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The present work focuses on the preparation, using a solution process, of flexible conductive nanocomposites based on polyurethane (PU)/polyaniline (PANI) with different mass percentages: 2, 3 and 4%. Because of the low conductivity of the PU + PANI films, these later were doped with inorganic NiCl2. PU + PANI undoped films were synthesized by a “one-shot” process. For doping process, PANI has been doped according to two different methods: The first one consists of the impregnation of the pristine PU + PANI film in a solution of inorganic salt dopant with a solvent (THF) during a soaking time, while the second method uses a “one-shot” process. The structural characterization and conductivity properties of the polymer blends were examined by differential scanning calorimetry, Fourier transform infrared spectroscopy and dielectric measurements spectroscopy. The results show that NiCl2 significatively increases the conductivity compared to pure PU + PANI blends, with better results using the second method of synthesis.

This report is the first one on a cationic waterborne polyurethane (cWPU) latex based on epoxidized hydroxyl telechelic natural rubber (eHTNR) polyol, providing potential for use as a coating made of renewable resources. A cWPU latex was synthesized by step growth emulsion polymerization from hydroxyl telechelic natural rubber (HTNR with M n = 3000 g.mol―1) with fixed N-methyl diethanol amine content of 5.6 wt% and 2,4-toluene diisocyanate (NCO index = 100). The effects of proportion of epoxide units on HTNR polyol from 0 to 30 % on preparing cWPU latex were investigated. Chemical structures of HTNR and eHTNR polyol were confirmed by 1H-NMR spectroscopy. The resulting HTNR and eHTNR polyols present a unimodal size exclusion chromatography trace. The viscosity increased with epoxide fraction. The synthesized cWPU latex based on eHTNR was a stable milky-blue emulsion with well-defined size dispersion. All cWPU-eHTNR films showed good wettability, good chemical resistance, and high thermal stability, improving with the proportion of epoxide units. The mechanical properties of cWPU-eHTNR films were studied from their stress-strain curves. Moreover, the electrical properties were investigated. The cWPU-eHTNR films showed relatively low conductivity. Wettability, chemical resistance, adhesion, thermal stability, and electrical properties of cWPU-HTNR films improved with the proportion of epoxide units on the HTNR polyol. These results demonstrate a new synthesis route to develop cWPU latex based on a biosource, for coating applications.

International audience; Renewable resource based cationic waterborne polyurethanes (cWPUs) have been prepared from hydroxyl telechelic natural rubber (HTNR) with a range of number average molecular weights (Mn) (2820, 1800, and 950 g mol−1), toluene-2,4-diisocyanate (TDI), N-methyl diethanolamine (NMDEA), and ethylene glycol (EG). The chemical structure of the cWPUs was confirmed by FT-IR and 1H NMR. Particle size and zeta potential of prepared cWPUs were also characterized by ZS nanosizer. By varying the levels of Mn of HTNR, the obtained cWPUs were stable with a milky blue appearance, forming yellowish films. The smallest particle sizes of 76.4 nm were achieved using Mn of HTNR of 2820 g mol−1 while zeta potential value ranges from 67 to 71 mV were observed with increasing Mn of HTNR. Lap shear testing of these WPUs indicates their potential in real cow leather adhesive applications, with the best adhesive result coming from cWPU based on an HTNR molecular weight of 1800 g mol−1. The results show the potential of natural rubber as a green adhesive material in suitable aqueous environments.

International audience; This paper reports on the synthesis and physical properties of conducting composites based on polyaniline and polystyrene. Polyaniline composite powders are synthesized by oxidative polymerization in an acidic medium. Thermal properties are characterized by thermo gravimetric analysis and differential scanning calorimetry. UV-Visible absorption spectroscopy is also used to study the optical properties of the deposited films. The optical gap decreases from 4.6 eV to 2.7 eV with increasing polyaniline content from 0.5 to 5 wt. % confirming the improvement of the semi-conductive properties. Due to the absorption properties in near infrared of the thin composite layers they can be promising materials for optoelectronic and photovoltaic applications.

