0000000000005078
AUTHOR
Boris Lakard
showing 6 related works from this author
From the solution processing of hydrophilic molecules to polymer-phthalocyanine hybrid materials for ammonia sensing in high humidity atmospheres.
2014
We have prepared different hybrid polymer-phthalocyanine materials by solution processing, starting from two sulfonated phthalocyanines, s-CoPc and CuTsPc, and polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), poly(acrylic acid-co-acrylamide) (PAA-AM), poly(diallyldimethylammonium chloride) (PDDA) and polyaniline (PANI) as polymers. We also studied the response to ammonia (NH3) of resistors prepared from these sensing materials. The solvent casted films, prepared from s-CoPc and PVP, PEG and PAA-AM, were highly insulating and very sensitive to the relative humidity (RH) variation. The incorporation of s-CoPc in PDDA by means of layer-by-layer (LBL) technique allowed to stabilize the fi…
Evaluation of adhesion forces for the manipulation of micro-objects in submerged environment through deposition of pH responsive polyelectrolyte laye…
2016
Optimization of surface treatment for reversible adhesion of micro-objects in liquid environment for the need in microassembly processes is presented. A spherical borosilicate probe and planar oxidized silicon wafer substrates were modified by deposition of pH sensitive polyelectrolyte films through layer-by-layer technique. Branched polyethylenimine (b-PEI) and poly(sodium styrenesulfonate) (PSS) were deposited in alternating manner on surfaces, and the influence of polyelectrolyte concentration, pH of deposition, and number of layers on the adhesion were successively examined. The multilayer buildup was followed by optical reflectometry (OR) and dissipative quartz crystal microbalance (QC…
Synthesis of polymer materials for use as cell culture substrates
2007
International audience; Up to today, several techniques have been used to maintain cells in culture for studying many aspects of cell biology and physiology. More often, cell culture is dependent on proper anchorage of cells to the growth surface. Thus, poly-L-lysine, fibronectin or laminin are the most commonly used substrates. In this study, electrosynthesized biocompatible polymer films are proposed as an alternative to these standard substrates. The electrosynthesized polymers tested were polyethylenimine, polypropylenimme and polypyrrole. Then, the adhesion, proliferation and morphology of rat neuronal cell lines were investigated on these polymer substrates in an attempt to develop ne…
Elaboration of ammonia gas sensors based on electrodeposited polypyrrole - cobalt phthalocyanine hybrid films
2013
The electrochemical incorporation of a sulfonated cobalt phthalocyanine (sCoPc) in conducting polypyrrole (PPy) was done, in the presence or absence of LiClO4, in order to use the resulting hybrid material for the sensing of ammonia. After electrochemical deposition, the morphological features and structural properties of polypyrrole/phthalocyanine hybrid films were investigated and compared to those of polypyrrole films. A gas sensor consisting in platinum microelectrodes arrays was fabricated using silicon microtechnologies, and the polypyrrole and polypyrrole/phthalocyanine films were electrochemically deposited on the platinum microelectrodes arrays of this gas sensor. When exposed to a…
Preparation of polyelectrolyte-modified membranes for heavy metal ions removal
2017
ABSTRACTPolyethersulfone membranes were modified by polyelectrolyte (PE) multilayers, made of poly(allylamine hydrochloride) with poly(styrene sulfonate), to remove Cu2+, Zn2+ and Ni2+ heavy metal cations from aqueous solutions in a wide range of metal concentration (50–1200 ppm). After characterization of the modified membranes, the efficiency of the process was estimated for single heavy metal ions solution leading to high rejection rates (>90% for 50 ppm) and good adsorption capacities (7.0–8.5 mg cm−2) whatever the metal ion tested. The stability in time of the modified membranes was proved by repeating successive filtrations with the same membrane. The filtration process was also used …
Microstructured electrodeposited polypyrrole–phthalocyanine hybrid material, from morphology to ammonia sensing
2012
Hybrid materials combining polypyrrole with ionic macrocycles as counterions are electrosynthesized at the surface of platinum interdigitated electrodes. The chemical composition of the hybrid films is characterized by infrared reflexion absorption spectroscopy (IRRAS) and glow discharge optical emission spectroscopy (GDOES) and their morphology is studied by a range of techniques such as optical topomicroscopy, scanning electron microscopy (SEM) and atomic force microscopy (AFM). The obtained films reveal to be more homogeneous, with smaller crystallites, compared to polypyrrole synthesized with small counterions. Finally, the films exhibit a higher sensitivity to ammonia, with a very good…