Functional gold nanoparticles as builiding-blocks for biosensors

Poster (2005, May 19)

Synthesis of new substituted poly(ε-caprolactone)s by comination of ring-opening polymerization, atom transfer radical addition and click reaction

Poster (2005, May 19)

During the last few years, a great research effort has been devoted to the synthesis of aliphatic polyesters, e.g. poly(ε-caprolactone) and polylactides. Indeed, their remarkable properties of ... [more ▼]

During the last few years, a great research effort has been devoted to the synthesis of aliphatic polyesters, e.g. poly(ε-caprolactone) and polylactides. Indeed, their remarkable properties of biodegradability and biocompatibility pave the way to many new applications in the biomedical field and as substitutes for non degradable polymers. In order to tailor the polyester properties, the grafting of functional groups along the polymer backbone is highly desirable. For the last few years, CERM has reported on the synthesis and the (co)polymerization of novel ε-caprolactones γ-substituted by various functional groups, e.g., ketal, ketone, olefin, protected alcohol and carboxylic acid. Nevertheless, the grafting of a specific functional group onto the aliphatic polyester backbone requires the synthesis of the parent substituted ε-caprolactone. There is accordingly a need for a strategy that would use a unique substituted ε-caprolactone, followed by derivatization by well-established reactions, so making available a wide range of pendent functional groups, polymeric or not. The derivatization reactions have however to be quantitative under mild conditions to prevent the aliphatic polyester from degrading. Moreover, these reactions must be compatible with the functional groups of interest, e.g., hydroxyl and carboxylic acid, in order to avoid the use of cumbersome protection/deprotection reactions. This communication aims at reporting that a-chloro-e caprolactone (αCLεCL) can be easily copolymerized with εCL into poly(αCLεCL-co-εCL) copolymers, which are precursors for various aliphatic polyesters, by using either Atom Transfer Radical Addition (ATRA) or Click reactions. The number of steps is limited whatever the "Click" or the "ATRA" strategy under consideration. In both cases, mild conditions have been found, such that degradation is minimized. Pendent hydroxyl, carboxylic acid and epoxide groups have been attached without using any protection/deprotection reaction. This strategy has been implemented for the synthesis of amphiphilic poly(εCL-g-ethylene oxide) graft copolymers, that have been used to prepare poly(D,L-lactide) nanoparticles for drug delivery applications. [less ▲]

Versatile functionalization and grafting of poly(epsilon-caprolactone) by Michael-type addition

in Chemical Communications (2005), (2), 274-276

The Michael-type addition of aliphatic (co)polyesters onto gamma-acryloyloxy epsilon-caprolactone units is a very straightforward technique of functionalization and grafting, which is tolerant to a ... [more ▼]

The Michael-type addition of aliphatic (co)polyesters onto gamma-acryloyloxy epsilon-caprolactone units is a very straightforward technique of functionalization and grafting, which is tolerant to a variety of functional groups and does not require intermediate protection/deprotection steps. [less ▲]

Process for depositing strong adherend polymer coating onto an electrically conductive surface

Patent (2004)

Process for depositing by electrografting a strong adherent polymer coating onto an electrically conductive surface comprising an electrochemical grafting at the surface of an active monomer for forming a ... [more ▼]

Process for depositing by electrografting a strong adherent polymer coating onto an electrically conductive surface comprising an electrochemical grafting at the surface of an active monomer for forming a primer coating P onto said surface and having as general formula: X0 (meth)acrylate wherein X is either part of a preformed polymer or is an intermediate agent for polyaddition reaction or is an anchoring group for attachment of a molecule having at least one complementary reactive group. Such process allows formation of new primer by one-step electro-grafting of a reactive polymer called macromonomer.; Such process also allows further modification of an initial electrografted polymer (called primer coating) to increase the coating thickness by the so-called grafting-from technique i.e. polymerization of a second monomer or to introduce other types of polymers(also called top coating) via covalent attachment between the primer and the top coating through the X ester group by the so called grafting onto technique. Such process also allows to graft onto the primer coating compounds like functional polymer, peptide, protein, oligonucleotide, dyes, drugs, anti-bacterian compounds. [less ▲]

