References of "Detrembleur, Christophe"
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See detailMultilayered chitosan-based fibers for skin regenaration applications
Croisier, Florence ULg; Detrembleur, Christophe ULg; Jérôme, Christine ULg

Poster (2014, May 26)

Chitosan is a natural polymer derived from the chitin of crustacean or mushroom shells, that intrinsically presents haemostatic, mucoadhesive, antimicrobial and immunostimulant properties. This ... [more ▼]

Chitosan is a natural polymer derived from the chitin of crustacean or mushroom shells, that intrinsically presents haemostatic, mucoadhesive, antimicrobial and immunostimulant properties. This polysaccharide has shown a great potential for biomedical and pharmaceutical applications, on account of its remarkable compatibility with physiological medium. Besides, it is degraded in a physiological environment into non-toxic products, which make chitosan an outstanding candidate for short- to medium-term applications. In this respect, nanometric fibers are highly interesting as their assembly mimics the skin extracellular matrix structure. Such nanofibrous materials can be prepared by electrospinning (ESP). This technique uses a high voltage to create an electrically charged jet of polymer solution or melt which leads to fibers formation. Depending on the polymer characteristics (a.o. molecular weight, solution viscosity and conductivity) and processing conditions (electric potential, distance between syringe-capillary and collection plate, concentration, flow rate), polymer fibers ranging from nanometers to a few microns in diameter can be obtained and subsequently used as potential scaffolds, a.o. to form a temporary, artificial extracellular matrix. In the present study, electrospinning technique was combined with layer-by-layer deposition method (LBL) - a well-known method for surface coating, based on electrostatic interactions - in order to prepare multilayered chitosan-based nanofibers. The antibacterial properties of the obtained material were then assessed, and the presence of a multilayered deposit was confirmed by several techniques. The multilayered chitosan-based nanofibers produced present great prospects for the preparation of new biomedical scaffolds - such as wound dressings that could improve skin regeneration. [less ▲]

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See detailPoly(methyl methacrylate)/graphene oxide nanocomposites by a precipitation polymerization process and their dielectric and rheological characterization
Thomassin, Jean-Michel ULg; Trifkovic, Milana; Alkarmo, Walid et al

in Macromolecules (2014), 47(6), 2149-2155

We report a method for achieving controlled dispersion of graphene oxide (GO) in poly(methyl methacrylate) (PMMA) via the precipitation polymerization process in a water/ methanol mixture. GO acts as a ... [more ▼]

We report a method for achieving controlled dispersion of graphene oxide (GO) in poly(methyl methacrylate) (PMMA) via the precipitation polymerization process in a water/ methanol mixture. GO acts as a surfactant and adsorbs on the interface between polymerized PMMA particles and solvent mixture. Scanning electron and transmission electron microscopy confirmed that the precipitate consists of polymer particles (<1 μm) surrounded by the GO sheets. Compression molding of the precipitate yields a polymer nanocomposite with the GO organized into a regularly spaced 3D network which percolates at 0.2 wt % GO. Simple thermal reduction of the GO sheets dispersed in PMMA at relatively low temperature (210 °C) achieved electrical conductivity higher than 10−2 S/m at 0.4 wt % of GO. Parallel dielectric and rheological characterization demonstrated that the thermal reduction is a quite fast process without significant degradation of the polymer. The study should open up new opportunities in the design of GO-based polymer nanocomposites. [less ▲]

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See detailPrecision design of ethylene- and polar-monomer-based copolymers by organometallic-mediated radical polymerization
Kermagoret, Anthony ULg; Debuigne, Antoine ULg; Jérôme, Christine ULg et al

in Nature Chemistry (2014), 6(3), 179-187

The copolymerization of ethylene with polar monomers is a major challenge when it comes to the manufacture of materials with potential for a wide range of commercial applications. In the chemical industry ... [more ▼]

The copolymerization of ethylene with polar monomers is a major challenge when it comes to the manufacture of materials with potential for a wide range of commercial applications. In the chemical industry, free-radical polymerization is used to make a large proportion of such copolymers, but the forcing conditions result in a lack of fine control over the architecture of the products. Herein we introduce a synthetic tool, effective under mild experimental conditions, for the precision design of unprecedented ethylene- and polar-monomer-based copolymers. We demonstrate how an organocobalt species can control the growth of the copolymer chains, their composition and the monomer distribution throughout the chain. By fine tuning the ethylene pressure during polymerization and by exploiting a unique reactive mode of the end of the organometallic chain, novel block-like copolymer structures can be prepared. This highly versatile synthetic platform provides access to a diverse range of polymer materials. [less ▲]

