Adsorption equilibria of two halogenated carbons on a carbon fiber

Chlorofluorocarbons (CFCs) are presently considered to be the prime contribution to stratospheric ozone depletion. In this study, a microporous activated carbon felt (KF-1500) was used as a useful adsorbent for adsorption of trichlorofluoromethane and methylene chloride. The isotherms of these organic vapors on a microporous carbon felt were measured and the equilibrium parameters based on Dubinin-Radushkevich correlation were evaluated. Besides, the isosteric heats of adsorption were evaluated from the equilibrium data. It was found that equilibrium data for this carbon felt were well described by Dubinin-Radushkevich correlation.     

Synthesis,characterization and structure effects of polyethylene glycol bis(2-isopropoxyethyl) dimethyl diphosphates on lanthanides extraction with supercritical carbon dioxide

Three new CO₂-philic open-chain organophosphorous chelating ligands, i.e. ethylene glycol bis(2-isopropoxyethyl) dimethyl diphosphate (EG2IPE), triethylene glycol bis(2-isopropoxyethyl) dimethyl diphosphate (EG3IPE), and tetraethylene glycol bis(2-isopropoxyethyl) dimethyl diphosphate (EG4IPE), were synthesized and characterized. Solubilities of these ligands in scCO₂ were determined at different combinations of temperature (313.15⿿333.15 K) and pressure (9⿿20 MPa), which generally showed considerable solubility in each case. These experimental data are in agreement with computed data via a semi-empirical model, in which the average absolute relative deviations lie in the range of 4.09⿿4.95%. The effect of these ligands on supercritical fluid extraction of selected rare earth metals (La³⁺, Ce³⁺, Pr³⁺, Nd³⁺, Sm³⁺, Gd³⁺, Er³⁺, and Yb³⁺) was investigated at 313.15 K and 20 MPa. The extraction efficiency of this system was found to increase in the order EG4IPE < EG3IPE < EG2IPE with a range from 55% to 79%. The rationale behind different selectivities toward these metals was also discussed in comparison to other traditional organophosphorous agents. A detailed experimental analysis of the complexation patterns by means of a combination of IR, ¹H NMR and ESI-MS has revealed that the interaction of ether oxygen group in EG4IPE with metals and the corresponding extraction mechanism.     

无卤阻燃PC/ABS合金的研究

研究了四苯基间苯二酚基二磷酸酷(RDP)和氢氧化铝复配阻燃体系对PC/ABS合金性能的影响;并以马来酸酐接枝丙烯腈-苯乙烯-丁二烯共聚物(ABS-g-MAH)为相容剂,考察了ABS-g-MAH的用量对合金性能的影响.结果表明,复配阻燃体系可显著提高PC/ABS合金的阻燃性能,当RDP为14份、Al(OH)3为6份时,氧指数可达到32%;相容剂的加人能够明显提高合金的力学性能,最佳用量为6%,但使体系的黏度增加,熔体质量流动速率降低.     

High halogenated nitrobenzene hydrogenation selectivity over nano Ir particles

The selective hydrogenation of halogenated nitrobenzene over noble metal catalysts (Pd,Pt,and It) has attracted much attention owing to its high efficiency and environmental friendliness.However,the effect of size on the catalytic performance varies among different metal catalysts.In this study,sub-nano (＜3 nm) Ir and Pd particles were prepared,and their catalytic properties for hydrogenation of halogenated nitrobenzene were evaluated.Results show that high selectivity (＞99％) was achieved over small Ir nanoparticles,in which the selectivity over the Pd with same size was much lower than that on lr nanoparticles.Meanwhile,Ir and Pd have different hydrogen consumption rates and reaction rates.Density functional theory calculations showed that p-chloronitrobenzene (CNB) has different adsorption properties on Ir and Pd.The distance between oxygen (cholorine) and Ir is much shorter (longer) than that between oxygen and Pd.The reaction barriers of dechlorination ofp-CNB and p-chloroaniline over different Ir models are much larger than those on Pd.Especially,lower coordination of lr leads to larger barriers of dechlorination reaction.These theoretical results explain the difference between Ir and Pd on hydrogenation of halogenated nitrobenzene.     