Commercial surfactants, which are inexpensive and abundant, were covalently grafted to flat and transparent electrodes, and it appears to be a simple functionalization route to design biomembrane sensors at large-scale production. Sparsely tethered bilayer lipid membranes (stBLM) were stabilized using such molecular coatings composed of diluted anchor-harpoon surfactants that grab the membrane with an alkyl chain out of a PEGylated-hydrogel layer, which acts as a soft hydration cushion. The goal of avoiding the synthesis of complex organic molecules to scale up sensors was achieved here by grafting nonionic diblock oligomers (Brij58 = C xH2 x+1(OCH2CH2) nOH with x = 16 and n = 23) and PEO short chains ((OCH2CH2) nOH with n = 9 and n = 23) from their hydroxyl (-OH) end-moiety to a monolayer of -Ar-SO2Cl groups, which are easy to form on electrodes (metals, semiconducting materials, ...) from aryl-diazonium salt reduction. A hybrid molecular coating on gold, with scarce Ar-SO2-Brij58 and PEO oligomers, was used to monitor immobilization and fusion kinetics of DOPC small unilamellar vesicles (SUV) by both quartz crystal microbalance (QCM) and surface plasmon resonance (SPR) techniques. Using flat and transparent thin chromium film electrodes, we designed biosensors to couple surface sensitive techniques for membranes, including X-ray reflectivity (XRR), atomic force microscopy (AFM) with subnanometer resolution, and optical microscopy, such as fluorescence recovery after photobleaching measurements (FRAP), in addition to electrochemistry techniques (cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS)). The advantages of this biomembrane-sensing platform are discussed for research and applications.

International audience; A new telechelic liquid natural rubber is used to elaborate thin coating (

International audience; Isoconversional analysis was applied to non-isothermal bulk cure kinetics of uncatalyzed polyurethane (PU) resins based on telechelic hydoxyl natural rubber (HTNR) and poly[(phenyl isocyanate)-co-formaldehyde] (P-MDI). The dependency of apparent activation energy on conversion led to the identification of two different kinetic models, each involving two activation energies: a phenomenological model based on the Kamal–Sourour equation with non integer reaction exponents; and a new semi-mechanistic model assuming a main second order reaction between alcohols and isocyanates forming urethane linkages and a secondary reversible reaction forming allophanates that is known to become significant above 120 °C. Such a model based on mechanistic considerations allowed us to explain the variations of reactivity of the HTNR polyols with its average molecular weight.

Grafting commercial surfactants appears to be a simple way to modify electrodes and conducting interfaces, avoiding the synthesis of complex organic molecules. A new surface functionalization route is presented to build surfactant coatings with monolayer thickness grafting molecules considered as nonreactive. A monolayer of -SO2Cl functions (from a p-benzenesulfonyl chloride) was first electrografted. It showed a high reactivity toward weak nucleophiles commonly found on surfactant end-moieties such as hydroxyl groups (-OH), and it was used to covalently graft the following: (1) nonionic diblock oligomers (Brij or CiEj, CxH2x + (OCH2CH2)nOH with x = 16 and n = 23 for Brij58, x = 16 and n = 10 for Brij C10, and x = 16 and n = 2 for Brij52); (2) poly(ethylene glycol) (PEG) short chains (PEO9 for (OCH2CH2)nOH with n = 9) and mixed formula. The surface modification due to these molecular coatings was investigated in terms of wetting properties and interfacial electrochemistry characteristics (charge transfer ...

Linear and crosslinked polyhydroxyurethanes (PHUs) based on natural rubber (NR) were synthesized by a polyaddition reaction without a solvent or catalyst to exploit the reactivity of diamines or triamines with dicyclic carbonate groups. Oligo-isoprenes were obtained from the controlled oxidative degradation of NR and successive modifications of the chain ends. The syntheses of linear PHU were carried out with two approaches. The first one consisted of a reaction between amino telechelic oligo-isoprenes and aromatic or aliphatic dicyclic carbonates. The second approach proceeded through a reaction between oligo-isoprenes bearing cyclic carbonate chain ends and difunctional or trifunctional amines. The evolution of these reactions was studied by Fourier transform infrared spectrometry. The influence of the carbonate-to-amine molar ratio, the chain length of the oligo-isoprenes, and the reaction temperatures were investigated. The thermal properties of the PHUs were studied by differential scanning calorimetry and thermogravimetric analysis. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45427.

International audience; A controlled degradation process enabling Natural Rubber (NR) depolymerization and using the olefin metathesis reaction in ionic liquid medium is reported. Using trihexyl-(tetradecyl)phosphonium chloride (Cyphos101) and N,N-dioctylimidazolium bromide (C8C8ImBr), low-dispersity telechelic polymers are produced. With N,N-dioctylimidazolium bromide (C8C8ImBr), the degradation process could be performed for five consecutive cycles with excellent control. This degradation process was successfully applied to waste tires.

Carbon and chromium surfaces were modified by electrochemical reduction of a diazonium salt formed in situ from the sulfanilic acid. The organic layer formed was activated by phosphorus pentachloride (PCl(5)) to form a benzene sulfonil chloride (Ar-SO(2)Cl). An electrochemical study of the blocking effect and the activity of this surface was carried out on a carbon electrode. The chromium surface study was completed by X-ray photoelectron spectroscopy and atomic force microscopy to characterize the formation of a compact monolayer (0.8 nm height and roughness 0.2-0.3 nm). The compactness and the activity of this organic monolayer allowed us to affix a length dsDNA with the aim of analyzing the formation of a complex between dsDNA and a protein. The interaction of a transposase protein with its target dsDNA was investigated. The direct imaging of the nucleoproteic complex considered herein gives new insights in the comprehension of transposase-DNA interaction in agreement with biochemical data.

