Philippe Poulin

• PhD
• Research Director at French National Centre for Scientific Research

Enzymatic modification of Kraft lignin under alkaline conditions was investigated using bilirubin oxidase (BOD) in borate buffer (pH 10). Control solubilization without enzyme addition revealed a notable increase in molar mass (up to 1.7-fold) and potential borate complexation with lignin hydroxyl groups, as evidenced by thermogravimetric and ¹¹B N...

The increasing prevalence of electromagnetic wave exposure in our daily life, particularly within the 100 MHz–300 GHz range, necessitates advancements in microwave absorption materials. This study explores the utilization of 3D printing and VAT photopolymerization to optimize material properties for efficient microwave absorption. While electricall...

Flowable electrodes, a versatile alternative to traditional solid electrodes for electrochemical applications, exhibit challenges of high viscosity and carbon content, limiting flow and device performances. This study introduces colloidal suspensions of thin multiwall carbon nanotubes (MWCNTs) with diameters of 10–15 nm as electrode materials. Thes...

The implementation of renewable energy sources to electrify ammonia (NH3) production is identified as a critical approach for achieving successful decarburization in the pursuit of a more sustainable future. A liquid metal‐based method is presented for synthesizing bismuth (Bi) nano‐electrocatalysts, enabling efficient and sustainable ammonia produ...

Due to the low energy density of commercial printable dielectrics, printed capacitors occupy a significant printing area and weight in printed electronics. It has long remained challenging to develop novel dielectric materials with printability and high energy-storage density. Here, we present a novel strategy for inkjet printing of all aqueous col...

To meet the demands of miniaturization and integration of next‐generation power systems, a major challenge is to improve the energy density of used dielectric capacitors. Polymer nanocomposites are of great potential for high‐energy‐density capacitors. However, most of them are prepared via melt blending at high temperatures or solution processing...

Digital Light Processing (DLP) allows the fast realization of 3D objects with high spatial resolution. However, DLP is limited to transparent resins, and therefore not well suited for printing electrically conductive materials. Manufacturing conductive materials will significantly broaden the spectrum of applications of the DLP technology. But cond...

Digital Light Processing (DLP) allows the fast realization of 3D objects with high spatial resolution. However, DLP is limited to highly transparent resins, and therefore not well suited for printing electrically conductive materials. Manufacturing conductive materials would significantly broaden the spectrum of applications of the DLP technology....

Due to the low energy density of commercial printable dielectrics, printed capacitors occupy a significant printing area and weight in fully printed electronics. It has long remained challenging to develop novel dielectric materials with printability and high energy-storage density. Here, we present the inkjet printing of all aqueous colloidal inks...

Colloids are attractive building blocks for the assembly of organized functional materials. However, their stabilizing surface charges limit the high voltage tolerance and the capacitive energy storage of resultant solid films, which has long remained challenging for dielectric applications of colloids. Here, we propose a strategy of electrostatica...

Artificial muscles are indispensable components for next-generation robotics capable of mimicking sophisticated movements of living systems. However, an optimal combination of actuation parameters, including strain, stress, energy density and high mechanical strength, is required for their practical applications. Here we report mammalian-skeletal-m...

Here, we develop a framework for assembly, understanding, and application of functional emulsions stabilized by few-layer pristine two-dimensional (2D) nanosheets. Liquid-exfoliated graphene and MoS2 are demonstrated to stabilize emulsions at ultralow nanosheet volume fractions, approaching the minimum loading achievable with 2D materials. These na...

We propose a universal strategy to 3D printing the graphene oxide (GO) complex structure with GO highly aligned and densely compacted, by the combination of direct ink writing and constrained drying. The constraints not only allow the generation of a huge capillary force accompanied by water evaporation at nanoscale, which induces the high compacti...

Carbon-based nanomaterials (CBNs), such as graphene and carbon nanotubes, display advanced physical and chemical properties, which has led to their widespread applications. One of these applications includes the incorporation of CBNs into cementitious materials in the form of aqueous dispersions. The main issue that arises in this context is that c...

Carbon suspension electrodes are promising for flow-assisted electrochemical energy storage systems. They serve as flowable electrodes in electrolyte solutions of flow batteries, or flow capacitors. They can also be used for other applications such as capacitive deionization of water. However, developments of such suspensions remain challenging. Th...

