Coated Polyethylene Terephthalate Research Articles

Controlling ZIF-67 film properties in water-based cathodic electrochemical deposition

One of the main approaches to increase the surface area of a substrate is through depositing a film of a porous materials such as Zeolite imidazole framework (ZIF). ZIF films have shown surpassing capabilities because of their zeolite-like features, including porosity, homogeneous pore size, structural tunability and remarkable thermal and chemical stability. Many methods have been proposed and tested to form such films. One of the techniques that have been documented is electrosynthesis which is considered to be the most practical, quick, and mildly conditioned.In this study, ZIF-67 films were cathodically electrodeposited on an electrically conductive Indium Tin Oxide (ITO) coated Polyethylene Terephthalate (PET) substrates. Unlike previous reports, in this study, water was used as a solvent. In addition to this, effect of crucial operating parameters such as applied potential, molar ratio of reactants and solution pH, on the formation of ZIF-67, was investigated for the first time. It was found that increasing the applied potential, increased the surface coverage and decreased the formed ZIF-67 crystal size. Changing the molar ratio between the organic ligand and the metal salt had a profound influence on the formed phase and crystal shape. It was also found that at neutral and mildly basic solution pH, ZIF-67 could not be formed. Also, statistical analyses were carried out showing low p-values (≪0.05), expressing strong relation between variables and robustness and reliability of the data collected in this study. Finally, mathematical expressions were fitted to experimental data to reveal the relation between applied potential, molar ratios of reactants, pH and conductivity of solutions, surface coverage and crystal size.This study revealed that surface coverage, crystal shape and size can be controlled by manipulating operating conditions.

Controlled silver electrodeposition on gold nanoparticle antibody tags for ultrasensitive prostate specific antigen sensing using electrochemical and optical smartphone detection

One of the current challenges in medicine is to achieve a rapid and unequivocal detection and quantification of extremely low levels of disease biomarkers in complex biological samples. Here, we present the development and analytical evaluation of a low-cost smartphone-based system designed for ultrasensitive detection of the prostate-specific antigen (PSA) using two detection alternatives: electrochemical or optical, by coupling the smartphone with a portable potentiostat or magnifying lenses. An antibody tagged with gold nanoparticles (AuNPs), and indium tin oxide coated polyethylene terephthalate platform (ITO-PET) have been used to develop a sandwich-type immunoassay. Then, a controlled silver electrodeposition on the AuNPs surface is carried out, enhancing their size greatly. Due to such strong nanoparticle-size amplification (from nm to μm), the final detection can be dual, by measuring current intensity or the number of silver-enlarged microstructures generated. The proposed strategies exhibited limit detections (LOD) of 102 and 37 fg/mL for electrochemical and optical detection respectively. The developed immunosensor reaches excellent selectivity and performance characteristics to quantify biomarkers at clinically relevant values without any pretreatment. These proposed procedures could be useful to check and verify possible recurrence after clinical treatment of tumors or even report levels of disease serum biomarkers in early stages.

Electrospun vanadium oxide hollow nanofibers based supercapacitor inspired triboelectric nanogenerator as self-powered visible-blind ultraviolet photodetector

Self-powered visible-blind ultraviolet (UV) photodetectors have emerged as sustainable alternatives in various sectors, including security, surveillance, and environmental monitoring. So, we report a vanadium oxide (V2O5) hollow nanofibers-based supercapacitor-inspired triboelectric nanogenerator (STENG) as a self-powered visible-blind UV photodetector. A novel designed STENG is fabricated using electrospun V2O5 hollow nanofibers-based coated on indium tin oxide coated polyethylene terephthalate sheet (ITO/PET) on top side and a layer of polyvinyl alcohol (PVA) & sulphuric acid over multi-walled carbon nanotubes (MWCNT) coated graphite sheet on bottom side. The optimized STENG demonstrates 34 V peak-to-peak open circuit voltage (Voc) and 2 μA of peak-to-peak short circuit current (Isc) by applying force via finger tapping. However, STENG's performance improves significantly to deliver 280 V Voc (peak-to-peak), and 6 μA Isc (peak-to-peak) with 0.49 W/m2 power density at 100 MΩ load resistance due to electrochemical charging. The output voltage of the STENG increases by 400 % under UV light, which refers to the excellent performance of STENG as a self-powered visible-blind UV photodetector with 266 V/W responsivity at 2.5 mW/cm2 intensity. Hence, the as-fabricated V2O5 hollow nanofibers-based STENG not only paves the way to fabricate a high-performance energy harvester, but can also be used as a self-powered UV-photodetector.