Bio-based polyurethane foam (PUF) was synthesized by a one-shot polymerization using hydroxyl telechelic natural rubber (HTNR) and polycaprolactone (PCL) diols as a soft segment. The effect of HTNR/PCL diol molar ratio (1/0, 1/0.5, 1/1 and 0.5/1) on the foam formation rate and physical and mechanical properties of the resulting PUF was investigated. The formation of urethane linkage and cross-linked structure were confirmed by FTIR analysis. The foams observed by scanning electron microscope revealed to have almost closed cells. The molar ratio of HTNR/PCL diol affected the foam formation rate, the average diameter of cell, the regularity of cell shape, the elongation at break and the compressive strength. The foam density slightly changed with this molar ratio whereas the specific tensile strength of all samples was in the same range. All PUFs showed relatively high compression set. The biodegradability was assessed according to a modified Sturm test. Low density polyethylene and sodium benzoate were used as a negative and positive control sample, respectively. PUF samples showed an induction time of 33 days in which the percentage of biodegradation was ~7–11 %. At the end of testing (60 days), the highest degradation (45.6 %) was found in the sample containing 1/0.5 of HTNR/PCL diol molar ratio.

This work was an initial study on the synthesis of polyurethane foams (PUF) by using diols obtained from the controlled degradation of waste tire crumbs and from polycaprolactone (PCL) followed by examination of their biodegradability. Natural rubber (NR, cis−1,4 polyisoprene) and butadiene rubber (BR) chains contained in waste tire crumbs were chemically modified into carbonyl telechelic (CTWT) and successively into hydroxyl telechelic oligomers (HTWT). Four types of PUF were prepared with different molar ratios between the HTWT and the PCL diols. CTWT and HTWT were analyzed by 1H-NMR, SEC, and FT-IR to confirm their chemical structure. Formation of the urethane bond was demonstrated by FT-IR spectra. The addition of the PCL diol increased the thermal degradation temperature of the PUF based on thermogravimetric analysis. According to scanning electron microscopy, polyhedral closed cells were obtained. The molar ratio of HTWT/PCL diols strongly affected the kinetic rate of foam formation and foam morphology. A low kinetic rate provided PUF with a high density, small cell size, and a broad cell size distribution. In order to assess biodegradation of PUF, the modified Sturm test was carried out for 60 days at ambient temperature (27–30 °C). The biodegradation of PUF containing only HTWT was 31.2% and 51.3% at 28 days and 60 days of testing, respectively whereas the PUF containing 1/0.5 HTWT/PCL diols (by mole) showed a higher biodegradation: 39.1% and 64.3% at 28 days and 60 days of testing respectively. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44251.

International audience; Rubber is a widely available potential carbon neutral resource, both as native natural rubber state and as vulcanized state in waste tires. Herein, we describe a model synthesis of acrylate telechelic natural rubber (AcTNR) oligomers and the use of such oligomers to prepare novel acrylate resins. AcTNR oligomers are synthesized according to a two steps procedure implying a controlled C = C bond's scission of high-molecular-weight natural rubber and a further chain ends functionalization. The molar mass of the resulting AcTNR is found to be 2300 g/mol as determined by 1H NMR. AcTNR-based resins are then prepared by mixing AcTNR oligomers with various reactive diluents (RD) such as styrene, 1,4-butanediol ether, tri(propylene glycol) diacrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate (AcTNR:RD weight ratio 7:3). These bio-based resins are afterward cured in the presence of methyl ethyl ketone peroxide as initiator and cobalt octoate as accelerator at 80 °C and postcured at 120 °C. The cured resins offer a wide range of mechanical, thermal, and dynamic-mechanical performances. This approach could be extended to rubber tire wastes. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43548.