Carbon suspension electrodes are promising for flow-assisted electrochemical energy storage systems. They serve as flowable electrodes in electrolyte solutions of flow batteries, or flow capacitors. They can also be used for other applications such as capacitive deionization of water. However, developments of such suspensions remain challenging. Th...

Flexible dielectrics that harvest mechanical energy via electrostatic effects are excellent candidates as power sources for wearable electronics or autonomous sensors. The integration of a soft dielectric composite (polydimethylsiloxane PDMS-carbon black CB) into two mechanical energy harvesters is here presented. Both are based on a similar cantil...

Polymers have been considered as promising materials for dielectric energy storage because of their high breakdown strength, favorable flexibility and processability. The achievable energy density of polymers is however limited by their intrinsic low dielectric constant. Until today, most of them are either melt-extruded at high temperatures or sol...

Graphitic structures, unlike polymers and metals, cannot be directly printed in 3D. We demonstrate here that graphitic structures can be shaped in 3D by using direct-ink writing (DIW) of lignin-graphene oxide solutions that are then dried and carbonized. Lignin is a promising precursor for the elaboration of bio-based carbon materials because of it...

A framework is developed to allow emulsification to be used to fabricate functional structures from, and study the properties of, pristine layered nanosheets. Liquid-exfoliated few-layer graphene and MoS2 are demonstrated to stablize emulsions which exhibit system-scale electrical conductivity at ultra-low nanosheet volume fractions. When deposited...

The heavy metal lead has been a pollutant in our environment for many centuries and at low concentrations, lead can damage the human central nervous system, liver, kidney, and cardiovascular system and cause physiological and neurological problems in developing children who are most susceptible to lead poisoning. Lead in drinking water is currently...

We present fiber electrodes which are made of assembled carbon nanotubes (CNTs). The present fibers are highly porous and of a few tens of microns in diameter. They exhibit promising performances as microelectrodes for enzymatic bio-fuel cells (BFCs), or electromechanical actuators. The electrodes are manufactured by a fiber wet spinning process in...

Electroanalytical methods can be used for the reliable detection of the toxic heavy metal lead in drinking water samples. Inkjet printed electrodes have potential for the rapid and affordable assessment of drinking water. Researchers have shown the electrochemical sensing applicability of inkjet printed electrodes. In this work, Pb 2+ was detected...

Lignin is considered as a promising bio-sourced precursor for more sustainable and low-cost carbon fibers (CFs). However, lignin-based CFs generally have a poor graphitic structure, compared to polyacrylonitrile CFs. In this paper, we present an original approach that uses graphene oxide liquid crystal (GOLC) as a templating agent to promote the fo...

High sensitivity is a critical feature for flexible pressure sensors and a novel and low-cost emulsion method has been invented to make capacitive sensors with higher sensitivity. A team of CNRS scientists from France led by Prof Annie Colin develops an unconventional approach for flexible and highly sensitive low-pressure capacitive sensors based...

Lignin is a promising bio‐based precursor for sustainable carbon fibers. Limiting factors for their development include the brittleness of lignin and the lack of large‐scale production routes. Here, a simple and economic wet‐spinning method, suitable for the fabrication of fibers based on softwood Kraft lignin (KL) and polyvinyl alcohol (PVA), is p...

Graphene oxide (GO) is considered as a promising component for electronics because of its unique anisotropy, easy processing and sometimes claimed giant permittivity. The latter would arise from an enhanced electronic polarizability due to the presence of functional groups at the surface and edge of GO flakes. As a matter of fact, a number of publi...

Getting the most out of muscles Materials that convert electrical, chemical, or thermal energy into a shape change can be used to form artificial muscles. Such materials include bimetallic strips or host-guest materials or coiled fibers or yarns (see the Perspective by Tawfick and Tang). Kanik et al. developed a polymer bimorph structure from an el...

Microenergy storage devices are appealing and highly demanded for diverse miniaturized electronic devices, ranging from microelectromechanical system, robotics, to sensing microsystems and wearable electronics. However, making high‐energy microcapacitors with currently available printing technologies remains challenging. Herein, the possibility to...

