CNRS Laboratory of Future

Bordeaux, France

CNRS Laboratory of Future

Bordeaux, France
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Grant
Agency: European Commission | Branch: H2020 | Program: MSCA-ITN-ETN | Phase: MSCA-ITN-2014-ETN | Award Amount: 3.90M | Year: 2015

The etymology of the word colloid stems from the Greek word for glue. The systematic study of colloids (as we perceive them nowadays) is considered to have begun in the middle of the 19th century. However, the word colloid itself had been mentioned before in very different senses. The development of the physics and chemistry of colloids really took off in the 20th century. Colloids found different applications in almost every part of our lives, and it might even seem that these systems are fully understood and tamed. In reality, this is far from the case! Both fundamental understanding and a clear application strategy are required. This is most evident when it comes to the relationship between the nature and arrangement of the colloidal particles and their macroscopic response to an external field (be that shear, electric, magnetic or gravitational fields). To elucidate this relationship we unite 7 academic and 2 industrial partners and 5 associate partners to train 15 ESRs. We aim to develop the concept of COLLoids with DEsigned respoNSE, leading to our acronym: COLLDENSE. Scientific projects are divided into three main workpackeges according to the complexity of the building blocks: deformable colloids, hybrid colloids and colloidal mixtures. The subjects vary from soft repulsive colloids, magnetic colloids, soft microgel particles, telechelic star polymers to droplets with interfaces stabilised by solid particles and DNA nano-constructs. The detailed analysis of mixtures of these components, as well as of their equilibrium and nonequilibrium thermodynamics and rheology, is the other important facet of the project. In order to obtain a complete understanding of the colloidal behaviour under an external drive we employ the three main tools of the modern natural science: experiment, computer simulations and analytical theory. This complete approach will also yield a broad training experience for the young members of the network.


Grant
Agency: European Commission | Branch: FP7 | Program: MC-ITN | Phase: FP7-PEOPLE-ITN-2008 | Award Amount: 4.71M | Year: 2009

With progress in nanotechnology, biophysics, and polymer synthesis, colloidal science has reached a new level of importance. A large variety of complex colloids of different shapes, with binding specificity, and variable softness has been synthesized, opening quite exciting ways for engineering materials at the nanoscale. The purpose of COMPLOIDS is to obtain a fundamental understanding of the Physics governing the self-organization and the dynamical behavior of complex colloidal particles in the bulk, under confinement and out of equilibrium. For this purpose, the partners will consider a variety of novel, experimentally accessible colloidal systems that share the common properties of anisotropy, associativity and softness of their constituent particles. A well-coordinated combination of experiment, theory and simulation will explore the fundamental Physics, define similarities and differences between the systems considered and search for common underlying mechanisms of self-organization that are distinct to these complex and highly versatile colloidal systems. The technical objective of COMPLOIDS is to apply the gained knowledge with the goal of engineering novel materials in close collaboration with participating high-technology EU-companies. Young researchers will also profit from COMPLOIDS in a variety of ways. They will be exposed in high-level research working, within a highly connected and interdisciplinary team of researchers and developing state-of-the art tools in the Statistical Physics of Soft Matter. Further, they will attend world-rate graduate programs and courses in the participating academic partners and they will obtain hands-on experience of the industry sector through the participation of industrial partners.


Selva B.,CNRS Laboratory of Future | Daubersies L.,CNRS Laboratory of Future | Salmon J.-B.,CNRS Laboratory of Future
Physical Review Letters | Year: 2012

We evidence experimentally and theoretically that natural convection driven by solutal density differences in a molecular binary mixture can boost the transport of colloids. We demonstrate that such buoyancy-driven flows have a negligible influence on the gradients that generate them, for moderate Rayleigh numbers in a confined geometry. These flows therefore do not homogenize the binary mixture but can disperse very efficiently large solutes. We illustrate the relevance of such effects thanks to several original experiments: drying of confined droplets, microfluidic evaporation, and interdiffusion in microfluidic flows. © 2012 American Physical Society.