水中挥发性卤代烃测定的不确定度评定

污水中挥发性卤代烃为国标优先检测项目之一,是污水检测的一个重要参考指标。为了提高挥发性卤代烃测量的准确度,对污水中4种挥发性卤代烃:三氯甲烷、四氯化碳、三氯乙烯、四氯乙烯进行测定,结果表明:不确定度主要来源于系统误差,建议尽量选用不确定度较小的标准溶液,误差较小的移液管和容量瓶,从而减小系统误差;且尽可能的进行多次重复测定,提高测量的精密度、准确度。     

Characterization of MgxM2 − xP2O7 (M = Cu and Ni) solid solutions

In this study, Mg_xM_2 − xP₂O₇ (M = Cu, Ni; 0 ≤ x ≤ 2) and Mg_3 − yNi_y(PO₄)₂ (0 ≤ y ≤ 3) compositions were synthesized by the chemical coprecipitation method and characterized by X-ray diffraction, UV-vis-NIR spectroscopy and CIE L* a* b* (Commission Internationale de l’Eclairage L* a* b*) parameters measurements.Solid solutions with α-Cu₂P₂O₇ and α-Ni₂P₂O₇ structures and solid solutions with Ni₃(PO₄)₂ structure were obtained from diphosphate and orthophosphate compositions respectively. Isostructurality of α-Ni₂P₂O₇ and α-Mg₂P₂O₇ structures enlarges the compositional range of solid solution formation respect to the Mg_xCu_2 − xP₂O₇ solid solutions one.The CIE L* a* b* parameters in Mg_xNi_2 − xP₂O₇ samples were obtained comparable with these parameters in others yellow materials suitable for ceramic pigments. Mg_0.5Ni_1.5P₂O₇ composition fired at 800 °C or 1000 °C is the optimal composition to obtain yellow materials with α-diphosphate structure in conditions of this study.     

Edge-halogenated graphene nanosheets as an efficient metal-free electrocatalyst for hydrogen evolution reaction

Application of carbonic materials as catalysts has recently been considered due to some advantages like tunable molecular structures, easy synthesis methods, abundance, and high tolerance in acidic and alkaline media. Here, a new metal-free electrocatalyst of halogenated reduced graphene oxide was prepared using cyclic voltammetry X (F, Br, and I)-RGO electrodeposition method. The prepared electrocatalysts were studied as a novel metal-free electrocatalyst for the hydrogen evolution reaction, and the presence of several halogen and oxygen functional groups on the surface of nanosheets was verified by the furrier transform infra-red, FT-IR, spectroscopy, and the presence of doped halogens on the RGO surface was confirmed by energy-dispersive X-ray, EDX, spectroscopy. The structural features and surface morphology of electrocatalysts were investigated by scanning electron microscopy (SEM) analysis. The electrochemical treatment of the X (F, Br, I)-RGO electrode was studied by some techniques like electrochemical impedance spectroscopy, EIS, chronoamperometry, CA, and linear sweep voltammetry, LSV. The X (F, Br, I)-RGO catalyst showed a lower onset potential (?0.81 V. vs. SHE), higher exchange current density (3.1 × ×10^?1 mA cm^?2), and lower charge transfer resistance (1.09 Ω cm²) related to the RGO catalyst due to the high active sites by heteroatoms and graphene nanosheets.     

四溴双酚S的合成

提出一种合成四溴双酚S的方法。此法操作简便,无三废产生,且收率高,对制备卤代双酚S或卤代双酚A具有普遍的适用性。     

Decomposition of 2-chlorophenol by supercritical water oxidation with zirconium corrosion

The 2-chlorophenol (2-CP) was oxidized in a continuous anti-corrosive supercritical water system. The variation of decomposition efficiency by the corrosion of zirconium 702 was also studied at the variation of feed concentration and reaction time. According to AES depth profile, the oxygen penetration depth to zirconium was not proportional to the exposure time. It might stem from the formation of zirconium oxide layer on the surface delaying the corrosion. However, the increase in feed concentration accelerated the corrosion of zirconium. The corrosion of zirconium at low feed concentration led to the improvement of decomposition efficiency due to the catalytic effect of formed zirconium oxides, while that at high feed concentration deteriorated the decomposition efficiency owing to large consumption of oxidant in corrosion.     

Simplified Gradient Theory Modeling of the Surface Tension for Binary Mixtures

In this work, the gradient theory was combined with the volume translation Peng-Robinson and Soave Redlich-Kwong equations of state (VTPR and VTSRK EOSs) and the influence parameter correlation to predict the surface tension of binary mixtures. The density profiles of mixtures across the interface were assumed to be linearly distributed to simplify the gradient theory model. The only two inputs of the theory are the Helmholtz free-energy density of the homogeneous fluid and the influence parameter of the inhomogeneous fluid. The VTPR and VTSRK equations of state were applied to determine the Helmholtz free-energy density and the bulk properties. The influence parameter of the inhomogeneous fluid was calculated from a correlation published previously (Lin et al. Fluid Phase Equilib 254:75, 2007). The only adjustable coefficient of the simplified gradient theory was set equal to zero, which made the theory predictive. The surface tension predicted by this model shows good agreement with experimental data for binary non-polar and polar mixtures.