Lignin nanofibers (NFs) have been fabricated by electrospinning of a new formulation system: lignin, polyvinyl alcohol (PVA), dimethyl sulfoxide (DMSO) mixture. The ternary phase diagram of this system has been realized in order to define bead free nanofibers electrospinnability domains. Resulting NFs mat were carbonized in a temperature range 550–...

This paper presents the approach of combining lignin with graphene oxide (GO) flakes in order to introduce a higher structuration inside amorphous carbon materials. Both the phase behavior of lignin-GO solutions and the properties of lignin-GO films are investigated in a first approach. A clear orientation within lignin-based solutions is obtained...

In view of the extensive increase of flexible devices and wearable electronics, the development of polymer microelectro- mechanical systems (MEMS) is becoming more and more important since their potential to meet the multiple needs for sensing applications in flexible electronics is now clearly established. Nevertheless, polymer micromachining for...

We present electrostrictive materials with excellent properties for vibrational energy harvesting applications. The developed materials consist of a porous carbon black composite, which is processed using water-in-oil emulsions. In combination with an insulating layer, the investigated structures exhibit a high effective relative dielectric permitt...

The chemical/thermal in situ reduction of graphene oxide (GO) in GO-polymer composite is consistently challenged by the presence of undesirable chemical residues/temperature degradation restriction of the polymer. In order to tackle this problem, an effective in situ supercritical fluid reduction strategy comprising of supercritical CO2 and ethanol...

In the present work, PVA-CNT fibers, pre-stretched at different ratios, were embedded into glass fiber reinforced polymer (GFRP) specimens to in-situ measure their electrical resistance change during quasi-static incremental tensile and cyclic mechanical tests. Glass-fiber reinforced polymer composite specimens with dimensions of length x width = 2...

Coupling between organic and inorganic components results in a biaxial liquid crystal

Polymer Micro ElectroMechanical Systems (MEMS) have the potential to constitute a powerful alternative to silicon-based MEMS devices for sensing applications. Although the use of commercial photoresists as structural material in polymer MEMS has been widely reported, the integration of functional polymer materials as electromechanical transducers h...

Drying graphene oxide (GO) films are subject to extensive wrinkling which largely affects their final properties. Wrinkles were shown to be suitable in biotechnological applications, however, they negatively affect the electronic properties of the films. Here, we report on wrinkle tuning and patterning of GO films under stress-controlled conditions...

High electromechanical coupling is critical to perform effective conversion between mechanical and electrical energy for various applications of electrostrictive polymers. Herein, a giant electrostriction effect is reported in liquid crystalline graphene doped dielectric elastomers. The materials are formulated by a phase transfer method which allo...

Some bacteria can act as catalysts to oxidize (or reduce) organic or inorganic matter with the potential generation of electrical current. Despite their high value for sustainable energy, organic compound production and bioremediation, a tool to probe the natural biodiversity and to select most efficient microbes is still lacking. Compartmentalized...

Recent advances in the field of microelectromechanical systems (MEMS) have generated great interest in the substitution of inorganic microcantilevers by organic ones, due to their low cost, high flexibility and a simplified fabrication by means of printing methods. Here, we present the integration of electrostrictive nanocomposites into organic mic...

In this work, we present a comprehensive study dealing with the modeling of the conversion process occurring in a redox flow cell. Experiments are carried out on an original millifluidic flow battery with ferrocyanide and iodide as electrolytes. A simulation model supports the experimental data. In flow, intensity recovery is limited by the mass tr...

Tensile ductility and fracture toughness of nano-reinforced epoxy resin with different types and concentrations of graphene nanoplatelets (GnPs) are investigated. GnPs types with small (2 nm) and large (15 nm) lateral size were used and for various weight percentages in order to fabricate a series of epoxy/GnPs nanocomposites. Tensile mechanical pr...

Novel carbon nanotube based electrodes of microbial fuel cells (MFC) have been developed. MFC is a promising technology for the wastewater treatment and the production of electrical energy from redox reactions of natural substrates. Performances of such bio-electrochemical systems depend critically on the structure and properties of the electrodes....

Solution-spinning was the major method for the production of polyacrylonitrile (PAN)-based carbon fibers (CFs). It was also applied to the manufacture of lignin-based CFs. In contrast to the melt-spinning process, a polymer is dissolved or synthesized in the solvents and then extruded into the coagulation bath/hot chamber where solvent diffusion/ev...