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See detailGlucose-, pH- and thermo-responsive nanogels crosslinked by functional superparamagnetic maghemite nanoparticles as innovative drug delivery systems
Liu, Ji ULg; Detrembleur, Christophe ULg; Debuigne, Antoine ULg et al

in Journal of Materials Chemistry B (2014), 2(8), 1009-1023

Reversibly crosslinked (RCL) nanogels made of thermo-responsive poly(vinyl alcohol)-b-poly(Nvinylcaprolactam) copolymers were combined with maghemite nanoparticles and developed as new drug delivery ... [more ▼]

Reversibly crosslinked (RCL) nanogels made of thermo-responsive poly(vinyl alcohol)-b-poly(Nvinylcaprolactam) copolymers were combined with maghemite nanoparticles and developed as new drug delivery systems (DDS). The crosslinking was formed via boronate/diol bonding from the surfacefunctionalized superparamagnetic maghemite nanoparticles, endowing the DDS with thermo-, pH- and glucose-responsiveness. The capability to load a hydrophobic drug model Nile red (NR) within the RCL nanogels was evaluated, and stimuli-triggered drug release behaviours under different conditions were tested. Zero premature release behaviour was detected at physiological pH in the absence of glucose, whereas triggered release was observed upon exposure to acidic pH (5.0) and/or in the presence of glucose. In light of the superparamagnetic properties of the maghemite nanoparticles and RCL nanogels, magnetically-induced heating, MR imaging performance, as well as remotely magnetically-triggered drug release under alternating magnetic field (AMF), were investigated. Cytotoxicity against fibroblast-like L929 and human melanoma MEL-5 cell lines was assessed via the MTS assay. In vitro stimuli-triggered release of tamoxifen, a chemotherapeutic drug, was also studied within MEL-5 cell cultures under different conditions. These innovative RCL nanogels, integrating different stimuli-responsive components, hydrophobic chemotherapeutic moieties and also diagnostic agents together via reversible crosslinking, are promising new theranostic platforms. [less ▲]

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See detailGold nanorods coated with a thermo-responsive poly(ethylene glycol)-b-poly(N-vinylcaprolactam) corona as drug delivery systems for remotely near infrared-triggered release
Liu, Ji ULg; Detrembleur, Christophe ULg; De Pauw, Marie-Claire ULg et al

in Polymer Chemistry (2014), 5(3), 799-813

Poly(ethylene glycol)-b-poly(N-vinylcaprolactam) (PEG-b-PNVCL) copolymers are prepared from a PEG macro-chain transfer agent in DMF at 65 °C via reversible addition-fragmentation chain transfer (RAFT ... [more ▼]

Poly(ethylene glycol)-b-poly(N-vinylcaprolactam) (PEG-b-PNVCL) copolymers are prepared from a PEG macro-chain transfer agent in DMF at 65 °C via reversible addition-fragmentation chain transfer (RAFT) polymerization. The well-defined PEG114-b-PNVCL237 copolymer with a cloud point temperature of 39 °C is used for the formation of a thermo-responsive polymer corona on the surface of gold nanorods (GNRs) via a “grafting-to” approach. Thermo-responsiveness and thermo-dependent optical properties of the as-obtained GNR@PEG-b-PNVCL nanoparticles are studied with dynamic light scattering and UV/vis spectroscopy techniques. Near infrared (NIR)-induced heating of GNR@PEG-b-PNVCL is also explored in aqueous suspension under NIR laser irradiation (802 nm, up to 250 mW). The potential of these GNR@PEG-b-PNVCL nanoparticles to be used as smart drug delivery systems (DDS) is then studied. A hydrophilic drug model, Rhodamine ® B, is used to assess the guest loading capacity, and triggered release behaviours are then evaluated under conventional external heating or internal heating induced by remote NIR irradiation. Cytotoxicity evaluation of the GNR@PEG-b-PNVCL against the fibroblast-like L929 cell line is carried out via the MTS assay in order to confirm the improved biocompatibility of the GNRs after polymer coating. These thermo-responsive GNR@PEG-b-PNVCL nanoparticles are promising DDS that combine the chemotherapeutic and phototherapeutic functions. [less ▲]

