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Lithium–sulfur (Li-S) batteries are promising energy storage devices owing to their high energy density and the low cost of sulfur. However, they are still far from being applied commercially because of the detrimental capacity fade caused by the dissolution of lithium polysulfide (LPS) in liquid electrolyte. In this study, we introduced a new polymer binder having a redox-mediating function that assists in the reduction of soluble LPS to Li2S at the cathode to suppress the shuttle effect as well as enhance sulfur utilization. An amine group containing benzo(ghi)perylene imide (BPI) was synthesized and grafted onto poly(acrylic acid) to produce a redox-mediating polymer binder. An Li-S cell fabricated using the new redox-mediating polymer binder demonstrated a capacity decay retention of 0.036% per cycle up to 500 cycles at 0.5 C with a coulombic efficiency of 98%.

Amyloid β oligomer (AβO) is a promising biomarker with potential to diagnose the Alzheimer’s disease (AD). To detect the low level of AβO is highly desirable for the early diagnosis of AD. Here we describe the fabrication and sensing performance of curcumin based AβO sensor. Curcumin-Ni was electropolymerized on Ni foam substrate, and the surface resistance change of the poly(curcumin-Ni) electrode depending on AβO concentration was confirmed by electrochemical impedance spectroscopy. The impedance response of the curcumin based sensor showed a proportional relationship with the concentrations of AβO in the range from 0.001 to 5 nM. The feasibility of the sensor was verified by the detection of AβO in artificial cerebrospinal fluid. The proposed AβO sensor presents valuable information related to early diagnosis of AD.

COVID-19 is a pandemic that has caused serious disruption in almost every day-to-day life around the world, and wearing a mask is essential for human safety from this virus. However, masks are non-recyclable materials, and the accumulation of masks used every day causes serious environmental issues. In this study, we investigate the recycling of mask materials for addressing the environmental problems and transforming as a high value-added material through chemical modification of masks. The recycled mask is applied as a separator for aqueous rechargeable batteries, and shows outstanding safety and electrochemical performance than the existing separator. This approach will lead to an advanced energy technology considering nature after overcoming COVID-19.

Zinc ion batteries (ZIBs) are promising candidates for application in next-generation energy storages because of their high capacity, low cost, and safety. However, structural issues such as irregular Zn growth, volume change, and electrochemical issues (side reactions and byproducts) hinder their practical application. Herein, we present an innovative method to develop a nanostructured conductive polymer shield for a Zn anode, which leads to an efficient and reversible ZIBs. The direct and spontaneous deposition of nanostructured conductive polymer on a Zn surface plays vital role of mechanical and electrochemical shield for Zn anode. The 3D-PPy@Zn anodes display high symmetric cycling stability for up to 1500 h at 1 mA cm−2, and the full cell assembled with a MnO2 cathode exhibits highly reversible battery performance.

The effects of ZnO particle size on crosslinking and thermal aging behavior of natural rubber (NR) were investigated. NR vulcanizates filled with nano ZnO allowed higher crosslink density, lower polysulfide crosslink, and stronger mechanical properties than those filled with micro ZnO. After thermal aging, NR filled with nano ZnO exhibited much more stable chemical and mechanical properties. The high crosslink density as well as the formation of more stable mono- and di-sulfidic crosslinks was attributed to the good dispersion and high surface area of the nano ZnO.

With a diffusion-assisted post-crosslinking method, polymer microspheres containing epoxy groups are crosslinked with ethylenediamine (EDA), gradually diffusing and reacting in the particles via amine/epoxy ring-opening reactions as confirmed by FT-IR and DSC results. Using a microcompression test, we find that the mechanical property (deformability under different applied force, breaking points, and recoverability) of the crosslinked microspheres is varied when different amounts of EDA are used in the system, resulting from different crosslinking density of the particles. An additional feature of the EDA treatment is to generate amine groups on the surface of the microspheres, enabling us to produce hybrid microspheres. We exploit them as immobilization sites for gold nanoparticles, forming gold-coated crosslinked microspheres. We also introduce a sequential functionalization method to fabricate crosslinked microspheres with selective functional groups on the surface. This approach can be a facile method to produce functional microspheres with controlled mechanical and surface properties.

The practical applications of lithium–sulfur batteries (LSBs) are extremely limited owing to their poor electrochemical performance, which results from the shuttling effect of lithium polysulfides (LPSs) and the growth of Li dendrites. Here, we propose the use of the metal oxide, Ga2O3, which has several types of oxygen vacancies, as a multifunctional shield for ultrastable LSBs. The Ga2O3 shield enhances LPS adsorption by improving the catalytic ability; it also provides stable Li plating and stripping by suppressing Li dendrite growth. The multifunctional shielding of the LSB by the Ga2O3 interlayer results in outstanding ultrastable cycling performance, where the capacity decay was only 0.010% over 4,000 cycles at a high rate of 2C. The proposed multifunctional shield is expected to have a wide range of applications in energy storage systems in addition to LSBs.