The photoinitiated polymerization of epoxidized hydroxytelechelic cis-1,4-polyisoprene and of a dual system (epoxidized/ acrylated) telechelic cis-1,4-polyisoprene in the presence of 2,2-dimethyl-1,2-hydroxyacetophenone or/and hexafluoro-phosphate triar- ylsulfonium salt has been studied by real-time infrared spectroscopy. The synthesis of photosensitives oligoisoprenes was achieved by chemical modifications of hydroxytelechelic cis-1,4-polyisoprene obtained by controlled degradation of high molecular weight cis-1,4- polyisoprene. Then, the effect of light intensity, photoinitiator concentration, addition of reactive diluent and concentration of func- tional groups on the photopolymerization process was evaluated. Concerning the cationic process, the results showed that the kinetic profile improves when photoinitiator concentration and light intensity increase. The optimum concentration of triarylsulfonium salt used as photoinitiator was determined as 5% (w/w) and the optimum light intensity was 50 mW cm � 2 . Reactive diluent (3-ethyl-3- hydroxymethyl oxetane) addition greatly improves the ultimate conversion and the polymerization rate. Subsequently, the photopoly- merization kinetic of a dual epoxidized/acrylated system was studied. The results obtained using different photoinitiator mixtures and different intensity of irradiation showed that the crosslinking of acrylate functions at the chain-end prevents the progression of the cationic process at the oxirane groups along the chain. Thus, the mobility of the cationic reactive centers was restricted by the cross- linking at the high conversion of the acrylate double bonds. V C 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 000: 000-000, 2012

Novel flexible polyurethane foams were successfully prepared from a renewable source, hydroxytelechelic natural rubber (HTNR) having different molecular weights (1000–3400 g mol−1) and variation of epoxide contents (EHTNR, 0–35% epoxidation) by a one-shot technique. The chemical and cell structures as well as physico-mechanical, thermal, and acoustic properties were characterized and compared with commercial polyol analogs. The obtained HTNR based foams are open cell structures with cell dimensions between 0.38 and 0.47 mm. The HTNR1000 based foam exhibits better mechanical properties but lower elongation at break than those of commercial polyol analog. However, the HTNR3400 based foam shows the best elastic properties. In a series of EHTNR based foams, the tensile and compressive strengths show a tendency to increase with increasing epoxide content and amount of 1,4-butanediol (BD). The HTNR based foams demonstrate better low temperature flexibility than that of the foam based on commercial polyol. Moreover, the HTNR based polyurethane foams was found to be an excellent absorber of acoustics. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Summary: Composite polyurethane/polyaniline (PU/PANI) films have been chemically prepared by oxidative in-situ polymerization of aniline inside the previously swelled PU film. Swelling kinetic studies have shown that for PU films the swelling degree of aniline is 25 wt.%. The dielectric and electrical properties of the composite films were measured using dielectric relaxation spectroscopy and four-probe method. Dielectric measurements as a function of temperature and frequency revealed the presence of a relaxation process for the composite PU/PANI-HCl film. This relaxation was explained in terms of interfacial polarization due to the double-layered structure of the composite film. The activation energy values found by dielectric and electrical measurements are close and this result confirms the conducting character of the PANI containing layer.

Composite polyurethane/polyaniline and polyamide-6/polyaniline films were chemically prepared by oxidative in situ polymerization of aniline inside the previously swelled matrix film. Swelling kinetic studies had shown that for polyurethane and polyamide-6 films the swelling degree of aniline was 25 wt.% and 15 wt.%, respectively. The dielectric and electrical properties of the composite films were established using dielectric relaxation spectroscopy and four-probe method. Dielectric measurements as a function of temperature and frequency revealed the presence of relaxation processes influenced by the nature of the polymer matrix, i.e. one relaxation process for the polyurethane based composite film and two relaxation processes for polyamide-6 based composite film. These relaxations were explained in terms of interfacial polarization caused by the polyaniline organisation as it was revealed by atomic force microscopy. Activation energy values obtained by dielectric and electrical measurements are close and this result confirms the conducting character of the polyaniline containing layer.

A poly(cyclopentadithiophene) matrix modified by DNA covalently fixed to the surface has been designed to study the redox and ion-exchange properties in surface-tethered DNA-conducting polymers. Voltammetric investigations show an improvement in conductivity, originating from DNA modification, probably due to changes in charged-density and size of dopant species. Cyclic voltammetry with concomitant QCM measurements indicate that the mass changes are consistent with an ejection of Na + cations associated to the anionic phosphate groups, attesting a DNA contribution to the p-doping process. So, in contrast to the classic doping patterns, the p-doping process of surface-tethered DNA-copolymer exhibits a cation-controlled transport mechanism. Impedimetric investigations indicate that for long enough DNA target sequence, nucleic acid preserves certain flexibility and is involved in the p-doping process through a diffusion-like motion. These results give new opportunities for genesensors development and for a better understanding of bioactive conducting surfaces.