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See detailPrecision synthesis of poly(ionic liquid)-based block copolymers by cobalt-mediated radical polymerization and preliminary study of their self-assembling properties
Coupillaud, Paul; Fèvre, Maréva; Wirotius, Anne-Laure et al

in Macromolecular Rapid Communications (2014), 35(4), 422-430

A poly(ionic liquid)-based block copolymer (PIL BCP), namely, poly(vinyl acetate)-b-poly(N-vinyl-3-butylimidazolium bromide), PVAc-b-PVBuImBr, is synthesized by sequential cobalt-mediated radical ... [more ▼]

A poly(ionic liquid)-based block copolymer (PIL BCP), namely, poly(vinyl acetate)-b-poly(N-vinyl-3-butylimidazolium bromide), PVAc-b-PVBuImBr, is synthesized by sequential cobalt-mediated radical polymerization (CMRP). A PVAc precursor is first prepared at 30 °C in bulk by CMRP of VAc, using bis(acetylacetonato)cobalt(II), Co(acac)2, and a radical source (V-70). Growth of PVBuImBr from PVAc-Co(acac)2 is accomplished by CMRP in DMF/MeOH (2:1, v/v). This PIL BCP self-assembles in the sub-micron size range into aggregated core–shell micelles in THF, whereas polymeric vesicles are observed in water, as evidenced by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Thin-solid sample cut from raw materials analyzed by TEM shows an ordered lamellar organization by temperature-dependent synchrotron small-angle X-ray scattering (SAXS). Anion exchange can be accomplished to achieve the corresponding PIL BCP with bis(trifluorosulfonyl)imide (Tf2N−) anions, which also gives rise to an ordered lamellar phase in bulk samples. A complete suppression of SAXS second-order reflection suggests that this compound has a symmetric volume fraction (f ≈ 0.5). SAXS characterization of both di- and triblock PIL BCP analogues previously reported also shows a lamellar phase of very similar behavior, with only an increase of the period by about 8% at 60 °C. [less ▲]

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See detailHeat-triggered drug release systems based on mesoporous silica nanoparticles filled with a maghemite core and phase-change molecules as gatekeepers
Liu, Ji ULg; Detrembleur, Christophe ULg; De Pauw-Gillet, Marie-Claire ULg et al

in Journal of Materials Chemistry B (2014), 2(1), 59-70

Core–shell nanoparticlesmade of a maghemite core and a mesoporous silica shell were developed as drug delivery systems (DDS). Doxorubicin® (DOX, DNA intercalating drug) was loaded within the mesoporous ... [more ▼]

Core–shell nanoparticlesmade of a maghemite core and a mesoporous silica shell were developed as drug delivery systems (DDS). Doxorubicin® (DOX, DNA intercalating drug) was loaded within the mesoporous cavities, while phase-change molecules (PCMs), e.g. 1-tetradecanol (TD) with a melting temperature (Tm) of 39 °C, were introduced as gatekeepers to regulate the release behaviours. An overall loading amount of ca. 20 wt% (TD/DOX ca. 50/50 wt/wt) was confirmed. Heat-triggered release of DOX evidenced a “zero premature release” (<3% of the entire payload in 96 h release) under physiological conditions (37°C), and however, a sustainable release (ca. 40% of the entire payload in 96 h) above Tm of TD (40 °C). It also demonstrated the possibility to deliver drug payloads in small portions (pulsatile release mode) via multiple heating on/off cycles, due to the reversible phase change of the PCMs. In vitro heattriggered release of DOX within cell culture of the MEL-5 melanoma cell line was also tested. It was found that DOX molecules were trapped efficiently within the mesopores even after internalization within the cytoplasm of MEL-5 cells at 37 °C, with the potential toxicity of DOX strongly quenched (>95% viability after 72 h incubation). However, continuous cell apoptosis was detected at cell culture temperature above Tm of TD, due to the heat-triggered release of DOX (<50% viability after 72 h incubation at 40 °C). Moreover, due to the presence of a maghemite core within the DDS, T2-weighted magnetic resonance imaging performance was also confirmed. These as-designed core–shell nanoparticles are envisaged to become promising DDS for “on-demand” heat-triggered release. [less ▲]