We demonstrate a novel strategy for the preparation of copper sulfide dendrite. Copper dendrite was electrodeposited on nickel foam by hydrogen gas bubbling and then, the surface of the Cu dendrite was treated by a vapor-phase sulfurization from thiourea at 185 °C for 30 min. The dendritic structure exhibits large surface area and high ability for fast electron transport. CuS dendrites electrode provides excellent performance in terms of electrocatalytic activity, response rate, and stability to glucose sensor. The CuS dendrite demonstrates a high sensitivity of 8337 μA mM −1 cm −2 in the wide linear detection range 0.001–4.9 mM with a detection limit of 0.05 μM. The CuS dendrite electrode can be a potential competitive candidate for application to biosensors.

Here, we introduce a layered hollow sphere (LHS) architecture of iridium-decorated carbon electrode. The electrode was prepared by coating of a solution composed of graphene oxide (GO), IrCl3, and polystyrene bead followed by subsequent pyrolysis. The morphology of the electrode was investigated according to the composition of solution, and the electrocatalytic properties were characterized. The usage of GO highly enhanced the electrochemical surface area of the electrode (by ∼6 times). The LHS electrode also showed outstanding electrocatalytic properties: a current density of 89.99 mA/cm2 could be obtained at a potential of 1.6 V.

In the advent of the miniaturized mobile devices, the packaging technology is required utmost high performance of the thin composite laminates in such materials properties as the coefficient of thermal expansion (CTE) and stiffness. Accordingly, the composition of a thermosetting resin becomes extremely complicated often including multiple fillers, monomers and/or catalysts in thermoset-based glass fiber prepregs. The prepreg systems is so complicated that it is usually difficult to obtain a reliable kinetic description and methodology that could be used for the complex thermal cycles including both isothermal and dynamic-heating segments in a facile manner. In this investigation, we propose an isoconversional kinetic using an ultra-thin glass fiber epoxy prepreg with highly loaded silica filler (the ultra-thin glass fiber/silica bead epoxy prepreg) as a model system. The activation energy was determined as a function of the conversion of curing reactions, which was fitted to linear models. The kinetic prediction using the linear models showed an excellent agreement to isothermal experiments. The master curve of a conversion-dependent function which derived from activation energy dependency used to investigate the complex reactions of the ultra-thin glass fiber/silica bead epoxy prepreg.

Morphology-controlled synthesis of nickel sulfide (Ni3S2) was performed directly on Ni foam using thioacetamide as a sulfur ion source. Various morphologies of nickel sulfide were fabricated using a hydrothermal process by adjusting the solvent composition of ethanol and water. In the water-dominant condition, a dendrite structure was obtained; otherwise, a flaky structure was achieved. A hierarchical cauliflower-like structure was obtained at a solvent mixture composition of 1:1 and was used as non-enzymatic glucose sensor. The hierarchical Ni3S2 electrode showed a high level of electro-catalytic activity toward the oxidation of glucose (16,460μAmM(-1)cm(-2)) over a wide range of detection (0.0005-3mM) and a low detection limit (0.82μM) with excellent selectivity in the presence of several electroactive species.

Li-S batteries (LSBs) are considered as next-generation energy-storage devices because of their high energy density. However, long-term use of LSBs is limited by the volume changes of sulfur and the shuttle effect. To address these issues, a multifunctional polymer binder is developed by combining a commercial binder and elastic rubber. Poly(vinyl pyrrolidone) (PVP) is used as the main binder, and carboxylated nitrile butadiene rubber (XNBR) is added to enhance its mechanical toughness and adsorb soluble lithium polysulfides. The XNBR is vulcanized with S to enhance its mechanical properties and chemical polarity. The combination of PVP and crosslinked-XNBR allows control of the volume change of sulfur, regulates soluble polysulfides, and ensures the good dispersion of the electrode material. LSBs with the proposed binder exhibit a remarkable battery-performance improvement of 300% after 500 cycles at 1C compared with an LSB using a PVP binder, as well as cycle stability, with a small capacity decay of 0.02% per cycle at 1C for 1000 cycles.

In this work, an ultra-sensitive amyloid beta oligomer (AβO) sensor is presented in the detection range at atomolar level. A hierarchical gold dendrite (AuD) was electrochemically prepared on a gold substrate. Poly(pyrrole-3-carboxylic acid) [PPy-3-COOH] was electrodeposited on AuD to maintain the outstanding electrochemical properties, such as high conductivity and large surface area. After immobilization of the cellular prion protein (PrPC) bioreceptor through amide bond formation, the electrochemical sensor was incubated in gradient concentrations of AβO. The impedance response of the dendritic PPy-3-COOH/PrPC biosensor showed a proportional relationship to the increase of AβO concentration from 10−9 to 10 nM. The sensitivity at an atomolar level and high selectivity to AβO can be used in the diseased mice and blood test for the early diagnosis of Alzheimer’s disease.

