References of "Aqil, Abdelhafid"
     in
Bookmark and Share    
See detailDesign and synthesis of Fe2O3 nanoparticles/N-doped porous carbon structures as high performance electrode for lithium ion battery
Alkarmo, Walid ULg; Ouhib, Farid ULg; Aqil, Abdelhafid ULg et al

Poster (2016, October 13)

Thanks to their fascinating physical properties such as high surface area, multidimensional electron transport pathways and good mechanical strength, three dimensionally (3D) interconnected carbon porous ... [more ▼]

Thanks to their fascinating physical properties such as high surface area, multidimensional electron transport pathways and good mechanical strength, three dimensionally (3D) interconnected carbon porous frameworks have emerged as attractive materials for various electrochemical energy storage/conversion devices, including Li-ion batteries (LIBs), Li−S batteries, supercapacitors and fuel cells. In this context, a hierarchically structured macro- and mesoporous N-doped carbon with dispersed Fe2O3 nanoparticles (NDC@Fe2O3) is prepared by thermal treatment of a novel composite composed by PMMA particles decorated by graphene oxide (GO), PPy and iron salts. The NDC@Fe2O3 composite exhibited high surface area with a hierarchical pores structure. The combination of Fe2O3 nanoparticles with porous carbon to form hybrid anode has been an efficient way to maintain the electronic integrity of the whole electrode since the carbon acts as a buffer layer to accommodate the volume variation and to provide multidimensional electron transport pathways during the charge/discharge process. [less ▲]

Detailed reference viewed: 24 (3 ULg)
See detailPILs as a new active material for radical organic batteries
Aqil, Mohamed ULg; Ouhib, Farid ULg; Aqil, Abdelhafid ULg et al

Poster (2016, October 13)

Detailed reference viewed: 17 (2 ULg)
See detailPAI Annual Meeting
Ouhib, Farid ULg; Aqil, Abdelhafid ULg; Dirani, Ali et al

Poster (2016, September 12)

Detailed reference viewed: 9 (1 ULg)
Full Text
Peer Reviewed
See detailTransparent superhydrophobic coatings from amphiphilic-fluorinated block copolymers synthesized by aqueous polymerization-induced self-assembly
Ouhib, Farid ULg; Dirani, Ali; Aqil, Abdelhafid ULg et al

in Polymer Chemistry (2016), 7(24), 3998-4003

Preparation of transparent and superhydrophobic coatings by co-deposition of an aqueous solution of an amphiphilic fluorinated block copolymer (FBC) with silica particles was developped. Spin- coating of ... [more ▼]

Preparation of transparent and superhydrophobic coatings by co-deposition of an aqueous solution of an amphiphilic fluorinated block copolymer (FBC) with silica particles was developped. Spin- coating of this aqueous solution onto glass followed by an appropriate thermal treatment promotes the self-assembly of the hybrid material with the formation of superhydrophobic, robust and transparent coatings. [less ▲]

Detailed reference viewed: 35 (6 ULg)
See detailPolymers bearing pendant catechols for organic electrode-active materials in lithium-ion batteries
Patil, Nagaraj ULg; Cordella, Daniela ULg; Aqil, Abdelhafid ULg et al

Conference (2016, May 23)

Herein, we describe the synthesis and organometallic-mediated radical polymerization of 1-vinyl-3-alkylimidazolium-type monomers bearing pendant catechols in its protected version, using a presynthesized ... [more ▼]

Herein, we describe the synthesis and organometallic-mediated radical polymerization of 1-vinyl-3-alkylimidazolium-type monomers bearing pendant catechols in its protected version, using a presynthesized alkyl‒cobalt(III) complex as monocomponent initiator/mediating agent in a controlled fashion. A neat post-polymerization deprotection, followed by facile anion exchange reactions afforded a novel multi-functional poly(ionic liquids)-bearing free catechol functionalities. Prototype Lithium-ion battery, consisting a binder- and current collector-free electroactive polymer-supported buckypaper as the composite cathode, delivered an impressive specific capacity in the range of 199–230 mA h g‒1, relatively at high discharge potential = 3.2–3.4 V (vs Li/Li+), as calculated from CV and galvanostatic charge-discharge experiments. The superior electrochemical performance of the composite cathode consisting of PIL-catechols active-material, in comparison with poly(dopaminde acrylamide) is ascribed to the intrinsic Li-ion conductivity and enhanced surface activity of the imidazolium backbone with TFSI counteranion, compared to the acrylamide backbone. [less ▲]

