Mustapha Jouiad

Bio: Mustapha Jouiad is an academic researcher from University of Picardie Jules Verne. The author has contributed to research in topics: Materials science & Superalloy. The author has an hindex of 22, co-authored 74 publications receiving 1446 citations. Previous affiliations of Mustapha Jouiad include Masdar Institute of Science and Technology & University of Poitiers.

Synthesis and Gas Transport Properties of Hydroxyl-Functionalized Polyimides with Intrinsic Microporosity

Abstract: A newly designed diamine monomer, 3,3,3′,3′-tetramethyl-1,1′-spirobisindane-5,5′-diamino-6,6′-diol, was successfully used to synthesize two types of polyimides for membrane-based gas separation applications. The novel polymers integrate significant microporosity and polar hydroxyl groups, showing the combined features of polymers of intrinsic microporosity (PIMs) and functional polyimides (PIs). They possess high thermal stability, good solubility, and easy processability for membrane fabrication; the resulting membranes exhibit good permeability owing to the intrinsic microporosity introduced by the highly contorted PIM segments as well as high CO2/CH4 selectivity that arises from the hydroxyl groups. The membranes show CO2/CH4 selectivities of >20 when tested with a 1:1 CO2/CH4 mixture for feed pressures up to 50 bar. In addition, the incorporation of hydroxyl groups and microporosity in the polymers enhances their affinity to water, leading to remarkable water sorption capacities of up to 22 wt % at 35...

Synthesis of silver nanoparticles for the dual delivery of doxorubicin and alendronate to cancer cells

Abstract: We present the synthesis of a silver nanoparticle (AgNP) based drug-delivery system that achieves the simultaneous intracellular delivery of doxorubicin (Dox) and alendronate (Ald) and improves the anticancer therapeutic indices of both drugs. Water, under microwave irradiation, was used as the sole reducing agent in the size-controlled, bisphosphonate-mediated synthesis of stabilized AgNPs. AgNPs were coated with the bisphosphonate Ald, which templated nanoparticle formation and served as a site for drug attachment. The unreacted primary ammonium group of Ald remained free and was subsequently functionalized with either Rhodamine B (RhB), through amide formation, or Dox, through imine formation. The RhB-conjugated NPs (RhB–Ald@AgNPs) were studied in HeLa cell culture. Experiments involving the selective inhibition of cell membrane receptors were monitored by confocal fluorescence microscopy and established that macropinocytosis and clathrin-mediated endocytosis were the main mechanisms of cellular uptake. The imine linker of the Dox-modified nanoparticles (Dox–Ald@AgNPs) was exploited for acid-mediated intracellular release of Dox. We found that Dox–Ald@AgNPs had significantly greater anti-cancer activity in vitro than either Ald or Dox alone. Ald@AgNPs can accommodate the attachment of other drugs as well as targeting agents and therefore constitute a general platform for drug delivery.

Multifunctional redox-tuned viologen-based covalent organic polymers

Abstract: The immobilization of molecular switches within materials can give rise to new bulk properties that are useful for a variety of applications. Here, we report the synthesis and characterization of covalent organic polymers composed of cyclotriphosphazene core moieties linked together by redox-switchable viologen units. The polymers are isolated as non-porous, micro- and nano-sized spherical particles whose constituent viologens allow access to three distinct redox states: dicationic, radical-cationic and neutral. With viologens in their dicationic state, the particles were used for magic printing, gaseous ammonia sensing, and efficient oxoanion capture. With viologens in any oxidation state, the polymers were capable of capturing 200 to 380% of their weight of iodine vapor. Iodine capture within all of the viologen-based polymers was fast, requiring minutes, as compared to capture by previously reported polymers, which requires hours. With viologens in their neutral state, the polymers exhibited the highest iodine loadings reported to date. Upon one and two-electron reduction, the polymers partially or completely lost their cationic character and, concomitantly, their anion removal capability.

MoS2–carbon nanotube hybrid material growth and gas sensing

Abstract: Hexagonal-shaped nanoplates (HNPs) of MoS2 on vertically aligned carbon nanotubes (CNTs) over a patterned area (a circular area of 1 cm2 diameter) are produced by chemical vapor deposition technique With an optimized initial Mo film thickness, a uniform coverage of MoS2 HNPs with a thickness around 20 nm is achieved The results confirm that the CNT template plays an important role in the MoS2 HNPs growth Each MoS2 HNP consists of abundant exposed edges, interesting for sensing and catalysis applications High crystallinity and quality of the as-produced material are revealed by X-ray photoelectron and Raman spectroscopies Furthermore, NO2 gas-sensing studies show better sensitivity and recovery for MoS2/CNT samples as compared to pristine CNTs The detection of NO2 gas in a few tens of parts per million to a few hundreds of parts per billion range, at room temperature, is achieved Density-functional theory calculation indicates that the exposed edges of MoS2 play a significant role in the NO2 sensing as compared to horizontally aligned MoS2 layers The present report can promote the research toward the fabrication of efficient and reliable MoS2-based hybrid materials for toxic gas-sensing applications for air quality monitoring in various environments

American Society for Testing and Materials

Abstract: The American Society for Testing and Materials (ASTM) is an independent organization devoted to the development of standards.

Cu and Cu-Based Nanoparticles: Synthesis and Applications in Catalysis.

Abstract: The applications of copper (Cu) and Cu-based nanoparticles, which are based on the earth-abundant and inexpensive copper metal, have generated a great deal of interest in recent years, especially in the field of catalysis. The possible modification of the chemical and physical properties of these nanoparticles using different synthetic strategies and conditions and/or via postsynthetic chemical treatments has been largely responsible for the rapid growth of interest in these nanomaterials and their applications in catalysis. In addition, the design and development of novel support and/or multimetallic systems (e.g., alloys, etc.) has also made significant contributions to the field. In this comprehensive review, we report different synthetic approaches to Cu and Cu-based nanoparticles (metallic copper, copper oxides, and hybrid copper nanostructures) and copper nanoparticles immobilized into or supported on various support materials (SiO2, magnetic support materials, etc.), along with their applications i...

Mapping surface plasmons on a single metallic nanoparticle

Abstract: Understanding how light interacts with matter at the nanometre scale is a fundamental issue in optoelectronics and nanophotonics. In particular, many applications (such as bio-sensing, cancer therapy and all-optical signal processing) rely on surface-bound optical excitations in metallic nanoparticles. However, so far no experimental technique has been capable of imaging localized optical excitations with sufficient resolution to reveal their dramatic spatial variation over one single nanoparticle. Here, we present a novel method applied on silver nanotriangles, achieving such resolution by recording maps of plasmons in the near-infrared/visible/ultraviolet domain using electron beams instead of photons. This method relies on the detection of plasmons as resonance peaks in the energy-loss spectra of subnanometre electron beams rastered on nanoparticles of well-defined geometrical parameters. This represents a significant improvement in the spatial resolution with which plasmonic modes can be imaged, and provides a powerful tool in the development of nanometre-level optics.