Improving surface quality of polyethylene terephthalate film for large area flexible electronic applications

Lamination is a method utilized to protect flexible electroluminescence device against environmental hazards, such as dust, moisture, and water vapor. The materials are typically joined together using adhesive or cohesion of the materials during the lamination process. Polyethylene terephthalate (PET) is commonly used as the substrate film where electroluminescence patterns are printed. However, PET film has a relatively low surface energy and high contact angle, which would cause relatively weak laminating strength. This paper discusses the use of atmospheric plasma as a surface treatment method to modify PET and laminating films’ interface to improve bonding and laminating quality. Experimental results revealed that atmospheric plasma process reduced the contact angle of both PET and laminating films. Functional groups favoring hydrophilicity were found on the films’ interface after the atmospheric plasma treatment. These effects consequently increased surface energies of both films and favored bonding between the films. The treated films thus had increased laminating strength by approximately six times without compromising the transparency quality.     

Studies with azoles and benzoazoles: A novel simple approach for synthesis of 3‐functionally substituted 3‐acylindoles

3‐Substituted acylindoles 8 are obtained via refluxing carboxylic acids with indole in acetic anhydride solutions. The formed 3‐substituted acylindole 8a is readily converted into 4‐aminopyrazol‐3‐ylindoles 20 , and into 22 . Indole reacts with chloroacetyl chloride to yield: 3‐chloroacetylindole 9 which could also be utilized for synthesis of a number of 3‐substituted indoles.     

Multifunctional Polyoxometalate Platforms for Supramolecular Light-Driven Hydrogen Evolution**

Multifunctional supramolecular systems are a central research topic in light-driven solar energy conversion. Here, we report a polyoxometalate (POM)-based supramolecular dyad, where two platinum-complex hydrogen evolution catalysts are covalently anchored to an Anderson polyoxomolybdate anion. Supramolecular electrostatic coupling of the system to an iridium photosensitizer enables visible light-driven hydrogen evolution. Combined theory and experiment demonstrate the multifunctionality of the POM, which acts as photosensitizer/catalyst-binding-site^[1] and facilitates light-induced charge-transfer and catalytic turnover. Chemical modification of the Pt-catalyst site leads to increased hydrogen evolution reactivity. Mechanistic studies shed light on the role of the individual components and provide a molecular understanding of the interactions which govern stability and reactivity. The system could serve as a blueprint for multifunctional polyoxometalates in energy conversion and storage.     

Integrated mathematical forms for update of physical parameter matrices of damped dynamic system

Mathematical modelling and updating of damped dynamic systems that involve some modelling errors and subsequent analysis based on those errors will lead to inaccuracy in the results. Because measured and analytical data are unlikely to be identical due to measurement noise and model inadequacies, it is necessary to estimate more accurate parameter matrices for design and analysis. By minimizing a cost function expressed as the sum of the norms of the difference between analytical and experimental parameter matrices, this study directly derives the integrated mathematical expressions for updated physical parameter matrices. In the derivation process, the eigenfunction of a damped dynamic system is utilized as a constraint equation for the updating. It is illustrated that the proposed methods take more explicit forms and can be widely utilized in the damped and undamped systems. Based on the comparison with other methods, the validity of the proposed methods is demonstrated in numerical applications.     

Electrical sorting of Caenorhabditis elegans

The nematode (worm) C. elegans is one of the widely studied animal model organisms in biology. It develops through 4 larval stages (L1-L4) in 2 to 3 days before becoming a young adult. Biological assays involving C. elegans frequently require a large number of animals that are appropriately staged and exhibit a similar behaviour. We have developed a new method to synchronize animals that relies on the electrotactic response (electric field-induced motion) of C. elegans to sort them in parallel based on their age, size and phenotype. By using local electric field traps in a microfluidic device, we can efficiently sort worms from a mixed culture in a semi-continuous flow manner (with a minimum throughput of 78 worms per minute per load-run) and obtain synchronized populations of animals. In addition to sorting larvae, our device can also distinguish between young and old adults efficiently. Unlike fluorescent based sorting systems that use active imaging based feedback, this method is passive and automatic and uses the innate behaviour of the worm. Considering that the entire procedure takes only a few minutes to run and is cost-effective, it promises to simplify and accelerate experiments requiring homogeneous cultures of worms as well as to facilitate isolation of mutants that have abnormal electrotaxis. More importantly, our method of isolating and separating worms using locomotion as a defining characteristic promises development of advanced microfluidics-based systems to study the neuronal basis of movement-related defects in worms and facilitate high-throughput chemical screening and drug discovery.     