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See detailReversibly crosslinked thermo- and redox-responsive nanogels for controlled drug release
Liu, Ji ULg; Detrembleur, Christophe ULg; Hurtgen, Marie ULg et al

in Polymer Chemistry (2014), 5(1), 77-88

Reversibly crosslinked poly(vinyl alcohol)-b-poly(N-vinylcaprolactam) PVOH-b-PNVCL nanogels were prepared by using a redox-responsive crosslinking agent, 3,30-dithiodipropionic acid (DPA), to crosslink ... [more ▼]

Reversibly crosslinked poly(vinyl alcohol)-b-poly(N-vinylcaprolactam) PVOH-b-PNVCL nanogels were prepared by using a redox-responsive crosslinking agent, 3,30-dithiodipropionic acid (DPA), to crosslink the PVOH corona, above the lower critical solution temperature (LCST) of the PNVCL block. The stability of the as-prepared nanogels against heating and diluting with water was studied by dynamic light scattering (DLS) to follow the evolution of the hydrodynamic diameter and size distribution. Stability under reductive conditions was also studied by DLS and transmission electron microscopy (TEM) after exposure to dithiothreitol (DTT) buffer solutions at different pH. The reversibility of the crosslinking was evaluated by treating the de-crosslinked nanogels with hydrogen peroxide (H2O2) above the LCST. As a hydrophobic drug model, Nile red (NR) was loaded into the nanogels, and triggered release behaviours were studied after exposure to the same DTT buffer solutions. Moreover, two PVOH-b-PNVCL copolymers with different compositions and LCST were used to evaluate the effect of the LCST on the release behaviours of the nanogels. The cytotoxicity of the nanogels against a mouse fibroblast-like L929 cell line was assessed via the MTS assay, and preliminary studies on cellular uptake of the nanogels within human melanoma MEL-5 cells were also carried out by fluorescence microscopy and fluorescence-activated cell sorting. [less ▲]

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See detailExpanding the scope of controlled radical polymerization via cobalt–tellurium radical exchange reaction
Kermagoret, Anthony ULg; Nakamura, Yasuyuki; Bourguignon, Maxime et al

in ACS Macro Letters (2014), 3(1), 114-118

Cobalt-mediated radical polymerization (CMRP) and tellurium-mediated radical polymerization (TERP) were combined for the first time, offering new perspectives in the precision design of macromolecular ... [more ▼]

Cobalt-mediated radical polymerization (CMRP) and tellurium-mediated radical polymerization (TERP) were combined for the first time, offering new perspectives in the precision design of macromolecular structures. In particular, the present work highlights the benefits of this strategy for the synthesis of novel poly(vinyl acetate)-based block copolymers. A range of well-defined poly(vinyl acetate)s (PVAc) were first produced via CMRP using the bis(acetylacetonato)cobalt(II) complex (Co(acac)2) as a regulating agent. Substitution of a methyltellanyl moiety for Co(acac)2 at the ω-chain end of the precursor was then achieved upon treatment with dimethylditelluride. In contrast to the PVAc prepared by TERP, the ones produced by sequential CMRP and Co/Te exchange reaction almost exclusively consist of regular head-to-tail-TeMe chain-end species that can be activated by TERP. Ultimately, a series of monomers problematic in Co(acac)2-mediated radical polymerization including N-isopropylacrylamide (NIPAM), 2-(dimethylamino)ethyl acrylate (ADAME), n-butyl acrylate (BA), isoprene (IP), and vinylimidazole (NVIm) were polymerized by TERP from the PVAc–TeMe macroinitiators leading to novel diblock copolymers that cannot be made by each technique used separately. [less ▲]

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See detailGold nanorods with phase-changing polymer corona for remotely near-infrared-triggered drug release
Liu, Ji ULg; Detrembleur, Christophe ULg; Grignard, Bruno ULg et al

in Chemistry : An Asian Journal (2014), 9(1), 275-288

Herein, we report a new drug-delivery system (DDS) that is comprised of a near-infrared (NIR)- light-sensitive gold-nanorod (GNR) core and a phase-changing poly(e-caprolactone)- b-poly(ethylene glycol ... [more ▼]

