Pejman Talemi

Synthesis and characterization of nano-peanuts of lead(II) coordination polymer [Pb(qcnh)(NO3)2]n with ultrasonic assistance: A new precursor for the preparation of pure-phase nano-sized PbO

A sonochemical method was used to synthesize nano-peanuts of a new lead(II) coordination 1D polymer, [Pb(qcnh)(NO3)2]n (1), where qcnh=2-quinolincarbaldehyde nicotinohydrazide. The compound was characterized by scanning electron microscopy (SEM), elemental analysis, IR spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray powder diffraction (XRD), and single crystal X-ray analysis. The X-ray structure revealed that the Pb(II) atom is coordinated by one oxygen and three nitrogen atoms from two qcnh ligands and five oxygen atoms from three nitrate ligands in an 8+1 fashion with a PbN3O6 donor set. One of the PdN distances in the vicinity of the central atom is a bit longer (Pb1N1=2.939(4) Å), which shows the effect of the 6s2 lone electron pair localized within the valence shell of the lead(II) atom. PbO nanoparticles were obtained by thermolysis of 1 at 180°C with oleic acid as a surfactant. The average diameter of the nanoparticles was estimated by XRD to be 28nm. The morphology and size of the prepared PbO nanoparticles were further studied using SEM.

Sonochemical synthesis and structural determination of novel the nano-card house Cu(II) metal-organic coordination system

A sonochemical method by using various time and concentrations of initial reagents and power of irradiation, was used to synthesize nano-card house of a new copper(II) metal-organic coordination system, {[Cu2(p-2yeinh)2Cl2]·(H2O)}n (1), where p-2yeinh=pyridin-2-yl ethylidene-isonicotinohydrazide. The compound was characterized by scanning electron microscopy (SEM), elemental analysis, IR spectroscopy, X-ray powder diffraction (XPRD), and single crystal X-ray analysis. The X-ray structure revealed that the Cu(II) atom is coordinated by one oxygen and three nitrogen atoms from two p-2yeinh ligands and one chloride anion with a CuN3OCl donor set with square pyramid geometry. This arrangement produces a large quadric nuclear square ring composed of four square pyramid Cu(II) moieties linked together by two p-2yeinh units (M4L4). The adjacent frameworks connected by strong hydrogen bonding interactions of methanol molecules that interact together and with the rings and π-π interactions of adjacent aromatic rings of p-2yeinh and other weak interactions. Consequently, the labile interactions also allow the discrete structure to form a 3D metal-organic coordination network. CuO nanoparticles were obtained by thermolysis of 1 at 180°C with oleic acid as a surfactant. The average diameter of the nanoparticles was estimated by XPRD to be 38nm. The morphology and size of the prepared CuO nanoparticles were further studied using SEM.

The effect of block copolymer additives for a highly active polymeric metal-free oxygen reduction electrode

Electrocatalytic materials play a critical role in emerging clean energy technologies such as batteries and fuel cells. Herein, we report the fabrication of a unique conducting polymer alloy thin film electrocatalyst based on poly(3,4-ethylenedioxythiophene) (PEDOT) and a polymeric additive, polyethylene glycol–polydimethylsiloxane–polyethylene glycol. These polymeric films displayed electrocatalytic activity for the Oxygen Reduction Reaction (ORR) higher than that of platinum or other polymeric electrodes. Furthermore, the metal-free polymeric electrodes were not susceptible to ‘poisoning’ when exposed to methanol. The fabrication parameters affecting the ORR performance of the polymeric electrodes and the mechanism of the improvement of the ORR catalysis were comprehensively investigated and benchmarked against commercial Pt electrodes. The application of the conducting polymer alloy electrode in a zinc–air battery demonstrated high power output and stable performance.

Organic energy devices from ionic liquids and conducting polymers

The use of smart technologies in our daily lives, from smartphones to auto-dimming windows to touch sensors, has become pervasive. With growing desire for these devices to be conformable and flexible, traditional materials are being replaced to create a class of products known as active organic electronic devices (OEDs). These new devices owe their ability to switch electrical and/or optical function to the intimate interaction between an inherently conducting polymer and electrolyte, typically an ionic liquid. Herein, we provide the first observations that specific ionic liquids can reduce or oxidise conducting polymers upon intimate contact in the absence of any electrical stimuli. The ability to reduce or oxidise the inherently conducting polymer depends on the cation and anion pair within the ionic liquid. Extending the utility of this phenomenon is made by fabricating OEDs such as prototype fuel cells, supercapacitors and smart windows.

Ultrasonic-assisted synthesis and the structural characterization of novel the zig-zag Cd(II) metal-organic polymer and their nanostructures

A sonochemical method was used to synthesize nano-rods of a novel cadmium(II) metal-organic coordination polymer, [Cd(p-2yeinh)(NO2)]n (1) (p-2yeinh = pyridin-2-yl ethylidene-isonicotinohydrazide). The effect of the synthesis parameters such as time, concentrations and irradiation power has been studied and optimized. It was shown that the thickness of rods has changed from 27 nm to 45 nm. The compounds were characterized by scanning electron microscopy (SEM), elemental analysis, IR spectroscopy, X-ray powder diffraction (XPRD), and single crystal X-ray analysis. The X-ray structure analysis revealed that the Cd(II) atom is coordinated by one oxygen and three nitrogen atoms from two p-2yeinh ligands and two oxygen atoms of single nitrite anion with a CuN3O3 donor set with distorted octahedral geometry. The crystal taking the form of a one-dimensional zig-zag polymer. The adjacent chains connected by π-π of adjacent aromatic rings of p-2yeinh and other weak interactions. Consequently, the weak interactions also allow the 1D zig-zag structure to form a 3D metal-organic coordination polymer. CdO nanoparticles were prepared by thermolysis of compound 1 at 180 °C with oleic acid as a surfactant. The average diameter of the nanoparticles was estimated by XPRD to be 23 nm. The morphology and size of the prepared CdO nanoparticles were further studied using SEM.

Progress in conductive polymer antennas based on free-standing polypyrrole and PEDOT: PSS

In this paper, various realizations of microwave antennas based on free-standing conductive polymers including polypyrrole (PPy) and PEDOT:PSS (PEDOT) are reviewed in regard to two significant aspects: improvement of their efficiency and exploitation of their mechanical flexibility for antenna designs. On the one hand, with strategies such as simple chemical material treatments, deployment of non-resonant antenna structure and multilayer configurations, very high antenna efficiencies can be achieved. On the other hand, through the utilization of the conductive polymers and flexible, robust and low-loss substrates, reproducible antenna mechanical conformability can be achieved. All these facts suggest that conductive polymers are promising as conductor materials for flexible and wearable antenna designs.