Investigation into the rotational bands of ~(185)Pt with the particle-rotor model

Theoretical calculations have been performed for the ν9/2+[624](i13/2) and ν7/2-[503](f7/2) bands of 185Pt in the framework of particle-rotor model. The band properties of signature splitting and configuration mixing have been analyzed. The level energy and signature splitting before the band crossing can be well interpreted by introducing triaxiality. The positive-parity yrast band is pro posed to be dominated by the ν9/2+[624](i13/2) component, while the negative-parity band shows strong mixing of ν7/2-[5...     

Electromagnetic interference shielding characteristics of fabric complexes coated with conductive polypyrrole and thermally evaporated Ag

Through the chemical coating of polypyrrole (PPy) doped with naphthalene sulfonic acid (NSA) on electrically insulating poly (ethylene terephthalate) (PET) woven fabric, PPy–NSA/PET complexes were synthesized. By using the electrochemical coating of PPy doped anthraquinone-2-sulfonic acid (AQSA) on PPy–NSA/PET complexes, PPy–AQSA/PPy–NSA/PET complexes were synthesized. The silver (Ag) was thermally vacuum evaporated on the surface of PPy–AQSA/PPy–NSA/PET complexes (Ag|PPy–AQSA/PPy–NSA/PET). Electromagnetic interference (EMI) shielding efficiency (SE) and dc conductivity (σ_dc) of fabric complexes were measured for EMI shielding characteristics and theoretical simulation. The measurement of EMI SE in the frequency range from 50 MHz to 1.5 GHz was performed by using ASTM D4935-99 method. The EMI shielding characteristics such as transmittance, reflectance and absorbance were obtained from the S (scattering)-parameter analysis. We control the contribution of the absorbance or the reflectance to total EMI SE through the coating of conductive PPy and the evaporation Ag.     

Autothermal reforming of methane to syngas for Fischer-Tropsch synthesis with promoted palladium and a fast start-up device

In this study, a Pd catalyst was prepared with promoters such as CeO₂, BaO and SrO in a washcoated form on a metallic monolith for autothermal reforming of methane to syngas for the Fischer-Tropsch synthesis. A reactor was installed with an electric heater in the form of the metallic monolith as a start-up device instead of a burner with which stable and fast start-ups (within 4 min) were achieved. Gas hourly space velocity and O₂/CH₄ governed, methane conversion, while H₂O/CH₄ controlled H₂/CO ratio. A methane conversion of approx. 96%, H₂+CO selectivity of approx. 85%, and H₂/CO of approx. 2.6 were obtained under the conditions of gas hourly space velocity (GHSV) at 103000 h^?1, O₂/CH₄=0.7 and H₂O/CH₄=0.35.     

Synthesis of amphiphilic graft copolymer brush and its use as template film for the preparation of silver nanoparticles

A microphase‐separated, amphiphilic graft copolymer consisting of a poly (vinyl chloride) (PVC) backbone and poly(oxyethylene methacrylate) (POEM) side chains, (PVC‐g‐POEM at 62:38 wt %) was synthesized via atom transfer radical polymerization (ATRP). Nuclear magnetic resonance (¹H NMR), FTIR spectroscopy, and transmission electron microscopy (TEM) clearly revealed that the “grafting from” method using ATRP was successful and that the graft copolymer molecularly self‐assembled into discrete nanophase domains of continuous PVC and isolated POEM regions. The self‐assembled graft copolymer film was used to template the growth of silver nanoparticles in solid state by introducing a AgCF₃SO₃ precursor and a UV irradiation process. The in situ formation of silver nanoparticles in the graft copolymer template film was confirmed by TEM, UV–visible spectroscopy, and wide angle X‐ray scattering. FTIR spectroscopy and X‐ray photoelectron spectroscopy also demonstrated the selective incorporation and in situ formation of silver nanoparticles within the hydrophilic POEM domains, presumably due to strong interactions between the silver and the ether oxygen in POEM. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3911–3918, 2008     

Amphiphilic polymer electrolytes consisting of PVC‐g‐POEM comb‐like copolymer and LiCF3SO3

