Formation of copper–polymer nanocomposite upon copper electrodeposition in the presence of poly(<Emphasis Type="Italic">N</Emphasis>-vinylpyrrolidone)

The composition and structure of products formed on a cathode upon electrodeposition of copper from copper sulfate–poly(N-vinylpyrrolidone) mixed solutions have been studied. These products have been shown to be nanocomposites consisting of copper nanoparticles and the polymer. It has been suggested that the composite is formed by a pseudotemplate mechanism via noncovalent interaction between macromolecules and copper particles growing on the cathode. The interaction is accompanied by deceleration of subsequent growth of particles because of their screening by the polymer. This decreases the sizes of copper particles in the reaction product and the rate of metal reduction. The sonication of the reaction system yields a nanocomposite sol containing nanoparticles of copper(I) oxide. The oxide results from rapid oxidation of copper metal particles that have passed to the sol with copper(II) ions.     

Development of polymer‐based lithium secondary battery

Novel polymer composites based on polydisulfide compounds are developed as a high energy density cathode material for lithium rechargeable batteries. A polymer composite composed of 2,5‐dimercapto‐1,3,4‐thiadiazole (DMcT) and conducting polymer polyaniline (PAn) on a copper current collector provides high charge density exceeding 225Ah/kg‐cathode with average discharge voltage at 3.4V. The composite cathode showed excellent rate capability and cyclability (>500 cycles). Surface analysis and electrochemical studies indicate that a DMcT‐Cu complex plays an important role in the observed improvement of the battery performances with a copper current collector. Large increase in the charge density to 550Ah/kg‐cathode is achieved by adding elemental sulfur (S₈) to the DMcT/PAn composite cathode.     

Electrochemical synthesis of copper-arabinoxylan nanocomposite for applications as antimicrobial agent and CO2 conversion catalyst

This study reports the electrochemical synthesis, antimicrobial and catalytic activity of copper-arabinoxylan nanocomposite. The synthesis was achieved without use of any hazardous reducing and stabilizing agent. The spherical copper nanoparticles (size approx. 40 nm) dispersed in the arabinoxylan matrix as they formed and got stabilized. In the absence of arabinoxylan the particles rapidly converted to copper oxide suggesting a high stability for the composite. Electrolysis was carried out with copper plate as the sacrificial anode, carbon rod as the cathode and sodium nitrate (1.00 % in 1 % arabinoxylan suspension) as an electrolyte. The copper nanoparticles dispersed in arabinoxylan were characterized by surface plasmon resonance spectroscopy, X-ray diffraction, electron microscopy and zeta potential measurements. The synthesized composite exhibited good antimicrobial activity against P. aeruginosa, Staph. aureus and E. coli and a catalytic activity in conversion of CO₂ to methanol.     

Structure and Electrocatalytic Properties of Copper-Containing Aniline–Melamine–Formaldehyde Polymer Composites

Mixed aniline–melamine–formaldehyde polymer was synthesized by parallel polycondensation of the monomers with formaldehyde. Copper(II) chloride and copper oxides (CuO, Cu₂O) were introduced in situ the process. X-ray diffraction analysis revealed the presence of crystalline CuO phases at introducing CuCl₂ into the polymer and the appearance of copper particles in all the synthesized composites after using them as catalysts in electrohydrogenation of o-nitroaniline, which is caused by electrochemical reduction of copper cations from copper oxides. The use of the synthesized composites for the cathode activation in electrohydrogenation of o-nitroaniline increases the process rate by a factor of 1.5–2.5 compared to electrochemical reduction, and with 100% conversion to o-phenylenediamine.     

