The Experts below are selected from a list of 2169 Experts worldwide ranked by ideXlab platform
Véronique Bounor-legaré - One of the best experts on this subject based on the ideXlab platform.
-
Specific properties of in situ Ruthenium-catalyzed polyamide 12/polydimethylsiloxane compatibilized blend
Journal of Polymer Science Part B: Polymer Physics, 2018Co-Authors: Philippe Cassagnau, Eliane Espuche, Pierre Alcouffe, Véronique Bounor-legaréAbstract:The main objective of this work focused on the chemical modification of polyamide 12 (PA12) properties through the reaction with a hydride‐terminated polydimethylsiloxane (PDMS‐SiH). The investigated PA12/PDMS‐SiH blend was compatibilized by Ruthenium Derivative catalyzed hydrosilylation reaction in molten state. This original route enhanced interfacial adhesion and avoid PDMS‐SiH leaching phenomenon between the two immiscible phases. More specifically, the size of PDMS‐SiH domains in the blend decreased from around 4 μm to 800 nm and from 30 to 1 μm after compatibilization with 10 and 20 wt % PDMS‐SiH, respectively. For the best compatibilized PA12/PDMS‐SiH blend, the introduction of PDMS lowered the surface free energy and the PA12‐based blend turned from hydrophilic to hydrophobic behavior, as evidenced by the water contact angle measurements. Gas permeability and CO2/H2 and CO2/He gas selectivity were also improved with the increase in PDMS content. Besides, the mechanical properties were enhanced with 13% increase in Young's modulus after in situ compatibilization with 15 wt % PDMS‐SiH. Thermal stability was also improved after compatibilization as the initial degradation temperature of reactive blends obviously increased compared with nonreactive ones.
Serge Ravaine - One of the best experts on this subject based on the ideXlab platform.
-
electrochemical and photoelectrochemical properties of new hybrid langmuir blodgett films containing prussian blue and a tris bipyridine Ruthenium Derivative
Journal of Physical Chemistry B, 2000Co-Authors: Gemma Romualdo Torres, Eliane Dupart, And Christophe Mingotaud, Serge RavaineAbstract:The elaboration of new Langmuir-Blodgett (LB) films containing Prussian blue and a surfactant Derivative of the Ruthenium tris(bipyridine) complex using a semi-amphiphilic approach is described in this paper. The redox and photoelectrochemical properties of these hybrid lamellar materials have been studied in aqueous KCl solutions. Dependencies of the cyclic voltammetry response on the number of deposited layers and the scan rate demonstrate that the hybrid LB films can be considered as a quasireversible system with a finite diffusion space. A large cathodic photocurrent is recorded when the LB films are irradiated with polychromatic light at a negative applied potential, indicating that both PB and the Derivative of Ruthenium tris(bipyridine) complex play an important role in the light-energy conversion process. A linear dependence of the cathodic photocurrent response on the number of deposited layers has also been exhibited and should be correlated to the presence of structural defects in the multilayers.
-
Electrochemical and Photoelectrochemical Properties of New Hybrid Langmuir−Blodgett Films Containing Prussian Blue and a Tris(Bipyridine) Ruthenium Derivative
The Journal of Physical Chemistry B, 2000Co-Authors: Gemma Romualdo Torres, Eliane Dupart, And Christophe Mingotaud, Serge RavaineAbstract:The elaboration of new Langmuir-Blodgett (LB) films containing Prussian blue and a surfactant Derivative of the Ruthenium tris(bipyridine) complex using a semi-amphiphilic approach is described in this paper. The redox and photoelectrochemical properties of these hybrid lamellar materials have been studied in aqueous KCl solutions. Dependencies of the cyclic voltammetry response on the number of deposited layers and the scan rate demonstrate that the hybrid LB films can be considered as a quasireversible system with a finite diffusion space. A large cathodic photocurrent is recorded when the LB films are irradiated with polychromatic light at a negative applied potential, indicating that both PB and the Derivative of Ruthenium tris(bipyridine) complex play an important role in the light-energy conversion process. A linear dependence of the cathodic photocurrent response on the number of deposited layers has also been exhibited and should be correlated to the presence of structural defects in the multilayers.
Philippe Cassagnau - One of the best experts on this subject based on the ideXlab platform.
-
Specific properties of in situ Ruthenium-catalyzed polyamide 12/polydimethylsiloxane compatibilized blend
Journal of Polymer Science Part B: Polymer Physics, 2018Co-Authors: Philippe Cassagnau, Eliane Espuche, Pierre Alcouffe, Véronique Bounor-legaréAbstract:The main objective of this work focused on the chemical modification of polyamide 12 (PA12) properties through the reaction with a hydride‐terminated polydimethylsiloxane (PDMS‐SiH). The investigated PA12/PDMS‐SiH blend was compatibilized by Ruthenium Derivative catalyzed hydrosilylation reaction in molten state. This original route enhanced interfacial adhesion and avoid PDMS‐SiH leaching phenomenon between the two immiscible phases. More specifically, the size of PDMS‐SiH domains in the blend decreased from around 4 μm to 800 nm and from 30 to 1 μm after compatibilization with 10 and 20 wt % PDMS‐SiH, respectively. For the best compatibilized PA12/PDMS‐SiH blend, the introduction of PDMS lowered the surface free energy and the PA12‐based blend turned from hydrophilic to hydrophobic behavior, as evidenced by the water contact angle measurements. Gas permeability and CO2/H2 and CO2/He gas selectivity were also improved with the increase in PDMS content. Besides, the mechanical properties were enhanced with 13% increase in Young's modulus after in situ compatibilization with 15 wt % PDMS‐SiH. Thermal stability was also improved after compatibilization as the initial degradation temperature of reactive blends obviously increased compared with nonreactive ones.
