules and the active layer, resulting in varying signals during the exposure to alcoholic vapor. The theoretical model is subsequently applied to these systems, demonstrating qualitative and quantitative agreement with the experimental results.

Effect of Process Parameters in Additively Manufactured Sensors prepared via Material Extrusion Processes: Correlation among Electrical, Mechanical and Microstructure Properties

Fusion-based Material Extrusion (MEX) Additive Manufacturing (AM) processes have been extensively used for the fabrication of smart structures with embedded sensors, proving to have several benefits such as reduction in cost, manufacturing time, and assembly. A major issue negatively affecting 3D printed sensors is related to their poor electrical conductivity, as well as inconsistent electrical performance, which leads to electrical power losses amongst other issues. In the present paper, a set of process parameters (ironing, printing temperature, and infill overlap) has been analyzed by performing a Design of Experiment (DoE) factorial plan to minimize the electrical resistance. The best process parameters configuration involves a remarkable reduction of electrical resistance of 47.9%, as well as an improvement of mechanical properties of 31.9% (ultimate tensile strength), 25.8% (elongation at break) and 28.14% (flexural stress). The microstructure of the obtained results has also been analyzed by employing a high-resolution, X-ray Computed Tomography (X-Ray CT) system showing a reduction of intralayer voids of 19.5%. This work demonstrates a clear correlation between process parameters and the corresponding electrical properties, mechanical properties, and internal microstructure. In the present research, it has been shown that i) it is possible to significantly improve the overall 3D printed sensors performance by process parameter selection, and ii) small changes in the microstructure lead to remarkable improvements in electrical and mechanical performance.

Synthesis of nickel particles for use in nickel/silicone rubber composites for the application of electromagnetic interference shielding gaskets

The effectiveness of electromagnetic interference (EMI) shielding is valuable for construction materials and can be enhanced by the addition of nickel particles to silicone rubber. This investigation reports the chemical reduction process employed to produce nickel powders. The resulting powders were analyzed through SEM imaging and X-ray diffraction analysis, which indicated the production of crystalline, pure nickel powders with spherical morphology. Subsequently, the study delves into nickel filler content enhances the shielding effectiveness (1.2–2.6 GHz) of gaskets by increasing the absorption loss SEA, due to the increase in electrical conductivity. The experimentation was conducted using three samples, revealing that increasing the weight percentage of filler from 30 to 70 % resulted in a considerable reduction in electrical resistivity to 0.6 Ω cm. Moreover, the shielding effectiveness was observed to increased to above 55 dBm when tested across a frequency range of 1.2–2.6 GHz.

Fabrication of predesigned 3D carbon based microstructures via two-photon vat photopolymerization and susceptor-assisted microwave post-processing

This study presents a fabrication strategy for 3D carbon microstructures using via two-photon vat photopolymerization (2p-VPP) and susceptor-assisted microwave pyrolysis (SMWP). Fabricating carbon-based electrode materials with miniaturized functional structures is pivotal for developing high-performance electrochemical microdevices. However, efficiently producing these structures in the submicron regime with desired materials is still challenging. To address this, a hybrid microfabrication strategy was developed, and 3D carbon-based microstructures with submicron resolution were successfully produced. A carbon nanotube nanocomposite photoresist (SCNT-PR1) with improved dispersibility was first prepared. After a comprehensive printability assessment, 3D microstructures with a resolution of 833 ± 54 nm were produced using 2p-VPP. Through SMWP, the microstructures were transformed into pyrolytic carbon (PyC) nanocomposite microstructures with retained geometrical features. SMWP was shown to produce PyC with a less disordered carbon atomic structure, thanks to the accelerated pyrolysis reaction under MW irradiation, when compared to pyrolysis using a conventional furnace. The resistivity was reduced by over 75% from 0.69 ± 0.13 Ω cm to 0.16 ± 0.01 Ω cm, and enhanced electrochemical performance was confirmed. The fabricated PyC nanocomposite showed a further 12% reduction in electrical resistivity and a 20% lower charge transfer resistance for the redox reaction when using SCNT-PR1 as the precursor. Overall, this hybrid fabrication strategy demonstrates the advantages of producing 3D carbon microstructures with precise control over the geometric features and enhancing electrical and electrochemical properties compared to the conventional pyrolysis method. Its potential could be extended to the fabrication of miniaturized electrochemical devices, including microelectronics and point-of-care devices.

