Enhanced separation and extraction of cadmium and lead by a novel magnetite-immobilized-gelatin nano-sorbent

A novel magnetic nano-sorbent was synthesized by Schiff’s base formation via covalent bonding of gelatin to the surface of nano-magnetite-immobilized-3-aminopropyltrimethoxysilane (Nano-Fe₃O₄-Si-N=Gelatin). The structure was confirmed by the FT-IR, TGA, and SEM. The maximum capacity of Cd(II) and Pb(II) were identified as 440 and 400 µmol g^?1, respectively. The separation characteristics were evaluated in presence of various controlling factors. The sorption processes of Cd(II) and Pb(II) were found to follow the postulates of Langmuir, Brunauer-Emmer-Teller, and Dubinin Radushkevich isotherm models. The potential applications of Nano-Fe₃O₄-Si-N=Gelatin in water treatment of Cd(II) and Pb(II) were successfully accomplished using a micro-column technique.     

Microwave-Assisted Synthesis of the Flexible Iron-based MIL-88B Metal–Organic Framework for Advanced Energetic Systems

The 3D metal–organic framework (MOF), MIL-88B, built from the trivalent metal ions and the ditopic 1,4-Benzene dicarboxylic acid linker (H₂BDC), distinguishes itself from the other MOFs for its flexibility and high thermal stability. MIL-88B was synthesized by a rapid microwave-assisted solvothermal method at high power (850 W). The iron-based MIL-88B [Fe₃.O.Cl.(O₂C–C₆H₄–CO₂)₃] exposed oxygen and iron content of 29% and 24%, respectively, which offers unique properties as an oxygen-rich catalyst for energetic systems. Upon dispersion in an organic solvent and integration into ammonium perchlorate (AP) (the universal oxidizer for energetic systems), the dispersion of the MOF particles into the AP energetic matrix was uniform (investigated via elemental mapping using an EDX detector). Therefore, MIL-88B(Fe) could probe AP decomposition with the exclusive formation of mono-dispersed Fe₂O₃ nanocatalyst during the AP decomposition. The evolved nanocatalyst can offer superior combustion characteristics. XRD pattern for the MIL-88B(Fe) framework TGA residuals confirmed the formation of α-Fe₂O₃ nanocatalyst as a final product. The catalytic efficiency of MIL-88B(Fe) on AP thermal behavior was assessed via DSC and TGA. AP solely demonstrated a decomposition enthalpy of 733 J g^?1, while AP/MIL-88B(Fe) showed a 66% higher decomposition enthalpy of 1218 J g^?1; the main exothermic decomposition temperature was decreased by 71 °C. Besides, MIL-88B(Fe) resulted in a decrease in AP decomposition activation energy by 23% and 25% using Kissinger and Kissinger–Akahira–Sunose (KAS) models, respectively.

     

Correction to: Recent advances in the design of metal–organic frameworks for methane storage and delivery

Journal of Porous Materials -     

Putative biomarkers and targets of estrogen receptor negative human breast cancer

Breast cancer is a progressive and potentially fatal disease that affects women of all ages. Like all progressive diseases, early and reliable diagnosis is the key for successful treatment and annihilation. Biomarkers serve as indicators of pathological, physiological, or pharmacological processes. Her2/neu, CA15.3, estrogen receptor (ER), progesterone receptor (PR), and cytokeratins are biomarkers that have been approved by the Food and Drug Administration for disease diagnosis, prognosis, and therapy selection. The structural and functional complexity of protein biomarkers and the heterogeneity of the breast cancer pathology present challenges to the scientific community. Here we review estrogen receptor-related putative breast cancer biomarkers, including those of putative breast cancer stem cells, a minor population of estrogen receptor negative tumor cells that retain the stem cell property of self-renewal. We also review a few promising cytoskeleton targets for ER alpha negative breast cancer.     

A global optimal formulation for the water integration in eco-industrial parks considering multiple pollutants

A mathematical programming formulation for the water integration in eco-industrial parks considering streams with several pollutants is presented. The formulation is based on a superstructure that allows the wastewater reuse in the same plant, the water exchange with different plants, and a shared set of interceptors that must be selected to determine the network configuration that satisfies process equipments and environmental constraints. The model formulation considers wastewater with several pollutants, and optimizes the network according to the minimum total annual cost, which includes the costs of fresh water, piping and regeneration. A new discretization approach is also proposed to handle the large set of bilinear terms that appear in the model in order to yield a near global optimal solution. The results obtained in several examples show considerable savings with respect to the solutions of the individual plant integration policy commonly employed for these types of problems.     

