Circular Dichroism and Circular Polarized Luminescence from a Green Fluorescent Protein—Initial Research for Chiroptical Emission of Biological Materials

Optical properties of a green fluorescent protein (GFP) are examined using optical absorption, circular dichroism (CD), and circular polarized luminescence (CPL) spectroscopies. The GFP has chiroptical activity and exhibits green circular polarized emission, although the g _em-factor is small. Poly(vinyl alcohol) (PVA)/GFP composite films are prepared to attempt long-term preservation of the GFP emission activity. After five years, the transparent PVA/GFP composite film still exhibits stable fluorescence that appears similar to the emission from the Aequorea jellyfish.     

Nano-structured metal-containing polymer precursors for high temperature non-oxide ceramics and ceramic fibers—syntheses,pyrolyses and properties

Nano-structured metal-containing ceramic polymer precursors have a potential for progress in the field of polymer-derived ceramics. In this paper the synthesis and characterization of nano-metallopolycarbosilanes (nMPCS) and their transformation into ceramic materials are reported. The formation of metal nano-particles via fast thermolysis of metal- containing compounds in polymer solution or melt previously developed by the authors was applied to preceramic polymers. Tetrabenzyltitanium, tetrabenzylzirconium, bis(cyclopentadienil)dichloride-titanium and zirconium as well as tetrachlorides of these metals and tetrakis(diethylamino)zirconium were used for the introduction of metal nano-particles. The products were characterized by thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), differential-thermal analysis (DTA), gel-penetration (GP)-chromatography, X-ray diffraction (XRD), scanning electron microscopy (SEM) and other special analyses. The results of these studies may be useful for the fabrication of non-oxide ceramic fibers, interphase coatings and high temperature ceramic matrix composite (HT-CMC) matrices. Cp₂ZrCl₂ and Zr[N(C₂H₅)₂]₄ provided nano-particles with diameters of 2–4 nm and turned out to be the most suitable compounds for the preparation of ceramic matrices. Besides, they open a new way of oxygen-free curing. Coreless fibers were obtained from nZrPCS with up to 3 mass% of metal. Future investigations will be focused on optimization of the oligocarbosilanes used as starting materials and the development of less reactive polycarbosilane (PCS)–metal-containing compound (MCC) systems.     

Chemical Analysis of Magnesia and Magnesia-Alumina Refractory Materials——Gravimetric method for determination of loss on ignition

GB/T 5069.1-1985 1 Scope This standard specifies the gravimetric method for determination of loss on ignition. This standard is used for the determination of loss on ignition of magnesia and magnesia-alumina refractory materials. Determination range: ≥…     

A fluorescence chemosensor for benzonitrile derived from in-situ synthesis of azolate–carboxylic acid and zinc(II) ions

A new zinc(II) homometallic coordination polymer (CP), {[Zn(TAA-OH)₂] · 1.5H₂O}_n (1) (HTAA-OH = 2-(5-hydroxy-1H-1,2,4-triazole-1-yl) acetic acid) has been synthesized via an in-situ synthetic approach and structurally characterized in detail. In 1, the HTAA-OH ligand is generated in-situ by the nucleophilic addition of 2-(1H-1,2,4-triazole-1-yl) acetic acid. CP 1 features a 2D structure with sql topology, where the neighboring Zn(II) ions are bridged through two oxygen atoms of carboxyl group and two nitrogen atoms of triazole from the HTAA-OH ligands. Luminescence study shows that 1 dispersed in acetonitrile performs a distinct luminescence enhancing effect upon addition of benzonitrile, indicating that 1 is a promising fluorescence chemosensor for benzonitrile.     