Nanostructured TiO2 thin films sputtered at room temperature as electron transport layer for flexible perovskite solar cell applications: Impact of varying RF power

This work examines the adoption of radio frequency (RF) sputtering at power ranging from 100 to 300 W to deposit nanostructured titanium dioxide (TiO2) thin films on indium tin oxide (ITO)-coated polyethylene terephthalate (PET) flexible substrate (ITO/PET) at room temperature. At higher RF power, X-ray diffraction (XRD) results exhibited evolution from amorphous into crystalline anatase with preferred (101) orientation and the films revealed spherical-like nanostructures with increasing grain size from 15.71 to 21.57 nm. Films transparency decreased from 79% to 70%. Estimated energy gap decreased from 3.57 to 3.36 eV, while refractive index increased from 2.19 to 2.25, denoting a red shift in the films. The thin film deposited at 300 W exhibited high conductivity and mobility of 19.65 × 10−5 Ω−1 cm−1 and 0.30 cm2/Vs, respectively. The film demonstrated its capability as an electron transport layer for flexible perovskite solar cells.

Ag seed layer effects on SnO2 thin films for triboelectric devices

Materials with triboelectric properties are critical to boosting the efficiency of triboelectric nanogenerators (TENG) by gathering power from waste force and mechanical movement. In this study, we explored tin-oxide (SnO2) thin films with silver (Ag) seed layer properties for friction surfaces at TENGs. Investigation of the triboelectric behavior of semi-conductor/polymer coupling structured TENGs formed by thin films with and without Ag seed layer after heat treatment was explored by X-ray diffraction (XRD), electron microscopy (SEM), atomic force microscopy (AFM), and semi-logarithmic current-voltage measurements. Similar structural characterization studies were carried out in indium tin oxide coated polyethylene terephthalate film (PET/ITO) for the polymer friction layer. Semiconductor/polymer coupling structured TENG efficiency was evaluated in contact-separation mode and the output voltage-current was enhanced to 80 V, 4 μA, and 210 μW of output power calculated by depositing a SnO2 thin film on an Ag seed layer, respectively. Our findings offer a different perspective for synthesizing the semi-conductor/polymer coupling structured TENGs for promising applications in a range of application technologies.

Flexible and durable conductive nickel/graphene‐coated polyethylene terephthalate fabric for highly efficient electromagnetic shielding

AbstractThis research describes a facile method to prepare durable and highly conductive polyethylene terephthalate (PET) fabrics for electromagnetic interference (EMI) shielding applications. The PET fabric surface was first coated with graphene (Gr), which converted PET to conductive Gr‐PET fabric. In addition, magnetic nickel (Ni) nanoparticles were deposited on the Gr‐PET substrate by an electroplating approach with different deposition time intervals (5–20 min). The surface morphology, microstructure, magnetic properties, electric conductivity, and EMIs shielding properties of the Ni/Gr‐PET fabrics were ascribed as a function of the deposition times. The Ni/Gr‐PET fabrics with different nickel nanoparticle morphologies display different microstructures. The manufactured Ni/Gr‐PET fabrics exhibited excellent electrical conductivity and saturation magnetization of 100–134 S/cm and 14–30 emu/g, respectively. The EMI shielding efficiency of the manufactured Ni/Gr‐PET fabrics with 15 min of deposition time reached −70.0 dB with a thickness of 0.33 ± 0.03 mm over the 8–12 GHz frequencies. The Ni/Gr‐PET fabrics maintained relatively durable electrical properties even after cyclic bending, ultra‐sonication, and treatment with organic solvents. It has been demonstrated that the properties of Ni/Gr‐PET fabrics can be controlled by changing the surface morphology and microstructure of the nickel nanoparticles, which provides a novel protocol to manufacture PET fabrics with highly efficient EMI shielding properties.

