This paper presents a thin nanocomposite film, composed of graphene and of a polymer acting as a binder. The challenge was to realize a conducting, homogeneous and adherent film on a copper based material substrates (CuSn8) used for electrical contacts applications with the aim of reducing corrosion. The first step was to find the right formulation, the deposition process and the post-treatment for the composite. Flakes of graphene were mixed to two different types of high molecular weight polymers in ethanol. The films were deposited by dip-coating of the substrates in the solution; they were then grafted to the substrate by UV curing. Films between 100 nm to 300 nm thick could be deposited. Good adhesion of the film to the substrate was obtained with poly-4-vinylpyridine (P4VP) acting as a binder. The weight ratio of graphene/polymer was important for the homogeneity of the deposited films. The next step was to plate the samples with a nickel layer. Very thin nanometric nickel films were deposited on the graphene/polymer composite by an electroless nickel-boron process (NiB). The nickel nanofilm, a few tens of nanometres thick, was observed to be covering the graphene flakes embedded in the composite. Various techniques were used to characterize the samples: SEM, AFM, conducting AFM, Raman and 4 point sheet resistance measurements. Finally the samples were coated with 1.2 μm of electrolytic nickel and 0.4 μm of electrolytic gold. They were then exposed to nitric acid vapor (NAV) and hypochlorite bleach corrosion tests for several hours. The graphene composite layer was observed to hinder the pore and pitting corrosion on the samples. This process is very versatile and can find many applications in the field of corrosion protection.

Current research directions with the aim of extending the applications of titanium nitride (TiN) in areas of microelectronics, electrocatalysis, biosensors etc. require identifying new and efficient methods to modify this durable material with desired organic functionalities. We have clearly demonstrated in this work that diazonium chemistry can be considered for surface modification of titanium nitride. Indeed, a near-monolayer of aminophenylene has been reported to be spontaneously grafted onto the TiN surface by simple immersion of the substrates into an acidic solution of the corresponding diazonium cations. X-ray photoelectron spectroscopy measurements strongly suggested a covalent coating of aminophenyl groups on titanium nitride. Surface functionalization with aminophenylene layers was also investigated in presence of hypophosphorous acid and iron powder. Effect of these homogeneous and heterogeneous reducing agents with respect to the formation of aryl layers at different thicknesses was discussed in detail on the basis of conventional hemolytic dediazoniation mechanism in combination with the XPS results.

Although the conventional methods for strong attachment of chitosan onto stainless steel require many steps in different solvents, it has been demonstrated in this work that covalent grafting of chitosan on a steel surface can be easily achieved through the formation of a self-adhesive surface based on aryldiazonium seed layers. Initially, a polyaminophenyl layer is grafted on a stainless steel surface by means of the one-step GraftFast(TM) process (diazonium induced anchoring process). The grafted aminophenyl groups are then converted to an aryldiazonium seed layer by simply dipping the substrate in a sodium nitrite acidic solution. That diazonium-rich grafted layer can be used as a self-adhesive surface for subsequent spontaneous coating of chitosan onto the steel surface. X-ray photoelectron and impedance electrochemical spectroscopies were used to characterize the pristine and modified steel samples. As evidenced from impedance and linear polarization results, the primary polyaminophenyl layer characterized by a high charge transfer resistance contributed to better protection against corrosion of the resulting chitosan-coated steel in sulfuric acid medium.

Among all the patterning techniques, inkjet printing has lately become a reliable technique at micrometer scale to produce localized modifi cations on material surfaces. Printing of polymer on material surface however leads to adsorbed patterns with poor adhesion. To overcome this drawback, a new process combining for the fi rst time inkjet printing and an effi cient covalent polymer grafting method was developed. This latter method is based on a photoassisted reduction of aryldiazonium salt/acrylate monomer ink, derived from the already published GraftFast process. In order to demonstrate its versatility, this new localized polymer grafting process is here combined as an example with the ligand induced electroless plating (LIEP) process to obtain metal interconnects onto fl exible and transparent substrates with excellent mechanical and electrical properties for applications in fl exible electronics devices.