Hierarchical Ni(OH) 2 hollow nanorods were deposited on zinc oxide (ZnO) nanorods by using a chemical bath deposition. The ZnO template was electrodeposited on ITO-glass and removed using an alkaline solution, and then, the hierarchical structure of the hollow Ni(OH) 2 consisted of nanoflakes was obtained. The morphology of the Ni(OH) 2 was confirmed via scanning electron microscopy and transmission electron microscopy, and its composition was determined via X-ray diffraction and X-ray photoelectron spectroscopy. The Ni(OH) 2 hollow nanorods exhibited a hierarchical structure with a large specific surface area and a high level of electrocatalytic activity for glucose oxidation in an alkaline condition. The Ni(OH) 2 hollow nanorod arrays had a wide detection range from 2 to 3862 μM, with a detection limit of 0.6 μM (s/n = 3). Furthermore, the modified electrode could detect glucose at a temperature as high as 75 °C with a sensitivity of 2904.9 μA mM −1 cm −2 . The glucose sensor showed excellent selectivity in the presence of several interfering electroactive species, and it can therefore be used to detect glucose in human serum samples.

A Mn2O3 nanorod array has been successfully prepared by using simple pulse-reverse electrodeposition that was then followed by transformation to a higher MnOx oxidation state via electrochemical oxidation. The surface morphology and composition of the MnOx nanorods was verified via scanning electron microscopy and X-ray photoelectron spectroscopy. The MnOx nanorod array exhibits excellent electrocatalytic activity toward glucose oxidation under alkaline conditions and these properties were confirmed by using cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperometry. The structure of the MnOx nanorod array not only provides a large surface area, but also facilitates electron transfer and mass diffusion. The optimum oxidation time was determined to be 30 min, at which the MnOx glucose sensor demonstrated a sensitivity at 811.8 μA mM−1, which is the highest among the various types of MnOx-based sensors that have been reported so far. Moreover, it also exhibited an excellent long-term stability and a good selectivity in the presence of interferents, such as ascorbic acid, dopamine, uric acid, urea, and aspartic acid. The practical applicability of MnOx sensor was also studied by detecting glucose in human serum, in which it demonstrated an excellent selectivity and reliability.

The electrocatalytic activity of over-oxidized polypyrrole nanowires electrode modified with nickel hydroxide nanoflakes (nf-Ni(OH)2@oPPyNW) was investigated for its application to an amperometric glucose sensor. The oPPyNW were electrodeposited on graphite electrode by chronoamperometry, and then, Ni(OH)2 nanoflakes were grown on the oPPyNW by chemical bath method. The surface morphology of the nf-Ni(OH)2@oPPyNW-modified electrode was characterized by scanning electron microscopy, and its composition was verified by X-ray photoelectron spectroscopy. Following the exploration of optimum deposition conditions, chronoamperometry was used to determine the varying concentrations of glucose in an alkaline solution. The as-prepared nf-Ni(OH)2@oPPyNW electrode demonstrated excellent performance in terms of electrocatalytic activity, response rate, and stability. It was capable of detecting glucose in a wide dynamic detection range of 0.001–4.863 mM and was able to selectively detect glucose in the presence of several electroactive species such as ascorbic acid, dopamine, l -aspartic acid, and uric acid. At the same time, the proposed electrode exhibited a high sensitivity of 1049.2 μA mM−1 cm−2 with a low detection limit of 0.3 μM, illustrating it as a tool in a potential strategy to develop a fast, sensitive, selective, and stable electrochemical sensor for early diabetes diagnosis.

A hierarchical nanorod structure containing a CuO core and a TiO 2 shell (CuO@TiO 2 ) was successfully prepared and demonstrated high capacity and cycle stability as an anode material for lithium-ion batteries. The Cu dendrites were prepared by galvanic displacement using an aluminum plate, and a layer of TiO 2 was coated on the Cu dendrites through sol–gel processing. Finally, the Cu@TiO 2 dendrites were evolved to CuO@TiO 2 nanorods by thermal oxidative annealing. Core–shell CuO@TiO 2 exhibited reversible specific capacity (400 mAhg −1 at 0.1C) and stable cyclability (97% after 100 cycles). This work suggests a facile and cost-effective strategy for the fabrication of a core-shell structure that has the potential to be useful in energy storage devices.

Lead ion is one of the most hazardous and ubiquitous heavy metal pollutants and poses an increasing threat to the environment and human health. This necessitates rapid and selective detection and/or removal of lead ions from various soil and water resources. Recently, we identified several Pb 2+ binding peptides via phage display technique coupled with chromatographic biopanning ( Nian et al., 2010 ) where a heptapeptide (TNTLSNN) capable of recognizing Pb 2+ with high affinity and specificity evolved. In the present study, an electrochemical sensor harnessing this Pb 2+ affinity peptide as a probe on a porous gold electrode was developed. The three dimensional porous gold electrode was obtained from electrochemical deposition using the dynamic hydrogen bubble template method. A thin layer of poly(thiophene acetic acid) (PTAA) was coated on the porous gold surface. The Pb 2+ recognizing peptide was immobilized via amide linkage on the PTAA. The developed biosensor was demonstrated to be fast, selective and reproducible in Pb 2+ detection, exhibiting Pb 2+ -specific peak current values around −0.15 V in a broad concentration range (1−1×10 7 nM) in 10 min despite the repeated use after regeneration.