Fabrication and characterization of copper and copper alloys reinforced with graphene

The consistent rise in current density within electrical wires leads to progressively more substantial heat losses attributed to the Joule effect. Consequently, mitigating the electrical resistivity of copper wires becomes imperative. To attain this objective, the development of a composite material that incorporates a more conductive reinforcement, like graphene, holds great promise. The conception of a copper/graphene composite using a powder metallurgy-based approach is presented. An optimum graphene quantity of 0.06 vol.% was obtained by calculation in order to limit the phenomenon of overlapping layers. This synthesis technique enables the dispersion of graphene and the meticulous control of the interface through the growth of CuO(Cu) nanoparticles that are tightly bonded to the reinforcement. The increase in the hardness of the various materials with separation of the graphene sheets by ultrasonic treatment (55.3 to 67.6 HV) was obtained. It is an indicator of the correct distribution of the reinforcement. The influence on the electrical properties of dendritic copper (ρe = 2.30 µΩ.cm) remains limited, resulting in a modest reduction in electrical resistance of around 1.4%. Nevertheless, for flake copper (2.71 µΩ.cm) and brass (7.66 µΩ.cm), we achieved a more substantial reduction of 2.7% and 10%, respectively. With the improvement of graphene quality, there exists a greater potential for further enhancing the electrical properties.

Upper glycolytic components contribute differently in controlling retinal vascular endothelial cellular behavior: Implications for endothelial-related retinal diseases.

Retinal degenerative diseases such as diabetic retinopathy and diabetic macular edema are characterized by impaired retinal endothelial cells (RECs) functionality. While the role of glycolysis in glucose homeostasis is well-established, its contributions to REC barrier assembly and cell spreading remain poorly understood. This study aimed to investigate the importance of upper glycolytic components in regulating the behavior of human RECs (HRECs). Electric cell-substrate impedance sensing (ECIS) technology was employed to analyze the real-time impact of various upper glycolytic components on maintaining barrier functionality and cell spreading of HRECs by measuring cell resistance and capacitance, respectively. Specific inhibitors were used: WZB117 to inhibit Glut1/3, lonidamine to inhibit hexokinases, PFK158 to inhibit the PFKFB3-PFK axis, and TDZD-8 to inhibit aldolases. Additionally, the viability of HRECs was evaluated using the lactate dehydrogenase (LDH) cytotoxicity assay. The most significant reduction in electrical resistance and increase in capacitance of HRECs resulted from the dose-dependent inhibition of PFKFB3/PFK using PFK158, followed by aldolase inhibition using TDZD-8. LDH level analysis at 24- and 48-hours post-treatment with PFK158 (1 μM) or TDZD-8 (1 and 10 μM) showed no significant difference compared to the control, indicating that the disruption of HRECs functionality was not attributed to cell death. Conversely, inhibiting Glut1/3 with WZB117 had minimal impact on HREC behavior, except at higher concentrations (10 μM) and prolonged exposure. Lastly, inhibiting hexokinase with lonidamine did not noticeably alter HREC cell behavior. This study illustrates the unique impacts of components within upper glycolysis on HREC functionality, emphasizing the crucial role of the PFKFB3/PFK axis in regulating HREC behavior. Understanding the specific contributions of each glycolytic component in preserving normal REC functionality will facilitate the development of targeted interventions for treating endothelial cell dysfunction in retinal disorders while minimizing effects on healthy cells.

Simple Iron Halides Enable Electrochemically Mediated ATRP in Nonpolar Media.

An electrochemically controlled atom transfer radical polymerization (eATRP) was successfully carried out with a minimal amount (ppm-level) of FeBr3 catalyst in a nonpolar solvent, specifically anisole. Traditionally, nonpolar media have been advantageous for Fe-based ATRP, but their low conductivity has hindered any electrochemical application. This study introduces the application of electrocatalytic methods in a highly nonpolar polymerization medium. Precise control over the polymerization was obtained by employing anhydrous anisole with only 400 ppm of FeBr3 and applying a negative overpotential of 0.3 V. Additionally, employing an undivided cell setup with two simple iron wire electrodes resulted in a significant 15-fold reduction in electrical resistance compared to traditional divided cell setups. This enabled the production of polymers with a dispersity of ≤1.2. Lastly, an examination of kinetic and thermodynamic aspects indicated that the ppm-level catalysis was facilitated by the high ATRP equilibrium constant of Fe catalysts in nonpolar environments.