Influence of buffer layer on copper doped tin sulfide solar cell: A Numerical approach

The proposed paper has examined the copper tin sulfide (CTS) semiconductor which is a ternary compound with extremely high absorption coefficient (105 cm−1) and ideal bandgap ranging from 0.9 to 1.6 eV. Non-toxic and widely available elements present on the earth constitute the elements of CTS. In this work, we have numerically simulated the structure: ITO coated polyethylene terephthalate (PET)/ZnO/(CdS, ZnS, CdZnS, TiO2)/CTS/Al using wx-AMPS software.In the structure different layers are: ITO coated PET which is a flexible substrate and acting as a front layer. It has been optimized by optimizing its layer thickness as 140 nm; ZnO as intrinsic layer; CdS/ZnS/CdZnS/TiO2 as buffer layers; CTS as absorber layer and Al as back contact. Different buffer layer variation was studied by varying its thickness and donor concentration. The QE curve shown in the result shows that at lower wavelength also, the QE value for CdZnS and TiO2 is high. Therefore, for furthermore investigation, these two buffer layers were considered. After optimizing the buffer layer, absorber layer optimization was carried out by varying its thickness, acceptor concentration and defect density values. By considering CdZnS as buffer layer, the optimized result which we got as, VOC = 0.819 V, JSC = 25.77 mA/cm2, FF = 85.59 %, η = 18.08 % and by considering TiO2 as buffer layer, the optimized result which we got as, VOC = 0.818 V, JSC = 25.55 mA/cm2, FF = 84.41 %, η = 17.66 %.

A high performance lead-free flexible piezoelectric nanogenerator based on AlFeO3 nanorods interspersed in PDMS matrix for biomechanical energy scavenging to sustainably power electronics

Since lead-based piezoelectric nanogenerators (PENGs) possess serious health risks, environmental problems, proper disposal issues, and biocompatibility concerns, this work presents the fabrication of a flexible piezoelectric nanogenerator utilizing lead-free orthorhombic AlFeO3 nanorods for biomechanical energy scavenging to sustainably power electronics. Hydrothermal technique is used to synthesize the AlFeO3 nanorods and the PENG was fabricated on Indium tin oxide (ITO) coated Polyethylene terephthalate (PET) flexible film with AlFeO3 nanorods interspersed in polydimethylsiloxane (PDMS). transmission electron microscopy proved that the AlFeO3 nanoparticles are of nanorods shape. Through x-ray Diffraction, it is validated that AlFeO3 nanorods have orthorhombic phase and crystalline structure. A high piezoelectric charge coefficient (d 33 ) of 400 pm V−1 is obtained from the piezoelectric force microscopy of AlFeO3 nanorods. With optimized concentration of AlFeO3 in the polymer matrix, an open circuit voltage (V OC) of 30.5 V, current density (J C) of 0.7888 μA cm−2 and an instantaneous power density of 240.6 mW m−2 are obtained under the application of a force of 1.25 kgf. To investigate the nanogenerator’s practical utility, the PENG is used for lighting multiple LEDs, charging of a capacitor and as a pedometer via biomechanical energy harvesting. Hence, it can be employed for developing various self-powered wearable electronics such as flexible skin, artificial cutaneous sensors, etc.

