Author
Bruno Dufour
Other affiliations: Hutchinson SA, Corning Inc., Centre national de la recherche scientifique
Bio: Bruno Dufour is an academic researcher from Carnegie Mellon University. The author has contributed to research in topics: Polyaniline & Conductive polymer. The author has an hindex of 21, co-authored 95 publications receiving 2285 citations. Previous affiliations of Bruno Dufour include Hutchinson SA & Corning Inc..
Papers published on a yearly basis
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TL;DR: In this article, the authors showed that in situ degradation of chlorinated solvents present as nonaqueous phase liquids (NAPL) can be accomplished using reactive zerovalent nanoiron particles.
Abstract: Rapid in situ degradation of chlorinated solvents present as nonaqueous phase liquids (NAPL) can be accomplished using reactive zerovalent nanoiron particles. Prior studies have shown that nanoiron...
435 citations
TL;DR: The ability of novel triblock copolymers to modify the nanoiron surface chemistry in a way that both promotes their colloidal stability in aqueous suspension and drives their adsorption to the oil/water interface is demonstrated.
Abstract: Reactive zero valent iron nanoparticles can degrade toxic nonaqueous phase liquids (NAPL) rapidly in contaminated groundwater to nontoxic products in situ, provided they can be delivered preferentially to the NAPL/water (oil/water) interface. This study demonstrates the ability of novel triblock copolymers to modify the nanoiron surface chemistry in a way that both promotes their colloidal stability in aqueous suspension and drives their adsorption to the oil/water interface. The ability of the copolymers to drive adsorption is demonstrated by the ability of copolymer-modified iron nanoparticles, but not the unmodified iron nanoparticles, to stabilize oil-in-water emulsions.
323 citations
TL;DR: The use of the novel infiltration method and PAN as a carbon precursor allowed us to obtain ordered mesoporous carbons (OMCs) with a desirable combination of features that has not been realized before for OMCs.
Abstract: Mesoporous carbons were synthesized from polyacrylonitrile (PAN) using ordered and disordered mesoporous silica templates and were characterized using transmission electron microscopy (TEM), powder X-ray diffraction, nitrogen adsorption, and thermogravimetry. The pores of the silica templates were infiltrated with carbon precursor (PAN) via polymerization of acrylonitrile from initiation sites chemically bonded to the silica surface. This polymerization method is expected to allow for a uniform filling of the template with PAN and to minimize the introduction of nontemplated PAN, thus mitigating the formation of nontemplated carbon. PAN was stabilized by heating to 573 K under air and carbonized under N2 at 1073 K. The resulting carbons exhibited high total pore volumes (1.5−1.8 cm3 g-1), with a primary contribution of the mesopore volume and with relatively low microporosity. The carbons synthesized using mesoporous templates with a 2-dimensional hexagonal structure (SBA-15 silica) and a face-centered cu...
195 citations
TL;DR: In this paper, a click chemistry reaction with sodium azide and zinc chloride was used to yield polymeric materials with 5-vinyltetrazole units, which had markedly better solubility or swellability in protic solvents compared to the precursors.
Abstract: Well-defined homo- and copolymers of acrylonitrile were prepared by atom transfer radical polymerization, which were further modified using a “click chemistry” reaction with sodium azide and zinc chloride to yield polymeric materials with 5-vinyltetrazole units. Using optimized reaction conditions ([NaN3]:[ZnCl2]:[RCN] = 4:1:1 in DMF at 120 °C for 48−50 h), essentially complete transformation of the nitrile groups was achieved, as judged from IR and 13C NMR spectra. The produced tetrazole-containing polymers had markedly better solubility or swellability in protic solvents (methanol or aqueous base solutions) compared to the precursors. Random copolymers of acrylonitrile and styrene were also grown from polystyrene and silica particles with immobilized initiator groups and were similarly modified to the corresponding tetrazole-containing polymers. All materials were characterized by means of thermogravimetry, which showed that the polymeric tetrazoles started to decompose with evolution of significant amo...
154 citations
TL;DR: The polyelectrolytes increased the magnitude of the electrophoretic mobility of NZVI over a broad pH range relative to unmodified NZVI and shifted the isoelectric point outside the typical groundwater pH range.
