Rapid Sonosynthesis of N‐Doped Nano TiO2 on Wool Fabric at Low Temperature: Introducing Self‐cleaning,Hydrophilicity, Antibacterial/Antifungal Properties with low Alkali Solubility,Yellowness and Cytotoxicity

Nano nitrogen‐doped titanium dioxide was rapidly prepared by hydrolysis of titanium isopropoxide at 75–80°C using in situ sonochemical synthesis by introducing ammonia. Various concentrations of titanium isopropoxide were examined to deposit nano nitrogen‐doped titanium dioxide through impregnation of the wool fabric in ultrasound bath followed by curing. The antibacterial/antifungal activities of wool samples were assessed against two common pathogenic bacteria including Escherichia coli and Staphylococcus aureus and the diploid fungus Candida albicans. The sonotreated wool fabrics indicated no adverse effects on human dermal fibroblasts. The presence of nanoparticles on the sonotreated wool fabrics were confirmed by FE‐SEM images and EDS patterns and X‐ray mapping and the crystalline size of nanoparticles were estimated through XRD results. The role of both pH and precursor concentration on the various properties of the fabric was investigated and the optimized conditions introduced using response surface methodology.     

Surface plasmon resonance detection of copper corrosion in biodiesel using polypyrrole-chitosan layer sensor

Copper corrosion is one of the important parameters used for evaluating the quality of biodiesel. In this work, a polypyrrole-chitosan sensing layer was utilized for the detection of Cu²⁺ in biodiesel using the surface plasmon resonance technique. With the sensitivity of this sensor being about 0.1 ppm, different corrosion levels could be recognized in samples that were classified as class 1a according to the standard copper strip test.     

Suzuki–Miyaura cross-coupling reactions in water using in situ generated palladium(II)–phosphazane complexes

The phosphazane derivatives(L1–3) were readily obtained by reaction of different ratios of PCl3 and PhNH2. The L1–3 derivatives were found to be efficient ligands in the palladium-catalyzed Suzuki C–C coupling reactions in water. It was determined that with the use of L1–3 /Pd(OAc)2 system as a catalyst, aryl halides undergo Suzuki cross-couplings with arylboronic acids to give the desired products in moderate to excellent yields.     

An environmentally friendly synthesis of 1,4-dihydropyrano[2,3-c]pyrazole derivatives catalyzed by tungstate sulfuric acid

An efficient three-component synthesis of 6-amino-4-aryl-5-cyano-3-metriyl-1-phenyl-1,4-dihydropyrano[2,3-c]pyrazoles via a reaction between 3-methyl-1-phenyl-2-pyrazolin-5-one,aromatic aldehydes and malononitrile using tungstate sulfuric acid as a catalyst was described.Mild conditions,good to excellent yields,easily available catalyst and easy work-up are the key features of this method.     

Solvent-Free Synthesis of Novel Highly Functionalized Dihydroanthra[1,2-b]furan-6,11-dione Derivatives

A convenient and environmentally friendly solvent-free procedure has been developed to react 1,5-dihydroxyanthraquinone with dialkyl acetylenedicarboxylates in the presence of triphenylphosphine in one pot to afford novel dialkyl (E)-2-{1,5-dihydroxy-6-[3-methoxy-1-(methoxycarbonyl)-3-oxo-2-(triphenyl-λ ⁵-phosphanylidene)propyl]-9,10-dioxo-9,10-dihydro-2-anthracenyl}-2-butanedioate 3a–c. As a result of intramolecular nucleophilic attack at 90 °C, novel dialkyl (E)-2–{2,7-dihydroxy-3-[2-methoxy-2-oxo-1-(triphenyl-λ ⁵ phosphanylidene)ethyl]-6,11-dioxo-6,11-dihydroanthra[1,2-b]furan-8-yl}-2-butanedioates 4a–c were produced in good yield.     