Herein, we report a new drug-delivery system (DDS) that is comprised of a near-infrared (NIR)- light-sensitive gold-nanorod (GNR) core and a phase-changing poly(e-caprolactone)- b-poly(ethylene glycol) polymer corona (GNR@PCL-b-PEG). The underlying mechanism of the drugloading and triggered-release behaviors involves the entrapment of drug payloads among the PCL crystallites and a heat-induced phase change, respectively. A low premature release of the pre-loaded doxorubicin was observed in PBS buffer (pH 7.4) at 37 °C (<10% of the entire payload after 48 h). However, release could be activated within 30 min by conventional heating at 50 °C, above the Tm of the crystalline PCL domain (43.5 °C), with about 60% release over the subsequent 42 h at 37 °C. The NIR-induced heating of an aqueous suspension of GNR@PCL-b- PEG under NIR irradiation (802 nm) was investigated in terms of the irradiation period, power, and concentrationdependent heating behavior, as well as the NIR-induced shape-transformation of the GNR cores. Remotely NIR-triggered release was also explored upon NIR irradiation for 30 min and about 70% release was achieved in the following 42 h at 37°C, with a mild warming (<4 °C) of the surroundings. The cytotoxicity of GNR@PCL-b-PEG against the mouse fibroblastic-like L929 cell-line was assessed by MTS assay and good compatibility was confirmed with a cell viability of over 90% after incubation for 72 h. The cellular uptake of GNR@PCL-b-PEG by melanoma MEL-5 cells was also confirmed, with an averaged uptake of 1250 ( ± 110) particles cell-1 after incubation for 12 h (50 mg mL-1). This GNR@PCL-b-PEG DDS is aimed at addressing the different requirements for therapeutic treatments and is envisaged to provide new insights into DDS targeting for remotely triggered release by NIR activation. [less ▲]

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See detailPoly(acrylic acid)-block-poly(vinyl alcohol) anchored maghemite nanoparticles designed for multi-stimuli triggered drug release
Liu, Ji ULg; Detrembleur, Christophe ULg; Debuigne, Antoine ULg et al

in Nanoscale (2013), 5(23), 11464-11477

Original core/corona nanoparticles composed of amaghemite core and a stimuli-responsive polymer coating made of poly(acrylic acid)-block-poly(vinyl alcohol) macromolecules were fabricated for drug ... [more ▼]

Original core/corona nanoparticles composed of amaghemite core and a stimuli-responsive polymer coating made of poly(acrylic acid)-block-poly(vinyl alcohol) macromolecules were fabricated for drug delivery system (DDS) application. This kind of DDS aims to combine the advantage of stimuli-responsive polymer coating, in order to regulate the drug release behaviours under different conditions and furthermore, improve the biocompatibility and in vivo circulation half-time of the maghemite nanoparticles. Drug loading capacity was evaluated with methylene blue (MB), a cationic model drug. The triggered release of MB was studied under various stimuli such as pH, ionic strength and temperature. Local heating generated under alternating magnetic field (AMF) application was studied, and remotely AMF-triggered release was also confirmed, while a mild heating-up of the release medium was observed. Furthermore, their potential application as magnetic resonance imaging (MRI) contrast agents was explored via relaxivity measurements and acquisition of T2-weighted images. Preliminary studies on the cytotoxicity against mouse fibroblast-like L929 cell line and also their cellular uptake within human melanoma MEL-5 cell line were carried out. In conclusion, this kind of stimuli-responsive nanoparticles appears to be promising carriers for delivering drugs to some tumour sites or into cellular compartments with an acidic environment. [less ▲]

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See detailStimuli-responsive magnetic nanohybrids for triggered drug release and potential tumor treatment via hyperthermia
Liu, Ji ULg; Detrembleur, Christophe ULg; Mornet, Stéphane et al

in Journal of Controlled Release (2013, November 28), 172(1), 39

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See detailStraightforward synthesis of symmetrical multiblock copolymers by simultaneous block extension and radical coupling reactions
Debuigne, Antoine ULg; Detrembleur, Christophe ULg; Jérôme, Christine ULg et al

in Macromolecules (2013), 46(22), 8922-8931

In situ combination of a polymerization step with a coupling reaction is demonstrated to accelerate the synthesis protocols for symmetrical multiblock copolymers. Predici simulations and experiments prove ... [more ▼]

In situ combination of a polymerization step with a coupling reaction is demonstrated to accelerate the synthesis protocols for symmetrical multiblock copolymers. Predici simulations and experiments prove on the example of cobalt-mediated radical polymerization and coupling (CMRP/C) reactions that such synthesis strategy can be very effective and easy to conduct. Treatment of a cobalt-terminated poly(acrylonitrile) precursor with a mixture of acrylate and isoprene led to the rapid polymerization of the acrylate before isoprene-assisted radical coupling of the macroradical chains forming a well-defined poly(acrylonitrile)-b-poly(acrylate)-b-poly(acrylonitrile) triblock. The degree of polymerization of the central block, resulting from the balance between propagation and coupling, could be tuned by adjusting the relative concentration and varying the structure of the acrylate and diene. The same convergent strategy also permits the synthesis of ABCBA-type pentablock copolymer starting from a cobalt-functional diblock. Simultaneous radical polymerization and coupling is thus a powerful macromolecular engineering approach for the straightforward design of symmetrical multiblock copolymers. [less ▲]

