Stretchable strain sensors based on polyaniline/thermoplastic polyurethane blends

Polymer Bulletin - Thermoplastic polyurethane/polyaniline-based stretchable strain sensors were prepared via in situ polymerization of aniline in the TPU solution in the form of thin films. The...     

From two-dimensional colloidal self-assembly to three-dimensional nanolithography

A number of "top-down" lithographic and "bottom-up" self-assembly methods have been developed to fabricate three-dimensional (3D) nanostructures to support the recent advances in nanotechnology. But they are limited by a number of factors such as fabrication cost, pattern resolution, and/or flexibility of geometry. Here we present a 3D nanolithography process that utilizes self-assembled nanospheres to create a periodic array of focal spots, which are then replicated across multiple depth in a transparent medium according to the Talbot effect. The Talbot field then exposes a pattern onto the underlying photoresist, recording the 3D intensity distribution. We have demonstrated designable complex 3D periodic structures with 80 nm minimum feature size, roughly one-fourth of the operating wavelength. This approach combines 2D colloidal self-assembly and 3D phase lithography, is robust, cost-effective, and widely applicable to nanoscale research and manufacturing.     

Synthesis,Characterization and Effect of a Solvent Mixture on the CMC of a Thio-Based Novel Cationic Surfactant Using a UV–Visible Spectroscopic Technique

A novel thio-based cationic surfactant has been synthesized by a new method. It was characterized by different techniques such as NMR, FTIR and its critical micelle concentration was determined by a UV–Visible spectroscopic technique. It is soluble in polar solvents like ethanol and partially soluble in water due to its thio-based functionality. The detailed study of the compound 4-chloro-N-((dodecanoyl(ethyl)ammonio)carbonothioyl)-N-ethylbenzenaminium bromide (4CDTB) was done using a UV–Visible spectrophotometric technique. The effect of solvent mixtures of different ratios was investigated. On the basis of solvent–solvent interaction the compound showed different results. The critical micelle concentration varied with solvent mixture ratios. The CMC of 4CDTB decreased as the ratio of water increased in the mixture of the ethanol–water system. The decrease in critical micelle concentration with the solvent mixture ratio has been discussed on the basis of solvent properties, structures, and their hydrophilic and hydrophobic interactions.     

Method to Characterize the Air Flow and Water Removal Characteristics During Vacuum Dewatering. Part II—Analysis and Characterization

This is part II of a study reported earlier on a method to characterize the air flow and water removal characteristics during vacuum dewatering. This article presents experimental data and analysis of results from the use of a cyclically actuated vacuum dewatering device for removing moisture from wetted porous materials such as paper with the intermittent application of vacuum and accompanying air flow though the material. Results presented include sheet moisture content as a function of residence time and hence water removal rate under a variety of process conditions. Also, experimental results on air flow through the wet porous structure and hence the role and importance of air flow during vacuum dewatering are presented. Vacuum dewatering process conditions include exit solids content between 11 and 20% solid under applied vacuum conditions of 13.5 to 67.7 kPa (4 to 20 in. Hg). Regression analysis indicated that the exit sheet moisture content exhibited a nonlinear relationship with residence time with exit solids reaching a plateau after a certain residence time. Final moisture content correlated linearly with the average overall flow rate of air through the paper sample and the basis weight of the material.     

SOME FUNDAMENTAL ATTRIBUTES OF FAR INFRARED RADIATION DRYING OF POTATO

ABSTRACT

Drying experiments were carried out using a far infrared heater to examine the drying characteristics of potato slices. The effect of several parameters e.g. radiation intensity, inlet air velocity and relative humidity on moisture and temperature history are presented. FIR drying of potato was observed to be a falling rate process. Drying rates were negatively correlated with air velocity. Relative humidity did not influence the drying rate. It was found that the modified exponential law describes the moisture removal of potato within an acceptable range.     