Analytical characterization of laser-generated copper nanoparticles for antibacterial composite food packaging

A new type of nanomaterial has been developed as antibacterial additive for food packaging applications. This nanocomposite is composed of copper nanoparticles embedded in polylactic acid, combining the antibacterial properties of copper nanoparticles with the biodegradability of the polymer matrix. Metal nanoparticles have been synthesised by means of laser ablation, a rising and easy route to prepare nanostructures without any capping agent in a liquid environment. As prepared, nanoparticle suspensions have been easily mixed to a polymer solution. The resulting hybrid solutions have been deposited by drop casting, thus obtaining self-standing antibacterial packages. All samples have been characterized by UV–Vis spectroscopy, X-ray photoelectron spectroscopy and electro-thermal atomic absorption spectroscopy. Ion release data have been matched with bioactivity tests performed by Japanese Industrial Standard (JIS) method (JIS Z 2801:2000) against Pseudomonas spp., a very common Gram-negative microbial group able to proliferate in processed food.     

Poly(N‐vinylpyrrolidone)‐Decorated Reduced Graphene Oxide with ZnO Grown In Situ as a Cathode Buffer Layer for Polymer Solar Cells

A ZnO@reduced graphene oxide–poly(N‐vinylpyrrolidone) (ZnO@RGO‐PVP) nanocomposite, prepared by in situ growth of ZnO nanoparticles on PVP‐decorated RGO (RGO‐PVP) was developed as a cathode buffer layer for improving the performance of polymer solar cells (PSCs). PVP not only favors homogeneous distribution of the RGO through the strong π–π interactions between graphene and PVP molecules, but also acts as a stabilizer and bridge to control the in situ growth of sol–gel‐derived ZnO nanoparticles on the surface of the graphene. At the same time, RGO provides a conductive connection for independent dispersion of ZnO nanoparticles to form uniform nanoclusters with fewer domain boundaries and surface traps. Moreover, the LUMO level of ZnO is effectively improved by modification with RGO‐PVP. Compared to bare ZnO, a ZnO@RGO‐PVP cathode buffer layer substantially reduces the recombination of carriers, increases the electrical conductivity, and enhances electron extraction. Consequently, the power conversion efficiency of an inverted device based on thieno[3,4‐b]thiophene/benzodithiophene (PTB7):[6,6]‐phenyl C₇₁‐butyric acid methyl ester (PC₇₁BM) with ZnO@RGO‐PVP as cathode buffer layer was greatly improved to 7.5 % with improved long‐term stability. The results reveal that ZnO@RGO‐PVP is universally applicable as a cathode buffer layer for improving the performance of PSCs.     

A Sensor for Selective Dopamine Determination Based on Overoxidized Poly-1,5-Diaminonaphthalene on Graphene Nanosheets

An effective nanocomposite sensor for selective electroanalytical dopamine (DA) determination using overoxidized conducting polymer of poly-1,5-diaminonaphthalene (OPoly-1,5-DAN) functionalized graphene nanosheets (GNS) was achieved. The OPoly-1,5-DAN/GNS nanocomposite polymer was prepared via an electropolymerization of 1,5-DAN on GNS/GCE after 7 cycles of potential scan (−0.2 V to +0.9 V), followed by an electrooveroxidation of the nanocomposite Poly-1,5-DAN/GNS by the potential cycle (0.0 V to +1.8 V) for 2 scans. The OPoly-1,5-DAN was effectively designed by GNS as a uniformly distribution of nanocomposite that caused more accumulations of analyte due to large electrocatalytic active positions created on electrode surface. The high specific and sensitive performance of the OPoly-1,5-DAN/GNS nanocomposite polymer was conducted to greater effective electrons transferring behavior for DA with copresent of vitamin C (VC). The stable and suitable formation of OPoly-1,5-DAN/GNS nanocomposite polymer showed rapid charge transport voltammogram and obvious electrocatalytic activity to DA and eliminated VC response. Moreover, the OPoly-1,5-DAN/GNS displays an excellent responses to DA determination with wide linear range (LR) 1.0–150 μM and lower detection limit (DL) 8.82±0.1 nM as comparing with other studies. Additionally, the excellent reproducibility of OPoly-1,5-DAN/GNS as well as long-term stability indicated that it is an excellent and effective electrochemical DA sensor. Finally, the electroanalytical application of the OPoly-1,5-DAN/GNS nanocomposite polymer was employed for the electroanalysis of DA in human urine.     

