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Paper, print media and biomaterials

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> Research > Doctorate, post-doctorate

LGP2 - Ph.D. thesis defended in 2010

Alireza SAIDI

December 14, 2010 - Fluid Mechanics, Energetics, Processes
Ph.D. title
Drop impact of yield stress fluids.
Supervision

Albert MAGNIN, Research Director, Laboratoire Rhéologie & Procédés (Grenoble) ♦♦ Céline MARTIN, Associate Professor, Grenoble INP-Pagora / LGP2
Abstract
The drop impact process occurs both in various industrial applications and our daily life. A drop of rain on a window, a drop of paint spray, ink droplet ejected from an inkjet printer... involve various surprising physical phenomena dependent on the impact velocity, the impacted media and the nature of the fluid. Control the final shape of the droplet then is of major importance. Upon impact, the drop may be broken thereby creating small droplets and splashes, it may also bounce on the support or, after spreading, retract... To minimize these instabilities, it is possible to act on intrinsic fluid properties including the introduction flow threshold.
In this study, millimeter drops were generated under their own weight through a capillary. Their dynamic behavior was visualized and caracterized from the formation to the balance after the impact and this, over a wide range of impact velocity. Just prior to impact, the drops lose their spherical shape when the yield point increases. They become more and more elongated. Thus, diets low in inertia, they collapse upon impact, under the effect of hydrostatic pressure. This subsidence phase is mainly governed by the interface properties of the substrate. In systems with high inertia, increasing of the yield point and of viscous properties of the fluid inhibits inertial spreading and withdrawal phases. Moreover, experimental data were correlated with theoretical data derived from models of drop impact of elastoplastic viscoplastic fluids, demonstrating the involvement of the two mechanisms both viscous and elastic in the impact process.
Other members of the jury
Didier CHAUSSY, Professor, Grenoble INP-Pagora / LGP2 ♦♦ Dominique DUPUIS, Professor, ENSISA-Laboratoire de Physique et Mécanique Textile (Mulhouse) ♦♦ Salaheddin SKALI-LAMI, Associate Professor, Université de Nancy ♦♦ Lazhar BENYAHIA, Professor, Université du Maine, Le Mans ♦♦ Brice LOPEZ, CEO, Siliflow (Valence)

Claudia SASSO

December 9, 2010 - Materials, Mechanical, Civil Engineering, Electrochemistry
Ph.D. title
Polymerization of pyrrole with wood composites and development of conductive films from lignocellulosic materials.
Supervision
Naceur BELGACEM, Professor, Grenoble INP-Pagora / LGP2 ♦♦ Didier CHAUSSY, Professor, Grenoble INP-Pagora / LGP2 ♦♦ Davide BENEVENTI, Researcher CNRS, LGP2
Abstract
This thesis deals with the development of compounds of polypyrrole (PPy) and derivatives of wood for applications in the field of organic electronics. Ligno-cellulose derivatives have been used as additives in a system where there was the polymerization of pyrrole (Py). These agents have been added due to their film-forming properties for the production of self-supporting films. Thus, the effect of the addition of carboxymethylcellulose (CMC), xylans, cellulose fibrils nano (NFC) and lignosulphonates on morphological and electrical properties of PPy was evaluated. The concentration of additives, the temperature and the polymerization time are the main parameters considered. It was shown that the xylan is more efficient to increase the conductivity of the PPy. These PPy particles were mixed in aqueous medium at different film formers (CMC and NFC) to produce self-supporting conductive films. The contribution of these binders in the electrical, mechanical and morphological properties of the films prepared was also studied.
Other members of the jury
Roberta BONGIOVANNI, Associate Professor, Politecnico di Torino (Italy) ♦♦ Alessandro GANDINI, Professor, Universidade de Aveiro (Portugal) ♦♦ Lionel HIRSCH, Professor, Université de Bordeaux 1 ♦♦ Elisa ZENO, Research Engineer, Centre Technique du Papier ♦♦ Jérôme FAURE-VINCENT, Commissariat à l'Énergie Atomique et aux Énergies Alternatives