New crosslinked ionic polyurethanes and copolyurethanes were yielded by reaction of telechelic cis-1,4-oligoisoprenes, bearing a variable number of ammonium and hydroxy groups, with isocyanurate of isophorone diisocyanate (I-IPDI). Aiming for a comparative study, polyurethane elastomers based on non-ionic telechelic oligomers were also synthesized. Thermo-mechanical behavior and crosslinking density of these three families of materials were investigated by DMTA and swelling test, respectively. Surface properties were examined by static contact angle measurements and AFM imaging. The bactericidal activity of the polymers was investigated by enumerating living Pseudomonas aeruginosa on material surfaces and on water suspensions. The number of attached living bacteria was found to depend on the chemical structure of the material and on the contact time between the microorganisms and the surface. An exclusive bactericidal activity was obtained with the ionic copolyurethane family. Materials with weak crosslinking density were found to release bactericidal moieties. The abilities of the polymers to prevent bacterial growth were examined through zone of inhibition experiments against P. aeruginosa, which shown a bacteriostatical effect for each synthesized material. These experiments were not sufficiently sensitive to detect the leaching of bactericidal moieties from the materials with weak crosslinking density. When the zone of inhibition experiments was performed on more sensitive bacteria, namely Staphylococcus epidermidis, the leaching of bactericidal moieties as well as bacteriostatic effect was detected. This work demonstrates the potentiality for making functional biomaterials from natural rubber, a renewable resource.

A conducting polymer sensor for direct label-free DNA detection based on a polythiophene bearing an electroactive linker group is investigated. DNA hybridization is studied by electrochemical impedance spectroscopy (EIS) and quartz crystal microbalance (QCM) techniques. Modelling of DNA hybridization by EIS measurements exhibits the contribution of nucleic acid to a superficial p-doping process. A 675-mer single-stranded DNA is produced using asymmetric PCR from a DNA sequence of a transposable element mariner and hybridized to the previously immobilized probe. Electrochemical stimulus leads to the release "on demand" of DNA fragments and the amount delivery permits to do PCR amplification.

Natural rubber (NR) is a renewable bio-based polymer, while poly(butylene succinate) (PBS) belongs to the family of biodegradable renewable polymers. In this article, novel polyurethanes (PUs) were prepared using hydroxyl telechelic natural rubber (HTNR) and hydroxyl telechelic poly(butylene succinate) (HTPBS) as soft segments, and using toluene-2,4-diisocyanate (TDI) and 1,4-butanediol (BDO) as hard segment. HTPBS oligomers of Mn¯ = 2000 and 3500 g mol−1 were synthesized by bulk polycondensation of succinic acid (SA) with BDO. The polyurethane materials were obtained by casting process after solvent evaporation. The influence of the hard segment content and the molecular weight of HTPBS on the materials’ thermo-mechanical properties were investigated by means of tensile testing, DSC, TGA, and DMTA. The obtained polyurethanes were amorphous with phase separations between hard and soft segments as well as between HTNR and HTPBS segments, and they exhibited good physical properties. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42943.

Carbonyl telechelic cis-1,4-oligoisoprene (CTPI) obtained from high molecular weight polyisoprene through an oxidative chain cleavage reaction have been chemically modified. Thus, new well defined amino telechelic cis-1,4-oligoisoprenes have been obtained in a mass range of 1600–2300 g/mol according to two different pathways. The first approach involved a standard mesylate displacement by sodium azide followed by smooth reduction using triphenylphosphine. The second pathway implied a reductive amination sequence. Primary or secondary amine functions have thus been selectively obtained at both oligomer chain-ends depending on reaction conditions. Peculiar NMR experiments conducted on these functional oligomers confirmed a precise control of functionality during the chemical modification. Moreover, their abilities to react with toluene diisocyanate or bis(succinimidyl)carbonate have been investigated.

Novel cationic waterborne polyurethanes (cWPU) were synthesized by step-growth polymerization of hydroxyl telechelic natural rubber, molecular weight of 2800 g mol−1, toluene-2,4-diisocyanate, N-methyl diethanolamine (NMDEA) as an emulsifier. The chemical structure of cWPU was confirmed by 1H-nuclear magnetic resonance and Fourier transform infrared spectroscopy. The amounts of NMDEA and ethylene glycol under isocyanate (NCO) index of 100 on the properties of cWPU were studied. It was found that cWPU was stable under the concentration of NMDEA more than 1.50 mol and the particle sizes decreased with increasing of NMDEA content. Also, contact angle shows more hydrophilic materials by increasing of NMDEA. Extended cWPU was found in two ranges of nano size. Chain extender has strongly affected cWPU film formation, increasing of mechanical properties, and thermal properties. In addition, stress–strain curve and scanning electron microscopy image shows the change of behavior from soft elastic to ductile plastic by adding ethylene glycol. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45715.