Composite design of two-dimensional inorganic nanosheets for flexible energy storage capacitors

We present a new approach for designing flexible energy storage capacitors using two-dimensional (2D) inorganic nanosheets. 2D dielectric Ca2Nb3O10 nanosheet and ferroelectric poly(vinylidene fluoride) (PVDF) were selected as model material systems. Langmuir–Blodgett deposition was utilized for layer-by-layer engineering of (Ca2Nb3O10/PVDF) nanocomposite films on an indium tin oxide (ITO)-coated polyethylene terephthalate (PET) substrate. Such a new composite design realized the simultaneous improvement of energy density (∼7 J cm−3) and efficiency (∼78 %) even in the ultrathin form (∼20 nm) on the ITO-coated PET substrate. Nanosheet-based flexible capacitors also maintained a stable performance even after 104 times bending cycles. These results indicate that our nanosheet approach is of technological importance for exploring new flexible dielectric capacitors.

Low fouling aptasensing of rivaroxaban in real samples using poly (toluidine blue) decorated by silver nanoparticle: A new platform for the cardiovascular disease analysis

A novel ultrasensitive electrochemical aptasensor was developed for the detection of rivaroxaban (RIV). For this purpose, poly toluidine blue (P(TB)), silver nanoparticles (AgNPs), aptamer conjugated with polyethylene glycol (PEG), and ITO-PET (indium tin oxide coated polyethylene terephthalate film) electrode was utilized. In order to fabrication of the low fouling aptasensor, the surface of ITO-PET was efficiently modified by P(TB-AgNPs) to provide a suitable substrate for the stable immobilization of aptamer sequence, 5′ SH-TAG GGA AGA GAA GGA CAT ATG ATG ACT CAC AAC TGG ACG AAC GTA CTT ATC CCC CCC AAT CAC TAG TGA ATT-3′). Using ITO PET-OH-P (TB-Ag)-PEG as substrate and aptamer as bioreceptor, RIV were measured in human plasma and exhaled breath condensate samples by chronoamperometry technique with limit of detections of 6.65 and 4.13 nM, respectively. Importantly, using PEG conjugated aptamer, a low fouling aptasensor was developed for the sensitive and selective determination of RIV in spiked samples. For the first time, a novel aptasensor for determination of RIV in human plasma and exhaled breath condensate (EBC) samples was developed which is able to use for therapeutic drug monitoring (TDM) studies.

Sequential intervention of anti-inflammatory and osteogenesis with silk fibroin coated polyethylene terephthalate artificial ligaments for anterior cruciate ligament reconstruction.

Graft-host integration after the anterior cruciate ligament (ACL) reconstruction sequentially follows the prognosis from the inflammation period to the regeneration period. However, due to insufficient bioactivity, polyethylene terephthalate (PET) artificial ligaments often require a long period for graft-host integration. To improve graft-host integration, sequential therapy targeting multifactor is widely advocated. In this study, a multilayer regenerated silk fibroin (RSF) coating loaded with heparin and bone morphogenetic protein binding peptide (BBP) for differentiated release was introduced on the surface of the PET artificial ligament by a stepwise deposition method. The drug release profiles of heparin and BBP on the coated PET artificial ligament indicated the features of differential drug release, i.e., with heparin in the outermost layer releasing a significant amount (more than 60%) during the first 5 days while BBP in the inner layer only releasing a small amount (ca. 30%) within 1 week without burst release. Based on the isometric ACL reconstruction model of rabbits, such drug-loaded RSF coating was verified to be able to modulate the early inflammatory response and promote the maturation of the graft in the articular cavity, meanwhile, it provided a continuous and stable signal of osteogenic induction to improve graft-bone integration. Thus, sequential intervention with heparin and BBP proved to be a reliable combination, and multifunctional RSF-coated PET artificial ligaments hold great potential for improving the clinical efficacy of ACL reconstruction.

Low-Cost Silicon Phthalocyanine as a Non-Fullerene Acceptor for Flexible Large Area Organic Photovoltaics.