A simple route to the energy shift between an electrically polarizable molecule and a magnetically susceptible molecule via the electromagnetic energy density

The van der Waals dispersion interaction between a molecule that is electrically polarizable and one that is magnetically susceptible, is recalculated within the framework of non-relativistic quantum electrodynamics. The energy shift is obtained in a simple way by calculating the response of a test polarizable body to the electromagnetic energy density due to a second source molecule. It is confirmed that the near-zone asymptote of the potential between an electric dipole polarizable molecule and a paramagnetic one varies as R ^{? 4}. Inclusion of the often neglected diamagnetic coupling term, however, results in an R ^?5 dependent short-range behaviour, which is seen to dominate over the paramagnetic contribution in the near-zone. For larger intermolecular distances, the expected R ^?7 dependence on separation is found for both paramagnetic and diamagnetic susceptible molecules interacting with an electric dipole polarizable one.     

On the value of homology models for virtual screening: discovering hCXCR3 antagonists by pharmacophore-based and structure-based approaches

Human chemokine receptor CXCR3 (hCXCR3) antagonists have potential therapeutic applications as antivirus, antitumor, and anti-inflammatory agents. A novel virtual screening protocol, which combines pharmacophore-based and structure-based approaches, was proposed. A three-dimensional QSAR pharmacophore model and a structure-based docking model were built to virtually screen for hCXCR3 antagonists. The hCXCR3 antagonist binding site was constructed by homology modeling and molecular dynamics (MD) simulation. By combining the structure-based and ligand-based screenings results, 95% of the compounds satisfied either pharmacophore or docking score criteria and would be chosen as hits if the union of the two searches was taken. The false negative rates were 15% for the pharmacophore model, 14% for the homology model, and 5% for the combined model. Therefore, the consistency of the pharmacophore model and the structural binding model is 219/273 = 80%. The hit rate for the virtual screening protocol is 273/286 = 95%. This work demonstrated that the quality of both the pharmacophore model and homology model can be measured by the consistency of the two models, and the false negatives in virtual screening can be reduced by combining two virtual screening approaches.     

Effect of oxidation treatment of multi-walled carbon nanotubes on the adsorption of pentachlorophenol from aqueous solution: Kinetics study

Multi-walled carbon nanotubes (MWCNTs) were oxidized using different oxidizing agents and the produced oxidized MWCNTs were characterized using different techniques. IR measurements showed the presence of carboxylic acid function groups especially for the MWCNTs oxidized with nitric acid and hydrogen peroxide. The adsorption of pentachlorophenol (PCP) to pristine and oxidized multi-walled carbon nanotubes (MWCNTs) has been studied. The results showed that the oxidation of the MWCNTs decreased their abilities to adsorb PCP compared with the pristine MWCNTs. The adsorption was studied kinetically and the results showed that the adsorption process occurs in two different steps. The first step involves the transfer of PCP to the surface of the oxidized MWCNTs, which was very fast due to the diffusion of PCP from the liquid phase to the solid phase. This step followed by a second slower step of adsorption could be due to intra-particle diffusion.     

Reactivity-selectivity study of the Friedel-Crafts acetylation of 3,3' -dimethylbiphenyl and the oxidation of the acetyl derivatives

ABSTRACT: BACKGROUND: Friedel-Crafts acetylation is an important route to aromatic ketones, in research laboratories and in industry. The acetyl derivatives of 3,3' -dimethylbiphenyl (3,3' -dmbp) have applications in the field of liquid crystals and polymers and may be oxidized to the dicarboxylic acids and derivatives that are of interest in cancer treatment. FINDINGS: The effect of solvent and temperature on the selectivity of monoacetylation of 3,3'-dmbp by the Perrier addition procedure was studied using stoichiometric amounts of reagents. 4-Ac-3,3' -dmbp was formed almost quantitatively in boiling 1,2-dichloroethane and this is almost twice the yield hitherto reported. Using instead a molar ratio of substrate:AcCl:AlCl3 equal to 1:4:4 or 1:6:6 in boiling 1,2-dichloroethane, acetylation afforded 4,4' - and 4,6' -diacetyl-3,3' -dmbp in a total yield close to 100%. The acetyl derivatives were subsequently converted to the carboxylic acids by hypochlorite oxidation. The relative stabilities of the isomeric products and the corresponding sigma-complexes were studied by DFT calculations and the data indicated that mono- and diacetylation followed different mechanisms. CONCLUSIONS: Friedel-Crafts acetylation of 3,3' -dmbp using the Perrier addition procedure in boiling 1,2-dichloroethane was found to be superior to other recipes. The discrimination against the 6-acetyl derivative during monoacetylation seems to reflect a mechanism including an AcCl:AlCl3 complex or larger agglomerates as the electrophile, whereas the less selective diacetylations of the deactivated 4-Ac-3,3' -dmbp are suggested to include the acetyl cation as the electrophile. The DFT data also showed that complexation of intermediates and products with AlCl3 does not seem to be important in determining the mechanism.