Studying the Effects of Annealing and Surface Roughness on Both the Magnetic Property and Surface Energy of Co60Fe20Sm20 Thin Films on Si(100) Substrate

In this study, Co60Fe20Sm20 alloy was employed for sputter deposition onto Si(100) substrate within a high vacuum environment, and subsequent thermal treatment was conducted using a vacuum annealing furnace. Thorough measurements and analyses were carried out to evaluate how various film thicknesses and annealing temperatures affect the material. The investigations encompassed observations of structural and physical properties, magnetic traits, mechanical behavior, and material adhesion. The results from the four-point probe measurements clearly demonstrate a trend of decreasing resistivity and sheet resistance with increasing film thickness and higher annealing temperature. Analysis through atomic force microscopy (AFM) shows that heightened annealing temperature corresponds to decreased surface roughness. Furthermore, when analyzing low-frequency alternating current magnetic susceptibility (χac), it became evident that the maximum magnetic susceptibility value consistently rises with increased film thickness, regardless of the annealing temperature. Through magnetic force microscopy (MFM) observations of magnetic domain images in the films, it became apparent that there was a noticeable reduction in the brightness contrast of the magnetic domains. Furthermore, nanoindentation analysis reveals a clear trend. Elevating the film thickness leads to a reduction in both hardness and Young’s modulus. Contact angles range between 67.7° and 83.3°, consistently under 90°, highlighting the hydrophilic aspect. Analysis of surface energy demonstrates an escalation with increasing film thickness, and notably, annealed films exhibit a substantial surge in surface energy. This signifies a connection between the reduction in contact angle and the observed elevation in surface energy. Raising the annealing temperature causes a decline in surface roughness. To summarize, the surface roughness of CoFeSm films at different annealing temperatures significantly impacts their magnetic, electrical, and adhesive properties. A smoother surface reduces the pinning effect on domain walls, thus enhancing the χac value. Furthermore, diminished surface roughness leads to a decline in the contact angle and a rise in surface energy. Conversely, rougher surfaces exhibit higher carrier conductivity, contributing to a reduction in electrical resistance.

Utilizing cluster percolation theory to analyze electrical resistivity jumps in high-entropy alloy thin films containing small atoms

The high-entropy alloy thin films (HEATFs) with non-metal small atoms have obvious characteristics of adjustable properties. However, the mismatch phenomenon of phase-transition and electrical resistivity jump usually occur during the interstitial-filling. To explain this phenomenon, a new method is proposed that transforms the multi-color percolation of HEATFs to two-color percolation. The [N/O-M6] clusters with high electrical resistivity and [▫-M6] clusters with low electrical resistivity in (NbMoTaW)100-xNx and (NbMoTaWV)100-xOx films are equivalent to black and white spheres, respectively (M and ▫ ▫-M6]) reaches the face-centered-cubic and amorphous percolation thresholds of 0.198 and 0.27, respectively, a conductive percolation path is formed, contributing to a significant reduction in electrical resistivity. This work enables it possible to predict the composition at sudden change in electrical resistivity of HEATFs with non-metallic small atoms, which has great significance for the functional composition design.

Short-range order in amorphous oxygen-deficient TaOx thin films and its relation to electrical conductivity

Thin films of tantalum oxide hold promising functional properties for electronic applications such as resistive random-access memory. For this aim, correlating the structure and charge transport properties of oxygen-deficient derivatives is crucial. Here, using electron scattering measurements from nanoscale volumes in a transmission electron microscope (TEM), we report how oxygen content affects short-range order in amorphous TaOx thin films, where 1.34 ≤ x ≤ 2.50. By extracting the bond lengths, we observe that the dominant type of Ta–Ta distances change with decreasing oxygen content from next-nearest-neighbor, ∼3.8 Å, to nearest-neighbor, ∼3 Å. We relate this decrease to the Ta–O polyhedral network within the film, namely decreasing oxygen content increases the presence of TaO5 at the expense of TaO6 polyhedra. The reduction in oxygen content is accompanied by a significant reduction of electrical resistivity of the films from over 4.3 × 103 to (4 ± 0.05)×10−3 Ω × cm. In particular, we observe a sharp percolative decrease in resistivity of three orders of magnitude, at x ∼ 1.9. Ta oxidation states, measured by x-ray photoelectron spectroscopy, suggest that the main polyhedral building block within the TaO2.5 film is TaO6, while in oxygen-deficient films, the relative fractions of TaO5 polyhedra and metallic Ta increase. At even lower oxygen content, x ∼ 1.34, TEM and x-ray diffraction detect crystallites of Ta with cubic and metastable tetragonal structures. We propose that TaO5 polyhedra and Ta crystallites increase conductivity due to direct bonding of Ta atoms, as manifested by nearest-neighbor Ta–Ta bond length, thus enabling conductive paths for charge transport.