International audience; The interaction of human Rad51 protein (HsRad51) with single-stranded deoxyribonucleic acid (ssDNA) was investigated by using quartz crystal microbalance (QCM) monitoring and atomic force microscopy (AFM) visualization. Gold surfaces for QCM and AFM were modified by electrografting of the in situ generated aryldiazonium salt from the sulfanilic acid to obtain the organic layer Au–ArSO3H. The Au–ArSO3H layer was activated by using a solution of PCl5 in CH2Cl2 to give a Au–ArSO2Cl layer. The modified surface was then used to immobilize long ssDNA molecules. The results obtained showed that the presence of adenosine diphosphate promotes the protein autoassociation rather than nucleation around DNA. In addition, when the BRC4-28 peptide inhibitor was used, both QCM and AFM confirmed the inhibitory effect of BRC4-28 toward HsRad51 autoassociation. Altogether these results show the suitability of this modified surface to investigate the kinetics and structure of DNA–protein interactions and for the screening of inhibitors.

International audience; So simple: The in situ synthesis of an aryldiazonium salt and an azo-aryldiazonium salt by azo coupling from sulfanilic acid and aniline is reported. Formation of a mixed organic layer is monitored by cyclic voltammetry and atomic force microscopy. A compact mixed layer is obtained with a global roughness of 0.4 nm and 10-15 % vertical extension in the range 1.5-6 nm.

International audience; Previous studies have demonstrated that ionic and non-ionic natural rubber-based coatings inhibit adhesion and growth of marine bacteria, fungi, microalgae, and spores of macroalgae. Nevertheless, the mechanism of action of these coatings on the different micro-organisms is not known. In the current study, antifouling activity of a series of these rubber-based coatings (one ionic and two non-ionic) was studied with respect to impacts on marine microalgal photosynthesis using pulse-amplitude-modulation (PAM) fluorescence. When grown in contact with the three different coatings, an inhibition of photosynthetic rate (relative electron transport rate, rETR) was observed in all of the four species of pennate diatoms involved in microfouling, Cocconeis scutellum, Amphora coffeaeformis, Cylindrotheca closterium, and Navicula jeffreyi. The percentage of inhibition ranged from 44% to 100% of the controls, depending on the species and the coating. The ionic coating was the most efficient antifouling (AF) treatment, and C. scutellum and A. coffeaeformis are the most sensitive and tolerant diatoms tested, respectively. Photosynthetic inhibition was reversible, as almost complete recovery of rETR was observed 48 h post exposure, after detachment of cells from the coatings. Thus, the antifouling activity seemed mostly due to an effect of contact with materials. It is hypothesized that photosynthetic activity was suppressed by coatings due to interference in calcium availability to the microalgal cells; Ca(2+) has been shown to be an essential micro/macro nutrient for photosynthesis, as well as being involved in cell adhesion and motility in pennate diatoms

International audience; Un polymère de type polythiophène comportant des groupements chlorure de parabenzenesulfonile a été synthétisé par voie électrochimique afin d'obtenir une surface destinée à ` l'immobilisation rapide et efficiente de biomolécules. Graceà une liaison sulfonamide, une protéine A a ainsi été fixée pour permettre l'accroche et l'orientation d'un anticorps spécifique. Le dispositif a pu être testé pour piéger une bactérie pathogène ''Salmonella enterica paratyphi''. La présence de la bactérie sur la surface a e ´té vérifiée conjointement par microbalance a ` quartz et par spectroscopie Raman. Les résultats obtenus ont e ´té comparés a ` ceux obtenus sur une surface d'or fonctionnalisée selon le même procédé et ils témoignent de la très grande réactivité de la surface polymère. Ce procédé de fonctionnalisation de surface, facile a ` mettre en oeuvre, spécifique et peu coûteux, constitue, par couplage avec la technique de diffusion Raman, une méthode alternative potentielle de détection et identification rapide de micro-organismes pathogènes.; A simple electrochemical procedure was used for the synthesis of a polythiophene containing para-ben-zenesulfonyl chloride groups. The obtained polymer was shown to be very reactive and directly able to covalently bind nucleophile biomolecules. Protein A and a specific antibody were then successively immobilized on the conductive polymer through a covalent bonding of Protein A with the as-prepared linker for bacteria trapping purpose. All reactions were controlled in situ by cyclic voltammetry, quartz crystal microbalance and Raman spectroscopy. The results were compared to those previously obtained on gold surface modified with the same chemical linker. The conductive polymer led to a very high rate of antibody recognition compared to the gold surface and to literature, probably due to a large available surface obtained after polymerization. One example of pathogenic bacteria ''Salmonella enterica paratyphi'' detection was successfully tested on the substrates. The presented results are promising for the future design of simple and inexpensive immunocapture-based sensors

Salmonella is a major cause of foodborne illness worldwide and is not allowed to be present in any food in all countries. The purpose of this study is to develop a simple alternative method for the detection of Salmonella based on functionalized polyethylene (PE) surfaces. Salmonella Typhimurium was used as a model bacterium. PE film was treated using dielectric plasma in order to alter the wettability of the PE surface and consequently introduce functionality on the surface. The PE film characterized by ATR-FTIR spectroscopy revealed the presence of C O stretching of ketones, aldehydes and carboxylic acids. The antibodies against O or H antigens of Salmonella and S. Typhimurium were then respectively immobilized on the PE surface after activation of the carboxylic group using NHS/EDC followed by protein A. The evidences from ATR-FTIR, scanning electron microscopy and optical microscopy showed the presence of S. Typhimurium attached to the plasma treated PE surfaces via the two types of anti-Salmonella antibody. The plasma treated PE film developed is simple and allows efficient association of bacterial cells on the treated surfaces without the necessity of time-consuming centrifugation and washing steps for isolation of the cells. This material is considered to be a smart material applicable for S. Typhimurium detection.

