The influence of ionic liquid's nature on free radical polymerization of vinyl monomers and ionic conductivity of the obtained polymeric materials

Various 1,3‐dialkylimidazolium and tetraalkylphosphonium ionic liquids (ILs), including novel ones, have been studied as reaction media for free radical polymerization of methyl methacrylate (MMA), acrylonitrile (AN) and 1‐vinyl‐3‐ethylimidazolium salts (ViEtIm⁺)Y^?. The influence of IL's nature upon the polymer formulation was investigated. The use of different ionic liquids allows not only to obtain the polymers with high molecular weight (PMMA, up to 5,770,000 g/mol; PAN, up to 735,000 g/mol and poly[(ViEtIm⁺)Y^?], up to 1,130,000 g/mol) in high yields, but also to control the polymerization rate and molecular mass. The physicochemical characteristics, including mechanical properties, thermal stability and heat‐resistance of the obtained polymers were studied in order to compare with those of polymers prepared in a traditional media. It was found that elongation, tensile modulus and strength of PAN, which was synthesized in ionic liquid, are reliatively higher. The influence of IL's nature upon their ionic conductivity and the formation of conductive polymers from molten‐salt‐type vinyl monomers was investigated. Molecular design of the polymers simultaneously with the influence of IL's nature in order to achieve higher ionic conductivity is discussed. Flexible, transparent polymer films, obtained in different ways, show relatively high ionic conductivity (of about 10^?5 S cm^?1 at 20°C). Copyright © 2006 John Wiley & Sons, Ltd.     

Light-scattering by optically soft randomly oriented spheroids

In the framework of the Rayleigh–Gans–Debye approximation and anomalous diffraction approaches, the light scattering characteristics of randomly oriented spheroids have been investigated. It has been proved that the system of randomly oriented spheroids is equivalent to the system of polydisperse spherical particles that have the same values of volume and surface area as nonspherical particles. The power law size distribution meeting these requirements has been obtained.     

Arylboronic compounds – novel carriers for catecholamine selective membrane electrodes

Arylboronic acids are used as novel carriers for membrane electrodes suitable for direct potentiometric determination of the catecholamine drug dobutamine. The carriers are capable of binding diol groups of catecholamines; solvent extraction data confirm the formation of an 1 : 1 complex. For the electrode based on octyloxyphenylboronic acid, the slope of electrode function is S = 58 mV decade^–1; the detection limit is 1.7 · 10^–5 mol/L, the linear range 5 · 10^–4– 1 · 10^–2 mol/L, the response time 10–20 s. The results suggest the potential use of boronic carriers for the detection of biogenic catecholamines. Received: 25 November 1998 / Revised: 2 March 1999 / Accepted: 11 March 1999     

Lagrange transformations and duality for corner and flag singularities

Singularities on a space with a fixed collection of subspaces are studied. Homological objects for the singularities are constructed. A Lagrange transformation of the singularities is defined. It is shown that on the set of the isolated singularities, the Lagrange, transformation is an involution realizing the duality of corresponding homological objects. Supported by grant No. 6836-2-96 of the Israel Science Ministry.     

Design,Cytotoxicity and Antiproliferative Activity of 4-Amino-5-methyl-thieno[2,3-d]pyrimidine-6-carboxylates against MFC-7 and MDA-MB-231 Breast Cancer Cell Lines

Novel 4-amino-thieno[2,3-d]pyrimidine-6-carboxylates substituted at the second position were prepared by cyclocondensation of 2-amino-3-cyano-thiophene and aryl nitriles in an acidic medium. The design of the target compounds was based on structural optimization. The derivatives thus obtained were tested in vitro against human and mouse cell lines. The examination of the compound effects on BLAB 3T3 and MFC-10A cells showed that they are safe, making them suitable for subsequent experiments to establish their antitumor activity. The photoirritancy factor of the compounds was calculated. Using the MTT test, the antiproliferative activity to MCF-10A, MCF-7 and MDA-MB-231 cell lines was estimated. The best antiproliferative effect in respect to the MCF-7 cell line revealed compound 2 with IC₅₀ 4.3 ± 0.11 µg/mL (0.013 µM). The highest selective index with respect to MCF-7 cells was shown by compound 3 (SI = 19.3), and to MDA-MB-231 cells by compound 2 (SI = 3.7). Based on energy analysis, the most stable conformers were selected and optimized by means of density functional theory (DFT). Ligand efficiency, ligand lipophilicity efficiency and the physicochemical parameters of the target 4-amino-thienopyrimidines were determined. The data obtained indicated that the lead compound among the tested substances is compound 2.     

Mechanism of formation of adsorption complexes amikacin–detonation nanodiamond

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Throughput optimization in robotic cells with input and output machine buffers: A comparative study of two key models

We consider the problem of scheduling operations in a robotic cell processing a single part type. Each machine in the cell has a one-unit input buffer and a one-unit output buffer. The machines and buffers are served by one single gripper robot. The domain considered is free-pickup cells with additive inter-machine travel time. The processing constraints specify the cell to be a flow shop. The objective is to find a cyclic sequence of robot moves that minimizes the long-run average time to produce a part or, equivalently, maximizes throughput. Bufferless robotic cells have been studied extensively in the literature. However, the few studies of robotic cells with output buffers at each machine have shown that the throughput can be improved by such a configuration. We show that there is no throughput advantage in providing machine input buffers in addition to output buffers. The equivalence in throughput between the two models has significant practical implications, since the cost of providing additional buffers at each machine is substantial.     

Polymerization of the new double‐charged monomer bis‐1,3(N,N,N‐trimethylammonium dicyanamide)‐2‐propylmethacrylate and ionic conductivity of the novel polyelectrolytes

The achievement of high ionic conductivity in single‐ion conducting polymer electrolytes is one of the important aims for various electrochemical devices including modern lithium batteries. One way to enhance the ionic conductivity in polyelectrolyte systems is to increase the quantity of charge carriers in each monomer unit. Highly charged poly(bis‐1,3(N,N,N‐trimethylammonium)‐2‐propylmethacrylate) with one of the most conducting anions, namely dicyanamide, was prepared via free radical bulk polymerization or using ionic liquids as reaction medium. The cationic polymers of the double‐charged monomer have molar masses up to = 1,830,000 g/mol and the ionic conductivity equal to 5.51 × 10^?5 S / cm at 25°C. The film forming ability, crystallinity, thermal stability, and glass transition temperatures of the new polymeric ionic liquids obtained from detailed studies are presented. Copyright © 2009 John Wiley & Sons, Ltd.