Improvement of Ball Mill Performance in Recycled Ultrafine Graphite Waste Production for Carbon Block Applications.

A carbon block is a carbonaceous material used in various applications such as bearings, mechanical seals, and electrical brushes. This work aims to fabricate carbon blocks from industrial graphite waste, a residue from the cutting and tooling process of graphite block production. The ball milling process was used to fabricate ultrafine graphite waste to enhance the packing of carbon blocks. The milling performance was profoundly affected by dispersing agents in which sodium dodecyl sulfate (SDS), lignosulfonate (LS), and mixed dispersant (LS-SDS) were applied. The results showed that LS-SDS had the best milling performance, the greatest grinding index, and a flowable slurry, indicating the potentiality of this formulation for the environmentally friendly manufacture of ultrafine graphite waste. Carbon blocks were prepared from oven-dried ultrafine graphite waste, which was mixed with amorphous carbon and pitch. This carbon mixture was formed a block by compaction before carbonization and impregnation. The density of the fabricated carbon blocks increased from 1.76 to 1.83 g/cm3 after impregnation along with the increase in hardness, flexural strength, and reduction in electrical resistivity from 83, 62 MPa, and 40 μΩ m to 88, 81 MPa, and 39 μΩ m, respectively. The physical properties of carbon blocks prepared from ultrafine graphite waste were comparable to the properties of typical pristine carbon products.

Rational strategy for construction of multifunctional coatings for achieving high fire safety, antibacterial, UV protection and electrical conductivity functions of textile fabrics

Sustainable and innovative multifunctional organic coatings were designed and developed for integrating effective flame retardancy, ultraviolet (UV) radiation protection, electrical conductivity and antibacterial functions to viscose textiles. The coatings-based nanocomposites were prepared from cellulose nanocrystal phosphate derived from waste cotton clothes, graphene sheets derived from mandarin shell, polyaniline nanofibers and polypyrrole (PPy) and elucidated using microscopic and spectroscopic tools. The nanomaterials-based coatings were first synthesized individually from their sustainable precursors and then utilized in nanocoatings fabrication. Variety of nanocoatings were developed from different combinations of nanofillers and mass ratios and then coated on viscose textile fabrics. The flammability, thermal stability, UV protection, electrical conductivity and antibacterial properties of the treated textile fabrics were studied and optimized. The flame retardancy properties of the developed textile fabrics were significantly improved achieving zero rate of burning compared to 193 mm/min for uncoated fabrics. This outstanding fire safety was ascribed to synergistic flame retardancy effect of coating layer based phosphorylated cellulose nanocrystals, graphene sheets and polyaniline nanofibers affording protective char barrier. The flame retardancy action was further elucidated using scanning electron microscopy (SEM) and Raman spectroscopy of protective char layer developed. Moreover, the coated fabrics affords excellent UV protection properties achieving ultraviolet protection factor (UPF) value of 90 compared to 2.7 for uncoated one. Additionally, new electrical conductivity feature was incorporated to the developed fabrics achieving reduction in electrical resistivity by 10,000 time affording conductive fabrics with convenient dissipation factor. Interestingly, the fabricated nanocoating integrates superior antibacterial properties against different bacteria strains Staphylococcus aureus (Gram-positive) and E-coli (Gram-negative) achieving clear antibacterial inhibition zone of 14.5 and 18.4 mm compared to zero mm inhibition for untreated one respectively. Furthermore, the influence of different nanocoatings on tensile strength properties of coated fabrics was studied and optimized.

Al, Mg Co-doped ZnO thin films: Effect of the annealing temperature on the resistivity and ultraviolet photoconductivity

Interesting electrical and optical properties can be obtained from sol-gel doped Zinc Oxide (ZnO) materials by controlled introduction of dopants in the precursor solution. In this work we investigate the effects of annealing temperature on Al and Mg co-doped ZnO thin films. All samples were dip coated from the same solution, using identical techniques and pre-heating temperature, but were annealed in air at various temperatures ranging from 500°C to 650°C. A three-order magnitude reduction in electrical resistivity was achieved for an increase of 100°C annealing temperature. The structural properties and the energy band-gap remained relatively unchanged during this process. Photocurrent measurements carried out using an ultraviolet excitation source indicate a 5x increase in magnitude, along with increase in persistence behavior. The mechanism behind these effects has been linked to temperature-induced variation in Mg to Al ratio in the films, measured using energy dispersive spectroscopy. Our results indicate that strong in-plane variation of resistivity in ZnO thin films can be carried out using localized heating, opening the way to simpler fabrication processes.