An amphiphilic comb‐like copolymer consisting of a poly(vinyl chloride) (PVC) backbone and poly((oxyethylene)₉ methacrylate) (POEM) side chains, PVC‐graft‐POEM was synthesized via atom transfer radical polymerization. This comb copolymer was complexed with LiCF₃SO₃ to form a solid polymer electrolyte. FTIR and FT‐Raman spectroscopy indicate that lithium salts are dissolved in the ion conducting POEM domains of microphase‐separated graft copolymer up to 10 wt % of salt concentration. Microphase‐separated structure of the materials and the selective interaction of lithium ions with POEM domains were revealed by transmission electron microscopy, wide angle X‐ray scattering, and differential scanning calorimetry. The maximum ionic conductivity of 4.4 × 10^?5 S/cm at room temperature was achieved at 10 wt % of salt concentration, above which salts are present as less mobile species such as ion pairs and higher order ionic aggregates, as characterized by FT‐Raman spectroscopy. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1443–1451, 2009     

Signal-Induced Release of Guests from a Photolatent Metal–Phenolic Supramolecular Cage and Its Hybrid Assemblies

The coordination chemistry of plant polyphenols and metal ions can be used for coating various substrates and for creating modular superstructures. We herein explored this chemistry for the controlled release of guests from mesoporous silica nanoparticles (MSNs). The selective adsorption of tannic acids (TAs) on MSN silica walls opens the MSN mesoporous channels without disturbing mass transport. The channel may be closed by the coordination of TA with Cu^II ions. Upon exposure to light, photolysis of Trojan horse guests (photoacid generators, PAGs) leads to acid generation, which enables the release of payloads by decomposing the outer coordination shell consisting of TA and Cu^II. We also fabricated a modular assembly of MSNs on glass substrates. The photoresponsive release characteristics of the resulting film are similar to those of the individual MSNs. This method is a fast and facile strategy for producing photoresponsive nanocontainers by non-covalent engineering of MSN surfaces that should be suitable for various applications in materials science.     

Closed-packed lattice model for polymer solution systems considering the chain length dependence effect: Correlating LLE,VLE, and gel swelling behaviors using identical interaction energy parameters

We propose a new Helmholtz energy of mixing equation following the original Flory–Huggins (F–H) closed-packed lattice model. Also, to overcome F–H mean-field approximation, we introduce new universal constants to consider chain length dependence of polymer in solvent and consider specific interactions to describe strongly interacting polymer systems. Our proposed model successfully describes liquid–liquid equilibria (LLE) for binary polymer–solvent systems using identical interaction parameters which do not depend on the polymer molecular weight. We also describe vapor–liquid equilibria (VLE) for polymer/solvent systems and swelling equilibria of thermosensitive hydrogel systems using the same energy parameters obtained from LLE calculations.     

QM/MM based 3D QSAR models for potent B-Raf inhibitors

Three dimensional (3D) quantitative structure-activity relationship studies of 37 B-Raf inhibitors, pyrazole-based derivatives, were performed. Based on the co-crystallized compound (PDB ID: 3D4Q), several alignment methods were utilized to derive reliable comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) models. Receptor-guided alignment with quantum mechanics/molecular mechanics (QM/MM) minimization led to the best CoMFA model (q ² = 0.624, r ² = 0.959). With the same alignment, a statistically reliable CoMSIA model with steric, H-bond acceptor, and hydrophobic fields was also derived (q ² = 0.590, r ² = 0.922). Both models were validated with an external test set, which gave satisfactory predictive r ² values of 0.926 and 0.878, respectively. Contour maps from CoMFA and CoMSIA models revealed important structural features responsible for increasing biological activity within the active site and explained the correlation between biological activity and receptor-ligand interactions. New fragments were identified as building blocks which can replace R1-3 groups through combinatorial screening methods. By combining these fragments a compound with a high bioactivity level prediction was found. These results can offer useful information for the design of new B-Raf inhibitors.     

Hydrogen bonding nature between calix[6]arene and piperidine/triethylamine

We investigated the binding nature of the 1,2,3-alternate calix[6]arene with one piperidine, two piperidines, and two triethyl amines with a special emphasis on the hydrogen bonding networks by density functional theory calculations. The 1,2,3-alternate calix[6]arene strongly binds with piperidines and triethylamines at two different binding sites, exo and endo sites. In the two binding sites, the hydrogen bonding nature shows a characteristic difference. In the exo site, there formed only one hydrogen bond, while in the endo site, two hydrogen bonds except for the triethylamine. The proton transfer within the hydrogen bonding and the hydrogen bonding types, normal hydrogen bonding (NHB), short strong hydrogen bond (SSHB), and low barrier hydrogen bonding (LBHB), will be discussed in detail.