Optimization of preparation conditions on the dielectric properties of polyaniline

The dielectric response in the microwave field of polyaniline prepared at different temperatures and using different inorganic and organic dopants was studied. Chemical oxidative polymerization of aniline was done at low temperature (0–5°C), at room temperature, and at high (60°C) temperature using different inorganic dopants like HCl, HNO₃, H₂SO₄, HClO₄, etc. Polyaniline was also prepared with different organic dopants like camphor sulfonic acid, Toluene sulfonic acid, and Naphthalene sulfonic acid. All polymers formed were characterized using IR, TGA, DSC, and SEM, etc. The dielectric responses of all polymers are studied using cavity perturbation technique in the microwave field. The studies indicates that the polyaniline prepared with perchloric acid at room temperature shows higher conductivity and absorption coefficient compared with all other samples. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Sorbent injection into a slipstream baghouse for mercury control: Project summary

A project led by the Energy and Environmental Research Center to test and demonstrate sorbent injection as a cost-effective mercury control technology for utilities burning lignites has shown effective mercury capture under a range of operating conditions. Screening, parametric, and long-term tests were carried out at a slipstream facility representing an electrostatic precipitator–activated carbon injection–fabric filter configuration (called a TOXECON™ in the United States). Screening tests of sorbent injection evaluated nine different sorbents, including both treated and standard activated carbon, to compare mercury capture as a function of sorbent injection rate. Parametric tests evaluated several variables including air-to-cloth (A/C) ratio, flue gas temperature, cleaning frequency, and dust loading to determine the effect on mercury control and systems operation. Long-term tests (approximately 2 months in duration) evaluated the sustainability of systems operation.     

Synthesis and characterisation of macroporous Yttria Stabilised Zirconia (YSZ) using polystyrene spheres as templates

Yttria Stabilised Zirconia (YSZ) is commonly used as an oxygen sensor and an oxygen pump in automotive and industrial applications, and is a choice electrolyte for Solid Oxide Fuel Cell (SOFC) technology. YSZ is also a major component of the SOFC electrodes, and is commonly mixed with 50% volume NiO to create a Ni/YSZ cermet anode. In both the adsorption and fuel cell applications homogeneous control of the porosity of YZS is important. Templating methods provide well ordered macroporous structures and have been used to prepare ordered, macroporous YSZ from metal nitrate precursors using polystyrene spheres of 1 μm as templates. Ordered three-dimensional structures were synthesised and the effects of sintering temperatures of 650–1400 °C on pore size, particle size and pore wall thickness were examined. Ordered porosity was maintained at all temperatures, though some structural degradation and sintering was observed at 1400 °C. This study demonstrated that templated porosity is maintained well above the conventional sintering temperature of the electrodes, and higher than previous studies reported. The stability of these structures at high temperatures makes this fabrication technique a promising alternative to conventional methods of synthesising porous materials.     

Alternating phenylenevinylene copolymers with dithienbenzothiadiazole moieties: Synthesis,photophysical, and photovoltaic properties

Two new soluble alternating phenylenevinylene copolymers S and L which contained dithienbenzothiadiazole moieties were synthesized by Heck coupling. The repeating unit of L was longer than that of S and contained two additional phenylene rings and two cyano‐vinylene bonds. Both copolymers were stable up to about 350°C and afforded char yield of 52–66% at 800°C in N₂. Their absorption spectra were broad and extended up to about 600 nm with a longer wavelength maximum at 447–502 nm and optical band gap of ～ 2.0 eV. These copolymers emitted yellow light in solution with PL maximum at 551–580 nm and orange‐red light in thin film with PL maximum at 588–661 nm. The emission maximum of L was considerably red‐shifted relative to S . Photovoltaic cells based on S (or L ) as donor and [6,6]‐phenyl C61‐butyric acid methyl ester as acceptor were investigated. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Efficient Synthesis of Highly Active Phospha‐Isosteres of the Influenza Neuraminidase Inhibitor Oseltamivir

With a Hunsdiecker–Barton iododecarboxylation strategy, we converted the carboxylate group of the oseltamivir precursor into exemplary phosphonate monoesters. In all cases, K_i values towards influenza virus sialidase remained in the sub‐nanomolar range. We have thus made valuable structural space available for the design of novel oseltamivir‐based tools for influenza virus research.

     

Evaluating the processability of film blowing resins

A key factor that limits the production rate in film blowing is bubble instability. Although processing conditions play an important role, it is well known that some resins are more resistant to instabilities than others. It is clear that long‐chain branching enhances stability, but it is not currently possible to model the process with sufficient accuracy to establish a quantitative relationship between rheological properties and blown film processability. It would thus be useful to be able to compare the processabilities of film resins by means of a laboratory measurement. We compared two laboratory tests that may be helpful in evaluating the ability of a resin to resist instabilities in the film blowing process. One of these was a film resin tester designed to simulate some aspects of the film blowing process, and the other was an extensional rheometer. We used a set of polyethylene resins that had been used previously in an extensive study of blown film stability. The extensional rheometer clearly shows the superiority of low‐density polyethylene but is not able to distinguish among polymers of other types. The melt tester, on the other hand, is sensitive to differences among linear polymers. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

Textile research and development in the UK – success or failure?

Although initially lagging behind the USA, the amount and quality of research and development carried out in the UK can be compared favourably with that from other major world countries. The industrial research association, although a well‐conceived concept to increase research and development efforts that gave significant results, was disappointing for several reasons. A major problem has been the dissemination, exploitation and commercialisation of research results. The activities of research organisations need to be reviewed regularly, as they may have a relatively short lifespan. The intermediate research and technology sector, given adequate support, may be the vehicle for better utilisation of research and development results.     

A Practical Method for Targeted Library Design Balancing Lead‐like Properties with Diversity

Choosing the right compounds to synthesise from large virtual combinatorial libraries is a current challenge for the pharmaceutical industry. Herein we describe a highly optimised method that aligns lead‐like properties with compound diversity. The methods are illustrated by considering a two‐dimensional library based on the interesting spirocyclic bis‐azetidine template.

     

Discovery of a Potent,CNS‐Penetrant Orexin Receptor Antagonist Based on an N,N‐Disubstituted‐1,4‐diazepane Scaffold that Promotes Sleep in Rats

Silent Night : Antagonism of the orexin (or hypocretin) system has recently been identified as a novel mechanism for the treatment of insomnia. Herein, we describe discovery of a dual (OX₁R/OX₂R) orexin receptor antagonist featuring a 1,4‐diazepane central constraint that blocks orexin signaling in vivo. In telemetry‐implanted rats, oral administration of this antagonist produced a decrease in wakefulness, while increasing REM and non‐REM sleep.

     

Aphid deterrence by glucose esters in glandular trichome exudate of the wild tomato,Lycopersicon pennellii

Settling of the potato aphid,Macrosiphum euphorbiae, on feeding membranes was deterred by methanolic leaf rinses ofLycopersicon pennellii, or of its F₁ with tomato,L. esculentum. The active compounds in theL. pennellii rinsates were identified as 2,3,4-tri-O-acylglucoses bearing short to medium chain length fatty acids. These compounds are localized in the glandular exudate of the type IV trichomes and may accumulate to levels in excess of 400 g/cm². In choice assays, purified glucose esters fromL. pennellii reduced aphid settling at concentrations as low as 25 g/cm²; at concentrations of 150 g/cm² or more, all aphids avoided treated areas. Glucose esters were also active in deterring aphid settling in no-choice assays. At 100 g/ cm², these esters resulted in increased levels of mortality after 48 hr.