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In this work, we target the preparation and characterization of asymmetric polysulfone nanocomposite charged membranes for hemodialysis application. The phase inversion technique was applied, using N-methylpyrrolidone and water as solvent and non-solvent, respectively. With the aid of blend method, the control membrane was modified using poly(acrylonitrile-co-sodium methallyl sulfonate) copolymer (AN69) and the montmorillonite clay (MMT). The estimation of MMT effect in polysulfone solution was carried out by a thermodynamic study using the titration method. Different techniques were applied in characterization of PSf/clay and PSf/AN69/clay membrane composites as Fourier transform infrared spectroscopy technique, coloration test, thermogravimetric analysis, differential scanning calorimetry analysis, X-ray diffraction, scanning electron microscopy, and water flux measurement. The obtained results show that the combination of hemocompatible PSf/AN69 blend and MMT nanocharge induces the formation of new hemodialysis composite membranes, with enhanced hydrophilic properties, good thermal sterilization resistance, better water permeability, and good capacity of protein adsorption. Besides, the obtained composite membranes have the ability to be easily functionalized due to the high density of negative charge resulting by the presence of AN69 and MMT clay at the membrane surfaces.

Chemicals such as polycyclic aromatic hydrocarbons (PAHs), phthalateesters, parabens, siloxanes and squalene, all of them classified as endocrine-disrupting chemicals (EDCs), have been reported to occur in all environmental compartments. The effects of EDCs on development, reproduction, growth, metabolism and obesity constitute a real public health issue. A list of EDCs (> 40 compounds) were characterised in total suspended particulates (outdoor soot: 92 samples) collected in July–September 2016 in an Algiers urban area; besides, settled indoor dusts (36 samples) were collected between November and December 2016 in schools, homes, manufacture and hospital of the same province. The analytical procedure consisted of ultrasonic bath extraction, column chromatography separation into fractions of different polarity and gas chromatographic-mass spectrometric processing. The total loads of phthalates ranging from 6.0 to 347 ng/m2 (median, 26 ng/m2) were determined in indoor dust and 4.6 to 11.6 ng/m3 (median, 7.9 ng/m3) in outdoor soot; meanwhile, PAHs ranged from 12.1 to 108 ng/m2 (median, 36 ng/m2) in indoor dust and ranged from 5.6 to 7.7 ng/m3 (median 5.7 ng/m3) in outdoor soot. Finally, illicit substances such as cocaine, cannabinol and Δ9-tetrahydrocannabinol were found to range from 0.5 to 11 pg/m3, 4.6 to 9.2 pg/m3 and 11 to 81 pg/m3, respectively, in outdoor soot.

CO2 emissions are a major contributor to the climate change due to the increase of CO2 concentration in the atmosphere. CO2 represents 70% of greenhouse gas emissions come essentially from human activities during the combustion of fossil resources such as petrol, natural gas, etc. Many initiatives that allow reducing the CO2 concentration are developed. One of the most promising approaches is to convert CO2 into fuels and into valuable chemicals through photocatalysis process. The CO2 photoreduction into hydrocarbon is a promising method to convert CO2 taking advantage of the readily available solar energy. To achieve the goal, it is necessary to develop an efficient photocatalyst and enhance both the CO2 reduction and the efficiency yields. This chapter reviews recent developments, challenges, and novel approaches of CO2 photoconversion for sustainable fuels. These include providing the photocatalytic properties of UV and visible light photocatalysts applied to CO2 reduction, as well as the recent advances in the design of photocatalytic systems. At the same time, doping TiO2 material with various metals or used as heterojunction allows an improvement photocatalytic activity under visible irradiation. Moreover, the effect of the doping can induce unique properties such as extended light absorption range, charge separation, and also an efficient reactivity. The contribution of carbon-based material and porous materials to the enhanced visible light-driven photocatalysis will be included. So, attractive properties make these materials as a good photocatalysts with immense potential in the elaboration of efficient visible light photocatalysts.

Chemicals such as polycyclic aromatic hydrocarbons (PAHs), phthalateesters, parabens, siloxanes and squalene, all of them classified as endocrine-disrupting chemicals (EDCs), have been reported to occur in all environmental compartments. The effects of EDCs on development, reproduction, growth, metabolism and obesity constitute a real public health issue. A list of EDCs ( 40 compounds) were characterised in total suspended particulates (outdoor soot: 92 samples) collected in July-September 2016 in an Algiers urban area; besides, settled indoor dusts (36 samples) were collected between November and December 2016 in schools, homes, manufacture and hospital of the same province. The analytical procedure consisted of ultrasonic bath extraction, column chromatography separation into fractions of different polarity and gas chromatographic-mass spectrometric processing. The total loads of phthalates ranging from 6.0 to 347 ng/m

The use of polymer materials becomes very important in our everyday life and their applications include several industries. The majority of such materials were synthesized for a long time via free radical polymerization FRP process. However, the obtained architectures were generally not controlled. In the mid 1990s, new controlled polymerization mechanisms were developed in the objective to synthesis a new controlled polymers able to satisfy our various needs in different sectors.