Aliphatic polyurethane–montmorillonite nanocomposite coatings: Preparation,characterization, and anticorrosive properties

Polyurethane (PU)–clay nanocomposite coatings were prepared by a sonication method. The stability and morphology of these coatings was characterized by turbidometry, X‐ray diffraction, and transmission electron microscopy. The anticorrosive properties of these coatings were investigated by salt‐spray and electrochemical impedance spectroscopy methods. According to the results, dispersed nanoclay layers in the matrix of the nanocomposite coating compositions led to superior anticorrosive characteristics compared to those of pure PU coatings. The best results were obtained with coatings containing about 5 wt % clay. The resistance of the coating containing 5% clay was about 9.002 GΩ after 225 days of immersion in a 3.5 wt % NaCl solution, whereas it was only 97 kΩ for the pure PU coating. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Surface Properties and Thermodynamic Parameters of Some Sugar-Based Ethoxylated Amine Surfactants: 1—Synthesis,Characterization, and Demulsification Efficiency

Several ethoxylated sugar-based amine surfactants have been synthesized and characterized by IR and ¹HNMR spectroscopy. The surface activity of the prepared compounds has been thoroughly studied and some of their surface properties (such as CMC, Γ_max, and A _min) have been calculated. The surface properties of the prepared compounds were correlated to their chemical structure. It was found that CMC decreases when increasing the molecular weight of polyethylene glycols, whereas A _min increases. Furthermore, the thermodynamic parameters of adsorption and micellization were also calculated. They include ΔG, ΔH, and ΔS of micellization and adsorption. The data show that the synthesized surfactants favor adsorption, so that they can be used as demulsifiers for crude oil emulsions. In this respect, the demulsification test was carried out and the results of demulsification efficiency were correlated to the chemical composition of the investigated compounds. Some factors that affect the demulsification efficiency were also considered.     

Synthesis and Evaluation of a New Cationic Surfactant for Oil-Well Drilling Fluid

A new additive cationic surfactant for drilling fluid was synthesized by alkylation of coal tar phenol with tetradecyl alcohol; then, the alkyl phenol reacts with formaldehyde and amine to produce the Mannich base product. This product was reacted with sodium chloroacetate to produce the cationic surfactant; the structure of the synthesized surfactant was confirmed by FTIR analysis, evaluation of the prepared surfactant by surface properties such as surface tension, emulsification power, and wetting power. The prepared cationic surfactant showed good results when utilized in the formulation of both oil-based mud and synthetic-based mud as the primary emulsifier.     

Direct electron transfer from glucose oxidase immobilized on a nano-porous glassy carbon electrode

A pair of well-defined and reversible redox peaks was observed for the direct electron transfer (DET) reaction of an immobilized glucose oxidase (GOx) on the surface of a nano-porous glassy carbon electrode at the formal potential (E°′) of −0.439 V versus Ag/AgCl/saturated KCl. The electron transfer rate constant (k_s) was calculated to be 5.27 s⁻¹. The dependence of E°′ on pH indicated that the direct electron transfer of the GOx was a two-electron transfer process, coupled with two-proton transfer. The results clearly demonstrate that the nano-porous glassy carbon electrode is a cost-effective and ready-to-use scaffold for the fabrication of a glucose biosensor.     

MHD flow and heat transfer of a micropolar fluid over a nonlinear stretching surface with variable surface heat flux and heat generation

An analysis has been carried out to study magnetohydrodynamic boundary layer flow and heat transfer of an electrically conducting micropolar fluid over a nonlinear stretching surface with variable wall heat flux in the presence of heat generation/absorption and a non‐uniform transverse magnetic field. The governing system of partial differential equations is first transformed into a system of ordinary differential equations using similarity transformation. The transformed equations are solved numerically. Results for the dimensionless velocity, micro‐rotation, and temperature profiles are displayed graphically delineating the effects of various parameters characterising the flow. The results show that the velocity profile decreases as the magnetic parameter and the velocity exponent increase, while it increases as the material parameter increases. The results show also that the temperature profile increases as the magnetic parameter, the velocity exponent, and the heat generation parameter increase. Furthermore, the temperature profile decreases as the material parameter, the heat absorption parameter, and the Prandtl number increase.