Friendly Medium Research Articles

Renewable diesel production by hydrothermal decarboxylation of fatty acids over platinum on carbon catalyst

For over a decade researchers have been investigating the potential to produce renewable diesel from fatty acid, possibly because it possesses good qualities such as very high cetane number, oxidative stability, and renewability, and can be produced and transported using existing refinery process facilities, making it a potential substitute for petroleum diesel. Most of these investigations required the use of organic solvents and hydrogen which might increase the cost of production. To avoid this, the current work was conducted in an aqueous medium without the addition of hydrogen, using hydrothermal decarboxylation of palmitic and oleic acids in the presence of 5% platinum on carbon catalyst. The performance of the primary products pentadecane and heptadecane obtained was optimized by determining the optimum operating conditions of temperature and residence time. The results showed that the highest molar yield of pentadecane from palmitic acid was 55.3% at the optimum conditions of 290 °C and 1.5 h, and that of heptadecane from oleic acid was 16.4% at 290 °C and 4 h. With these results the cost of production might be reduced and using a benign, environmentally friendly medium would help to reduce the risk associated with the use of organic solvents.

Synthesis of a Novel Disperse Reactive Dye Involving a Versatile Bridge Group for the Sustainable Coloration of Natural Fibers in Supercritical Carbon Dioxide.

Disperse reactive dyes with appropriate chemical structure are key for the coloration of natural fibers in the water‐free environmentally friendly medium of supercritical carbon dioxide with various advantages. The objective of this work is to design and synthesize a novel anthraquinonoid disperse reactive dye involving a versatile bridge group to improve the coloration properties of the dye in supercritical carbon dioxide. Cross‐coupling condensation based on an Ullmann reaction between N‐phenylethylenediamine and 1‐chloroanthraquinone in a ligand‐free system is investigated by optimizing the synthesis parameters. Notable influences are observed from the dosages of N,N‐dimethyl formamide and potassium hydroxide, as well as the system temperature and reaction duration, on the isolated yield of the dye precursor. An optimized process is also recommended for synthesizing the designed novel dye. Then, the chemical structure, color characteristics, and coloration properties of the obtained dye are further investigated and successfully characterized by utilizing Fourier‐transform infrared analysis, 1H and 13C nuclear magnetic resonance spectroscopy, UV–vis absorption spectroscopy, elemental analysis, and liquid chromatography‐mass spectrometry. Additionally, practical coloration experiments are performed with cotton, silk, and wool in a supercritical carbon dioxide medium.

Yolk-Shell-Mesostructured Silica-Supported Dual Molecular Catalyst for Enantioselective Tandem Reactions.

Yolk-shell-mesostructured silica was used as a support in the development of an active-site-isolated bifunctional catalyst that can mediate a sequential organic transformation. Herein, through immobilization, the location of two catalytic species is controlled: a base functionality is anchored in the channels of the outer silica shell and a chiral ruthenium/diamine functionality is anchored on the inner silica yolk. The result is a yolk-shell-mesostructured silica-supported active-site-isolated dual molecule catalyst. Structural analysis through solid-state carbon 13 C NMR spectroscopy reveals its well-defined single-site dual active centers. Electron microscopy investigations disclose its uniformly distributed mesoporous nanoparticles. As envisaged, this bifunctional catalyst enables a controllable aza-Michael addition/asymmetric transfer hydrogenation catalytic sequence, where the base-catalyzed aza-Michael addition of enones and amines to aryl-substituted -secondary amino ketones is followed by a Ru-catalyzed asymmetric transfer hydrogenation. Various aryl-substituted γ-secondary amino alcohols are obtained in high yields and enantioselectivities via this one-pot enantioselective organic transformation. Furthermore, the heterogeneous catalyst can be applied in a continuous-flow process, which was shown to be particularly attractive for the practical preparation of aryl-substituted γ-secondary amino alcohols in an environmentally friendly medium.