Preparation of poly(epsilon-caprolactone) brushes at the surface of conducting substrates

in Langmuir (2004), 20(24), 10670-10678

This paper reports on the preparation of polyester brushes at the surface of electrically conducting materials. A two-step strategy has been worked out that consists of the electropolymerization of an ... [more ▼]

This paper reports on the preparation of polyester brushes at the surface of electrically conducting materials. A two-step strategy has been worked out that consists of the electropolymerization of an acrylate under a cathodic potential, such that the polyacrylate layer is chemisorbed at the surface. In a second step, either preformed poly(epsilon-caprolactone) chains are grafted onto the polyacrylate sublayer or the ring-opening polymerization of epsilon-caprolactone is initiated from it. [less ▲]

Process for depositing strong adherend polymer coating onto an electrically conductive surface

Patent (2004)

Process for depositing by electrografting a strong adherent polymer coating onto an electrically conductive surface comprising the step of electrochemical grafting of an active monomer for forming a ... [more ▼]

Process for depositing by electrografting a strong adherent polymer coating onto an electrically conductive surface comprising the step of electrochemical grafting of an active monomer for forming a primer coating P onto the surface and having as general formula: X0 (meth)acrylate wherein X is either part of a preformed polymer or is an intermediate agent for polyaddition reaction or is an anchoring group for attachment of a molecule having at least one complementary reactive group. Such process allows formation of new primer by one-step electro-grafting of a macromonomer. Such process also allows further modification of an initial electrografted polymer to increase the coating thickness by the grafting-from technique. Such process also allows to graft onto the primer coating compounds like functional polymer, peptide, protein, oligonucleotide, dyes, drugs, anti-bacterian compounds. [less ▲]

Process for depositing strong adherend polymer coating onto an electrically conductive surface

Patent (2004)

Process for depositing by electrografting a strong adherent polymer coating onto an electrically conductive surface comprising an electrochemical grafting at the surface of an active monomer for forming a ... [more ▼]

Process for depositing by electrografting a strong adherent polymer coating onto an electrically conductive surface comprising an electrochemical grafting at the surface of an active monomer for forming a primer coating P onto said surface and having as general formula: X0 (meth)acrylate wherein X is either part of a preformed polymer or is an intermediate agent for polyaddition reaction or is an anchoring group for attachment of a molecule having at least one complementary reactive group. Such process allows formation of new primer by one-step electro-grafting of a reactive polymer called macromonomer.; Such process also allows further modification of an initial electrografted polymer (called primer coating) to increase the coating thickness by the so-called grafting-from technique i.e. polymerization of a second monomer or to introduce other types of polymers(also called top coating) via covalent attachment between the primer and the top coating through the X ester group by the so called grafting onto technique. Such process also allows to graft onto the primer coating compounds like functional polymer, peptide, protein, oligonucleotide, dyes, drugs, anti-bacterian compounds. [less ▲]

Preparation of reactive surfaces by electrografting: a route to biosensors

Poster (2004, May 27)

Electrochemical formation of polypyrrole nanowires

in Synthetic Metals (2004), 142(1-3), 207-216

This paper aims at approaching the mechanism of formation of polypyrrole (PPy) nanowires by an all-electrochemical process, which consists in electrografting a poly(alkylacrylate) film onto the surface of ... [more ▼]

This paper aims at approaching the mechanism of formation of polypyrrole (PPy) nanowires by an all-electrochemical process, which consists in electrografting a poly(alkylacrylate) film onto the surface of a cathode, followed by the anodic electropolymerization of pyrrole (Py) at the surface of this organomodified electrode. The experimental conditions for the pyrrole oxidation, including solvent and concentrations of monomer and supporting electrolyte, have been changed with the purpose to tune the characteristic features of the polypyrrole nanowires. The polyacrylate template has also been modified, all other conditions being the same, in an effort to design the shape and size of the wires. The electrochemical behavior of the as-prepared PPy wires has been characterized. [less ▲]

Design of nanoobjects endowed with specific properties

Conference (2004, March)