Jacq-André NGUEGAN BOTOO

December 2, 2010 - Fluid Mechanics, Energetics, Processes
Ph.D. title
Study of the introduction of hydrogen peroxide in the process of water treatment by activated sludge: quality and quantity of sludge produced.
Supervision
Marc AUROUSSEAU, Professor, Grenoble INP-Pagora / LGP2 ♦♦ Agnès GUILLET, Associate Professor, Grenoble INP-Pagora / LGP2
Abstract
Management of sewage sludge is global, one of the major concerns of operators of wastewater treatment plants (WWTP) a qualitative and quantitative point of view. Increasing volumes of sludge from WWTP and significant treatment costs lead to seek new strategies to reduce sludge production.
Therefore, in this context, this thesis focuses on the potential of H2O2 used without catalyst or activator, the quantity and quality of sludge from an activated sludge process treating municipal or stationers wastewater effluents. Different cropping patterns (discontinuous, SBR, continuous) and scale (2L, 5L and 70L) with H2O2 doses between 0.08 and 2 g / g DCOentrante have been studied and do not demonstrate a significant reduction in the sludge production. However, if no significant change in the reduction of carbon compounds are observed, a process/speed change of nitrogen transformation cycle is highlighted.
Moreover, various analytical techniques, including spectroscopy X and environmental scanning electron microscopy, show that the action of the H2O2 is located on the surface of the flocs and leads to a change in the nature and amount of present functional groups. This results in improving the settleability and filterability of the sludge treated with H2O2. Finally, a disintegration of flocs partly attributed to the solubilization of exopolysaccharides was highlighted and helped explain the measured improvement in the ability to sludge dewatering.
Other members of the jury
Etienne PAUL, Professor, INSA Toulouse ♦♦ Evelyne GONZE, Professor, Université de Savoie ♦♦ Bruno BARILLON, Project Engineer, Suez Environnement ♦♦ Eric FOUREST, Project Manager, Centre Technique du Papier

Aurore DENNEULIN

October 26, 2010 - Materials, Mechanical, Civil Engineering, Electrochemistry
Ph.D. title
Inkjet printing of conductive inks for RFID technology : Influence of substrate, ink and process.
Supervision
Anne BLAYO, Lecturer-Researcher, Grenoble INP-Pagora / LGP2 ♦♦ Julien BRAS, Associate Professor, Grenoble INP-Pagora / LGP2
Abstract
This work investigates the inkjet printing process to print conductive patterns for producing low cost electronic components. Three fields were explored: (i) substrates, (ii) conductive inks, and (iii) process. Substrate surface properties su ch as roughness or surface energy have a significant impact on conductivity of printed tracks. An innovative solution to make any paper suitable for printed electronics has then been proposed. Infrared and electrical treatments were tested as potential sintering alternatives of nanometallic inks, and new conductive inks based on carbon nanotubes (CNT) and conductive polymers were formulated. This new CNT-based ink has been studied more in details by analyzing influence of inkjet printing parameters and their impact on the CNT network organization and on the conductivity. This study represents an important step in the field of printing electronics, and also opens windows to new low cost applications such as smart packaging or flexible electronics.
Other members of the jury
Arthur SOUCEMARIANADIN, Professor, Université Joseph Fourier (Grenoble) ♦♦ Philippe COLLOT, Professor, École Nationale Supérieure des Mines de Saint-Étienne ♦♦ Tim CLAYPOLE, Professor, Swansea University (UK) ♦♦ Stéphane CROS, Research Engineer, CEA-INES, Chambéry ♦♦ Charles NEUMAN, CEO, Polypore

Jérémie VIGUIE

May 10, 2010 - Fluid Mechanics, Energetics, Processes
Ph.D. title
Mechanical and hygroexpansif behavior of lignocellulosic materials for rigid packaging.
Supervision
Evelyne MAURET, Professor, Grenoble INP-Pagora / LGP2 ♦♦ Isabelle DESLOGES, Lecturer Researcher, Grenoble INP-Pagora / LGP2 ♦♦ Pierre DUMONT, Associate Professor, Grenoble INP-Pagora / LGP2
Abstract
This thesis is a particularly important topic in the field of manufacturing and processing of paper and cardboard. Indeed, the behavior of cartons conventional conditions is not always well known and understood, which greatly limits the possibilities of optimization of these structures.
In this context, the study focused specifically on the hygroexpansif behavior of boxboard and mechanical behavior of corrugated packaging structures. The hygroexpansifs wide fiber network mechanisms of such laminates have been studied from a 2D correlation method of images from X-ray microtomography. This method revealed, for example, the relationship between density of layers boxboard and their hygroexpansion in thickness. The compression behavior of simple geometries packaging corrugated boxes G flute profile has been studied from a broad base of experimental data. A method stereocorrelation images allowed us to describe the kinematic fields associated buckling panels of these boxes. These data can be used to improve behavior patterns in order to optimize the packaging structures.
Other members of the jury
Christine DELISEE, Associate Professor, Université de Bordeaux 1 ♦♦ Alain VAUTRIN, Professor, École des Mines de Saint-Étienne ♦♦ Frédéric JACQUEMIN, Professor, Université de Nantes ♦♦ Per ISAKSSON, Professor, Mid Sweden University (Sweden) ♦♦ Pierre VACHER, Professor, Université de Savoie