Synthesis and structure of mycolactone E isolated from frog mycobacterium

The structure of mycolactone E, isolated from the frog pathogen Mycobacterium liflandii, was established via organic synthesis. Within the mycolactone family of metabolites, a structural variation has been seen only at the unsaturated fatty acid moiety thus far, and mycolactone E follows this observation. Interestingly, the absolute configuration of its unsaturated fatty acid matches that of the mycolactones from human mycobacteria, rather than the structurally more closely related mycolactone F from fish mycobacteria.     

Investigation of the effects of the local environment on the surface-enhanced Raman spectra of striped gold/silver nanorod arrays

The effects of the local environment on surface-enhanced Raman scattering (SERS) spectra utilizing gold, silver, and gold/silver striped nanorod array substrates was investigated. The arrays were fabricated using an electrochemical metal deposition into an anodic aluminum oxide template. The analyte chosen for this study was p-nitroso-N,N-dimethylaniline (p-NDMA), which has an electronic structure that is highly sensitive to its surrounding environment. Changes in the peak positions and peak ratios were used to probe the influence of water and the striping pattern on the SERS signal of p-NDMA. We present the results of the fabrication and characterization of the nanorod array substrates, as well as SERS spectra of p-NDMA in both polar and nonpolar environments and SERS spectra on a variety of striped nanorod arrays. The Raman data suggests that the p-NDMA molecule exists in a more polarized state when bound to the gold as compared to the silver rods. We have attempted to use these differences to determine whether the SERS signal predominantly arises from the tips of the rods or from the interior of the array.     

Simulation and theory of flexible equilibrium polymers under poor solvent conditions

Grand canonical Monte Carlo simulation and simple statistical thermodynamic theory are used to model the aggregation and phase separation of systems of reversibly polymerizing monomers, capable of forming chains with or without the ability to cyclize into rings, with isotropic square-well attractions between nonbonded pairs of monomers. The general trend observed in simulation of chain-only systems, as predicted in a number of published theoretical works, is that the critical temperature for phase separation increases and the critical monomer density decreases with rising polymer bond strength. Introduction of the equilibrium between chains and rings into the theory lowers the predicted critical temperature and increases the predicted critical density. While the chain-only theories predict a vanishing critical density in the limit of complete polymerization, when ring formation is taken into account the predicted critical density in the same limit approaches the density of the onset of the ring-chain transition. The theoretically predicted effect of cyclization on chemical potential is in good qualitative agreement with a subset of simulation results in which chain-only systems were compared with equilibrium mixtures of rings and chains. The influence of attractions on the aggregation number and radius of gyration of chains and rings observed in simulations is also discussed.     

Coupling of air-assisted liquid–liquid microextraction method with partial least squares for simultaneous spectrophotometric determination of some preservatives

An air-assisted liquid–liquid microextraction method coupled with a multivariate calibration method, namely partial least squares (PLS), was developed for the extraction and simultaneous determination of benzoic acid (BA) and sorbic acid (SA) via a spectrophotometric approach. In this work, a two-step microextraction method was used. In the first step, analytes were extracted from acidic aqueous solution into octanol, as an organic solvent, and in the second step, the analytes were simultaneously back-extracted into an alkaline aqueous solution. The high absorption signal of octanol was the main reason to perform this back-extraction step. The effects of different parameters on the method efficiency were investigated; the parameters included extraction solvent volume, ionic strength of aqueous solution, pH, number of extraction cycles, and aqueous sample volume. Under optimum conditions, calibration graphs were seen to be linear over the range of 0.1–2.0 µg mL^?1 for the both analytes. Other analytical parameters were obtained as follows: Enrichment factors (EFs) were found to be 14.98 and 13.03, and limits of detection were determined to be 0.03 and 0.04 µg mL^?1 for BA and SA, respectively. As the last step, binary mixtures of the analytes were prepared and simultaneously extracted using the proposed method. Finally, PLS modeling was used for multivariate calibration of spectrophotometric data. It was successfully utilized for the analysis of the target analytes in real samples.