Ionic PMMA/nanosilica interfaces from grafting ionic liquids under supercritical CO2 conditions

Supercritical carbon dioxide (scCO2) was considered as an environmental friendly medium for grafting the surface of silica nanoparticles with a series of reactive imidazolium-based ionic liquids (IL), denoted as IL-silanes. The effects of the reaction conditions on the resulting IL-grafted layers on the silica surface were characterized from thermogravimetric (TGA) and transmission electronic microscopy (TEM) analyses. The IL-grafted nanoparticles were introduced into poly(methyl methacrylate) (PMMA) via melt mixing in order to design nanocomposites and to demonstrate the ability of IL-grafted nanoparticles to be dispersed into a polymer medium. The role of the IL-grafted surfaces on the morphology of PMMA-based nanocomposites was evidenced by TEM and small angle neutron scattering (SANS). It was demonstrated that longer the alkyl chain length of the IL-silane, better the state of dispersion of nanoparticles within PMMA. In addition, better thermal stabilities and mechanical performances, as well as new surface properties were observed for the designed PMMA-based nanocomposites.

Theoretical study on the interaction of heptafluoro-iso-butyronitrile decomposition products with Al (1 1 1)

ABSTRACTSeeking environmentally friendly gas-insulated medium has become a research hotspot in recent years. At present, C3F7CN (Heptafluoro-iso-butyronitrile) is considered to be a potential SF6 environment-friendly alternative gas and some achievements have been made in the study of its insulation and decomposition characteristics, but there are few reports on the compatibility between its characteristic decomposition products and materials. The investigation of compatibility between gas-insulated medium and material is an important part of evaluating its comprehensive performance. In this paper, we investigated the interaction between C2F5CN, CF3CN, COF2 and CF4 with the aluminium widely used in electrical equipment. It was found that the interaction between C2F5CN, CF3CN and Al (1 1 1) surface is strong. There are obvious charge transfer and electron orbital overlap between the C atom, N atom in CN group and Al (1 1 1). The interaction between COF2, CF4 and Al (1 1 1) surface is weak and van der Waal’s forces play the major role. Relevant results reveal the characteristics of C3F7CN decomposition products and provide theoretical guidance for evaluating the material compatibility between C3F7CN decomposition products and aluminium.

Palladium nanoparticle‐decorated magnetic pomegranate peel‐derived porous carbon nanocomposite as an excellent catalyst for Suzuki–Miyaura and Sonogashira cross‐coupling reactions

Porous carbon (PC) material was prepared from the carbonization of pomegranate peel waste. Subsequently, magnetically separable Fe3O4@PC was synthesized from Fe3O4 nanoparticles decorated on PC by the co‐precipitation method of iron ions. Finally, Fe3O4@PC was successfully decorated with palladium nanoparticles in a simple route by reducing H2PdCl4 in the presence of sodium dodecylsulfate, which was used as both surfactant and reducing agent. Additionally, the effect of temperature on the carbonization process was studied. The Pd/Fe3O4@PC nanocomposite was used as an efficient and heterogeneous catalyst for Suzuki–Miyaura and Sonogashira cross‐coupling reactions in an environmentally friendly medium.

Introduction of Environmental Measures in the Heat Power Industry of the Central Ecological Zone of the Baikal Natural Territory

Presented the results of calculations of emissions of pollutants into the atmosphere from heat sources and their comparison with the permissible values for Lake Baikal basins. The ecological ranging of the territory made it possible to determine the areas of greatest emissions: Slyudyansky, North Baikal and the town of Severobaikalsk. As potential directions to reduce anthropogenic impact from heat source proposed: improving the system for cleaning off gases: transition to more environmentally friendly energy carrier medium, as well as renewable energy sources. For each of the directions of environmental protection measures, the areas of rational use were identified and the reduction of emissions of harmful substances into the atmosphere during their implementation. Considered only the possible environmental effect from the introduction of particular direction to reduce the impact on the atmosphere of thermal power facilities, without taking into account the technical and economic assessment of environmental measures, the identification of legislative measures, the development of preferential tariffs, energy prices and other financial and economic mechanisms.