Synthesis of Silver Nanoparticles Using Syzygium malaccense Fruit Extract and Evaluation of Their Catalytic Activity and Antibacterial Properties

Journal of Inorganic and Organometallic Polymers and Materials - In this study, green synthesis of silver nanoparticles, an aqueous Syzygium malaccense fruit extract, was employed...     

Ureidosulfocoumarin Derivatives As Selective and Potent Carbonic Anhydrase IX and XII Inhibitors

Owing to severe allergic reactions (anaphylaxis) and resistance exhibited by sulfonamide-based carbonic anhydrase (CA) inhibitors, non-classical or non-sulfonamide CA inhibitors are gaining increased attention by medicinal chemists. In this context, we report the design and synthesis of 30 new non-sulfonamide sulfocoumarin derivatives as CA inhibitors. They were investigated against hCA I and II (cytosolic isozymes) as well as hCA IX and XII (transmembrane, tumor-associated enzymes). All compounds showed prominent selectivity for the tumor-associated isoenzymes hCA IX and XII over the cytosolic isoenzymes hCA I and II. Among all synthesized compounds, 1-(2,2-dioxidobenzo[e][1,2]oxathiin-6-yl)-3-(o-tolyl)urea( 5 j )and1-(3-fluorophenyl)-3-(8-methoxy-2,2-dioxidobenzo[e][1,2]oxathiin-6-yl)urea( 5 q )were found to be more potent and to have better inhibition constant values against hCA IX than the standard acetazolamide (AAZ), with K_i values of 23.6 and 23.3 nM, respectively. All other compounds were found to be active under K_i=920 nM against hCA IX and XII.This study provides a new perspective for the future development of non-sulfonamide derivatives as selective CA inhibitors.     

Polyurethane‐ and Polystyrene‐Supported 2,2,6,6‐Tetramethyl‐ piperidine‐1‐oxyl (TEMPO); Facile Preparation,Catalytic Oxidation and Application in a Membrane Reactor

In this contribution, the facile synthesis of two new polymer‐supported 2,2,6,6‐tetramethylpiperidine‐1‐oxyl (TEMPO) catalysts and their application in the catalytic oxidation of alcohols to carbonyl compounds are described. For attachment of the TEMPO group to the polymer an isocyanate functionalized polymer is chosen. This new approach facilitates the synthesis in comparison with previously existing methods which generally require deprotonation of TEMPO prior to reaction with the polymer. Following this approach, polyurethane (PU)‐ and polystyrene (PS)‐based TEMPO catalysts are prepared in a one‐step reaction from commercially available compounds. Both polymer‐supported catalysts showed promising yields for a variety of substrates using inorganic and/or organic co‐oxidants in biphasic and/or monophasic systems. The recyclability of the corresponding catalysts was studied in repetitive batch experiments using filtration or distillation depending on the support type. Furthermore, application of the homogeneous polyurethane‐supported TEMPO for the selective oxidation of benzyl alcohol in a continously operated membrane reactor is demonstrated.     

Energy optimisation from co-digested waste using a two-phase process to generate hydrogen and methane

The total energy produced from co-digested food waste and sewage sludge was compared for single phase mesophilic anaerobic digestion producing methane and two-phase hydrogen production followed by methane production. Both single and two-phase reactors were operated at close to optimum conditions. The single phase methaniser had a methane yield of 0.48 m³ methane/kg VS destroyed. The two-phase system had a hydrogen yield of 0.13 m³ hydrogen/kg VS destroyed, and a methane yield of 0.67 m³ methane/kg VS destroyed. Introduction of a hydrogen producing, pre-treatment phase increased the overall VS destruction 69-89%, however the total energy yield decreased by 13.4% due to the low hydrogen yield obtained in the first stage. The release of ammonia in the hydrogeniser was low and so with less alkalinity available, pH control was necessary. It was much higher in the methaniser and adequate to buffer any pH change. This also ensures more nitrogen in the digestate to enhance its value for recycling. The two-stage process is an attractive option where solids destruction is an important consideration but further optimisation of the hydrogen production stage is still required.