Using an emulsion road and optimizing the dispersion process, we prepare polymer carbone nanotubes (CNT) and polymer reduced graphene oxyde (rGO) composites. The introduction of conductive nanoparticles into polymer matrices modifies the electronic properties of the material. We show that these materials exhibit giant electrostriction coefficient i...

This article investigates the possibility of exploiting innovative polyvinyl alcohol fibers reinforced with carbon nanotubes (PVA-CNT fiber) as a strain sensor in cement mortars used in the restoration of Cultural Heritage Monuments. Two types of PVA-CNT fibers were embedded in the matrix at a short distance from the bottom of the beam and their re...

Flow batteries and flow capacitors are promising technologies to store and generate electrical power. However, to increase their energy performances, low viscosity, electronic conductive suspensions loaded with active material are required. Comparing the behavior of three types of carbon black particles in water suspensions, we show that compressed...

Many promising graphene-based materials are kept away from mainstream applications due to problems of scalability and environmental concerns in their processing. Hydro-/solvothermal techniques overwhelmingly satisfy both the aforementioned criteria, and have matured as alternatives to wet-chemical methods with advances made over the past few decade...

This chapter describes the chemical composition, phase behavior and structure of recently investigated carbon nanotube (CNT) based liquid crystals. Because nanotubes are long and thin rigid cylinders, their phase behavior shares several similarities with many other systems such as rigid polymers and rod-like particle suspensions. CNT liquid crystal...

Electrostrictive materials are promising for mechanical energy harvesting applications because of their high power density, low cost and scalability. In this paper, strain sensitive nanocomposite materials based on reduced graphene (rGO) and PDMS are used for energy harvesting; they are characterized by a high electrostrictive coefficient (2.4x10⁻¹...

Microwave plasma splitting of biogas to solid carbon forms is a promising technique to produce large quantities of sustainable carbon based nano materials. Well defined graphitic nano carbons have been produced exhibiting graphene multilayers in turbostratic packing. After heat treatment, the purified material has been used to formulate stable, aqu...

We report the exfoliation of graphite and simultaneous N doping of graphene by two methods; by supercritical ammonia treatment and by liquid phase exfoliation with NH4OH. While the supercritical ammonia allowed N doping at a level of 6.4 at.% in 2 h, the liquid phase exfoliation with NH4OH allowed N doping at a level of 2.7at.% in 6 h. The N doped...

Significance Bending of a thin plate simultaneously involves contraction and stretching of matter relative to a neutral plane, and tensile rigidity dictates the ability of a thin platelet to be bent. If graphene or graphene oxide (GO) were actually behaving as thin platelets, they would display high bending rigidity. Bending measurements for atomic...

The continuous miniaturization and increased functionality of modern electronic devices highly demand the development of high-performance dielectric materials. High-k or low-k polymer nanocomposites are receiving a fast-growing interest due to their large tunability of dielectric constant and easy processing. The dielectric properties are usually t...

The fouling of neurotransmitter during electrochemical detection can dramatically jeopardize the viability of the sensor. Several recent developments in electrode fabrication and design have helped mitigating this issue. For instance, carbon nanotube fiber (CNTF) electrodes were found to be more resistant to fouling than the traditional carbon fibe...

Electrostriction is based on the variation of permittivity of a dielectric material when subjected to mechanical strain. Until now, the use of electrostrictive materials is limited to the actuation of Micro Electro Mechanical Systems (MEMS) operating mostly in static mode. Here, we present the use of electrostriction as integrated transduction sche...

Supercritical-fluids science and technology predate all the approaches that are currently established for graphene production by several decades in advanced materials design. However, it has only recently been proposed as a plausible approach for graphene processing. Since then, supercritical fluids have emerged into contention as an alternative to...

We report an easy method to prepare thin, flexible and transparent electrodes that show enhanced inertness toward oxidation using modified silver nanowires (Ag NWs). Stabilization is achieved through the adsorption of triphenylphosphine (PPh3) onto the Ag NW hybrid dispersions prior to their 2D organization as transparent electrodes on polyethylene...

We report an extensive study of the concentration process of aqueous polymer solutions confined within microfluidic channels, owing to the pervaporation of water through the matrix of the chip. Concentration of polymer continuously increases up to the formation of a dense material which eventually invades the channel. This technology can be used to...