Mansard V.,CNRS Laboratory of Future | Colin A.,CNRS Laboratory of Future
Soft Matter | Year: 2012

In this article, we provide an up-to-date review dealing with the flow of soft glassy materials, that is, concentrated hard and soft particle assemblies. Because of the existence of short range forces, steric forces, and polydispersity, the structure of soft glassy materials remains frustrated and disordered. Their structure explores the energy landscape by thermally overcoming barriers to lower the total energy of the system. As the system ages, the barriers it must overcome become higher. Eventually, the system falls into a steep valley, from which it can no longer escape during the observation time; thus, it becomes non-ergodic. These disordered structures and rearrangements provide the origin of the rheological behavior of soft glassy materials, which give rise to solid behavior at low applied stresses. Rearrangement is a critical process that must be considered in the modeling of the rheological response of soft glassy materials. In this review article, we describe generic laws that relate stress to deformation, a relationship that we call local rheology. We also present the failures of this law that arise from hysteresis, particle migration, finite-size and non-local effects. We show that a generic framework corresponds to all the systems. © 2012 The Royal Society of Chemistry.


Cuenca A.,CNRS Laboratory of Future | Bodiguel H.,CNRS Laboratory of Future
Physical Review Letters | Year: 2013

Pressure-driven flows of high molecular weight polyacrylamide solutions are examined in nanoslits using fluorescence photobleaching. The effective viscosity of polymer solutions decreases when the channel height decreases below the micron scale. In addition, the apparent slippage of the solutions is characterized macroscopically on similar surfaces. Though slippage can explain qualitatively the effective viscosity reduction, a quantitative comparison shows that the slip length is greatly reduced below the micron scale. This result indicates that chain migration is suppressed in confined geometries. © 2013 American Physical Society.


Cuenca A.,CNRS Laboratory of Future | Bodiguel H.,CNRS Laboratory of Future
Lab on a Chip - Miniaturisation for Chemistry and Biology | Year: 2012

Velocity measurement is a key issue when studying flows below the micron scale, due to the lack of sensitivity of conventional detection techniques. We present an approach based on fluorescence photobleaching to evaluate flow velocity at the nanoscale by direct visualization. Solutions containing a fluorescent dye are injected into nanoslits. A photobleached line, created through laser beam illumination, moves through the channel due to the fluid flow. The velocity and effective diffusion coefficient are calculated from the temporal data of the line position and width respectively. The measurable velocity range is only limited by the diffusion rate of the fluorescent dye for low velocities and by the apparition of Taylor dispersion for high velocities. By controlling the pressure drop and measuring the velocity, we determine the fluid viscosity. The photobleached line spreads in time due to molecular diffusion and Taylor hydrodynamic dispersion. By taking into account the finite spatial and temporal extensions of the bleaching under flow, we determine the effective diffusion coefficient, which we find to be in good agreement with the expression of the two dimensional Taylor-Aris dispersion coefficient. Finally we analyze and discuss the role of the finite width of the rectangular slit on hydrodynamic dispersion. © 2012 The Royal Society of Chemistry.


Daubersies L.,CNRS Laboratory of Future | Salmon J.-B.,CNRS Laboratory of Future
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2011

We present a model that describes the drying of solutions and colloidal dispersions from droplets confined between two circular plates. This confined geometry, proposed by Clément and Leng, casts a perfect control of the evaporation conditions, and thus also of the concentration kinetics of the solutes in the droplet. Our model, based on simple transport equations for binary mixtures, describes the concentration process of the solute inside the droplet. Using dimensionless units, we identify the different numbers that govern the concentration field of the solute, and we detail how to extract kinetic and thermodynamic information on the binary mixture from such drying experiments. We finally discuss, using numerical resolution of the model and analytical arguments, several specific cases: dilute solutions, a colloidal hard sphere dispersion, and a binary molecular mixture. © 2011 American Physical Society.