Synthesis and characterization of graphene oxide/modified poly(<Emphasis Type="Italic">N</Emphasis>-isopropylacrylamide) nanocomposite

In this study, the graphene oxide/poly(N-isopropylacrylamide) nanocomposite modified with 2-mercaptoethanol (GO/MPNIPAM) was synthesized in three stages. N-Isopropylacrylamide polymerization was firstly performed in the presence of azobisisobutyronitrile as an initiator, which was discovered by Homer, and 2-mercaptoethanol as a modifier. Then, the graphene oxide/modified polymer nanocomposite was synthesized by the covalent interactions between carboxylic acids of the graphene oxide and hydroxyl groups of the modified polymer during the esterification reaction. The GO/MPNIPAM nanocomposite includes some percentage of the polymer that improves solubility and stability of the GO sheets in physiological applications; due to the interaction between the MPNIPAM and the modified GO polymer, a bridge-like connection is formed between the GO sheets and the process that leads to remove a large number of hydrophilic groups on the GO nanocomposite and therefore, the GO/MPNIPAM is well dissolved in organic solvents. This property is beneficial for anti-cancer drug delivery as well as π–π interactions between the nanocomposite and aromatic drugs. The nanocomposite is not a toxic material for human body at all and has high capacity for drug delivery. Structure and morphology of the nanocomposite were studied by FTIR, SEM, XRD, UV, TGA and Raman analysis. The analysis done by X-ray diffraction pattern confirmed the presence of graphene oxide in nanocomposites and improved crystalline polymer in nanocomposites.     

Impact of in situ polymer coating on particle dispersion into solid laser-generated nanocomposites

The crucial step in the production of solid nanocomposites is the uniform embedding of nanoparticles into the polymer matrix, since the colloidal properties or specific physical properties are very sensitive to particle dispersion within the nanocomposite. Therefore, we studied a laser-based generation method of a nanocomposite which enables us to control the agglomeration of nanoparticles and to increase the single particle dispersion within polyurethane. For this purpose, we ablated targets of silver and copper inside a polymer-doped solution of tetrahydrofuran by a picosecond laser (using a pulse energy of 125 μJ at 33.3 kHz repetition rate) and hardened the resulting colloids into solid polymers. Electron microscopy of these nanocomposites revealed that primary particle size, agglomerate size and particle dispersion strongly depend on concentration of the polyurethane added before laser ablation. 0.3 wt% polyurethane is the optimal polymer concentration to produce nanocomposites with improved particle dispersion and adequate productivity. Lower polyurethane concentration results in agglomeration whereas higher concentration reduces the production rate significantly. The following evaporation step did not change the distribution of the nanocomposite inside the polyurethane matrix. Hence, the in situ coating of nanoparticles with polyurethane during laser ablation enables simple integration into the structural analogue polymer matrix without additives. Furthermore, it was possible to injection mold these in situ-stabilized nanocomposites without affecting particle dispersion. This clarifies that sufficient in situ stabilization during laser ablation in polymer solution is able to prevent agglomeration even in a hot polymer melt.     

Synthesis of poly(arylene disulfide)-vermiculite nanocomposites via in situ ring-opening reaction of cyclic oligomers

An exfoliated poly(4,4^′-oxybis(benzene)disulfide) (POBDS)/vermiculite (VMT) nanocomposite was prepared by using cyclo(4,4^′-oxybis(benzene)disulfide) (COBDS) oligomers and cetyltrimethyl ammonium bromide exchanged VMT. The POBDS/VMT nanocomposites were fabricated in two steps. First, the COBDS oligomers were used to swell and exfoliate organo VMT to afford COBDS-VMT nanocomposite precursor. Subsequently, the exfoliated POBDS-VMT nanocomposite can be made via in situ and instant melt ring-opening polymerization of the COBDS-VMT nanocomposite precursor. High molecular weight POBDS polymer can be formed in a few minutes. The nano scale dispersion of VMT layers within POBDS polymer was confirmed by both the X-ray diffraction patterns and TEM examinations. This methodology provides a potential approach to synthesize high performance polymer nanocomposite.     

