Clouding Behavior of Ethylene Oxide‐Propylene Oxide Block Copolymer P85: The Effect of Additives

The characteristic feature of nonionic poly(ethylene oxide)‐poly(propylene oxide)‐poly(ethylene oxide) (PEO‐PPO‐PEO) triblock copolymers is that at higher temperatures they undergo clouding and liquid‐liquid phase separation. The clouding temperature of such block copolymers can be profoundly altered in the presence of various additives. In this work the effect of various additives on the clouding phenomenon of triblock copolymer P85[(EO)₂₆(PO)₃₉(EO)₂₆] is discussed.     

Controlled Nanofiber Composed of Multi‐Wall Carbon Nanotube/Poly(Ethylene Oxide)

We have successfully fabricated poly(ethylene oxide) (PEO) nanofibers containing embedded multi‐wall carbon nanotubes (MWCNTs). An initial dispersion of the MWCNTs in distilled water was achieved using sodium dodecyl sulfate. Subsequently, the dispersion was decanted into a PEO solution, which enabled separation of the MWCNTs and their individual incorporation into the PEO nanofibers on subsequent electrospinning. Initially, the carbon nanotube (CNT) rods were randomly oriented, but owing to the sink‐like flow in the electrospinning wedge, they became gradually oriented along the streaming direction, in order that oriented CNTs were obtained on entering the electrospun jet. Individual MWCNTs became embedded in the nanofibers, and were mostly aligned along the fiber axis. Evidence of load transfer to the nanotubes in the composite nanofiber was observed from the field‐emission scanning electron microscopy, transmission electron microscopy and conductivity data.     

Synthesis and Application of Polyethylene Oxide Macromers (Ⅰ——Synthesis and Characterization of Poly(Ethylene Oxide)Macromers with Allyl-End Group

Polyethylene oxide(PEO) macromers with allyl-end group were synthesized by two different methods(initiating and deactivating).The products obtained were characterized accurately by means,of several techniques including H NMR,IR,VPO,GPC and the double-bond titration,and the results show that such kinds of product possess expected structure.The macromers were copolymerized with small molecular acrylamide,and a series of copolymers with different composition,were obtained by adjusting copolymerization conditions.Moreover,some evidence concerning allyl-group rearrangement in synthesis of the macromers was observed and suitable condition for laboratorial preparation of the macromers is proposed.     

A Study on Side Reactions of Hydroxyethylation of 3-Nitro-4- chlorobenzenesulfinic Acid with Ethylene Oxide

2-Nitro-4-(β-hydroxyethylsulfonyl)chlorobenzene (NHCB) is an important intermediate for C.I. Reactive blue 220 (NHCB) which can be obtained by reacting 3-nitro-4- chlorobenzenesulfinic acid (NCBS) with ethylene oxide (EO). ClO2NSO2H H2COCH2 ClO2NSO2CH2…     

Ethylene addition to Ru(CH2)(O)3 – A theoretical study

Quantum chemical calculations using density functional theory (B3LYP) were carried out to elucidate the reaction pathways for ethylene addition to the ruthenium compound RuO₃CH₂. These investigations show that the parent compound is relatively unstable and its rearrangement gives access to very diverse isomers and addition products with comparable relative energies and reaction barriers. The results are compared to our previous study on the analogous osmium system OsO₃CH₂ and we show that reactivity of both compounds towards ethylene is quite similar. In both cases, the [3 + 2]_C,O cycloaddition pathway is preferred kinetically and thermodynamically. The exothermicity (–68.8 kcal/mol) of this reaction is higher for the ruthenium system than for the osmium homologue. While this pathway is unrivaled for the osmium system, the [3 + 2]_O,O cycloaddition pathway is able to compete kinetically for the ruthenium system.     