International audience; In this work, we report the use of the diffusion-ordered spectroscopy (NMR DOSY) nuclear magnetic resonance (NMR) technique to follow the nitroxide-mediated polymerization (NMP) of methyl methacrylate (MMA), well known as a difficult monomer to polymerize by NMP. Two syntheses were carried out either in the presence or absence of a small amount of styrene at 80 °C, using N-tert-butyl-N-(1-diethylphosphono-2,2-dimethylpropyl)nitroxide (SG1) as a control agent and 2-methylaminoxypropionic-SG1 alkoxyamine (BlocBuilder) as the initiator. Diffusion coefficients determined from NMR DOSY experiments could be accurately correlated to the weight average molar masses Mw of PMMA, and could thereby be used to confirm that the polymerization of pure MMA by NMP is uncontrolled due to disproportionation side reactions leading to non-reversible termination (i.e. dead chains). In a similar manner, the livingness of the PMMA chains grown in the presence of a small amount of styrene was confirmed by the linear evolution of the diffusion coefficient versus time (conversion) and the retention of the alkoxyamine chain end. Livingness was further assessed by NMR DOSY analysis of chain extensions with n-butyl acrylate. This all-in-one technique permits disproportionation side reactions, livingness, and evolution of the molar masses with time to be simultaneously followed.

cited By 0; International audience; The first nitroxide-mediated polymerization of butyl acrylate/methyl methacrylate and/or styrene diblock copolymers-based nanoclay composites is reported. Polybutyl acrylate (PBA) macroinitiators synthesized in the presence of raw and modified clays are used for chain extension. All materials are characterized by proton nuclear magnetic resonance, size exclusion chromatography, X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry techniques. The obtained proton nuclear magnetic resonance and size exclusion chromatography results show that all syntheses are carried out in controlled manner. X-ray diffraction analysis of hybrid materials reveals the formation of different structures varying between exfoliated and disordered ones. These structures depend on nanoclay distribution in different (co)polymer matrix and probable polymer/nanoclay interactions. All PBA composites and hybrid diblock materials register the enhanced thermal stability and show two glass transition temperature Tg values corresponding to the two diblock acrylic macromolecular features. Montmorillonite diblock nanocomposites of poly(butyl acrylate-b-methyl methacrylate) and poly(butyl acrylate-b-styrene) copolymers are obtained from raw and polybutylacrylate PBA macroinitiator-modified clays by in situ nitroxide-mediated polymerization. All syntheses are carried out in a controlled manner, and hybrid materials reveal the formation of different structures, varying between exfoliated and disordered ones, relating to the enhancement of their thermal stability. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In this work, we describe the “in situ” synthesis of “all-acrylic” copolymer (n-butyl acrylate-co-methyl methacrylate)/clay materials at different low contents of raw and modified Montmorillonite (1–4 wt % versus monomer). The cationic 2,2′ azobis-(amidinopropane)dihydrochloride initiator was used to modified the clay by cation exchange in combination with the N-tert-butyl-N-[1-diethylphosphono-(2,2-dimethylpropyl)] (SG1) nitroxide to synthesize the polymer/clay nanocomposite via nitroxide mediated controlled radical polymerization. All synthesized materials are characterized by proton nuclear magnetic resonance, size exclusion chromatography, thermogravimetric analysis and differential scanning calorimetry techniques. The thermo-mechanical properties of the synthesized materials are also reported. The results show that a decrease in molar masses and/or slight changes in molar compositions of poly (n-butyl acrylate- co-methyl methacrylate)/clay systems can be balanced by clay loading in polymer matrix, and consequently compensated or masked clay effects on physical properties of obtained materials. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

cited By 20; International audience; In this work, we report the synthesis of poly(n-butyl acrylate-co-methyl methacrylate) copolymers by the nitroxide mediated polymerization (NMP) technique, using N-tert-butyl-N-(1-diethylphosphono-2,2-dimethylpropyl)nitroxide (SG1) as a control agent and 2-methylaminoxypropionic-SG1 alkoxyamine (BlocBuilder®) as the initiator. The copolymers are synthesized either by batch or semi-batch processes and the gradient profile is examined via the determination of the instantaneous fraction of monomer incorporated in the copolymer. A control of the molar mass together with low molar mass distribution (Mw/Mn < 1.4) is observed. The dependence of the copolymer glass transition temperature with conversion was followed by differential scanning calorimetry. The copolymers are investigated by carbon nuclear magnetic resonance and heteronuclear multiple bond correlation (HMBC) NMR sequences to study the effect of the monomer addition mode on the microstructure of copolymers. The thermomechanical properties of gradient copolymers are finally reported to establish the effect of the composition on the mechanical behaviour of the copolymers. © 2011 The Royal Society of Chemistry.