In the present study, a novel impedance aptasensor was developed by immobilizing HER2 (human epidermal growth factor receptor 2)-specific single stranded DNA aptamer onto the monolayer of 3-mercaptopropionic acid self-assembled on gold nanoparticles electrode. The efficiency of each electrode modification step and the performance of thus constructed aptasenor were assessed by impedance spectroscopy. The impedance response of the aptasensor showed a proportional relationship with the concentrations of HER2 ranged from 10 −5 to 10 2 ng/mL. The aptasensor showed fast HER2 detection with negligible cross reactivity to various compounds likely to exist in human serum samples (e.g. glucose, IgG, DNA and RNA), indicative of excellent sensitivity and specificity of the aptasensor. The aptasensor could be regenerated by a simple pH-shift method. Considering these advantages of the developed aptasensor, it could provide a good potential sensing platform for non-invasive early detection of breast cancer biomarkers.

article i nfo In this study, a solution-processable precursor of melamine and silicon oxide, was prepared and thermally converted into inorganic thin films of SiNxCyOz. Using tetra-ethoxysilane and hydroxyl-methyl-melamine, a transparent coating with a high loading content of silica of up to 50% was achieved through the hydrolysis/ condensation reactions, which provided a transmittance of 85.1% (thickness of 1.5 ± 0.2 μm) and hard coat- ing grade of 4H pencil test. When the silica/melamine coating was further heat-treated up to 900 °C in an inert environment, the organic melamine was converted into an inorganic compound composed of Si, N, C, and O atoms in the form of SiNxCyOz. The relative compositions of films varied with the heat-treatment tem- perature, e.g., providing SiN0.03C0.59O1.87 for the thin film heat-treated at 700 °C. The resulting inorganic thin films were mechanically strong and optically shiny with a low root mean square of roughness (b1.0 nm) giv- ing dielectric constants varying from 2.75 to 1.82 with heat treatment temperature that could be used as low-k materials in commercialized optoelectronic devices.

A facile method for detection of lipopolysaccharide (LPS) on metal complex immobilized gold electrode is described. The metal complex modified electrode was constructed from a gold electrode modified with Cu and nitrilotriacetic acid (NTA) complex, which binds to the O-side chain of LPS in gram-negative cells. The electrochemical impedance spectroscopy (EIS) was used to detect interaction of LPS with NTA–Cu complex. The performance of the NTA–Cu sensor was investigated by EIS and a linear relationship was observed between charge transfer resistance ( R et ) and LPS concentration in the range of 0.0001–0.1 ng mL −1 . The NTA–Cu complex exhibited insignificant binding to DNA, RNA, bovine serum albumin, glucose, and cholesterol whereas LPS interacted strongly in the biological species. Furthermore, the NTA–Cu sensor was easily regenerated from EDTA solution, and the regenerated sensor demonstrated response sensitivities similar to the original sensor with a deviation of only 4%. These findings show that the NTA–Cu modified gold electrode can be used to detect LPS in real-time.

Platinum nanoparticles (Pt NPs) were deposited on a layer-by-layer (LBL) assembled carbon nanotube (CNT) thin film via the spontaneous reduction of H 2 PtCl 6 at the functional defect sites of the CNT surface. This nanostructure was characterized by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The modified electrode can be used for the nonenzymatic detection of cholesterol by chronoamperometry (CA) in neutral PBS. We also studied the optimal number of CNT layer for obtaining high sensitivity. The sensor with 24 bilayer of CNT shows very low detection limit and a wide linear range from 0.005 mM to 10 mM with a sensitivity of 8.7 μA mM −1 cm −2 . The result is attributed to the LBL assembled structure and more continuous intercalated pathways for electron transport in LBL assembled CNT film and the fact that the CNT film can provide a larger surface area for Pt NP loading. The sensor has good anti-interferent properties in the presence of glucose, ascorbic acid, and dopamine.

The electrochemical characteristics of electric double layer capacitors composed of solid polymer electrolytes with different thicknesses were investigated. A solid polymer electrolyte membrane was fabricated using electrospun fibers through solvent-assisted or thermally induced compression molding. Through the solvent-assisted or thermally induced compression molding processes, the poly(acrylonitrile) (PAN) microfibers consolidated together by the interlocking of the fibers under compression. A solid polymer electrolyte membrane clearly exhibited a free-standing shape with a bending capability. The electrospun PAN non-woven fabric and electrolyte salt composites showed higher ionic conductivity (>10−3 S cm−1 at 298 K) and capacitance compared with the liquid organic electrolyte. The solid polymer electrolytes provided a 10.6% increase in the energy density, seemingly due to the decrease in the IR drop and increase in the capacitance.