Ultrashort single-walled carbon nanotubes, i.e. with length below ~30 nm, display length-dependent physical, chemical and biological properties that are attractive for the development of novel nanodevices and nanomaterials. Whether fundamental or applicative, such developments require that ultrashort nanotube lengths can be routinely and reliably c...

CNT-polymer composites are promising high permittivity materials. The main challenge in the field consists in finding compromises that allow high permittivity and low losses in frequency ranges of interest. Using an emulsion approach and optimizing the size of the droplets and the curing procedure, we obtain unprecedented performances and measure g...

Amphiphilic block copolymers composed of a poly(3-hexylthiophene) (P3HT) segment and a sulfonated polystyrene (PS-stat-PSS) sequence with well-defined and easily tunable structure were synthesized through Grignard metathesispolymerization (GRIM), RAFT polymerization and sulfonation of PS. Because of the hydrophilic nature and ionic conductivityof t...

The invention relates to a method for manufg. macroscopic fibers of titanium dioxide (TiO2) by continuous extrusion in a one-way flow, to the macroscopic fibers of TiO2 that can be obtained by such a method, to the use of said fibers in heterogeneous photocatalysis for decontamination of org. pollutants from gaseous environments, and to a method fo...

Graphene flakes with giant shape anisotropy are extensively used to establish connectedness electrical percolation in various heterogeneous systems. However, the percolation behaviour of graphene flakes has been recently predicted to be far more complicated than generally anticipated on the basis of excluded volume arguments. Here we confirm experi...

Smart energy storage materials, which not only store electrochemical energy but also exhibit sensitivity to environmental stimuli, can provide novel multi-functionalities. Here, we report a smart shape memory fiber supercapacitor constituted with a highly stretchable shape memory polymer nanocomposite fiber substrate, multi-walled carbon nanotubes...

The electrical connection of enzymes and microelectrodes is usually achieved via the direct deposition of biomolecules at the electrode surface. Optimization of this interface can be done either by using conductive nanomaterials such as carbon nanotubes, adding shuttles of electrons and/or by tuning the geometry of the electrode. However, immobiliz...

Carbon nanotube (CNT)-based transparent conducting films (TCFs) have been prepared by filtration of (i) surfactant-based aqueous dispersions and (ii) organic solutions obtained by reductive dissolution of an alkali metal salt of polyelectrolyte nanotubes. Starting from the same source of nanotubes, it is shown that films obtained by the reductive d...

Transparent conductive films are made from aqueous surfactant stabilized dispersions of carbon nanotubes using an up-scalable rod coating method. The processability of the films is governed by the amount of surfactant which is shown to alter strongly the wetting and viscosity of the ink. The increase of viscosity results from surfactant mediated at...

The local functionalities of biocompatible objects can be characterized under conditions similar to their operating ones by scanning electrochemical microscopy (SECM). In the case of alginate beads entrapping carbon nanotubes (CNTs), SECM allows evidencing the local conductivity, the organization, and the communication between CNTs. It shows that t...

We present the piezoresistive transduction of an all-organic microelectromechanical (MEMS) resonant sensor fabricated through a low-cost and highly versatile process. The MEMS resonator consists of a U-shaped cantilever beam resonator made of a thin layer of a piezoresistive nanocomposite (SU-8 epoxy resin filled with industrially produced carbon n...

We describe the generation and properties of TiO2-based macroscopic fibers designed for the photodecomposition of volatile organic compounds (VOC). We made use of a continuous industrially scalable extrusion process employing hybrid sols of amorphous titania nanoparticles, polyvinyl alcohol (PVA), and optionally latex nanoparticles. This process al...

In here we depict the morphogenesis and associated properties of TiO 2 -based macroscopic fibers designed for the photodecomposition of volatile organic compounds (VOC). We employed a continuous industrially scalable extrusion-based process making the use of hybrid sols of amorphous titania nanoparticles, polyvinyl alcohol (PVA) and occasionally la...

Recent developments in the field of carbon nanotube (CNT)-based wet-spun fibers are described in this chapter. Wet spinning essentially enables a wide variety of polymers to be spun into fibers. It has been used to produce composite fibers composed of polymers loaded with CNTs, and even fibers solely composed of CNTs. Fibers obtained by wet-spinnin...