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See detailBio-inspired polymers for the functionalization of surfaces by green processes
Detrembleur, Christophe ULg

Conference (2013, November 20)

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See detailCarbon nanotubes/polypropylene nanocomposites foams for EMI shielding applications
Tran, Minh Phuong ULg; Detrembleur, Christophe ULg; Thomassin, Jean-Michel ULg et al

Conference (2013, September 12)

In order to reduce the undesired effect of the electromagnetic interference, the developing of the materials with high capacity of electromagnetic interference (EMI) shielding has attracted a great ... [more ▼]

In order to reduce the undesired effect of the electromagnetic interference, the developing of the materials with high capacity of electromagnetic interference (EMI) shielding has attracted a great attention to scientific and industrial communities during last two decades.Indeed, polymer carbon nanotubes (CNTs) nanocomposites foams are addressed due to their high electrical conductivity and a great potential applications in electrostatic dissipation (ESD) and in electromagnetic interferences (EMI) shielding. However, the shortcoming of the addition of CNTs is that it usually leads to an increase of permittivity which results in enhancing undesirably the electromagnetic reflectivity due to the mismatch between the wave impedances for the signal propagating into air and into the absorbing material, respectively. To solve this problem, the introduction of air into these nanocomposites by the formation of foam will be favorable in order to reduce the permittivity of conductive composites. A good understanding of the influence of the foam structural parameters on the electrical properties of the foam will ultimately enable the optimum design of these materials for the targeted applications. A wide range of poly (propylene)/CNTs nanocomposites foams were synthesized using the supercritical CO2 technology. Different foaming parameters, such as the temperature, impregnation pressure will be controlled to modify the foam structure. Nanocomposite foams show higher electrical conductivity than non-foamed nanocomposites at the same volume content of CNTs. Effects of foam morphology such as cell density, pore size, volume expansion, and cell-wall thickness on electrical conductivity were comprehensively assessed. Similarly to our previous study on PMMA foam nanocomposites, the electrical conductivity of foams show higher value when the volume expansion is increased and when the average pore size is decreased. The preliminary EMI performances have highlighted that PP/CNTs foams containing 0.1 vol%CNTs are able to absorb about 90% of the incident radiation in the 25 to 40 GHz frequency range. [less ▲]

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See detailMorphology and electrical conductivity of poly(propylene)/multi-walled carbon nanotubes nanocomposites foams compatibilized by poly(propylene) -graft-maleic anhydride (PP-g-MA)
Tran, Minh Phuong ULg; Detrembleur, Christophe ULg; Alexandre, Michaël et al

Poster (2013, September 09)

The agglomerate of carbon nanotubes (CNTs) in poly(propylene) (PP) matrix often results in low electrical conductivity and poor mechanical properties. In order to improve the dispersion of CNTs, different ... [more ▼]

The agglomerate of carbon nanotubes (CNTs) in poly(propylene) (PP) matrix often results in low electrical conductivity and poor mechanical properties. In order to improve the dispersion of CNTs, different amounts of compatibilizer based on poly(propylene-graft-maleic anhydride) (PP-g-MA) were added in the PP matrix. Carbon nanotubes materbatches pre-dispersed at a high loading in the compatibilizer were used to create the samples used in this study. The nanocomposites of PP/PP-g-MA/CNTs were then foamed in supercritical carbon diozide (scCO2) followed by analysis of the foam morphology and the electrical conductivity. The presence of PPgMA did not significantly change the foam morphology, which exhibits good homogeneity and highly uniform closed-cells with penta-heptagonal cell-form. The expansion volume of the foams is not adversely affected by the addition of the compatibilizer; very high expansion volume (around 15 - 25 times) was achieved. The most interesting point is that the PP-PPgMA - 4wt%CNTs foams show a significantly higher electrical conductivity than the uncompatibilized PP-4wt%CNTs at the same volume percent content of CNTs [less ▲]

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