a b s t r a c t High thermal-conductivity fillers of aluminum nitride (AlN) and boron nitride (BN) were incorporated in the epoxy matrix in order to identify the effects of the particle size and the relative composition on the thermal conductivity of composites. In the bimodal distribution of polygonal AlN and planar BN parti- cles, the optimal thermal conductive path was strongly affected by the packing efficiency and interfacial resistance of the particles in a sensitive way and, consequently, the maximum thermal conductivity was achieved up to 8.0 W/mK in the 1:1 volume ratio of AlN:BN particles. In the optimal volume ratio of the two fillers at 1:1, the relative filler size, which was represented by the shape factor (or the diameter ratio of the two filler particles, RD), also influenced the thermal conductivity giving the maximum con- ductivity at the shape factor RD ≈ 1. The optimal morphology and composition of the AlN/BN composite systems were clearly visualized and thoroughly discussed in the filler distribution curves plotting the filler-appearance frequency as a function of particle size. The developed methodology validated that two different particles should be packed well to fill up the interstitial space and, simultaneously, the contact resistance and the contact area of the fillers should be optimized to maximize the thermal conductivity. © 2012 Published by Elsevier B.V.

Kenaf fibers were heterogeneously benzylated in aqueous alkaline solution. The benzylated kenaf fibers were characterized by Fourier Transform Infrared (FTIR), dynamic mechanical analysis (DMA), scanning electron microscope (SEM), universal tensile machine (UTM), and the contact angle test. The results showed that the degree of benzylation depended on the reaction time, as assessed by the weight gain. The DMA analysis showed that the glass transition temperature of kenaf fiber decreased from 140 to 118 °C after benzylation, while the weight gain increased from 5 to 120%. The benzylated kenaf fibers exhibited good melt processability and were readily hot pressed into sheets. The sheet containing with fibers, which were benzylated for 3 h, exhibited 17.5 MPa in tensile strength, and the hydrophilic property of the sheet was greatly decreased as a function of benzylation time.

Lipopolysaccharide (LPS), also known as endotoxin, triggers a fatal septic shock; therefore, fast and accurate detection of LPS from a complex milieu is of primary importance. Several LPS affinity binders have been reported so far but few of them have proved their efficacy in developing electrochemical sensors capable of selectively detecting LPS from crude biological liquors. In this study, we identified 10 different single-stranded DNA aptamers showing specific affinity to LPS with dissociation constants ( K d ) in the nanomolar range using a NECEEM-based non-SELEX method. Based on the sequence and secondary structure analysis of the LPS binding aptamers, an aptamer exhibiting the highest affinity to LPS (i.e., B2) was selected to construct an impedance biosensor on a gold surface. The developed electrochemical aptasensor showed excellent sensitivity and specificity in the linear detection range from 0.01 to 1 ng/mL of LPS with significantly reduced detection time compared with the traditional Limulus amoebocyte lysate (LAL) assay.

Few-layer graphene (FLG) was investigated as an electrically-conductive interleaf layer for one-step electroplating and patterning of metal on nonconductive polymer substrates without using multiple and toxic pretreatment processes in traditional electroplating. An individual FLG (5–10 nm of thickness with 6.4% of oxygen content) was obtained by expanding graphite with microwave followed by exfoliating the expanded graphite with sonication in N -methyl-pyrrolidone. Stacking FLG in the in-plane direction, a robust FLG film was obtained by the vacuum-assisted filtering and drying methods, and transferred to a polyethylene terephthalate (PET) substrate via an intermediate transfer to the water surface. The sheet resistance of the FLG film on the PET substrate was 0.9 kΩ/sq with a thickness of 80 nm and the root-mean-square roughness of 29 nm. In the electroplating of nickel on the FLG film, hemisphere-shape metal seeds appeared in the early stage of electroplating and they subsequently grew up to 200–480 nm, which became connected to form a continuous nickel layer. The thickness of the continuous nickel layer increased linearly with electroplating time. The developed electroplating method demonstrated its capability of selective patterning on nonconductive substrates using a simple masking technique.

A novel synthetic route to the highly-loaded rubber nanocomposite was developed by a stabilization–destabilization process of colloidal mixtures using montmorillonite (MMT) and natural rubber (NR) as a model system. By analyzing the zeta potentials of the MMT and NR colloids, the stable and unstable conditions of their mixture were identified and subsequently used as the mixing and precipitating process conditions, respectively. The NR drops and MMT nanoplatelets were homogeneously mixed due to their electrostatic repulsion in the stabilized condition of pH > 10.5 and, then the stabilized colloidal mixture were forced to precipitate quickly by changing to pH

Polypyrrole (PPy)/carbon nanotube (CNT) composite electrodes are fabricated on ceramic fabrics for electrochemical capacitor applications. The CNTs are grown on the ceramic fabrics by the chemical vapor deposition (CVD) method and PPy is subsequently coated on them by chemical polymerization. The large surface area and high conductivity of the CNTs on the porous ceramic fabrics enhance their energy storage capacity. PPy provides not only additional capacitance as an active material, but also enhances the adhesion between the CNTs and ceramic fabrics. Furthermore, PPy acts as a conducting binder for connecting every individual CNT to increase the capacitance. The morphology of the PPy–CNTs on the ceramic fabrics is confirmed by SEM and TEM, and the electrochemical characteristics are investigated by cyclic voltammetry and galvanostatic charge–discharge tests.

