Ultra-long carbon nanotube growth on catalyst

Ultra-long carbon nanotube growth with Fe particles sitting at tip end as a function of reaction time, reaction temperature, diameter of the carbon nanotube, damping factor of the system, and the type of catalyst in chemical vapor deposition is investigated by using a theoretical analysis on the phonon vibration of the system. Simulations demonstrate that metal cluster makes and keeps the carbon atoms at tip end reactive. So carbon nanotube grows more than 4 cm. In addition, results show carbon nanotubes with larger diameter grow lesser owing to higher damping factors. In addition, effect of temperature on growth is discussed and it is shown that there is an optimum temperature for growth process. Lastly, dependence of type of catalyst on growth process is investigated.     

Design,Synthesis, EPR‐Studies and Conformational Bias of Novel Spin‐Labeled DCC‐Analogues for the Highly Regioselective Labeling of Aliphatic and Aromatic Carboxylic Acids

Novel types of spin‐labeled N,N′‐dicyclohexylcarbodiimides (DCC) are reported that bear a 2,2,6,6‐tetramethylpiperidinyloxyl (TEMPO) residue on one side and different aromatic and aliphatic cyclohexyl analogues on the other side of the diimide core. These readily available novel reagents add efficiently to aliphatic and aromatic carboxylic acids, forming two possible spin‐labeled amide derivatives with different radical distances of the resulting amide. The addition of aromatic DCC analogues proceeds with excellent selectivity, giving amides where the carboxylic acid is exclusively connected to the aromatic residue, while little or no selectivity was observed for the aliphatic congeners. The usefulness of these adducts in structural studies was demonstrated by EPR (electron paramagnetic resonance) measurements of biradical adducts of biphenyl‐4,4′‐dicarboxylic acids. These analyses also reveal high degrees of conformational bias for aromatic DCC derivatives, which further underlines the powerfulness of these novel reagents. This observation was further corroborated by quantum chemical calculations, giving a detailed understanding of the structural dynamics, while detailed information on the solid state structure of all novel reagents was obtained by X‐ray structure analyses.     

Efficient synthesis of novel quinazoline-4(1H)-one derivatives by N-halosulfonamides

Research on Chemical Intermediates - In this research, a facile, effective and one-pot synthesis of new quinazoline-4(1H)-one derivatives is reported. Isatoic anhydride, acid hydrazides or ammonium...     

A facile synthesis,drug-likeness,and in silico molecular docking of certain new azidosulfonamide–chalcones and their in vitro antimicrobial activity

Monatshefte für Chemie - Chemical Monthly - New azidosulfonamide–chalcone derivatives were designed and synthesized. Their structures were elucidated by 1H and 13C NMR spectral analyses,...     

Activated persulfate by chelating agent Fe·/complex for in situ degradation of phenol: intermediate identification and optimization study

Research on Chemical Intermediates - Due to its high toxicity, phenol is classified as a priority. In this paper, the removal of phenol from aqueous solutions was investigated using EDTA and...     

Chemical and biology aging of novel green membranes made of PVA and wood flour fibers reinforced with nanosilica manufactured by compression molding process

The purpose of this work was to improve the biodegradable properties of polyvinyl alcohol (PVA)/nanowood flour membranes consisting of nanosilica which were manufactured by compression molding process. Cross-linking of PVA was used to improve the mechanical properties and prevent high solubility of the obtained transient membranes. Plasticizer used to increase the plasticity of transient membranes. The biodegradability of transient membranes was evaluated under UV accelerated weathering as well as soil burial test. The transient membranes were characterized by Fourier transform infrared spectra and X-ray diffraction to study the chemical structure. Mechanical strength was appointed to characterize and reveal the mechanical, thermal analysis and the structural properties of such transient membranes. Scanning electron microscope was used to characterize the morphology of transient membranes. Swelling test and weight loss due to biodegradation were also evaluated. The results showed that the developed transient membranes can be used as food packaging bags due to biodegradability (weight loss) under irradiation and during burial soil which making them environmentally friendly.     

MultiSimplex optimization of the dispersive solid-phase microextraction and determination of fenitrothion by magnetic molecularly imprinted polymer and high-performance liquid chromatography

A magnetic molecularly imprinted polymer (MMIP) was fabricated and used as the sorbent for the MMIP-dispersive solid-phase microextraction of fenitrothion prior its determination by high-performance liquid chromatography equipped with an ultraviolet detector. The MMIP was prepared using functionalized Fe₃O₄ nanoparticles as the magnetic supporter. Methacrylic acid, ethylene glycol dimethacrylate and fenitrothion were used as the functional monomer, the cross-linker and the template, respectively. The properties of the resultant MMIP were evaluated using X-ray diffraction spectroscopy, Fourier transform infrared spectroscopy and scanning electron microscopy. The sorbent exhibited high selectivity and affinity toward fenitrothion compared to other organophosphate pesticides with the maximum adsorption capacity of 31.5 mg g^?1. The effective variables on the extraction were optimized by univariable and MultiSimplex methods. The calibration curve exhibited linearity over the concentration range of 0.3–50.0 μg L^?1 with the limit of detection of 0.1 μg L^?1. The relative standard deviations at 10.0 μg L^?1 level of FNT (n = 5) for intra- and inter-day assays were 1.6 and 3.1%, respectively. The proposed method was successfully used for the determination of trace amounts of FNT in food and water samples.     

Excited State Structural Changes of 10-Cyano-9-tert-butyl-anthracene (CTBA) in Polymer Matrices

Two main deactivation processes are suggested to be present in the electronic excited state of 10-cayano-9-tert-butyl-anthracene (CTBA): one leading to the Dewar strucure resulted from photochemical effect, similar to the case of 9-tert-butyl-anthracene (TBA), which is enhanced in solution, and another leads to a more planar structure leading to a Charge Transfer (CT) state and is enhanced in polymers. The presence of donor (tert-butyl group) and an acceptor (cyano group) along the line of 9,10 positions in CTBA confirm our hypothesis of CT state. Our suggestions were supported by steady state and time resolved fluorescence spectra results.     

Polyisobutylene‐based biomaterials

This article highlights the biomaterial‐related research of the Macromolecular Engineering Research Centre (MERC). The MERC group concentrated on polyisobutylene (PIB)‐based biomaterials. In this article, first the unique properties of PIB are discussed, followed by a review of PIB‐based potential biomaterials. MERC's systematic research program aimed to develop novel PIB‐based biomaterials is then highlighted, including surface modification and biocompatibility studies. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3091–3109, 2004