Simple Plug-In Synthetic Step for the Synthesis of (−)-Camphor from Renewable Starting Materials

Racemic camphor and isoborneol are readily available as industrial side products, whereas (1R)-camphor is available from natural sources. Optically pure (1S)-camphor, however, is much more difficult to obtain. The synthesis of racemic camphor from α-pinene proceeds via an intermediary racemic isobornyl ester, which is then hydrolyzed and oxidized to give camphor. We reasoned that enantioselective hydrolysis of isobornyl esters would give facile access to optically pure isoborneol and camphor isomers, respectively. While screening of a set of commercial lipases and esterases in the kinetic resolution of racemic monoterpenols did not lead to the identification of any enantioselective enzymes, the cephalosporin Esterase B from Burkholderia gladioli (EstB) and Esterase C (EstC) from Rhodococcus rhodochrous showed outstanding enantioselectivity (E>100) towards the butyryl esters of isoborneol, borneol and fenchol. The enantioselectivity was higher with increasing chain length of the acyl moiety of the substrate. The kinetic resolution of isobornyl butyrate can be easily integrated into the production of camphor from α-pinene and thus allows the facile synthesis of optically pure monoterpenols from a renewable side-product.     

Special Issue on “Advanced Materials and Technology for Solar Energy”

1. Summary and Scope Solar energy is one of clean and renewable energies with great usages. Solar cells, solar absorber, photocatalytic nanomaterials are the main directions in the field nowadays. Three topics about high photovoltaic efficiency in perovskite materials, high-temperature stabilized spectral selective absorbing coatings.     

New fields of application of materials and articles from refractory fibers in the Al2O3 — SiO2 system

Basic properties of materials and articles from refractory fibers that save resources, cut heat loss, and reduce the consumption of material for furnaces are presented. A new direction in the development of materials and articles from refractory fibers for converter production is described     

Surface properties of surfactants derived from natural products. Part 1: Syntheses and structure/property relationships—Solubility and emulsification

Several novel and some previously known, mostly sugar-based, surfactants have been synthesized and some of their surface properties have been characterized and compared with those of commercial nonylphenol ethoxylates. The surfactant solubility in water, ethanol, and dodecane was studied. The properties of these compounds as emulsification agents in systems composed of the surfactant with water/isopropyl myristate, water/rapeseed oil, and water/dodecane are presented. The aqueous solubility of the surfactants follows the general trend expected from their hydrophilic-lipophilic balance according to Griffin (HLBG), but it is also clear that the nature of the headgroup and the structure of the nonpolar part affect the solubility in a manner not aptured in the standard HLBG concept. An ester or amine group as the connecting unit between the hydrophile and the hydrophobe produces a more water-soluble surfactant than the corresponding amide derivative. Some effective emulsifiers were found. For instance, the surfactants with a dehydroabietic nonpolar group appear to be promosing emulsifiers. Most sugar-based surfactants were able to form macroemulsions of up to around 2 wt/vol% of oil. The stability of many of these amulsions was very high, extending for months.     

Synthesis of zinc oxide nanoparticles reinforced clay and their applications for removal of Pb (Ⅱ) ions from aqueous media

The aim of the study was to synthesize zinc oxide nanoparticles (ZnONPs) composite with clay by a novel route and then to explore the capability of composite of ZnONPs and silty clay (SC) as adsorbents for Pb (Ⅱ) eradication from aqueous media by batch adsorption method. The effect of different operating factors like temperature, pH, dose and time of contact on the adsorption process were studied to optimize the conditions. Langmuir, Freundlich, Dubinin–Radushkevich (D-R) and Temkin isotherms were applied for the interpretation of the process. The R2 and q values obtained from Langmuir model suggested that the process is best interpreted by this model. The values of adsorption capacity (qm) noted were 12.43 mg·g-1 and 14.54 mg·g-1 on SC and ZnONPs-SC respectively. The kinetic studies exposed that pseudo second order (PSO) kinetics is followed by the processes suggesting that more than one steps are involved to control the rate of reactions. Various thermodynamic variables such as change in free energy (ΔGΘ), change in enthalpy (ΔHΘ) and change in entropy (ΔSΘ) were calculated. Thermodynamic data suggested that Pb (Ⅱ) adsorption on SC and ZnONPs-SC are spontaneous, endothermic and feasible processes.     