Interaction and surface binding characteristics of staphylococcal protein A (SpA) and an anti-Escherichia coli immunoglobulin G (IgG) were studied using the Raman spectroscopy. The tyrosine amino acid residues present in the α-helix structure of SpA were found to be involved in interaction with IgG. In bulk interaction condition the native structure of proteins was almost preserved where interaction-related changes were observed in the overall secondary structure (α-helix) of SpA. In the adsorbed state, the protein structure was largely modified, which allowed the identification of tyrosine amino acids involved in SpA and IgG interaction. This study constitutes a direct Raman spectroscopic investigation of SpA and IgG (receptor-antibody) interaction mechanism in the goal of a future biosensor application for detection of pathogenic microorganisms.

Owing to its origin, Natural Rubber exhibits more variation than synthetic polymers. If, over the years, NR specifications have evolved from mere visual inspections towards the more complex Technically Specified Rubber (TSR) schema, industrial practice shows that, even for typical TSR grades, significant variations still exist within each shipment, especially in regard to processability. It follows that mastication is quite systematically needed in industrial operations, without or with processing aids or so-called peptizers. Typical NR compounding operations consume therefore time and mixer capacity, a situation, which obviously calls both better characterization methods of (gum) natural rubber and eventually improved grades. There are nowadays promising new techniques to analyze and characterize polymer materials, some of which are a priori attractive for a better specification of NR grades. One such technique is the so-called Fourier Transform rheometry, a dynamic testing method to investigate both the linear and the non-linear viscoelastic domains of polymer materials. Other are spectroscopic methods like solid Nuclear Magnetic Resonance (NMR), either liquid or solid, whose results might be complemented by Size Exclusion Chromatography with special detection techniques, e.g. SEC-MALS, and Differential Scanning Calorimetry (DSC). The purpose of the work reported here was to investigate a series of gum NR grades using such techniques, with the objectives not only to demonstrate their interest but also to cross-validate their results. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

We present a new and advanced methodology, developed for surface functionalisation of gold and to study immobilisation of an immuno-specific system of proteins. A combination of electrochemical quartz crystal microbalance and Raman spectroscopy techniques allowed a complete understanding of the system starting from surface functionalisation and progressing to the functional structure analysis of immobilised proteins. A simple electrochemical procedure was formulated to prepare sulphonyl chloride terminated gold surfaces that form a strong sulphonamide bond with the receptor protein staphylococcal protein A (SpA). On the SpA grafted surfaces, the immobilisation of a human IgG and consecutive binding of an immuno-specific anti-human IgG was observed. The surface functional groups form a strong interaction with SpA without disturbing its functional properties. The native functional structure of SpA and also the IgGs was found to be retained in their immobilised state.

Telechelic oligoisoprenes were successfully prepared by the selective controlled degradation of natural rubber, a renewable source, via epoxidation and cleavage reactions. The molar mass of the oligoisoprene product obtained depends on the degree of epoxidation of the starting materials. The chemically modified structures obtained via epoxidation, hydrogenation, and ring opening of epoxide groups were also studied, and the chemical structures and thermal properties of the oligoisoprene products were determined. Moreover, the preliminary study of preparation of hydroxytelechelic natural rubber (HTNR)-based polyurethane foam was performed. A novel HTNR-based polyurethane foam was successfully prepared and its thermal properties were investigated and the results indicated that the HTNR-based polyurethane foam has a good low temperature flexibility. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

A biosensor for direct label-free DNA detection based on a polythiophene matrix is investigated by electrochemical impedance spectroscopy (EIS). Impedimetric experiments are performed with and without redox probe in solution. The non-Faradaic impedance measurements reveal two relaxation processes located at 50 Hz and 5 kHz, respectively. The first relaxation process, located at low frequencies, allows to detect biorecognition events by measuring the phase angle decrease, in accordance with a hindrance of the polaronic conduction. The second relaxation process, located at 5 kHz and originating from DNA modification, seems to increase with the length of the target sequence. These results suggest that this loaded support provides a platform for impedimetric detection of hybridization at high frequencies, leading to less time-consuming detection procedure. For a better understanding, results obtained in non-Faradaic mode are compared with Faradaic approach.