Stiffness constants prediction of nanocomposites using a periodic 3D‐FEM model

Predictive models, which enable the prediction of nanocomposite properties from their morphologies and account for polymer orientation, could greatly assist the exploitation of this new class of materials in more diversified and demanding market fields. This article focuses on the prediction of effective elastic properties (Young's moduli) of polymer nanocomposite films (copolyamide‐6/nanoclay) using 3D analytical (based on the Mori‐Tanaka theory) and 3D finite element (FE) models. The analytical model accounts for the orientation of polymer chains induced by drawing. 3D FE model exploits the representative volume element concept and accounts for the nanocomposite morphology as determined from transmission electron microscopy experiments. Model predictions were compared with experimental results obtained for nanocomposite films produced by means a pilot‐scale film blowing equipment and collected at different draw ratios. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012     

Effect of nanoscale CeO<Subscript>2</Subscript> on PVDF-HFP-based nanocomposite porous polymer electrolytes for Li-ion batteries

New poly (vinylidenefluoride-co-hexafluoro propylene) (PVDF-HFP)/CeO₂-based microcomposite porous polymer membranes (MCPPM) and nanocomposite porous polymer membranes (NCPPM) were prepared by phase inversion technique using N-methyl 2-pyrrolidone (NMP) as a solvent and deionized water as a nonsolvent. Phase inversion occurred on the MCPPM/NCPPM when it is treated by deionized water (nonsolvent). Microcomposite porous polymer electrolytes (MCPPE) and nanocomposite porous polymer electrolytes (NCPPE) were obtained from their composite porous polymer membranes when immersed in 1.0 M LiClO₄ in a mixture of ethylene carbonate/dimethyl carbonate (EC/DMC) (v/v = 1:1) electrolyte solution. The structure and porous morphology of both composite porous polymer membranes was examined by scanning electron microscope (SEM) analysis. Thermal behavior of both MCPPM/NCPPM was investigated from DSC analysis. Optimized filler (8 wt% CeO₂) added to the NCPPM increases the porosity (72%) than MCPPM (59%). The results showed that the NCPPE has high electrolyte solution uptake (150%) and maximum ionic conductivity value of 2.47 × 10⁻³ S cm⁻¹ at room temperature. The NCPPE (8 wt% CeO₂) between the lithium metal electrodes were found to have low interfacial resistance (760 Ω cm²) and wide electrochemical stability up to 4.7 V (vs Li/Li⁺) investigated by impedance spectra and linear sweep voltammetry (LSV), respectively. A prototype battery, which consists of NCPPE between the graphite anode and LiCoO₂ cathode, proves good cycling performance at a discharge rate of C/2 for Li-ion polymer batteries.     

IDM release behavior and surface characteristics of the novel Cu/IDM/LDPE nanocomposite for intrauterine device

Copper/indomethacin/low-density polyethylene (Cu/IDM/LDPE) nanocomposite was prepared as a novel material for intra-uterine device (IUD). IDM release profile of the nanocomposite was investigated by using spectrophotometer. The results show that IDM release rate of Cu/IDM/LDPE nanocomposite is higher in simulated uterine solution than that in methanol, confirming that the release process of IDM is dominated mainly by pore diffusion. The decrease in copper particle size and the increase in copper mass content all accelerate IDM release, indicating that IDM release rate can be adjusted by changing copper loading or copper particle size. The surface of the incubated nanocomposite was characterized by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray microanalysis. A few deposits composed of P, Cl, Ca, Cu and O were observed on the nanocomposite surface, which may be related to the presence of IDM particles with large particle size.     