Polymer optical fibers for textile applications – Bicomponent melt spinning from cyclic olefin polymer and structural characteristics revealed by wide angle X-ray diffraction

To obtain thin and flexible polymer optical fibers (POFs) for textile applications, bicomponent melt-spun fibers with a cyclo-olefin polymer (COP) in the core and a tetrafluoroethylene–hexafluoropropylene–vinylidene fluoride terpolymer (THV) in the sheath have been co-extruded on the pilot scale. With higher draw ratio, the orientation within the amorphous COP core increases and the preferred interchain distances gradually change in response to the drawing parameters, as could be revealed by wide angle X-ray diffraction (WAXD). The bicomponent arrangement can promote the formation of a regular core surface because irregularities at the interface between the core and the sheath component can even out thanks to thermal shielding by the sheath component. Light propagation loss (9 dB/m at 652 nm for the most transparent fibers) and tensile properties of the fibers turned out to be adequate to enable their use in industrially produced luminous textiles.     

Using expansion units to improve CO_2 absorption for natural gas purification——A study on the hydrodynamics and mass transfer

The usage of capillary tubes for CO₂ absorption suffers from small residence time, which leads to reduced performance for large throughput. This work presents a method of connecting expansion units to capillary tubes to serve as a residence time delayer. The effect of the expansion unit on gas-liquid hydrodynamics, pressure drop and mass transfer coefficient (k_La) are investigated under various operating pressures up to 4.0 MPa, for both physical and chemical absorption. A novel periodic jetting flow is found in the expansion unit, which can intensify the CO₂ absorption. Experimental results show that the strategy can significantly decrease the pressure drop while maintaining the absorption performance to a large extent. The overall k_La for physical and chemical absorption are correlated to pressure drop, respectively. Besides, CO₂ loading in rich absorbents increases dramatically compared to literature studies with only micromixers or capillary tubes, which is beneficial to regenerate solvent. The study verifies the concept that pre-treatment with water can largely reduce the usage of amines, and can also provide a guide for process design in natural gas purification such as biogas recovery.     

Palladium,Gold, and Gold–Palladium Nanoparticle-Supported Carbon Materials for Cyclohexane Oxidation

Transition metal supported porous carbon materials have become a promising aspirant in energy storage, solid catalysis, and material chemistry. Palladium, gold, and gold–palladium anchored carbon composites (CPC-25/170, CGC-25/170, and CGPC-25/170) with two different sized carbon cages (～25 and 170 nm) were constructed using nano-silica ball (NSB) as the template and a pyrolysis fuel oil (PFO) based pitch residue as the carbon source. The Pd, Au, and Au–Pd doped carbon nanoreactors were characterized by various physicochemical analysis methods. The developed materials were used as heterogeneous catalysts for the oxidation of cyclohexane to cyclohexanol and cyclohexanone using H₂O₂ at room temperature (25°C) and atmospheric pressure. The most active catalyst CGC-170 showed combined cyclohexanol and cyclohexanone yield of 7.7% after 4 h reaction time. The conversion of 2.4%, 0.05%, and 0.32% was achieved using CGC-25, CGPC-25, and CGPC-170 catalysts, respectively. Recyclability of the catalysts maintains no observable loss of performance during catalytic oxidation reaction.     

Effect of Rre Earth Oxides and Silica on Sintering and Microstructure of AZS—40 Materials

Effect of the content of La2O3,CeO2 and SiO2 on the sintering behavior and microstruc-ture of AZS-40 material has been studied by means of sintering test and SEM examination,The results show that the porosity of the AZS-40 clinker with addition of 0.5% La2O3 or CeO2 could reach 2% under the ondition of 1600℃ for 4 hours.But it is not beneficial to the sintering and microstructure of the clinkers when the addition of the rare earth oxides increases to more than 0.5%,AZS-40 materials become difficult to be sintered as the addition of SiO2 in the materials incereases.     