Monitoring and characterization of water infiltration in soil unsaturated zone through an integrated geophysical approach

This paper presents an integrated geophysical method to characterize the vadose zone by conducting lab-scale infiltration experiments, during which time-lapse electrical resistivity tomography (ERT) sections and ground penetrating radar (GPR) profiles were simultaneously and continuously captured together with soil moisture and temperature probing devices installed at various depths. Time series water content data obtained from the moisture sensors, coupled with discreetly calibrated petrophysical relationships and time-lapse datasets from ERT and GPR, were combined to monitor the spatial–temporal evolution of soil water content during wetting and drying and to track the downward progression of wetting front. Reduction in electrical resistivity as well as increment in dielectric constant were converted to rising soil moisture, and then further scaled into cumulative infiltration through integration with corresponding wetting depth as observed through the experiment. Robust estimates regarding controlling vadose zone parameters such as infiltration rate and hydraulic conductivity were subsequently achieved by fitting the results from complementary investigations with an unsaturated infiltration model. With calibrated saturated hydraulic conductivity fitted well with reported and experimentally derived ranges, it’s suggested that the model is capable of reflecting average changes in infiltration rate at the lab scale. However, the model intrinsically lacks the ability to provide spatial variations of hydraulic parameters, thereby further investigation is essential to establish a suitable model for characterizing the more complex vadose zone at field scale.

Multifunctional cellulose-based aerogel for intelligent fire fighting

Multifunctional biomass-based aerogels with mechanically robust and high fire safety are urgently needed for the development of environmentally-friendly intelligent fire fighting but challenging. Herein, a novel polymethylsilsesquioxane (PMSQ)/cellulose/MXene composite aerogel (PCM) with superior comprehensive performance was fabricated by ice-induced assembly and in-situ mineralization. It exhibited light weight (16.2 mg·cm−3), excellent mechanical resilience, and rapidly recovered after being subjected to the pressure of 9000 times of its own weight. Moreover, PCM demonstrated outstanding thermal insulation, hydrophobicity and sensitive piezoresistive sensing. In addition, benefiting from the synergism of PMSQ and MXene, PCM displayed good flame retardancy and improved thermostability. The limiting oxygen index of PCM was higher than 45.0 %, and it quickly self-extinguished after being removed away from fire. More importantly, the rapid electrical resistance reduction of MXene at high temperature endowed PCM with sensitive fire-warning capability (trigger time was less than 1.8 s), which provided valuable time for people to evacuate and relief. This work provides new insights for the preparation and application of the next-generation high performance biomass-based aerogels.

Time-resolved monitoring of electroless copper deposition on woven cellulose fabrics

This study investigates the performance of electroless copper deposition on woven cellulose fabrics. Silver seeds were printed in a straight line of defined dimensions on the fabrics, which were then subjected to electroless copper deposition. Varying the deposition time allowed to study the evolution of the layer formation on the coated fabrics and their conductivity. With increasing deposition time, an initial rapid reduction of electrical resistance could be observed, which was followed by a plateau after 120 min. The initially high strain sensitivity of 105 found after 30 min deposition decreased significantly as the deposition time increased. Percolation efficiencies were calculated from empirically measured and theoretically calculated resistance values. Microscopic imaging showed that feature of the substrate construction, e.g. yarn crossings, exert a strong influence on overall conductive performance and percolation efficiency of the coated fabrics.

Fabrication of layer-by-layer ion exchange membrane by applying PDA-POSS nanocomposite onto heterogeneous cationic substrate for water treatment

Double layer Cation Exchange Membranes (DLCEMs) have been prepared by surface polymerization of dopamine-co-POSS nanoparticles on a PVC based heterogeneous cation exchange membrane. FTIR and FESEM images proved relatively uniform forming of intended DLCEMs. The FESEM images illustrated almost integrity dispensation of nanoparticles through the surface layer. Results represented that developing nanocomposite layer resulted in surface hydrophilicity enhancement. The obtained data for Cu2+ and Cr2+ removal percentage for the prepared membranes represents higher capacity for DLCEMs to remove heavy metals compared to pristine cationic membrane. Also membranes showed higher Cr2+ removal capacity rather than Cu2+. The membrane surface modification by introducing PDA nanocomposite also caused to improving sodium permeability and flux. Furthermore, transport number and permselectivity of the prepared CEMs generally follow an increasing procedure nearly. It should be noticed that incorporation of POSS nanoparticles into the surface layer resulted in electrical resistance reduction obviously.