Detailed reference viewed: 81 (4 ULg)
See detailFe2O3 nanoparticle-functionalized N-doped carbon with interconnected, hierarchical porous structures as high-performance electrode for lithium ion batteries
Alkarmo, Walid ULg; Ouhib, Farid ULg; Aqil, Abdelhafid ULg et al

Poster (2016, May 23)

Thanks to their fascinating physical properties such as high surface area, multidimensional electron transport pathways and good mechanical strength, three dimensionally (3D) interconnected carbon porous ... [more ▼]

Thanks to their fascinating physical properties such as high surface area, multidimensional electron transport pathways and good mechanical strength, three dimensionally (3D) interconnected carbon porous frameworks have emerged as attractive materials for various electrochemical energy storage/conversion devices, including Li-ion batteries (LIBs), Li−O2 batteries, Li−S batteries, supercapacitors, and fuel cells. A hierarchically structured macro- and mesoporous N-doped carbon with dispersed Fe2O3 nanoparticles (NDC@Fe2O3) is prepared by thermal treatment of a novel composite composed by PMMA particles decorated by graphene oxide (GO), PPy and iron salts. The NDC@Fe2O3 composite exhibited high surface area with a hierarchical pores structure. Integrated as a lithium ion battery anode, NDC@Fe2O3 exhibited high reversible capacity of 930 mA h/g over 200 cycles. The combination of Fe2O3 nanoparticles with porous carbon to form hybrid anode has been an efficient way to maintain the electronic integrity of the whole electrode since the carbon acts as a buffer layer to accommodate the volume variation and to provide multidimensional electron transport pathways during the charge/discharge process. [less ▲]

Detailed reference viewed: 261 (7 ULg)
See detailChitosan-based nanofibers mats for tissue engineering
Aqil, Abdelhafid ULg; Croisier, Florence ULg; Colige, Alain ULg et al

Conference (2016, May)

Polymer hydrogels resemble the natural living tissue due to their high water content and soft consistency. They find many applications in the design and production of contact and intraocular lenses ... [more ▼]

Polymer hydrogels resemble the natural living tissue due to their high water content and soft consistency. They find many applications in the design and production of contact and intraocular lenses, biosensors membranes, matrices for repairing and regenerating a wide diversity of tissues and organs. Polysaccharides such as chitosan and hyaluronic acid based hydrogels have shown a great potential for biomedical and pharmaceutical applications, on account of their remarkable compatibility with physiological medium. Besides, it is degraded in a physiological environment into non-toxic products, which make them outstanding candidates for short- to medium-term applications, especially for tissue engineering. In this respect, the preparation of nanometric fibers mats based on this polysaccharide are highly interesting as such structure mimics the one of skin extracellular matrix. Such nanofibrous materials can be prepared by electrospinning (Figure 1). This technique uses a high voltage to create an electrically charged jet of polymer solution to obtain polymer fibers ranging from nanometers to a few microns in diameter. We thus have investigated strategies allowing to generate chitosan based nanofiber mats exhibiting a mechanical resistance strong enough to be easily handled while keeping the peculiar features of chitosan hydrogels favoring the interaction with cells and soft tissues to provide efficient tissue reconstruction. In a first strategy, polysaccharide-based nanofibers with a multilayered structure were prepared by combining electrospinning (ESP) and layer-by-layer (LBL) deposition techniques. Elastic nanofibers bearing charges at their surface were firstly prepared by electrospinning poly(ε-caprolactone) (PCL) with a polyelectrolyte precursor. After activation by adjusting the pH, the layer-by-layer deposition of chitosan and hyaluronic acid, can be used to coat the electrospun fibers. A multilayered structure is then achieved by alternating the deposition of the positively charged chitosan with the deposition of a negatively charged polyelectrolyte. These novel polysaccharide-coated PCL fiber mats remarkably combine the mechanical resistance typical of the core material (PCL) – particularly in the hydrated state –, with the surface properties of chitosan. Besides, crosslinked nanofibrous mats of chitosan and polyethylene oxide blends, were successfully prepared via electrospinning technique followed by heat mediated chemical crosslinking. This chemical cross-linking allows adjusting the mechanical resistance of the mats while preserving their biocompatibility. In both cases, the control of the nanofiber structure offered by the electrospinning technology, makes the developed processes very promising to precisely design biomaterials for tissue engineering. Preliminary cell culture tests corroborate the potential use of such systems in wound healing applications. [less ▲]