Piezoelectric quartz tuning fork has drawn the attention of many researchers for the development of new atomic force microscopy (AFM) self-sensing probes. However, only few works have been done for soft biological materials imaging in air or aqueous conditions. The aim of this work was to demonstrate the efficiency of the AFM tuning fork probe to perform high-resolution imaging of proteins and to study the specific interaction between a ligand and its receptor in aqueous media. Thus, a new kind of self-sensing AFM sensor was introduced to realize imaging and biochemical specific recognition spectroscopy of glucose oxidase enzyme using a new chemical functionalization procedure of the metallic tips based on the electrochemical reduction of diazonium salt. This scanning probe as well as the functionalization strategy proved to be efficient respectively for the topography and force spectroscopy of soft biological materials in buffer conditions.

Covalent immobilization of unmodified biological materials as proteins has been performed through a one-step and soft method. This process is based on a polyazidophenylene layer derived from the electroreduction of the parent salt 4-azidobenzenediazonium tetrafluoborate on gold substrates. The wavelength used (365 nm) for the photochemical grafting of a large variety of molecules as biomolecules is a key point to this nondestructive immobilization method. This simple process is also versatile and could be used for covalently binding a wide range of molecules such as polyethylene glycol moieties, for example. To validate this approach for biochip or microarray fabrication, a surface plasmon resonance imaging (SPRi) platform for immobilization of various antibody families was created by grafting G-protein through this process. This SPRi antibodies platform was tested with several consecutive cycles of antigen injections/regeneration steps without loss of activity.

This paper describes recent developments in new solid-liquid extraction method, called SOLIEX, to remove cesium from alkaline solutions. SOLIEX relies on the use of a reversible complexing system comprising a carbon felt bearing molecular traps (calixarenes). This complexing system exhibits a high selectivity for Cs, and is thus expected to be helpful for the treatment of highly diluted cesium wastes even with a high concentration of competing alkali metal cations. As additional advantage, this complexing system can be adapted by molecular engineering to capture other radionuclides, such as Sr, Eu, Am. Finally, this complexing system can be easily and efficiently regenerated by using a cost effective stripping procedure, which limits further generation of waste to meet 'zero liquid' discharge requirements for nuclear facilities. (authors)

A tuning fork AFM (atomic force microscope) scanning probe has been used to study the chemical grafting between a functionalized tip and BSA (bovine serum albumin) protein. A non-conventional chemistry based on diazonium salts has been applied to control the hydrophobicity and hydrophilicity of the tip termination, and to graft proteins on surface. Unfolding signatures during the protein stretching have been observed, using amplitude modulation (AM-AFM) control of the probe. We propose a methodology to obtain quantitative information of the withdrawal forces from the amplitude and phase signals. Our results demonstrate the great potential of this new piezoelectric probe combined in term of sensitivity and versatility of the chemical functionalization of the tip to analyze biological materials.

Conducting probe atomic force microscopy (CP-AFM) has been used to perform mechanical and electrical experiments on graphene layers bonded to polyaminophenylene (PAP) films grafted on gold substrates. This technique is a new approach for the characterization of graphene sheets and represents a complementary tool to Raman spectroscopy. The combination of friction and electrical imaging reveals that different stacked graphene sheets have been successfully distinguished from each other and from the underlying PAP films. Lateral force microscopy has shown that the friction is greatly reduced on graphene sheets in comparison with the organic coating. The electrical resistance images show very different local conduction properties which can be linked to the number of underlying graphene sheets. The resistance decreases very slowly when the normal load increases. Current-voltage curves display characteristics of metal-molecule-metal junctions. (C) 2011 Elsevier B.V. All rights reserved.

Corrosion of gold coated electrical contacts remains a problem often avoided by keeping the final gold coating thicknesses over 1 mu m. Graphene has recently been shown to be an outstanding material: among its astonishing properties are the theoretical carrier mobility at room temperature (200 000 cm(2)/V(-1)s(-1)) and the Young modulus (1.5 TPa). Graphene is a one-atom thick two-dimensional carbon crystal and has been first produced by mechanical exfoliation to obtain high purity defect free sheets. Chemical vapour deposition (CVD) is another method producing larger areas of graphene. Much work has been dedicated to graphene oxide (GO) deposition and reduction processes for applications ranging from electronics to sensors. In this work we describe briefly how a method of liquid exfoliation and spray deposition can be used to produce nanometric films of graphene flakes which can be more or less uniform and continuous according to the tuning of the process. Films were sprayed in different conditions on various substrates: laboratory substrates such as evaporated gold on glass, Si wafers and metallic coupons. The coupons under study were cut from cuprous alloy strips with a 2 mu m Ni underlayer and a 0.8 mu m Au layer. The coupons were coated with graphene films; they were then submitted to a four gas corrosion environmental test of the GR-1217-CORE Nov. 1995 type. A significant protection effect was observed for the sprayed graphene films. The deposition method by means of a spraying device was difficult to characterise but Raman spectroscopy and SEM images of the sprayed films showed evidence of the film formation. Contact resistance measurements and friction tests in a ball plane configuration were performed; low values of resistance and very low friction coefficients were measured. These first results show the very strong potential of graphene films deposited by a spraying method for electrical contacts applications and particularly for corrosion protection.