We demonstrate large-area (1 cm2) organic photovoltaic (OPVs) devices based on bis(tri-n-butylsilyl oxide) silicon phthalocyanine (3BS)2-SiPc as a non-fullerene acceptor (NFA) with low synthetic complexity paired with poly(3-hexylthiophene) (P3HT) as a donor polymer. Environment-friendly nonhalogenated solvents were used to process large area OPVs on flexible indium tin oxide (ITO)-coated polyethylene terephthalate (PET) substrates. An alternate sequentially (Alt-Sq) blade-coated active layer with bulk heterojunction-like morphology is obtained when using (3BS)2-SiPc processing with o-xylene/1,3,5-trimethylbenzene solvents. The sequential (Sq) active layer is prepared by first blade-coating (3BS)2-SiPc solution followed by P3HT coated on the top without any post-treatment. The conventional sequentially (Sq) blade-coated active layer presents very low performance due to the (3BS)2-SiPc bottom layer being partially washed off by processing the top layer of P3HT. In contrast, alternate sequentially (Alt-Sq) blade-coated layer-by-layer film shows even better device performance compared to the bulk heterojunction (BHJ) active layer. Time-of-flight secondary ion mass spectroscopy (TOF-SIMS) and atomic force microscopy (AFM) reveal that the Alt-Sq processing of the active layer leads to a BHJ-like morphology with a well-intermixed donor-acceptor component in the active layer while providing a simpler processing approach to low-cost and large-scale OPV production.

Spectroscopic Ellipsometry Studies on Solution-Processed OLED Devices: Optical Properties and Interfacial Layers.

Τhe fabrication of organic light-emitting diodes (OLEDs) from solution involves the major problem of stack integrity, setting the determination of the composition and the characteristics of the resulting interfaces prerequisite for the optimization of the growth processes and the achievement of high devices' performance. In this work, a poly(9,9-dioctylfluorene) (F8) and poly(9,9-dioctylfluorene-alt-benzothiadiazole) (F8BT) blend is used for the emissive layer (EML), poly-3,4-ethylene dioxythiophene; poly-styrene sulfonate (PEDOT:PSS) is used for a hole transport layer (HTL), and Poly(9,9-bis(3'-(N,N-dimethyl)-N-ethylammoinium-propyl-2,7-fluorene)-alt-2,7-(9,9-dioctylfluore-ne))dibromide (PFN-Br) for an electron transport layer (ETL) to produce the OLED device. All the layers are developed using the slot-die process, onto indium tin oxide (ITO)-coated polyethylene terephthalate (PET) flexible substrates, whereas Ag cathode was formed by ink-jet printing under ambient conditions. Spectroscopic ellipsometry measurements were performed upon completion of the successive films' growth, in sequential steps, for the multilayer OLED development. Ellipsometry analysis using different models demonstrate the degree of intermixing within the layers and provide information about the interfaces. These interfacial properties are correlated with the emission characteristics as well as the final performance of the OLED devices.

Adsorption Capacity of Plastic Foils Suitable for Barrier Resuscitation

Chest compressions and ventilation attempts can generate aerosols during resuscitation. It is important to determine whether different materials suitable for the blanketing of cardiac arrest patients can diminish exposure to aerosols. In this study, three volatile organic compounds, ethanol, acetone, and isoprene, commonly found in human breath in moistened air, acted as substitutes for aerosols. Here, we present information on the adsorption of these volatiles to three blanketing materials: polyvinyl chloride, polyethylene, and aluminum coated polyethylene terephthalate. After exposure to the surfaces of these materials the test volatiles were quantified by the proton transfer reaction-time of flight-mass spectrometry. There was a trend towards a potentially higher reduction for acetone (p = 0.071) and isoprene (p = 0.050) on polyethylene, compared to polyvinyl chloride and aluminum coated polyethylene terephthalate during the rise interval. Adsorption capacity did not differ between the foils and was between 67% and 70%. From our studies, we propose that the aluminum-coated polyethylene terephthalate surface of space blankets prove adequate to diminish exposure to volatiles in moistened air, and hence to aerosols.