Study of Anticancer Properties of Graphene Oxide–Metal Oxide Composite

Graphene and graphene oxide (GO) have garnered significant attention due to their exceptional properties. GO, enriched with various functional groups such as epoxy, hydroxyl, and carboxylic groups, has exhibited remarkable potential in biomedical applications. The combination of GO with metals has proven to be a promising platform for cellular imaging, with this study focusing on the preparation of diverse hybrids of GO with metal oxides (GO/MO) and their potential as anticancer agents. In this research, GO is functionalized with MOs like TiO₂, Fe₃O₄, and Cu₂O using specific chemical methods and investigated for the anticancer activity for the application as cancer therapeutic agent. The resulting GO/MO hybrids exhibits favorable thermal and mechanical properties. Moreover, their cytotoxicity against human lung cancer cells is assessed in vitro, revealing the promising anticancer activity of GO/MO hybrids. Notably, the GO/Cu₂O hybrid demonstrates particularly high cytotoxicity in human lung cancer cells.     

Studies on Catalytic Conversion of Ethylene

FCC dry gas contains a large amount of ethylene.It is used by most of the refineries in China as fuel or simply burned in atmosphere.Few refineries make good use of the dry gas,so the precious ethylene resource in the dry gas is wasted.In this article,the possibility of catalytic conversion of ethylene to C_3,C_4,and some high molecular weight hydrocarbons in a fixed bed micro-reactor using LTB-1 catalyst,with pure ethylene as feedstock was studied.Effects of reaction temperature,reaction pressure,and feedstock flow rate,on the conversion of ethylene and the distribution of products were investigated to determine the proper reaction parameters to be used in practice.Good results indicate that this study may provide a new way of using the ethylene resource in the FCC dry gas.     

Studies of Laser-induced-MOCVDZinc Oxide Films

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Coating Carbon Nanotubes with Europium Oxide

Carbon nanotubes (CNTS) coating with europium oxide by a simple method is reported in this letter for the first time. The CNTS were refluxed in a solution of nitric acid containing europium nitrate, and the pH value was subsequently ajusted with ammonia solution. At last, the mixture was filtered and annealed. The TEM micrograph showed that the CNTS were covered with a uniform thin layer with thickness of about 15 nm. The XRD results revealed that the CNTS were coated with europium oxide.     

Thermal Characterization of Vinyl Acetate—Ethylene Copolymers

Copolymers of vinyl acetate and ethylene were prepared by emulsion polymerization using ammonium persulphate and sodium metabisulphite as initiators in presence of cyclohexane. Several copolymer samples were prepared by changing initial pressure of ethylene from 100 to 250 psi. The copolymer composition was determined by ¹H-NMR and thermogravimetric analysis in nitrogen atmosphere.This revised version was published online in November 2005 with corrections to the Cover Date.     

Phase Diagram of the Ethylene Glycol–Dimethylsulfoxide System

The phase diagram of ethylene glycol (EG)–dimethylsulfoxide (DMSO) system is studied in the temperature range of +25 to ?140°C via differential scanning calorimetry. It is established that the EG–DMSO system is characterized by strong overcooling of the liquid phase, a glass transition at ?125°C, and the formation of a compound with the composition of DMSO · 2EG. This composition has a melting temperature of ?60°C, which is close to those of neighboring eutectics (?75 and ?70°C). A drop in the baseline was observed in the temperature range of 8 to ?5°C at DMSO concentrations of 5–50 mol %, indicating the existence of a phase separation area in the investigated system. The obtained data is compared to the literature data on the H₂O–DMSO phase diagram.     

Effect of Calcium Oxide Additive on Sorbent for High-Temperature the Performance of Iron Oxide Coal Gas Desulfurization

The effect of calcium oxide additive in iron oxide sorbent for hot gas desulfurization was investigated by XRD and TPR techniques. XRD characterization showed that CaO was highly dispersed after the calcination of sorbents. Calcium sulfate formed in the desulfurization was decomposed and regenerated to CaO by reacting with CO before the next sulfidation process. Calcium participated in every sulfidation/regeneration cycle and contributed to the enhancement of sulfur capacity. The TPR results showed that the reduction temperature of the sorbent increased with the increase of the content of calcium. Calcium played a role of retarding reduction. Therefore, the addition of calcium oxide additive will benefit the utilization of iron oxide sorbent in strongly reducing atmospheres.     