In situ immobilized palladium nanoparticles (Pd NPs) on fritillaria imperialis flower extract-modified graphene and their catalytic activity for reduction of 4-nitrophenol

Abstract In this study, a complete green synthesis method to reduced graphene oxide-Pd nanoparticles hybrid by applying extract of Fritillaria imperialis flower as both stabilizing and reducing agent was reported. Fritillaria imperialis flower extract reduce graphene oxide and adsorb on the reduced graphene oxide surface. Moreover, the surface adsorbed Fritillaria imperialis flower extract can more in situ reduce Pd ions to Pd nanoparticles and stabilize them. The physicochemical and structure properties of the produced nanohybrid were examined in detail by X-ray diffraction (XRD), UV–vis spectroscopy, field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), wavelength-dispersive X-ray spectroscopy (WDX), inductively coupled plasma (ICP) and X-ray photoelectron spectroscopy (XPS). The obtained results showed that Pd nanoparticles uniformly distributed on the functionalized graphene surface. The catalytic efficiency of the resulting heterogeneous nanocatalyst (Pd NPs/FGO) was evaluated at room temperature for the 4-nitrophenol (4-NP) reduction in an environmental friendly medium. The enhanced catalytic activity observed with our nanocatalyst is attributed to the graphene surface's coated by biopolymers of Fritillaria imperialis flower extract which stabilizes and attracting the aryl nitro substrates adjacent to the catalytic sites which in turn facilitates the reduction of nitro groups. The catalyst was recycled by centrifugation and reapplied several times without any significant catalytic activity loss.

Organolithium Chemistry in an Environmentally Friendly Medium

Organolithium Chemistry in an Environmentally Friendly Medium

333 SOUNDCLOUD SEBAGAI MEDIA ALTERNATIF DISTRIBUSI KARYA MUSIK MUSISI INDIE KOTA MAKASSAR

ABSTRACT The purpose of this research is: (1) To find motive of indie musicians on using Soundcloud as an alternative media distribution for musical pieces. (2) To find effort of indie musicians on using Soundcloud as an alternative media distribution for musical pieces. This research is in Makassar, on indie musicians who using Soundcloud. As for the method of this research used Descriptive Qualitative. The result of this research shows that indie musicians in Makassar have different motives on using Soundcloud as an alternative media distribution. The first, musicians used soundcloud to promote their works. The second, as an effort to distribute their works through the download feature. The third, Soundcloud is unsophisticated and very friendly media. The fourth, Soundcloud is utilized by musicians for the sake of protection feature for their uploaded works. The fifth, musicians used Soundcloud as a means of documentation for their works. The variety of Soundcloud uses been applied by indie musicians. The musician effort to utilize the feature not just confined by uploaded the works. Makassar indie musicians also integrated their Soundcloud account to another social media. Furthermore, they are providing download feature for their listeners, so they can download it for free. However, no musicians yet utilized description feature to describe the music context of their works.

Deep Eutectic Solvents as Reaction Media for the Palladium-Catalysed C-S Bond Formation: Scope and Mechanistic Studies.

A unique jigsaw catalytic system based on deep eutectic solvents and palladium nanoparticles where C-S bonds are formed from aryl boronic acids and sodium metabisulfite, is introduced. The functionalization step is compatible with a broad spectrum of reagents such as nucleophiles, electrophiles or radical scavengers. This versatile approach allows the formation of different types of products in an environmentally friendly medium by selecting the components of the reaction, which engage one with another as pieces in a jigsaw. This simple procedure avoids the use of toxic volatile organic solvents allowing the formation of complex molecules in a one-pot reaction under mild conditions. Despite the fact that only 1 mol % of metal loading is used, the recyclability of the catalytic system is possible. Kinetic experiments were performed and the reaction order for all reagents, catalyst and ligand was determined. The obtained results were compared to palladium nanocrystals of different known shapes in order to shed some light on the properties of the catalyst.

Multistep Organic Transformations over Base‐Rhodium/Diamine‐Bifunctionalized Mesostructured Silica Nanoparticles

AbstractThe assembly of multiple catalytic functionalities within a single mesoporous silica as a catalyst for multistep enantioselective organic transformations in an environmentally friendly medium is a significant challenge in heterogeneous asymmetric catalysis. Herein, we took advantage of a BF4− anion hydrogen bonding strategy to anchor a chiral cationic rhodium/diamine complex within base‐functionalized mesostructured silica nanoparticles conveniently to construct a bifunctional heterogeneous catalyst. The solid‐state 13C NMR spectrum discloses the well‐defined chiral Rh/diamine active species, and we used XRD, N2 adsorption–desorption, and electron microscopy to reveal the ordered mesostructure. The combination of bifunctionality in the silica nanoparticles enables two kinds of efficient enantioselective organic transformations with high yields and enantioselectivities, in which the asymmetric transfer hydrogenation of α‐haloketones followed by epoxidation provides various chiral aryloxiranes, and the amination of α‐haloketones with anilines followed by asymmetric transfer hydrogenation produces various β‐amino alcohols. Furthermore, the catalyst can be recovered and recycled for seven times without a loss of catalytic activity, which is an attractive feature for multistep organic transformations in a sustainable benign process.