A conducting polymer is tested for DNA delivery trials. The conducting matrix used is successful for electrochemical delivery of DNA accumulated by covalent immobilization. The electrochemical process consists of the reduction of arylsulfonamide moieties, which occur as linker groups. The specific design of the polymer allows the electronic properties to be promoted, making available the cleavage potential in physiological media. The amount of DNA released from a modified platinum electrode is investigated by quartz crystal microbalance. The released species used to prove the system performance are long sequences of DNA strands, which are amplified by PCR after liberation and identified by electrophoresis migration.

Electrochemical behaviour of a functionalized fluorenylidene 1 is studied in comparison with a cyclopentadithiophene analogue 2. The influence of the main aromatic group on the electropolymerization ability is reported. We demonstrated that the lack of sulfur atoms in the monomer structure leads to an absence of polymerization due to the spin density located on the methylidene bridge in the radical cation. From modelling considerations, we have evaluated the participation of the methylidene bridge in the p-doping process. The good correlation between the p-doping level and the partial atomic charge carried by the methylidene bridge for poly(2) and poly(3) indicates that an extension of the conjugated area improves the p-doping level when the side chain is electronically connected to the main chain of polymer.

The first selective reductive amination of carbonyl telechelic oligoisoprene (CTPI) using NaBH(OAc)3 as the reducing agent is described. An access to tri- and tetrafunctionalized oligoisoprenes is realized in two or three steps from CTPI in high yield.

New segmented polyurethanes (thermoplastic-elastomers) based on previously described hydroxytelechelic cis-1,4-polyisoprene (HTPI), miscellaneous isocyanates and chain extenders at various equivalent ratios were prepared by the classical one-shot method. The influence of the nature of isocyanate and chain extender, as well as their equivalent ratios, on the mechanical and thermal materials behavior was investigated. Thus, a comparative assessment of material properties was performed. Microphase separation of hard and soft segments was observed by DMTA, DSC and AFM. Moreover, according to Thermogravimetric Analysis (TGA), linear relationships depending on the isocyanate and chain extender nature were found between the weight loss (%) and the percentages of hard segments. A classification of thermal stability in terms of weight loss was established. With the aim of a thermo-mechanical comparative study, polyurethane elastomers based on HTPI and isocyanates without chain extender, were also synthesized.

Cathodic sensitive group (CSG) connected to a conducting polybithiophene by a π-conjugated spacer has been designed to study the conduction through the unsaturated spacer. By comparison with the electrochemical behaviour of the saturated spacer analogue, the cyclic voltammetry shows that, when the electronic communication is ensured, the CSG becomes reducible at the same potential than that of conducting matrix. This suggests that the electrons injected in the conducting polymer, CP, during the n-doping process can promote the CSG reduction. A n-doping catalytic process is evoked to explain this electron transfer mediated reduction. Furthermore, an electrocleavable group used as CSG, allows the access to a wide range of organic materials suitable for electrochemically controlled delivery systems. Keywords: Cyclopentadithiophene, π-Conjugated spacer, n-Doping catalytic process, Electrical stimulus, Controlled delivery

A conducting polythiophene sensor for direct label-free DNA detection is investigated by electrochemical impedance spectroscopy (EIS) and by quartz crystal microbalance. The end-modified DNA probe is covalently immobilized by using a new anchorage function. The hybridization detection is studied by EIS experiments. An equivalent circuit is suggested and the variations of individual values of parameters deduced from impedance fits are connected to the change of conformation during the hybridization process.

New telechelic cis -1,4-polyisoprene oligomers bearing an hydroxyl group at the end of the polyisoprene backbone and possessing controlled molecular weights were used as soft segments in the elaboration of polyurethane elastomers. Besides, the well defined hydroxytelechelic cis -1,4-polyisoprene (HTPI) structure obtained through a controlled methodology, was chemically modified leading to hydrogenated and epoxidized oligomers based polyurethanes. The influence of the structural changes of these precursors on the polyurethanes properties have been studied. Thus, mechanical parameters as well as glass transition and mechanical transition temperature measurements indicated an increase in PUs hardness when the length of soft segment decreases and when the degree of epoxidized and hydrogenated isoprenic moieties increases. Moreover, based on thermogravimetric analysis (TGA), a linear relationship was established between the weight loss in the urethane stage degradation and the amount of hard segments in the PUs. Otherwise, the hydrogenated soft segments were found more thermally stable than the epoxidized and the non modified ones. By comparison with similar investigations developed from commercial oligodienes (PBHT R20 LM ® and EPOL ® ), this study mainly showed that the PUs based on hydrogenated hydroxytelechelic cis -1,4-polyisoprenes were more thermally stable and softer than the EPOL ® based analogues.