Detailed reference viewed: 471 (12 ULg)
Full Text
Peer Reviewed
See detailA new design of organic radical batteries (ORBs): carbon nanotube buckypaper electrode functionalized by electrografting
Aqil, Abdelhafid ULg; Vlad, Alexandru; Piedboeuf, Marie-Laure ULg et al

in Chemical Communications (2015), 51(45), 9301-9304

A novel hybridmaterial displaying a fast and reversible charge storage capability is prepared by electrografting of an alkoxyamine-bearing acrylate onto a carbon nanotube buckypaper, followed by the quan ... [more ▼]

A novel hybridmaterial displaying a fast and reversible charge storage capability is prepared by electrografting of an alkoxyamine-bearing acrylate onto a carbon nanotube buckypaper, followed by the quan- titative generation of an electroactive polynitroxide. [less ▲]

Detailed reference viewed: 84 (16 ULg)
See detailControlled synthesis of multi-functional polymers bearing pendant catechols for surface modifications
Patil, Nagaraj ULg; Aqil, Abdelhafid ULg; Jérôme, Christine ULg et al

Poster (2015, June)

Poly(ethylene glycol) (PEG)-based polymers have been widely employed in anti-fouling coating applications due to their robust bio-relevant properties including water solubility and biocompatibility ... [more ▼]

Poly(ethylene glycol) (PEG)-based polymers have been widely employed in anti-fouling coating applications due to their robust bio-relevant properties including water solubility and biocompatibility. However, limited by its poor adhesion towards surfaces, demands an addition modification strategies. Mussel adhesive proteins (MAPs) are potential models for adhesive polymers, which exhibits underwater adhesion towards dissimilar materials under environmentally challenging conditions. Most often experimentally simple, but structurally complex poly(dopamine) has been used as an analogues of MAPs for metal chelation, cross-linking and surface binding purposes. Inspired by MAPs, we have developed catechol-bearing copolymers for surface adhesion of stainless steel. This study describes the synthesis and reversible addition−fragmentation chain transfer (RAFT) polymerization of mussel-inspired acetonide-protected dopamine (meth)acrylamide monomers (ADA and ADMA). A series of well-defined P(PEGAm-b-ADAn) and P(ADMAn-b-PEGMAm) copolymers across a range of molar masses (13−42 kg/mol) with low molar mass dispersities (Đ = 1.12−1.25) were reported for the first time. Post polymerization TFA treatment yields block copolymers bearing free –catechol units in quantitative yields (>95%). The self-assembling nature of amphiphilic block-copolymers was studied by 1H-NMR, DLS and TEM. Surface functionalization and anti-fouling experiments were performed in real time using quartz crystal microbalance coupled with dissipation (QCM-D). The copolymer upon oxidation yields reactive quinones, which can be exploited to cross-link with chitosan (also, polymers with free –NH2 and –SH groups), thereby producing nano(macro)gels. In general, these novel class of block copolymeric ligand systems can be foreseen as versatile ingredients in material chemistry to obtain biocompatible multifunctional systems, benefited by high water solubility with inherent stealth ability and protein-repellency, as well as effective chelating groups, and may find application for a variety of biomedical fields, of which we have illustrated an important example. [less ▲]

Detailed reference viewed: 53 (2 ULg)
Full Text
Peer Reviewed
See detailDual stimuli-responsive coating designed through layer-by-layer assembly of PAA-b-PNIPAM block copolymers for the control of protein adsorption
Osypova, Alina; Magnin, Delphine; Sibret, Pierre ULg et al

in Soft Matter (2015), 11(41), 8154-8164

In this paper, we describe the successful construction, characteristics and interaction with proteins of stimuli-responsive thin nanostructured films prepared by layer-by-layer (LbL) sequential assembly ... [more ▼]