Preparation and characterization of polymer/silica nanocomposites via double in situ miniemulsion polymerization

Polymer/SiO₂ nanocomposite microspheres were prepared by double in situ miniemulsion polymerization in the presence of methyl methacrylate, butyl acrylate, γ‐methacryloxy(propyl) trimethoxysilane, and tetraethoxysilane (TEOS). By taking full advantage of phase separation between the growing polymer particles and TEOS, inorganic/polymer microspheres were fabricated successfully in a one‐step process with the formation of SiO₂ particles and the polymerization of organic monomers taking place simultaneously. The morphology of nanocomposite microspheres and the microstructure, mechanical properties, thermal properties, and optical properties of the nanocomposite films were characterized and discussed. The results showed that hybrid microspheres had a raspberry‐like structure with silica nanoparticles on the shells of polymer. The silica particles of about 20 nm were highly dispersed within the nanocomposite films without aggregations. The transmittance of nanocomposite film was comparable to that of the copolymer film at around 70–80% from 400 to 800 nm. The mechanical properties and the fire‐retardant behavior of the polymer matrix were improved by the incorporation of silica nanoparticles. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3128–3134, 2010     

Enhanced dielectric response in P(VDF‐TrFE) based all‐organic nanocomposites

A nanocomposite with enhanced dielectric response is developed using poly(vinylidene fluoride‐trifluoroethylene) [P(VDF‐TrFE)] as matrix and Chemically modified high dielectric constant organic semiconductor—copper phthalocyanine oligomer (CuPc)—as filler. Transmission electron microscope (TEM)‐observed morphologies reveal that in the nanocomposite the average size of CuPc particles is about 25 nm [1/24 of that of CuPc in physical blend of P(VDF‐TrFE) and CuPc]. The hot‐press nanocomposite film with 15 wt % CuPc can realize a dielectric constant of 540 at 100 Hz. The enhanced dielectric response in the nanocomposite demonstrates the significance of the interface effect in raising the material responses far beyond that expected by simple mixing rules when there is a large dielectric contrast between the polymer matrix and the dielectric filler in the composite. It is also interesting to note that at high frequencies (such as 100 MHz) the nanocomposite has a dielectric constant of ～100 and this value is comparable to those of current materials used in microwave applications. At 105 °C that is near the ferroelectric‐to‐paraelectric phase transition temperature of the P(VDF‐TrFE) ferroelectric, a much higher dielectric constant (about 1200 at 100 Hz) is obtained. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 490–495, 2010     

电解重量法测定混合铜矿中自由氧化铜

建立了用于混合铜矿石中自由氧化铜测定的方法。试样用含亚硫酸钠(6g/L)的硫酸(10%)溶液浸取2h,选择性溶解铜氧化物,过滤并煮沸滤液,用去离子水稀释后电解。溶液中的铜离子电积至阴极铂网上。用火焰原子吸收光谱法检测残余于电解后液中的铜离子;同时用硝酸(1+1)溶解铂网上的铜,并用火焰原子吸收光谱法检测与阴极铜共电积的杂质元素含量,用铂阴极差重加上电积后液残余铜含量并减去共电积的杂质元素含量可计算出氧化铜矿中酸溶铜含量。与碘量法相比,不用肉眼观察颜色变化确定终点,人为误差小,结果稳定、准确。通过对加拿大氧化铜矿标准物质AMIS0050进行测定(n=12),方法准确度可靠。并选取15批次的氧化铜矿检测,与经典碘量法比对,结果令人满意。     

The mechanism of electroreduction of nitrate ions on a hybrid electrode nanodispersed copper-MK-40 membrane

Based on a MK-40 sulfocation-exchange membrane, a hybride electrode material containing nanodispersed copper is prepared. The methods of scanning electron microscopy and X-ray diffraction (XRD) analysis reveal the formation of copper agglomerates measuring 250–470 nm and consisting of individual particles of 20–30 nm. The procedure of multistage chemical deposition of copper into the ion-exchange carrier makes it possible to obtain a continuous cluster of metal particles which determines the electron conducting properties of the resulting hybrid material. The electrochemical activity of the nanocomposite electrode is studied in the reaction of nitrate ion electroreduction. Nanodispersed copper deposited into the membrane is shown to intensify the electroreduction of nitrate ions by a factor of 1.5–2 as compared with a compact copper electrode. The electroreduction of nitrate ions on compact copper is shown to involve 6 electrons, whereas the electroreduction on the nanocomposite involves 8 electrons. The electroreduction products of nitrate ions are identified by the IR spectroscopy method.     