Supramolecular Engineering of Discrete Pt(II)···Pt(II) Interactions for Visible-Light Photocatalysis

Visible-light photosensitizers have emerged as a sustainable and environmentally friendly medium for organic transformation. Herein, we have developed a supramolecular strategy for manipulating visible-light photosensitization and photocatalytic efficiencies. With the elaborate manipulation of aggregated Pt(II)···Pt(II) interactions, the discrete tetranuclear Pt complexes not only show high binding affinity (Ka ∼ 106 M–1) but also feature bathochromic-shifted metal–metal-to-ligand charge transfer transitions. Both factors are crucial for their 1O2 generation capability upon low-energy visible-light irradiation (λ ≥ 590 nm). More interestingly, when a terpyridine moiety is embedded in the structure of a supramolecular photosensitizer, breakup of tetranuclear Pt(II)···Pt(II) complexation can be realized upon addition of Zn(OTf)2. As a consequence, photo-oxidation of a secondary amine to the corresponding imine can be deactivated and reactivated, via the sequential addition of Zn(OTf)2 and unsubstituted terp...

Valorization of hazelnut shell waste in hot compressed water

Hydrothermal conversion of waste hazelnut shell in hot compressed water, green and environmentally friendly medium, was investigated under different operating conditions to clarify the effects of reaction temperature, reaction time, acid concentration and acid kind (H2SO4 and H3PO4) on the production of value-added chemicals with high temperature/high pressure autoclave. In literature, to our best knowledge, there is no study about the production of levulinic acid, as a high value chemical, from waste hazelnut shell in hot-compressed water without using any mineral and heterogeneous catalyst. Hydrothermal reactions were conducted at 150–280°C for reaction times of 15 to 120min with various H2SO4 and H3PO4 concentrations varying from 0 to 125mM. The detailed liquid product species were identified with High Performance Liquid Chromatography (HPLC) and gaseous products were analyzed by Gas Chromatography with a Thermal Conductivity Detector (GC-TCD). The main identified liquid compounds were levulinic acid, acetic acid and furfural while carbon dioxide and carbon monoxide were the major gaseous products. Increasing the reaction temperature (280°C) and reaction time (120min) resulted in a significant increment on the conversion (65.40%) as well as levulinic acid yield (13.05%). The production of levulinic acid was enhanced with H2SO4 addition; whereas treatments with H3PO4 improved the furfural production.

Evaluation of Versatile CdS Nanomaterials Based Liquid Crystals Switchable Device.

Novel synthesis and properties of versatile CdS nanostructures (e.g., Nano-brush, nano-cube, nanosphere) dispersed liquid crystals application in chemical friendly medium exploring this article. Most recent studies, CdS nano-wire brush with the stacking fault structures were hydrothermally synthesized through a dissolution-recrystallization approach in concentrated ammonia solvent in one step solution, for the first time. Those structures-property relations with respect to ferroelectric hydrogen-bonded liquid-crystalline complex (HBLC; AC + 5BAO) controlled and efficient formation of surface relief nanostructures. A successful attempt has been made to form hydrogen bonding between CdS nanostructures and supramolecular LC with p–n-alkyloxy benzoic acids (n-OBA). The formation of an inter-H-bond is evinced through FTIR study, as well as Gaussian simulation also ensures complete formation of intermolecular hydrogen bond optimized geometry. In contrast, a new sensitive response of smectic G ordering observed in this series is investigated by constructing a phase diagram obtained from two binary mixtures of CdS nanostructures influenced by homogeneous liquid crystals. Temperature-dependent dielectric relaxation, tilt angle, electro-optical switching measurements allow for monitoring very unique and useful behavior in that the polarization of the emission from the semiconductor nanostructures can be controlled by an external bias. It reveals electrically tunable interaction of the composites may allow for engineering of practical electro-optic switchable device.