Bovine Serum Albumin-Based Thin-Film Capacitors for Flexible Electronic Applications

Metal–insulator–metal (MIM) thin-film capacitors having different dielectric layer thicknesses have been fabricated by forming bovine serum albumin (BSA) layers on electrically conductive and optically transparent indium tin oxide (ITO) coated polyethylene terephthalate (PET) substrates by using spin coating technique; the metal contacts at the top surface of BSA films have been deposited via thermal evaporation of gaseous phase aluminum. The capacitance-voltage (CV) measurements reveal the fact that the CV-characteristics of the BSA-based MIM capacitors show variable non-linearity with the change in the thickness of the insulating layer (BSA-layer). The experimentally measured CV-data are fitted with 2nd degree polynomial equations and it has been found that the quadratic voltage coefficient of capacitance (VCC) changes its sign from negative to positive as the thickness of the BSA-layer reduced below 2.0 µm. Finally, successful mechanical flexibility tests, as well as curvature tests have been carried out in order to confirm the possibility of using BSA-based MIM thin-film capacitors in flexible electronic applications in near future.

Color combination of polythiophene films doped with three dye molecules for electrochromism

The electrochromic polythiophene/dopants (PTh/dopants) films were synthesized by the electrochemical polymerization on fluorinated tin dioxide (FTO) coated polyethylene terephthalate (PET) electrode. The dopants include Ponceau 4R (P4R), Naphthol red G (NrG), Acidblue 74 (A74) and sodium dodecyl sulfate (SDS). The morphologies, electrochemical, optical and spectroelectrochemical performance of the films were studied. The morphological analysis of the PTh/dopants films indicated that the surface roughness (SR): SRPTh/A74-SDS < SRPTh/NrG-SDS < SRPTh/P4R-SDS. The result of the electrochemical analysis indicated that the existence of each P4R, NrG, or A74 with SDS, had an outstanding synergy effect on the electrochemical stability of films. The study of optical analysis indicated that the polaron and bipolaron were formed in PTh chains. In addition, in all PTh/dopants films, the fully doped states were observed and the energy bandgaps were reduced. The result of spectroelectrochemical analysis indicated that the PTh films with the dopant (simultaneous use of the surfactant and each dye molecule) showed excellent electrochromic characteristics, optical properties and electrochemical stability. For example, the color contrast of PTh/P4R-SDS at oxidized λmax was 52%, while this data in control sample (PTh/ClO4−) was 22%. Furthermore, the anodic and cathodic coloration efficiency of PTh/dye-SDS is 5–6 times higher than that of PTh/ClO4−. Therefore, these results confirmed that decreasing the dimension of dye molecule and increasing its number of anions as dopant played an important role in improving the electrochemical and electrochromic performance of the films.

Numerical modelling and simulation of heat sink assisted thermal sintering of titania film on polymer substrates for the fabrication of high-performance flexible dye sensitized solar cells

In this paper, we report a mathematical model developed to study thermal characteristics of heat sink assisted elevated temperature sintering of TiO2 coated polymer photoelectrode used for the fabrication of high-performance flexible dye sensitized solar cells (FDSSCs). Thermal sintering of TiO2 film deposited indium tin oxide coated polyethylene terephthalate (ITO PET) is usually restricted by the polymer serviceability temperature limit (~ 150 °C), but the heat sink assisted sintering process increases sintering temperature without affecting the polymer integrity, produces effectively sintered TiO2 film on the polymer surface and boosts the photovoltaic performance of FDSSCs. The developed model involves simultaneous heat transfer and coolant flow within the system which is dynamically coupled with an external coolant reservoir. Using this model, effects of various parameters such as coolant flow rate, heat sink material, heat sink geometry, and sintering duration on the thermal characteristics of TiO2 sintered on polymer substrate are studied. Also, the FDSSCs fabricated using this sintering method have shown power conversion efficiency increased significantly because of the rise in sintering temperature is controlled by the heat sink thermal parameters. Besides, possibilities of scaling-up of this sintering system for the fabrication of large area FDSSCs are investigated.