Chengxiao Zhang - One of the best experts on this subject based on the ideXlab platform.
-
Electrogenerated Chemiluminescence Bioassay of Two Protein Kinases Incorporating Peptide Phosphorylation and Versatile Probe.
Analytical chemistry, 2016Co-Authors: Xia Liu, Manman Dong, Qiang Gao, Chengxiao ZhangAbstract:A sensitive electrogenerated chemiluminescence (ECL) bioassay was developed for the detection of two protein kinases incorporating the peptide phosphorylation and a versatile ECL probe. Cyclic adenosine monophosphate-dependent protein kinase (PKA) and casein kinase II (CK2) were used as proof-of-concept targets while a PKA-specific peptide (CLRRASLG) and a CK2-specific peptide (CRRRADDSDDDDD) were used as the recognition substrates. Taking advantage of the ability of protein A binding with the Fc region of a variety of antibodies with high affinity, a Ruthenium Derivative-labeled protein A was utilized as a versatile ECL probe for bioassay of multiple protein kinases. A specific peptide substrate toward target protein kinase was first self-assembled on the surface of gold electrode and then serine in the specific peptide on the electrode was phosphorylated by target protein kinase in the presence of adenosine-5′-triphosphate. After recognition of the phosphorylated peptide by monoclonal antiphosphoserine ...
-
Electrogenerated chemiluminescence aptamer-based method for the determination of thrombin incorporating quenching of tris(2,2'-bipyridine)Ruthenium by ferrocene
Electrochemistry Communications, 2008Co-Authors: Yage Peng, Qiang Gao, Chengxiao ZhangAbstract:Abstract A novel electrogenerated chemiluminescence (ECL) aptamer-based biosensing method for the determination of thrombin was developed on basis of a structure-switching ECL-dequenching mechanism. A thiolated ss-DNA capture probe, composing of a ss-DNA sequence to adopt two distinct structures-a DNA double strand with a complementary DNA sequence tagged with a ECL signal producer tris(2,2 ′ -bipyridyl)Ruthenium Derivative and a DNA duplex with a thrombin-binding aptamer tagged with a ECL-quencher ferrocene (FcDNA), was self-assembled onto surface of a gold electrode. In the presence of thrombin, the aptamer sequence prefers to form the aptamer-thrombin complex and the switch of the binding partners occurs in conjunction with the generation of a strong ECL signal owing to the dissociation of FcDNA. The integrated ECL intensity versus the concentration of thrombin was linear in the range from 2.0 × 10 −10 M to 2.0 × 10 −7 M. The detection limit was 6 × 10 −11 M. The relative standard derivation for 2.0 × 10 −9 M was 5.7% ( n = 7). This work demonstrates that the sensitivity and specificity of ECL aptamer-based method for proteins can be greatly improved using quenching ECL signal producer by a chemical quencher such as ferrocene.
-
Ultrasensitive electrogenerated chemiluminescence detection of DNA hybridization using carbon-nanotubes loaded with tris(2,2'-bipyridyl) Ruthenium Derivative tags.
Talanta, 2007Co-Authors: Fang Fang, Chengxiao ZhangAbstract:Abstract An ultrasensitive electrogenerated chemiluminescence (ECL) detection method of DNA hybridization based on single-walled carbon-nanotubes (SWNT) carrying a large number of Ruthenium complex tags was developed. The probe single strand DNA (ss-DNA) and Ruthenium complex were loaded at SWNT, which was taken as an ECL probe. When the capture ss-DNA with a thiol group was self-assembled onto the surface of gold electrode, and then hybridized with target ss-DNA and further hybridized with the ECL probe to form DNA sandwich conjugate, a strong ECL response was electrochemically generated. The ECL intensity was linearly related to the concentration of perfect-matched target ss-DNA in the range from 2.4 × 10 −14 to 1.7 × 10 −12 M with a detection limit of 9.0 × l0 −15 M. The ECL signal difference permitted to discriminate the perfect-matched target ss-DNA and two-base-mismatched ss-DNA. This work demonstrates that SWNT can provide an amplification platform for carrying a large number of ECL probe and thus resulting in an ultrasensitive ECL detection of DNA hybridization.
Pierre Alcouffe - One of the best experts on this subject based on the ideXlab platform.
-
Specific properties of in situ Ruthenium-catalyzed polyamide 12/polydimethylsiloxane compatibilized blend
Journal of Polymer Science Part B: Polymer Physics, 2018Co-Authors: Philippe Cassagnau, Eliane Espuche, Pierre Alcouffe, Véronique Bounor-legaréAbstract:The main objective of this work focused on the chemical modification of polyamide 12 (PA12) properties through the reaction with a hydride‐terminated polydimethylsiloxane (PDMS‐SiH). The investigated PA12/PDMS‐SiH blend was compatibilized by Ruthenium Derivative catalyzed hydrosilylation reaction in molten state. This original route enhanced interfacial adhesion and avoid PDMS‐SiH leaching phenomenon between the two immiscible phases. More specifically, the size of PDMS‐SiH domains in the blend decreased from around 4 μm to 800 nm and from 30 to 1 μm after compatibilization with 10 and 20 wt % PDMS‐SiH, respectively. For the best compatibilized PA12/PDMS‐SiH blend, the introduction of PDMS lowered the surface free energy and the PA12‐based blend turned from hydrophilic to hydrophobic behavior, as evidenced by the water contact angle measurements. Gas permeability and CO2/H2 and CO2/He gas selectivity were also improved with the increase in PDMS content. Besides, the mechanical properties were enhanced with 13% increase in Young's modulus after in situ compatibilization with 15 wt % PDMS‐SiH. Thermal stability was also improved after compatibilization as the initial degradation temperature of reactive blends obviously increased compared with nonreactive ones.