Effect of Calcium Oxide Additive on the Performance of Iron Oxide Sorbent for High-Temperature Coal Gas Desulfurization

The effect of calcium oxide additive in iron oxide sorbent for hot gas desulfurization was investigated by XRD and TPR techniques.XRD characterization showed that CaO was highly dispersed after the calcination of sorbents.Calcium sulfate formed in the desulfurization was decomposed and regenerated to CaO by reacting with CO before the next sulfidation process.Calcium participated in every sulfidation/regeneration cycle and contributed to the enhancement of sulfur capacity.The TPR results showed that the reduction temperature of the sorbent increased with the increase of the content of calcium.Calcium played a role of retarding reduction.Therefore,the addition of calcium oxide additive will benefit the utilization of iron oxide sorbent in strongly reducing atmospheres.     

Gas Phase Polymerisation of Ethylene with Supported Titanium-Nickel Catalysts

Olefins gas phase polymerization uses generally supported titanium catalyst systems inindustrial production. The polymerization of olefins with late transition metal catalysthas recently attracted considerable interestl-2. The new catalyst family shares many ofthe advantages of metallocene catalysts in terms of activity and control of polymerproperties and, in addition, the new catalysts yield homopolymer of ethylene with veryhigh branching degrees and branching degree can be controlled.A new …     

Phase Diagram of an Ethylene Glycol–Hexamethylphosphorotriamide System

The phase diagram of an ethylene glycol (EG)–hexamethylphosphorotriamide (HMPT) system is studied over two wide temperature intervals (+25°С…?90°С…+40°С) and (?150°С…+40°С) by means of differential scanning calorimetry using INTERTECH DSC Q100 and METTLER TA4000 DSC instruments (Switzerland) in the DSC30 mode with variable cooling/heating rates. Substantial overcooling of the liquid phase, a glass transition, and different types of interaction are observed in the system. No thermal effects are observed in intermediate range of concentrations during the slow cooling/heating processes, and the system remains liquid until the glass transition. The presence of such a metastable phase is attributed to a sharp rise in the viscosity of the system due to different kinds of interaction between the components. HMPT: 2EG and HMPT: EG compounds with crystallization temperatures of +5 and ?0.5°С, respectively, are observed upon rapid cooling and slow heating. Changes in enthalpy are calculated for all of the observed thermal effects. The distinction from the phase diagram of H₂O–HMFT (literary data) is explained by the difference in the interactions between system components and by the structural differences between EG and H₂O.     

Reaction of Phenyl-Substituted o-Quinodimethanes with Nitric Oxide. Are Benzocyclobutenes Suitable Precursors for Nitric Oxide Cheletropic Traps?