Abstract: Polyelectrolyte coatings significantly increase the mobility of nanoscale zerovalent iron (NZVI) in saturated porous media. The effect can be attributed to improved colloidal stability of NZVI suspensions, decreased adhesion to soil surfaces, or a combination of the two effects. This research explicitly examines how coatings control NZVI adhesion to model soil surfaces. NZVI was coated with three different polyeleotrolyte block copolymers based on poly(methacrylic acid), poly(methyl methacrylate or butyl methacrylate), and poly(styrenesulfonate) or with a poly(styrenesulfonate) homopolymer. SiO2 and a humic acid film served as model soil surfaces. The polyelectrolytes increased the magnitude of the electrophoretic mobility of NZVI over a broad pH range relative to unmodified NZVI and shifted the isoelectric point outside the typical groundwater pH range. Quartz crystal microgravimetry measurements indicated extensive adhesion of unmodified NZVI to SiO2. Polyelectrolyte coatings decreased adhesion by approximately 3 orders of magnitude. Adding 50 mM NaCL to screen electrostatic repulsions did not significantly increase adhesion of modified NZVI. Coated NZVI did not adhere to humic acid films for either 1 mM NaHCO3 or 1 mM NaHCO3 + 50 mM NaCl. The lack of adhesion even in a high ionic strength medium was attributed to electrosteric repulsion, as opposed to electrostatic double layer repulsion, between the polyelectrolyte-coated NZVI and the negatively charged surfaces. The lack of significant adhesion on either model surface was observed for all polymer architectures investigated.
142 citations
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TL;DR: In this article, a review of recent mechanistic developments in the field of controlled/living radical polymerization (CRP) is presented, with particular emphasis on structure-reactivity correlations and "rules" for catalyst selection in ATRP, for chain transfer agent selection in reversible addition-fragmentation chain transfer (RAFT) polymerization, and for the selection of an appropriate mediating agent in stable free radical polymerisation (SFRP), including organic and transition metal persistent radicals.
2,869 citations
TL;DR: The current status and future perspectives in atom transfer radical polymerization (ATRP) are presented in this paper, with a special emphasis on mechanistic understanding of ATRP, recent synthetic and process development, and new controlled polymer architectures enabled by ATRP.
Abstract: Current status and future perspectives in atom transfer radical polymerization (ATRP) are presented. Special emphasis is placed on mechanistic understanding of ATRP, recent synthetic and process development, and new controlled polymer architectures enabled by ATRP. New hybrid materials based on organic/inorganic systems and natural/synthetic polymers are presented. Some current and forthcoming applications are described.
2,188 citations
TL;DR: This review presents an overview of the classes of NP relevant to the environment and summarizes their formation, emission, occurrence and fate in the environment.
2,093 citations
TL;DR: This data indicates that self-Assembled Monolayers and Walled Carbon Nanotubes with high adhesion to Nitroxide-Mediated Polymerization have potential in the well-Defined Polymer Age.
Abstract: Keywords: Fragmentation Chain-Transfer ; Self-Assembled Monolayers ; Walled Carbon Nanotubes ; Well-Defined Polymer ; Nitroxide-Mediated Polymerization ; Block-Copolymer Brushes ; Poly(Methyl Methacrylate) Brushes ; Transfer Raft Polymerization ; Quartz-Crystal Microbalance ; Poly(Acrylic Acid) Brushes Reference EPFL-REVIEW-148464doi:10.1021/cr900045aView record in Web of Science Record created on 2010-04-23, modified on 2017-05-10
1,542 citations
TL;DR: The metal catalyzed azide/alkyne "click" reaction (a variation of the Huisgen 1,3-dipolar cycloaddition reaction between terminal acetylenes and azides) represents an important contribution towards this endeavor.
Abstract: The modification of polymers after the successful achievement of a polymerization process represents an important task in macromolecular science. Cycloaddition reactions, among them the metal catalyzed azide/alkyne ‘click’ reaction (a variation of the Huisgen 1,3-dipolar cycloaddition reaction between terminal acetylenes and azides) represents an important contribution towards this endeavor. They combine high efficiency (usually above 95%) with a high tolerance of functional groups and solvents, as well as moderate reaction temperatures (25–70 °C). The present review assembles recent literature for applications of this reaction in the field of polymer science (linear polymers, dendrimers, gels) as well as the use of this and related reactions for surface modification on carbon nanotubes, fullerenes, and on solid substrates, and includes the authors own publications in this field. A number of references (>100) are included.
1,452 citations