Liquid wastes decontamination processes are mainly based on two techniques: Bulk processes and the so called Cartridges processes. The first technique has been developed for the French nuclear fuel reprocessing industry since the 60’s in Marcoule and La Hague. It is a proven and mature technology which has been successfully and quickly implemented by AREVA at Fukushima site for the processing of contaminated waters. The second technique, involving cartridges processes, offers new opportunities for the use of innovative adsorbents. The AREVA process developed for Fukushima and some results obtained on site will be presented as well as laboratory scale results obtained in CEA laboratories. Examples of new adsorbents development for liquid wastes decontamination are also

Atomic force microscopy (AFM) has been widely used in biotechnological research to visualize proteins or cell components with a sub-nanometric resolution. Most of the commercial AFM systems use the standard optical lever method of detection. However, the optical beam deflection technique integrated in AFM presents some disadvantages such as the thermal drift due to cantilever elongation and bending caused by the heat dissipation of the laser diode. Also, optical artifacts and interferences are usually observed in liquid environment with the optical detection, and the laser beam alignment procedure can be an elaborate process in liquid environment. Thus, it is extremely interesting to find an alternative approach to resolve such type of problems. Herein, we introduce a self-sensing piezoelectric tuning fork atomic force microscope (AFM) for molecular imaging on individual proteins. AFM measurements were performed on antibodies samples (IgG and IgM) to study the stability and applicability of this sensor for investigation of soft materials with high dynamical tendency. In this work, we could characterize the substructure of isolated IgG and IgM antibodies adsorbed onto mica surface in air with high resolution imaging. Moreover, we have identified clearly different conformations and substructure differences of individual antibodies with AFM operating in Amplitude Modulation (AM-AFM) and Phase Modulation (PM-AFM) imaging. The used methodology revealed to be very promising approach for high resolution imaging of isolated proteins with well-defined structures.

The "ligand induced electroless plating (LIEP) process" is a simple process to obtain localized metal plating onto flexible polymers such as poly(ethylene terephtalate) and polyvinylidene fluoride sheets. This generic and cost-effective process, efficient on any common polymer surface, is based on the covalent grafting by the GraftFast process of a thin chelating polymer film, such as poly(acrylic acid), which can complex copper ions. The entrapped copper ions are then chemically reduced in situ and the resulting Cu-0 species act as a seed layer for the electroless copper growth which, thus, starts inside the host polymer. The present work focuses on the application of the LIEP process to the patterning of localized metallic tracks via two simple lithographic methods. The first is based on a standard photolithography process using a positive photoresist masking to prevent the covalent grafting of PAA in designated areas of the polymer substrate. In the second, the patterning is performed by direct printing of the mask with a commercial laser printer. In both cases, the mask was lifted off before the copper electroless plating step, which provides ecological benefits, since only the amount of copper necessary for the metallic patterning is used.

Laboratoire de Génie Electrique de Paris, CNRS UMR8507; SUPELEC; UPMC Univ Paris 06; Univ Paris-Sud, 11 rue Joliot Curie, F-91192, Gif-sur-Yvette, France CEA, IRAMIS, SPCSI Chemistry of Surfaces and Interfaces Group, F-91191 Gif-sur-Yvette, France CEA, IRAMIS, LLB, Laboratory for Molecular Electronics, F-91191 Gif-sur-Yvette, France Univ. Paris-Sud, ICMMO, UMR CNRS 8182, 15 rue Georges Clemenceau, F-91440 Orsay, France ∗Corresponding author: laurent.baraton@lgep.supelec.fr