In this paper, we describe the successful construction, characteristics and interaction with proteins of stimuli-responsive thin nanostructured films prepared by layer-by-layer (LbL) sequential assembly of PNIPAM-containing polyelectrolytes and PAH. PAA-b-PNIPAM block copolymers were synthesized in order to benefit from (i) the ionizable properties of PAA, to be involved in the LbL assembly, and (ii) the sensitivity of PNIPAM to temperature stimulus. The impact of parameters related to the structure and size of the macromolecules (their molecular weight and the relative degree of polymerization of PAA and PNIPAM), and the interaction with proteins under physico-chemical stimuli, such as pH and temperature, are carefully investigated. The incorporation of PAA-b-PNIPAM into multilayered films is shown to be successful whatever the block copolymer used, resulting in slightly thicker films than the corresponding (PAA/PAH)n film. Importantly, the protein adsorption studies demonstrate that it is possible to alter the adsorption behavior of proteins on (PAA-b-PNIPAM/PAH)n surfaces by varying the temperature and/or the pH of the medium, which seems to be intimately related to two key factors: (i) the ability of PNIPAM units to undergo conformational changes and (ii) the structural changes of the film made of weak polyelectrolytes. The simplicity of construction of these PNIPAM block copolymer-based LbL coatings on a large range of substrates, combined with their highly tunable features, make them ideal candidates to be employed for various biomedical applications requiring the control of protein adsorption. [less ▲]

Detailed reference viewed: 25 (6 ULg)
Full Text
Peer Reviewed
See detailRAFT polymerization of an alkoxyamine bearing acrylate, towards a well-defined redox active polyacrylate
Aqil, Mohamed ULg; Aqil, Abdelhafid ULg; Ouhib, Farid ULg et al

in RSC Advances (2015), 5(103), 85035-85038

A new strategy for the synthesis of a well-defined redox active poly- mer, a polyacrylate bearing TEMPO, and its grafting onto a gold substrate is described. It consists of polymerizing an acrylate ... [more ▼]

A new strategy for the synthesis of a well-defined redox active poly- mer, a polyacrylate bearing TEMPO, and its grafting onto a gold substrate is described. It consists of polymerizing an acrylate bearing an alkoxyamine by RAFT, followed by aminolysis of the trithiocar- bonate chain-end into a thiol that is exploited for the polymer grafting onto the gold sensor. Thermal activation of the alkoxyamine under air provides the redox polymer with a high yield. Its electroactivity is evaluated by a electrochemical quartz crystal microbalance (EQCM). [less ▲]

Detailed reference viewed: 32 (4 ULg)
Full Text
Peer Reviewed
See detailPreparation and characterizations of EGDE crosslinked chitosan electrospun membranes
Aqil, Abdelhafid ULg; Tchemtchoua, Victor T.; Colige, Alain ULg et al

in Clinical Hemorheology and Microcirculation (2015), 60(1), 39-50

Composite Crosslinked nanofibrous membranes of chitosan, ethylene glycol diglycidyl ether (EGDE) and polyethy- 10 lene oxide was successfully prepared with bead free morphology via electrospinning ... [more ▼]

Composite Crosslinked nanofibrous membranes of chitosan, ethylene glycol diglycidyl ether (EGDE) and polyethy- 10 lene oxide was successfully prepared with bead free morphology via electrospinning technique followed by heat mediated 11 chemical crosslinking. Architectural stability of nanofiber mat in aqueous medium was achieved by chemical crosslinking of 12 only 1% EGDE, and tensile strength tests revealed that increasing EGDE content has considerably enhance the elastic modu- 13 lus of nanofibers. The structure, morphology and mechanical properties of nanofibers were characterized by Attenuated Total 14 Reflection-Fourier Transform Infrared spectroscopy (ATR–FTIR), scanning electron microscopy (SEM) and Instron machine, 15 respectively. Skin fibroblasts and endothelial cells showedgood attachment, proliferation and viability on crosslinked electrospun 16 membranes. The results indicate a good biocompatibility and non-toxic nature of the resulted membrane. [less ▲]

Detailed reference viewed: 71 (19 ULg)
See detailGraphene functionalization using electrografting for energy storage application
Aqil, Abdelhafid ULg; Ouhib, Farid ULg; Aqil, Mohamed ULg et al

Conference (2014, November 04)

Many methods have been developed in the last few decades to obtain high-quality graphene thin sheets. They are based on very different physicochemical processes. Here we demonstrate a novel one step and ... [more ▼]