Grant
Agency: European Commission | Branch: FP7 | Program: MC-ITN | Phase: FP7-PEOPLE-2012-ITN | Award Amount: 4.13M | Year: 2012

SMARTNET (Soft materials advanced training network) is an ITN at the interface of chemistry, physics, and biology, and deals with the science and technology of molecular soft materials. Soft matter (e.g. gels, emulsions, membranes) is of great societal and economic impact in fields such as food industry, cosmetics, oil extraction and increasingly in high value areas such as biomedicine and nanotechnology. Soft matter is formed when fluids are mixed with molecular additives, giving rise to molecular level structuring. Polymers and inorganic materials have been widely used in this context, but are unlikely to meet future performance requirements for high-tech applications. SMARTNET is focused on conceptually novel approaches towards the next generation of soft matter, based on self-assembling small molecules as promising alternatives to existing systems. The design of molecular components and control of self-assembly processes allows for organization across length scales leading to emergent properties and functions, and will impact on 21st century health care, biomedicine and energy-related technologies. SMARTNET provides a unique multidisciplinary training opportunity and a step change in understanding and exploitation of these systems. A competitive advantage will be achieved by close integration of world-class expertise in molecular design, self-assembly and nanofabrication, photo-chemistry and -physics, multiscale modeling, state-of-the-art scattering and spectroscopy, with application areas such as biomedical, opto-electronic and catalytic materials. SMARTNET consolidates, through international and cross-disciplinary coordination and integration of 9 teams, leading EU research efforts in the area of supramolecular soft matter and offers unique opportunities to the highest level of training-through-research projects.


Grant
Agency: European Commission | Branch: FP7 | Program: CP | Phase: ICT-2011.3.6 | Award Amount: 11.87M | Year: 2011

X10D aims to enable organic photovoltaics (OPV) to enter the competitive thin-film PV market. It will achieve this by pooling the knowledge and expertise of the leading research institutes and start-up companies in Europe, and is the first project of its kind to leverage this knowledge irrespective of the processing technology. It will use the strengths available in device efficiency and architectures in both solution processed as well as small molecule based OPV.The objective for X10D is to develop efficient, low-cost, stable tandem organic solar cells by applying new designs, materials and manufacturing technologies to create market-competitive OPV modules. Therefore, X10D proposes to bring together partners that compose a complete and unique OPV research and development consortium, from academic partners, research centers, SMEs, and large companies. Together, the X10D partners cover each segment of the complete value chain: materials development and up scaling, device development and up scaling, large area deposition equipment and processes, novel transparent conductors, laser scribing equipment and processes, encapsulation technologies, energy, life-cycle, and cost analysis and finally end-users.The main objectives for X10D can be quantified more explicitly as:- To increase the power conversion efficiency to achieve at least a 12% on cell level (1cm), and 9% on module level (100 cm)- To guarantee a minimum of 20 years life for OPV modules on glass, and 10 years on foil- To decrease the cost under 0.70 /Watt-peak


Grant
Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: NMP-2008-2.2-2 | Award Amount: 5.44M | Year: 2009

The objective of the METACHEM collaborative project is to use the extreme versatility of nano-chemistry to design and manufacture bulk meta-materials exhibiting non-conventional electromagnetic properties in the range of visible light. This spectral domain requires nano-scale patterns, typically around 50 nm in size or less. Our strategy consists in designing and synthesizing ad-hoc nano particles as optical plasmonic nano-resonators and organising them through self-assembly methods in 2 or 3 dimensional networks in order to produce dense highly ordered structures at a nano-scale level. Several subprojects corresponding to different routes are proposed, all of them based on existing state-of-the-art chemical and self assembly methods. In addition, the important issue of losses inherent to the plasmonic response of the nano-objects is addressed in an original way by the adjunction of loss-compensating active gain media. A special effort is made on the difficult measurement of the non conventional meta-properties as they constitute the first demonstration of the validity of the concept. A technological and an industrial point are added towards the search of efficient, cost-effective and industrially feasible metamaterials. The key point of the METACHEM project joining 9 partners from 7 European states is that it brings together for the first time European experts of three complementary fields namely nanochemistry, self-assembly methods and metamaterials science. The majority of the partners are members of FP7 virtual institutes related to these fields i.e. respectively EMMI, SOFTCOMP and METAMORPHOSE II. Main goals: Design and synthesize optically isotropic meta-materials with exotic and extreme properties realized by simple and cheap chemical methods. Target properties: artificial optical magnetic and dielectric properties, optical left-handed materials, near-zero permittivity/permeability; negative index materials, low-loss plasmonic structures.

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