Sonochemical Synthesis and Photocatalytic Properties of Metal Hydroxide and Carbonate (M:Mg, Ca, Sr or Ba) Nanoparticles

In this work Mg(OH)₂, Ca(OH)₂, CaCO₃, SrCO₃ and BaCO₃ nanoparticles were synthesized via a simple sonochemical reaction at room temperature. Nanoparticles were synthesized via a surfactant-free reaction solvent water. Nanostructures materials were characterized by scanning electron microscopy, X-ray diffraction and fourier transform infrared spectroscopy. The photocatalytic behavior of nanoparticles was evaluated using the degradation of a methyl orange aqueous solution under ultraviolet light irradiation. The results show that metal hydroxide and metal carbonate nanoparticles are promising materials with excellent performance in photocatalytic applications.     

Structural chemistry of azo complexes

Summary Complexes of Co^II, Ni^II, Cu^II, Pd^II, and Pt^IV with 2,4,5-trihydroxybenzoic acid and its substituted phenylazoderivatives have been prepared, together with some mixed-metal (Co, Cu or Ni, Cu) complexes of itsm-nitro,m-carboxy andm-hydroxyarylazo derivatives. The stereochemistries and the modes of bonding of the complexes were elucidated by spectral and magnetic susceptibility measurements.Abstracted from her Ph.D. thesis.     

An investigation on the influence of the shape of the vortex generator on fluid flow and turbulent heat transfer of hybrid nanofluid in a channel

Journal of Thermal Analysis and Calorimetry - The purpose of this study is to numerically investigate flow field and turbulent heat transfer of hybrid nanofluid, water–DWCNT–TiO2 in a...     

Develop dissipative particle dynamics method to study the fluid flow and heat transfer of Ar and O2 flows in the micro- and nanochannels with precise atomic arrangement versus molecular dynamics approach

Fluid atomic behavior is an important factor for industrial applications. Computer simulations based on simple models predict Poiseuille flow for these atomic structures with the presence of external force. In this work, we describe the dynamical properties of Ar and O₂ flows with precise atomic arrangement via dissipative particle dynamics (DPD) and molecular dynamics (MD) simulation approaches. In these methods, each model is represented by using Large-scale Atomic/Molecular Massively Parallel Simulator package. Simulation results show that maximum rate for velocity of Ar flow in platinum and copper microchannels is 0.100 (unit less)/0.091 Å ps^?1 and 0.121 (unit less)/0.105 Å ps^?1 by using DPD/MD approach. This atomic parameter changes to 0.111 (unit less)/0.102 Å ps^?1 and 0.125 (unit less)/0.108 Å ps^?1 for O₂ fluid with mentioned approaches. By decreasing the microchannel size, the maximum rate of velocity reaches to 0.101 (unit less)/0.099 Å ps^?1 and maximum temperature rate decreases to 485 (unit less)/440 K with DPD/MD approaches. These calculated parameters can be used in industrial application designing for some processes such as heat transfer in structures. It was seen that the developed DPD approach was able to simulate the fluid flow and heat transfer of various types of fluids at micro- and nanoscales with suitable accuracy versus MD.

     

纳米尺度氧化石墨烯层作为高效碳催化剂用于苄醇与芳香醛的绿色氧化

合成了纳米尺度氧化石墨烯(NGO)层,用作碳催化剂高效催化苄醇与芳香醛的氧化反应.对于醇氧化反应,当80℃时H2O2存在下,NGOs(20 wt％)可高效催化醇选择性生成醛,其反应速率和产率取决于醇上取代基的性质.对于4-硝基苄醇,反应24 h后,只有10％可转换为相应羧酸.相反,4-甲氧基苄醇和二苯基甲醇分别反应仅9和3h则可完全转化为对应的羧酸和酮.NGO碳催化剂上芳香醛氧化速率高于醇氧化速率.对于所有的醛,采用7 wt％ NGO作催化剂,在70℃反应2-3 h后,就可完全转化为相应羧酸.我们讨论了NGO催化剂结构对苄醇和芳香醛氧化反应影响的可能机理.     

Rapid production of monodisperse cross-linked red blood corpuscle-like particles via scalable one-pot dispersion polymerization

Cross-linked polystyrene (PS) particles having red blood corpuscle (RBC)-like shape were synthesized by one-pot dispersion polymerization of styrene with ethanol/water mixture and ethylene glycol dimethacrylate (EGDMA) as the reaction medium and cross-linker, respectively. Monitoring of the reaction showed that RBC-like shape forms due to asymmetric shrinkage of a cross-linked network during the phase separation. In addition, three dimensional phase diagram was generated based on the yielded data that showed that the formation of such unique shape extremely depends on the polarity of the medium and injection time of the cross-linker. In situ synthesis of RBC-like particles, as promising biomaterials in targeted drug delivery and a model for the understanding of the cell behavior, via such fast and high solid content approach makes it to be conducive to subsequent scale up, i.e. potential commercial adoption.     

In situ crystallization of ZnAl2O4/ZnO nanocomposite on alumina granule for photocatalytic purification of wastewater

Research on Chemical Intermediates - ZnAl2O4/ZnO nanocomposites with different ZnO (20, 30, and 40 mol%) concentrations and coated samples on supports were successfully prepared through...     

Effects of Zr addition on solidification characteristics of Al–Zn–Mg–Cu alloy using thermal analysis

The effect of Zr as a grain refiner on the solidification behavior, micro- and macrostructure of a new Al–Zn–Mg–Cu aluminum super-high strength alloy containing high Zn content was studied. The addition of 2 mass% Zr reduced the grain size from 1500 to 190 μm. Moreover, the dendritic structure of the alloy altered from a coarse, elongated and non-uniform morphology to a rosette-like shape and more uniform one. The parameters of liquidus region of cooling curve obtained from thermal analysis were in a good correlation with grain size results. The maximum of first derivative in the liquidus region was introduced beside recalescence undercooling which could predict the grain refinement level even after disappearing of recalescence in the cooling curve. Furthermore, the addition of 1 mass% Zr enhanced fraction of solid in dendrite coherency point from 21 to 31% and lessened the amounts of porosity from 2.3 to 1.4%.     

Kinetics and thermodynamics of uranium ion adsorption from waste solution using Amberjet 1200 H as cation exchanger

The present work deals with the adsorption of uranium from a nitric acid waste solution using the cation exchange resin Amberjet 1200 H (AHR) . Batch experiments were performed in order to assess the performance of AHR in uranium adsorption. The influences of pH, contact time, initial uranium concentration and temperature have been enhanced. The physical parameters including the adsorption kinetics, the isotherm models and the thermodynamic data have also been determined to determine the nature of the uranium adsorption by AHR. The studied resin has been agreed with both the pseudo second order reaction and Langmuir isotherm.