Polypyrrole (PPy) micro-rod actuators were electrochemically prepared into a porous polycarbonate (PC) by template synthesis. The linear actuation of the PPy micro-rod actuators at various potentials was consecutively monitored with in situ mode using an optical microscope (OM) and converted into 3-dimesional images. Scanning electron microscopy (SEM), atomic force microscopy (AFM), and a potentiostat–galvanostat were used to confirm the actuation of PPy micro-rods during the redox process. Linear stretching actuation in the longitudinal dimension was successfully demonstrated.

An alkylthiol functionalized monomer based on 3,4-ethylenedioxythiophene methanol (EDTM), namely 3-((2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)methoxy)propane-1-thiol (EDTMSHA), was synthesized and confirmed by 1H NMR, 13C NMR, and gas chromatography mass spectroscopy (GC/MS). The new monomer successfully produced a self-assembled monolayer (SAM), which was deposited on a gold disc electrode and then electrochemically polymerized. The SAM formation of the new conducting polymer films exhibited relatively low oxidation potentials with a well defined reversible and stable electrochemical behavior compared to conventional electropolymerized film.

A highly conductive polymer-based bipolar plate is fabricated using phenolic resin and graphite for proton exchange membrane fuel cells (PEMFCs). In order to load graphite fillers up to 90 wt% and minimize the void volume, the wetting properties of the graphite and phenolic resin are key factors for ensuring high electrical conductivity of the bipolar plates through good contact and uniform dispersion of graphite fillers. Since the surface free-energies of the phenolic resin and graphite are significantly different at 107.77 and 43.3 mJ m−2, respectively, to give a high contact angle of 87.1°, methanol with 19.6 mJ m−2 of surface energy is incorporated to decrease the contact angle between the matrix and graphite to 11.2°. By adjusting the surface energy of the matrix system, the conductivity of a composite containing 90 wt% of graphite reaches 379 S cm−1. The air permeability of the composite containing 80 wt% of graphite is less than 5 × 10−6 cm3 cm−2 s without open pores. The flexural modulus ranges from 6700 to 11000 MPa for graphite loads between 60 and 80 wt%, respectively.

In this study, ruthenium oxide-polypyrrole (RuOx-PPy) composite nanostructures were prepared as electrode materials for electrochemical capacitors. Pyrrole was electrochemically polymerized in the pores of an anodized aluminum oxide (AAO) template. RuOx was further deposited on the surface of the PPy nanorod array by an electrochemical method. The morphology and composition of the RuOx-PPy nanocomposites were observed by SEM and EDX. The capacitive performance of the RuOx-PPy nanocomposites was investigated by the galvanostatic charge/discharge test as a function of the amount of RuOx. The maximum specific capacitance of the RuOx-PPy nanocomposite electrode was 419 mF cm−2/681 F g−1.

In this study, a novel synthesis methodology is presented for the generation of a new type of polymer/metal core-shell structure. Poly(divinylbenzene) (PDVB) particles 2–4 μm in size were produced through precipitation polymerization. The surfaces of these PDVB particles were modified by the sulfonation reaction to produce sulfonic acid groups (–SO3H), and coated with a thin layer of polypyrrole (PPy), a electrical conducting polymer material, using chemical oxidative polymerization in order to improve their electrical properties as well as adhesion property with metal layer. Tiny gold grains in seed form were adsorbed on the surface of the PPy/PDVB core. An oxidation/reduction procedure was repeated on the gold grains in the solution using HAuCl4 and sodium borohydride to form the uniform gold layers comprising the core-shell of the Au/PPy/PDVB structure. The structure of the Au/PPy/PDVB core-shells was investigated by scanning electron microscopy (SEM).

In this work, we prepared ITO-free photovoltaic devices ( PVDs) using a transparent poly(3,4-ethylenedioxythiophene):silicate (PEDOT:SiO x ) composite anode equipped with low surface resistance and high transparency. A mixture of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C 60 butyric acid methyl ester (PCBM) was used as a photoactive layer. PEDOT:SiO x film was fabricated with an inorganic silicate network via the oxidative polymerization of EDOT and in-situ sol–gel process of TEOS, which should allow enhanced adhesion and bonding strength between the conducting polymers and the glass substrates to be obtained without any significant deterioration of the desired electronic properties of the conducting polymers. The transmittance and surface resistance of the PEDOT:SiO x film were varied in the ranges of 55–94% at 510 nm and 80–380 Ω/sq, respectively. The power conversion efficiency of the ITO-free PVD with PEDOT:SiO x anode was ca 1.2% under an illumination of AM 1.5 G (100 mW/cm 2 ).