Enhanced ionic conductivity in novel nanocomposite gel polymer electrolyte based on intercalation of PMMA into layered LiV3O8

In the present work, a novel polymer electrolyte based on poly(methyl methacrylate) (PMMA)/layered lithium trivanadate (LiV₃O₈) nanocomposite has been investigated. X-ray diffraction (XRD) study shows that d-spacing is increased from 6.3?±?0.1 Å to 12.8?±?0.1 Å upon intercalation of the polymer into the layered LiV₃O₈. Room temperature ionic conductivity of the obtained nanocomposite gel polymer electrolyte is found to be superior to that of conventional PMMA-based gel polymer electrolyte. Enhancement in ionic conductivity of the nanocomposite gel electrolyte is attributed to the formation of a two-dimensional channel as a result of decreased interaction between Li⁺ and V₃O ₈ ^? layers as confirmed by FTIR. SEM results show aggregation of nanocomposite particles resulting from extension of some of the polymer chains from interlayer to the edge providing paths for Li⁺ ion transport. Interfacial stability of nanocomposite gel electrolyte is also found to be better than that of the conventional PMMA-based gel polymer electrolyte.     

Antibacterial nanocomposite supporting cell growth and spheroid formation by chemical surface treatment of polymer foil

Octenidine dihydrochloride (OCT) has a wide spectrum of antibacterial, antifungal and virucidal activity. OCT is also newly used in tissue engineering. The aim of this work was to create a new nanocomposite consisting of OCT-grafted polymer with (i) antibacterial effect and/or (ii) surface for better cell adhesion and proliferation. The polymer foils were chemically activated with Piranha solution and subsequently grafted with OCT. Changes in surface properties before and after modifications were detected by electrokinetic analysis, goniometry, atomic force microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy. The final nanocomposite polymer/OCT exhibits antibacterial activity against Staphylococcus epidermidis (S. epidermidis). The new nanocomposite material has also been shown to support the growth of B14 cell culture on the substrate and to form cell multilayers, which could lead to the formation of spheroids. This behaviour strongly depends on the concentration of OCT grafted onto the polymer surfaces. This new nanocomposite could be used in medicine, for bioapplications, environmental protection.     

Copper sols stabilized by poly(ethylene glycol-600-monolaurate) and its complexes with poly(acrylic acid)

Copper sols stabilized by a polymer-colloid complex are studied via dynamic light scattering and transmission electron microscopy. It is shown that the polymer-colloid complex including poly(acrylic acid) and the nonionogenic polymeric surfactant poly(ethylene glycol-600-monolaurate) is an effective protector of copper nanoparticles formed via the reduction of Cu²⁺ ions in an aqueous medium. The sizes of sol particles of the nanocomposite consisting of the polymer-colloid complex and copper nanoparticles depend on the method of preparation of the nanocomposite. The incorporation of the copper nanoparticles being formed (an average diameter of 5 nm) into particles of the polymer-colloid complex leads to an insignificant change in the sizes of the complex particles. The same sizes are typical for particles of the nanocomposite formed during the introduction of surfactant micelles in the copper sol formed in the solution of poly(acrylic acid). The interaction of copper nanoparticles formed in an aqueous medium with surfactant micelles entails their aggregation; as a result, these nanoparticles turn out to be incorporated into large aggregates with equivalent radii of up to 100 nm. When poly(acrylic acid) is incorporated into this sol, the sizes of its particles insignificantly change apparently because of the low rate of structural rearrangements accompanying the formation of the polymer-colloid complex.