A low-profile consolidated metastructure for multispectral signature management

This work pertains to the design, numerical investigation, and experimental demonstration of an optically transparent, lightweight, and conformable metastructure that exhibits multispectral signature management capabilities despite its extremely low-profile configuration. In comparison to the existing hierarchical approaches of designing multispectral stealth solutions, attention has been paid to accommodate the conflicting requirements of radar and infrared (IR) stealth using a single metasurface layer configuration, which required a few constraints to be incorporated during the design stage to ensure compatibility. This methodology promulgates the desired multispectral response with minimal manufacturing footprint and facilitates an efficient integration with the other existing countermeasure platforms. The resulting design exhibits a polarization-insensitive and incident angle stable broadband microwave absorption with at least 90% absorption ranging from 8.2 to 18.4 GHz. Concomitantly it also exhibits an averaged IR emissivity of 0.46 in the 8–14 µm long-wave IR regime, along with high optical transparency (71% transmission at 632.8 nm). Notably, the total thickness of the metastructure stands at 0.10 ( corresponds to the wavelength at lowest frequency). The metastructure has been fabricated with indium tin oxide coated polyethylene terephthalate sheets, on which the frequency selective pattern is machined using Excimer laser micromachining, and the performances are verified experimentally. Furthermore, a hybrid theoretical model has been developed that not only provides crucial insights into the operation of metastructure but also presents a methodical semi-analytical approach to design.

Graphene-Polymer Nanocomposites and Roll-to-Roll (R2R) Compatible Flexible Solid-State Supercapacitor Based on Graphene Nanoplatelets and Ionic Liquid-Polymer Gel

We present the electrical and supercapacitive performance of graphene nanoplatelets in polymer nanocomposites and flexible solid state electrical double layer capacitors (EDLC) respectively. Graphene-doped poly (3,4-ethylenedioxythiophene) (PEDOT) coated polyethylene terephthalate (PET) and glass exhibited transmittance above 95% and electrical conductivity of 2.70 × 10ˉ1 S·cmˉ1 and 9.01 × 10ˉ1 S·cmˉ1 respectively. Graphene loaded polymethyl methacrylate (PMMA) and polystyrene (PS) nanocomposites showed electrical conductivity as high as 2.11 × 10ˉ1 S·cmˉ1 at low loadings of 2 wt%. The use of graphene was necessitated by the need to increase the EDLC capacitance and energy density since it provides high effective surface area. The polymer gel membrane made from polyvinylidene fluoride-co-hexafluoropropylene (PVDF-co-HFP) and the Ionic Liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate exhibited high porosity which made it suitable for use as separator in the EDLC. The highest recorded specific capacitance was 133.82 F/g which can be attributed to the porosity of the IL containing PVDF-co-HFP membrane and the large surface area of the graphene electrodes. At an operating voltage of 3.5 V the energy density was found to be 56.92 Wh·Kgˉ1. All chemicals were research grade and were obtained from Sigma Aldrich.

Influence of electrochemical co-deposition of bimetallic Pt–Pd nanoclusters on polypyrrole modified ITO for enhanced oxidation of 4-(hydroxymethyl) pyridine

Bimetallic Pt–Pd nanoparticles were dispersed on polypyrrole coated indium-tin oxide coated polyethylene terephthalate sheets (ITO-PET sheets). The excellent filming property of pyrrole gives a high porous uniform active area for the proper adsorption of bimetallic transition metal nanoparticles. Electrochemical behavior of the modified electrodes was determined using cyclic voltammetry and impedance studies. The physicochemical properties of the modified electrodes were analyzed by scanning electron microscopy, X-ray diffraction spectroscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. To study the electrochemical oxidation of 4-(hydroxymethyl) pyridine in the presence of sodium nitrate in aqueous acidic medium, the modified electrode was used. It is evident from the study that the modified electrode shows better electrochemical activity towards the oxidation of 4-(hydroxymethyl) pyridine.