This paper studies the detection of copper ions by using an iminodiacetatic acid (IDA) modified conducting copolymer electrode. The copolymer film comprising 3-methyl thiophene (3MT) and 3-thiophene acetic acid (3TA) was chosen as the selective metal cation sensing electrode. The carboxylic group of the copolymer was modified to produce IDA group for metal ion capture. The modified electrode was used for the electrochemical analysis of trace copper ions by square wave voltammetry (SWV) technique. The electrode was found to be highly selective to Cu 2+ in the range of 0.1–10 μM. The modified electrode offered an excellent way, with a high stability and reusability, for selective determination of Cu 2+ in a solution of mixed metal ions.

In this work, modified poly(3,4-ethylenedioxythiophene) (PEDOT) was used as an anode in polymer photovoltaic devices (PVDs) based on poly(3-hexylthiophene) (P3HT):[6,6]-phenyl-C 60 -butyric acid methyl ester (PCBM). We synthesized poly(3,4-ethylenedioxythiophene methanol) (PEDTM) with a transmittance of 87% (at 510 nm) and a conductivity of 700 S/cm. PEDTM was applied in photovoltaic devices as a hole transporting layer on indium-tin oxide (ITO) electrode as well as a direct anode layer. PVDs with PEDTM as hole transporting layers on ITO showed a very high short-circuit density of 14.87 mA/cm 2 and power conversion efficiency of 2.67% under an illumination of AM 1.5 G (100 mW/cm 2 ). In addition, we also fabricated ITO-free PVDs using PEDTM as an anode, which exhibited a performance of 0.61% with a result of J sc of 4.48 mA/cm 2 , V oc of 0.51 V, and FF of 27%.

A new biomimetic actuation system by artificial muscle actuator based on dielectric elastomer is presented in this paper. A novel linear actuator called “multi-stacked actuator” is introduced, which can be embedded in the phalanges of the finger and ensures a compact design of the overall system. The performance of the proposed actuation system is demonstrated using two degree–of–freedom robot finger. A pulse-width-modulation proportional-integral-derivative (PWM-PID) feedback controller based on the discharging circuit is implemented and tested. The proposed system can be extended to the multi–fingered robot hand easily, and applied even for articulated mechanisms such as legged robots etc.

A new type of polypyrrole (PPy) nanorod actuator was fabricated by electrochemical polymerization of pyrrole in the pores of anodized aluminum oxide (AAO) template. The electrochemical characteristics and the actuation behavior of PPy nanorod actuator were characterized by cyclic voltammetry and SEM, respectively. During the redox process of nanorod PPy actuator, the linear stretching actuation in the longitudinal dimension has been successfully demonstrated. It was also observed that the linear displacement increased with increasing anion-size of the salts in the liquid electrolytes.

Poly(3,4-ethylenedioxythiophene) (PEDOT) films were synthesized by electropolymerization under an applied magnetic field on ITO glass. The effects of the magnetic field on the electrochemical polymerization of EDOT and the redox behavior were examined. The cyclic voltammetry (CV) result indicated that the applied magnetic field exceedingly accelerated the polymerization rate. The effect of the conformation of the PEDOT chains under applied magnetic field was studied by Raman spectroscopy. Scanning electron microscopy (SEM) showed the morphological changes of PEDOT film in the presence of the magnetic field. The parallel applied magnetic field induced the formation of more expanded chain structure as well as sharp crystalline morphology.

Poly(3,4-ethylenedioxythiophene)/copper (PEDOT/Cu) composites were prepared by an in situ redox reaction of 3,4-ethylenedioxythiophene (EDOT) and copper(II) chloride. During the reaction, EDOT was oxidatively polymerized by Cu(II) chloride, while the Cu(II) ions were reduced to produce Cu metal particles. PEDOT/Cu composite films were also successfully prepared on CuCl2-coated poly(ethylene terephthalate) (PET) films by the vapor phase polymerization of EDOT. PEDOT/Cu films were characterized using UV–vis spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) to confirm the formation of PEDOT, and the presence of metallic Cu particles.

The hydrophobicity of the poly( l -lactide) (PLLA) surface was modified by incorporating hydroxyapatite (HAp) nanocrystalline particles during the electrospinning process for the engineered scaffold applications. The HAp nanocrystals were synthesized with 30 nm in diameter and 100–120 nm in length, which subsequently formed micrometer-sized agglomerates in the range of 2.5 μm. The synthesized HAp agglomerates were electrospun in the PLLA solution, and the HAp nanocrystals were desirably exposed on the surface of the electrospun PLLA fibers to give higher surface energy and lower contact angles with water. The surface-exposed hydrophilic HAp nanocrystals substantially increased the precipitation of various salts on the HAp/PLLA fiber surfaces in a buffer solution due to the hydrophilic nature and ionic affinity of HAp. Finally, the developed HAp/PLLA fibers desirably sustained the fibrous structural integrity during the accelerated-aging test in water, which was not the case with the pristine PLLA fibers.