Many methods have been developed in the last few decades to obtain high-quality graphene thin sheets. They are based on very different physicochemical processes. Here we demonstrate a novel one step and simple electrografting acrylate monomer method to exfoliate highly oriented pyrolytic graphite (HOPG) into thin nanoplatelets and even down to the single graphene sheet level. Among the high research activity in the area of surface modification, electrografting is a very powerful method which has received comparatively little attention. This is surprising because this technique has many attractive features for modification of conducting or semi-conducting surfaces. The main interest of the electrografting process is to solve the recurrent problem of the organic/substrates interface weakness. The electrografting warranties a robust polymer/substrates interface and offers the possibility to tailor the functionality of the grafted polymer film opening the door to a wide range of demanding technological applications. The graphene sheets obtained through electrografting process give a stable suspension in dimethyl formamide (DMF), and they can self-precipitate on the surface of substrates after adding water as an antisolvent due to their strong surface hydrophobicity. Interestingly, the continuous films obtained exhibit ultratransparency (∼98% transmittance), and the lateral size of the exfoliated graphene sheets observed by AFM ~1nm. Raman and TEM characterizations corroborate that the graphene sheets exfoliated by our electrochemical method preserve the intrinsic structure of grapheme and give preferentially monolayered graphene sheets. The electrochemical behaviour of the acrylate monomer grafted graphene sheets was evaluated in lithium-half cells with no addition of conductive additive or binder. The PAN grafted graphene dispersed in DMF was coated on Cu foil and dried in a vacuum oven at 55°C for 12h. After 200 cycles, the reversible capacity was still kept at 300mAh/g at the current density of 50mA/g. These results indicate that the prepared high quality graphene sheets possess good electrochemical performances for lithium storage. This work provides an efficient approach to obtain high-quality, cost-effective, and scalable production of “graphene ink”, which may pave a way toward future applications in lithium-ion batteries. [less ▲]

Detailed reference viewed: 93 (5 ULg)
Full Text
Peer Reviewed
See detailA facile and fast electrochemical route to produce functional few-layer graphene sheets for lithium battery anode application
Ouhib, Farid ULg; Aqil, Abdelhafid ULg; Thomassin, Jean-Michel ULg et al

in Journal of Materials Chemistry A (2014), 2(37), 15298-15302

A simple approach for the production of polymer functionalized graphene nanosheets is reported. The resulting polyacrylonitrile chemisorbed on graphene sheets is made of 1 to 2 layers, with a large ... [more ▼]

A simple approach for the production of polymer functionalized graphene nanosheets is reported. The resulting polyacrylonitrile chemisorbed on graphene sheets is made of 1 to 2 layers, with a large majority of graphene single-layers. This novel functionalized graphene exhibits good cycling stability as an anode in Li-ion batteries without a conductive additive or binder. [less ▲]

Detailed reference viewed: 65 (12 ULg)
See detailElectrografting of acrylate monomer, versatile method for coatings and thin films technologies
Aqil, Abdelhafid ULg; Jérôme, Christine ULg

Conference (2014, September)

Among the high research activity in the area of surface modification, electrografting is a very powerful and effective technique. When conducted under appropriate conditions of solvent and cathodic ... [more ▼]

Among the high research activity in the area of surface modification, electrografting is a very powerful and effective technique. When conducted under appropriate conditions of solvent and cathodic potential, the electropolymerization of (meth)acrylic monomers results in the chemisorption of the polymer on the conducting surface. This one-step electrografting technique is very easily implemented, can be applied to a wide range of (semi)-conducting surfaces by keeping the same chemistry and requires commonly used, readily available (meth)acrylate monomers. The wide variety of acrylic monomers suitable for this process makes available a broad range of surface properties including bactericidal, superhydrophobic and proteins repellent coatings. Electrografted smart coatings able to respond to external stimuli are also of interest particularly for sensors and actuators. [less ▲]

Detailed reference viewed: 29 (4 ULg)
See detailPhysical, chemical and cyctotoxi properties of cross-linked chitosan electrospun fiber mats
Aqil, Abdelhafid ULg; Tchemtchoua, Victor T.; Colige, Alain ULg et al

Poster (2014, May)

Detailed reference viewed: 19 (4 ULg)