An efficient one-pot synthesis of functionalized chromeno[4,3-b]pyridine derivatives under catalyst-free conditions.

A concise, efficient one-pot synthesis of functionalized chromeno[4,3-b]pyridine derivatives via a three-component reaction of 4-oxo-4H-chromene-3-carbaldehydes, malononitrile or cyanoacetates, and aromatic amines under catalyst-free conditions in an environmentally friendly medium (ethanol-water, 3:1 v/v) is described. This synthesis involves a group-assisted purification process, which avoids traditional recrystallization and chromatographic purification methods.

Greener approach for synthesis of monodispersed palladium nanoparticles using aqueous extract of green tea and their catalytic activity for the Suzuki–Miyaura coupling reaction and the reduction of nitroarenes

A facile and green route for the synthesis of palladium nanoparticles (NPs) was developed utilizing non‐toxic and renewable natural green tea extract as the reducing, stabilizing and capping agent. The as‐prepared Pd‐NPs@G.Tea extract was characterized using UV–visible spectroscopy, X‐ray diffraction, Fourier transform infrared spectroscopy, field‐emission scanning electron microscopy, transmission electron microscopy and energy‐dispersive X‐ray spectroscopy. The Pd‐NPs@G.Tea extract could be used as an efficient and heterogeneous catalyst for Suzuki coupling reactions between phenylboronic acid and a range of aryl halides containing iodo, bromo and chloro moieties, and also for the reduction of nitroarenes using sodium borohydride in an environmentally friendly medium. Excellent yields of products were obtained with a wide range of substrates and the catalyst was recycled multiple times without any significant loss of its catalytic activity.

Green synthesis of palladium nanoparticles mediated by black tea leaves (Camellia sinensis) extract: Catalytic activity in the reduction of 4-nitrophenol and Suzuki-Miyaura coupling reaction under ligand-free conditions

The present study was conducted to synthesize palladium nanoparticles (Pd NPs) through a facile and green route using non-toxic and renewable natural black tea leaves (Camellia sinensis) extract, as the reducing and stabilizing agent. The as-prepared Pd@B.tea NPs catalyst was characterized by UV–vis spectroscopy, X-ray diffraction (XRD), fourier transformed infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). The Pd@B.tea NPs catalyst could be used as an efficient and heterogeneous catalyst for Suzuki coupling reactions between phenylboronic acid and a range of aryl halides (X=I, Br, Cl) and also the reduction of 4-nitrophenol (4-NP) using sodium borohydride in an environmental friendly medium. Excellent yields of products were obtained with a wide range of substrates and the catalyst was recycled 7 times without any significant loss of its catalytic activity.

A new medium for boriding of Ti6Al4V alloy for biomedical applications

This study presents a low-cost and environmentally friendly medium for the pack boriding (boronizing) of a Ti6Al4V alloy. Titanium and its alloys are known to be highly reactive and to have extreme oxygen affinity. Therefore, boriding is performed under vacuum or in protective atmospheric conditions. This work evaluated the pack boriding heat treatments of a Ti6Al4V alloy under atmospheric conditions via the various boriding media used by previous researchers. In addition, a new pack boriding medium was developed by adding aluminum. Consequently, this study demonstrated that it is possible to obtain an undamaged titanium surface by applying solid-state boriding under atmospheric conditions.

Biosynthesis of palladium nanoparticles as a heterogeneous and reusable nanocatalyst for reduction of nitroarenes and Suzuki coupling reactions

A facile and green route for the synthesis of palladium nanoparticles (Pd‐NPs) was developed utilizing non‐toxic and renewable natural green tea extract as the reducing, stabilizing and capping agent. The as‐prepared Pd‐NPs@Oak Gum catalyst was characterized using UV–visible spectroscopy, X‐ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy and energy dispersive X‐ray spectroscopy. The Pd‐NPs@Oak Gum catalyst could be used as an efficient and heterogeneous catalyst for Suzuki coupling reactions between phenylboronic acid and a range of aryl halides containing iodo, bromo and chloro moieties and also for the reduction of nitroarenes using sodium borohydride in an environmental friendly medium. Excellent yields of products were obtained with a wide range of substrates and the catalyst was recycled multiple times without any significant loss of its catalytic activity. Copyright © 2016 John Wiley & Sons, Ltd.