A facile method was developed to load a large amount of silver nanoparticles into a biodegradable and biocompatible cellulose acetate (CA) nanofibrillar aerogel in a controlled manner. The micro-sized CA fibrils were separated into nano-sized fibrils by salt-assisted chemical treatment in a water–acetone co-solvent to give a nanofibrillar structure with a diameter of 20–50 nm, BET surface area of 110 m2/g, and porosity of 96%. Using the high electron-rich oxygen density in the CA macromolecules and the large surface area of the CA nanoporous structure as an effective nanoreactor, the in-situ direct metallization technique was successfully used to synthesize Ag nanoparticles with an average diameter of 2.8 nm and a loading content of up to 6.98 wt%, which can hardly be achieved by previous methods. This novel procedure provides a facile and economic way to manufacture Ag nanoparticles supported on a porous membrane for various biomedical applications.

Platinum (Pt) nanoparticles were synthesized inside a Nafion polyelectrolyte membrane for use as a catalyst membrane integrated layer in fuel cells. The integrated membrane was prepared by making use of the cation exchange between the tetraammineplatinum (II) cations ([Pt(NH3)4]2+) and sulfonic groups in the Nafion molecules, followed by film casting and chemical reduction. The synthesized Pt nanoparticles, which had a cubic shape with diameters of 11.5–14.5 nm, dispersed in the recast Nafion film, increased its proton conductivity and open circuit voltage compared with the pristine Nafion membrane. The Pt-incorporated membrane provided a 29% increment of the maximum power density, seemingly by oxidizing the crossover methanol passing through the proton-exchange membrane. At a high loading of Pt (over 3 wt.% in this study), the Nafion clusters were likely squeezed by the synthesized Pt nanoparticles so as to decrease the water uptake and proton conductivity. This hypothesis was also supported by the increased Ohmic resistance in the I–V polarization curve.

The surface morphology of poly(3,4-ethylenedioxythiophene) (PEDOT) was investigated in the vapor-phase polymerization of the thiophene monomer on a flexible polyethyleneterphthalate (PET) substrate film. The PET surface was modified with ethylene diamine maintaining the surface roughness within 2 nm to create amine and amide groups for the enhanced hydrophilic interaction with Fe(III)-tosylate (Fe(OTs) 3 ) and for the desirable hydrogen bonding with thiophene monomer as well as PEDOT. Polymerization rate was reduced by incorporating pyridine as a reaction retardant to control the surface roughness and conductivity of PEDOT thin films. The optimal conditions of pyridine and glycerol were found at a pyridine/Fe(OTs) 3 molar ratio of 0.5 and a glycerol concentration of 4–5 wt.%, respectively, providing the conductivity up to 500 S/cm and the surface roughness

Multiwalled carbon nanotubes (MWCNTs) were incorporated into a poly(methyl methacrylate) (PMMA) solution to develop a transparent and flexible composite conductive film. Monitoring the MWCNT-granule size in the PMMA solutions as well as after the film casting, the self-aggregation of MWCNTs was thoroughly investigated to provide a highly-dispersed polymeric conductor. In addition to the degree of acid treatment of MWCNTs, the dipole moment of solvent and the random-coil length of polymer were considered to be the key factors for the MWCNTs to retain the highly-dispersed state in the polymer matrix after solidification. Investigating several solvent systems, dimethylformamide was found to have the best dispersing capability for the MWCNT/PMMA system to give a surface electrical conductivity up to 10−2 S/cm at ca. 3.0 wt% of MWCNT, which was considered to be well above what had been reported for such a low level of MWCNT loading, with a light transmittance over 95%. Finally, the polymer-rich layer, which is usually formed on the coating surface due to the surface tension and wetting characteristics of the MWCNT/PMMA mixture, was mechanically peeled off to give an increase in electrical conductivity of nearly two orders of magnitude.

In this study, a dry type conducting polymer actuator was prepared. Nitrile rubber (NBR) containing ionic liquid, 1-butyl-3-methyl imidazolium bis(trifluoromethyl sulfonyl)imide (BMITFSI), was utilized as the solid polymer electrolyte exhibiting high ionic conductivity as well as electrical stability. Various grades of NBRs having different amounts of acrylonitrile (ACN), viz. 23, 35 and 40 mol%, were found to be well compatible with BMITFSI. The thermomechanical property and ionic conductivity of the solid polymer electrolyte were characterized by dynamic mechanical analysis and impedance analysis, respectively. A maximum conductivity of 2.54 × 10−4 S cm−1 at 20 °C was achieved in the NBR sample containing 40 mol% ACN activated in BMITFSI. A conducting polymer, poly(3,4-ethylenedioxythiophene) (PEDOT), was synthesized on the surface of the solid polymer electrolyte by chemical oxidative polymerization to yield the structure of solid polymer actuator. The effect of the NBR composition on the actuation behavior was examined.