Prospects for Creating H+- or OH–-Conducting and Hydrogen- or Oxygen-Producing Surfaces in a Reaction Apparatus from Polyvinyl Chloride Materials

Theoretical Foundations of Chemical Engineering - The possibility of chemical encapsulation of surfaces of technological equipment made of PVC materials into porous H+- or OH–-conducting and...     

Preparation,properties, and laser processing of poly(ɛ-caprolactone)/poly(lactic acid) blends with addition of natural fibers as a potential for printing plates application

In this research, biodegradable blend of poly(ɛ-caprolactone) (PCL) and poly(lactic acid) (PLA) is proposed as a new material for the production of a printing plate for embossing process. Printing plates for embossing consist of raised printing elements and recessed nonimage elements. In production of printing plates, laser technology was used in order to form a relief printing plate. The embossing process is based on the principle of the pressure of the relief printing plate into the printing substrate, which causes the controlled deformation of the substrate and three-dimensional (3D) effect. Coir fibers (CFs) were added as a natural filler to PCL/PLA blends to improve and adjust the properties of produced blends. Scanning electron microscopy micrographs, dynamic mechanical analysis analysis, roughness, and hardness were measured on prepared materials, and 2D and 3D microscopy was conducted on laser engraved printing plates. Results have shown that the addition of CFs improved the mechanical properties of produced materials. DMA results indicate the semicrystalline structure of all prepared blends, and that the addition of CFs raises the elasticity of the composites. Laser engraving showed that it is possible to engrave the produced biodegradable materials and to use it as a material for production of printing plates.     

Surface properties of surfactants derived from natural products. Part 2: Structure/property relationships—Foaming,dispersion, and wetting

Several novel and some previously known, mostly sugar-based, surfactants have been synthesized, and their surface properties have been characterized and compared with commercial nonylphenol ethoxylates. The dispersion properties of the surfactants were studied by mixing carbon black into an aqueous surfactant solution. It was found that open sugars, as the headgroup, give rise to higher conformational repulsion and hence more effective dispersion properties than ringclosed sugar headgroups (e.g., furanoside or pyranoside forms). No conclusions could be made about the differences in dispersion properties between surfactants with aliphatic or aromatic tail groups. Increasing the area of the tail group, however, by using twin-chain tail groups increased the dispersion properties of the surfactants further. The surfactants’ ability for wetting a hydrophobic parafilm surface was studied. The sugar-based surfactants were found generally to possess poor wetting properties.     

Process Development for the Removal of Zinc and Cadmium from Wastewater Using Slag—A Blast Furnace Waste Material

Abstract

Blast furnace slag, a waste generated in steel plants in India, has been converted into a low cost potential adsorbent. The resulting product has been characterized and used for the removal of zinc and cadmium. The effect of particle size, contact time, and surface loading of zinc and cadmium on the adsorbent for their removal have been studied at the optimum pH (6.0 for Zn²⁺ and 5.0 for Cd²⁺). Kinetic studies were undertaken to show the mechanistic aspects of the process and to obtain the thermodynamic parameters. Sorption data have been correlated with both Langmuir and Freundlich adsorption models. Column operations were also performed in an attempt to simulate industrial conditions. Some feasibility experiments have been performed with a view to recovering Zn²⁺ and Cd²⁺ and for the chemical regeneration of the spent columns without dismantling them.     

Development and Applicatio of Refractories for Self—heating opper—smelting Furnace

The development and application of high quality refractories for self-heating copper-smelting furnae (SHCSF),which adopts the most advanced copper-smelting process in the world,has been introduced in this paper. The service life of the furnace has been increased from one and a half months to around 20 months by using high quality refractiories and improving the mason method.