In order to elucidate the potential of substituted o-quinodimethanes as reagents for the trapping of nitric oxide (NO) in biological systems, the reaction of alkoxyl- and alkyl-substituted 7,8-diphenyl- and 7,7,8-triphenyl-o-quinodimethanes with nitric oxide in solution was investigated by ESR spectroscopic and UV/vis stopped-flow techniques. Photolytic decarbonylation of 1,3-diphenyl- and 1,1,3-triphenylindan-2-ones gave the corresponding phenyl-substituted benzocyclobutenes as the major products and low photostationary concentrations of o-quinodimethanes. During 266-nm laser flash photolysis (LFP) of 1,3-dimethoxy-1,3-diphenylindan-2-one and 1-methoxy-1,3,3-triphenylindan-2-one in acetonitrile, species absorbing in the 400-600 nm range were produced, which were attributed to configurational isomers of the corresponding 7,7,8,8-substituted o-quinodimethanes. The isomeric o-quinodimethanes decayed at significantly different rates, indicating a strong influence of the relative orientation of the terminal substituents on their stability. Reaction of the raw photolysates of the 2-indanones with NO produced strong ESR spectra of the corresponding cyclic nitroxide radicals, isoindolin-2-oxyls. The nitroxide radicals were generated in a two-phase process, the first, rapid phase being attributed to the reaction of NO with the photolytically formed o-quinodimethanes and the second, slow phase reflecting the reaction with small amounts of o-quinodimethanes, generated by thermal ring opening of the phenyl-substituted benzocyclobutenes and probably a direct reaction of NO with the benzocyclobutenes. The kinetics of both steps, as evaluated by stopped-flow UV/vis and ESR spectroscopy, revealed a strong dependence of the rate constants of the o-quinodimethane + NO reaction on the substitution pattern of the o-quinodimethanes, with rate constants spanning a range of 10-4000 M(-)(1) s(-)(1). The rate constants ((0.4-7.5) x 10(-)(4) s(-)(1)) for the reaction of NO with the 7,7,8,8-tetrasubstituted benzocyclobutenes are much less influenced by the substitution pattern. The utility of phenyl-substituted benzocyclobutenes as "reservoirs" for o-quinodimethane-type nitric oxide traps is discussed.     

Electrochemical Sensor for Detection of p-Nitrophenol Based on Nickel Oxide Nanoparticles/α-Cyclodextrin Functionalized Reduced Graphene Oxide

p-Nitrophenol (p−NP) is a high priority toxic pollutant and that has harmful effects on human, animals and plants. Thus, the detection and determination of p−NP present in the environment is an urgent as well as highly important requisite. The present article, therefore focused on the construction of a novel electrochemical sensor based on NiO nanoparticles/α-cyclodextrin functionalized reduced graphene oxide modified glassy carbon electrode (NiO−NPs-α-CD-rGO-GCE) for the selective and sensitive detection of p−NP. UV-vis, high resolution transmission electron microscopy (HR-TEM), selected area electron diffraction pattern (SAED) and X-ray diffraction (XRD) analysis confirms the formation of highly pure NiO nanoparticles. Field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), and cyclic voltammetry (CV) were used to characterize the step-wise electrode modification process. DPV was carried out to quantify p−NP within the concentration range of 1−10 μM and found the detection limit of 0.12 nM on the basis of the signal-to-noise ratio S/N=3. The electrode can able to detect different isomers of nitrophenols. Interferences of other pollutants such as phenol, p-aminophenol, o- and m- nitrophenol, 4-chlorophenol, 2,6-dichlorophenol and ions like K⁺, Cd²⁺, Cl⁻, SO₄²⁻ did not affect the sensing of p−NP. The newly developed sensor exhibited diffusion controlled kinetics and had excellent sensitivity, selectivity and reproducibility for the detection of p−NP. The electrode showed good recoveries in real sample analysis.     

Effects of Ethylene Oxide Spacer Length on solution Properties of Water—Soluble Fluorocarbon—Containing Hydrophobically Associating Poly（Acrylic Acid—co—Rf—PEG Macromonomer）

Poly(acrylic acid)s (PAAs) modified with a series of fluorocarbon group (Rf) end-capped Poly(ethylene glycol) (PEG) macromonomers(number of ethylene oxide unit:1,9,23,45) and corresponding copolymers without fluorocarbon end groups were synthesized.It was found that the effect of the hydrophobic association of fluorocarbon groups on the solution viscosity prevailed over that of the hydrogen bond between grafted PEG and the backbone.Rheological measurement on the aqueous solutions of these poly(acrylic acid-co-Rf-PEG macromonomer) s demonstrated that the best thickening performance was shown when the number of ethylene oxide unit (EO number) was 23.     

Kinetic Studies on Reactions of Monocyclic Oxyphosphoranes with Ethylene Glycol

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