Franck MEDLEGE

April 13, 2010 - Fluid Mechanics, Energetics, Processes
Ph.D. title
Manufacture of electrodes for lithium-ion flexographic.
Supervision
Grenoble INP-Pagora / LGP2 ♦♦ Commissariat à l'Énergie Atomique et aux Énergies Alternatives
Abstract
Demand of special rechargeable batteries in various fields require electrodes shapes. The best way to produce them is to use a printing process such as flexography. The difference between an electrode coating paste and a printing ink is the low surface tension of fluorinated binder used, PVDF, which limits the transfer of ink. The PVDF was mixed with a second polymer to increase the polar contribution of the surface energy of the binder. The behavior of polymer blends was studied using the Flory-Huggins theory and a permanent binder, based on a PVDF / PVA (polyvinyl alcohol) mixture, allowed to give the ink a good transfer on a flexographic printing unit, with dry ink thicknesses around 80 microns on four passages. Functional prototypes of batteries with printed electrodes were performed. Furthermore, high-performance electrodes fabricated by coating were carried out with the new binder, which is the subject of a patent.
Other members of the jury
Hervé CHERADAME, Professor, Université d'Evry-Val-d'Essonne ♦♦ Antonio L. TORRES, Professor, Universitat Politècnica de Catalunya (Spain) ♦♦ Renaud BOUCHET, Associate Professor, Université de Provence ♦♦ Jacques FOULETIER, Professor, Grenoble INP-LEPMI ♦♦ Hélène ROUAULT, Researcher, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Grenoble ♦♦ Naceur BELGACEM, Professor, Grenoble INP-Pagora / LGP2

Gilberto DE FREITAS SIQUEIRA

March 3, 2010 - Materials, Mechanical, Civil Engineering, Electrochemistry
Ph.D. title
Processing and thermo-mechanical characterization of polymer bionanocomposites reinforced with microfibrillated cellulose and cellulose whiskers .
Supervision
Alain DUFRESNE, Professor, Grenoble INP-Pagora / LGP2 ♦♦ Julien BRAS, Associate Professor, Grenoble INP-Pagora / LGP2
Abstract
This work describes the use of some Brazilian natural fibers (Sisal, Luffa Cylindrica and Capim Dourado) as sources of cellulose nanowhiskers and microfibrillated cellulose (MFC) for the preparation of polymeric nanocomposites. It proposes a new way of obtaining cellulose nanoparticles and exploits their intrinsic properties. For this purpose two main routes were investigated, namely (i) use of chemically grafted cellulosic nanoparticles reacted with isocyanates and incorporated in a []-polycaprolactone (PCL) matrix, and (ii) direct use of cellulose nanoparticles as reinforcement in a natural rubber (NR) matrix. The thermo-mechanical properties were investigated by DSC and DMA. In both cases it was demonstrated that low amounts of fillers provides high mechanical properties when compared to the neat matrix, PCL or NR. The study of crystallization kinetics of PCL and PCL-nanocomposites provided additional information for cellulosic nanofillers acting as nucleating agents accelerating the crystallization process of nanocomposites. Enzymes were also used to prepare such nanoparticles thus yielding nanofillers with different morphologies. As a result, the final NR-nanocomposites showed different mechanical performances and gain in both Young's and storage modulus with respect to the neat polymeric matrix.
Other members of the jury
Redouane BORSALI, Research Director, CERMAV ♦♦ Tanja ZIMMERMANN, Senior Scientist, Group Leader Cellulose Nanocomposites, EMPA (Suisse) ♦♦ Jannick DUCHET-RUMEAU, Associate Professor, INSA (Lyon) ♦♦ Anne BERGERET, Professor, Ecole des Mines d'Alès

Shree Prakash MISHRA

February 24, 2010 - Fluid Mechanics, Energetics, Processes
Ph.D. title
Bleaching of cellulosic paper fibres with ozone : effect on the fibre properties.
Supervision
Dominique LACHENAL, Professor, Grenoble INP-Pagora / LGP2 ♦♦ Christine CHIRAT, Associate Professor, Grenoble INP-Pagora / LGP2
Abstract
The effect of ozone on viscosity, fibre morphology, beating behaviour and strength properties of kraft pulp has always been a matter of discussion among the mill experts, ozone suppliers and research groups. The present thesis research work is aimed at further advancing and enriching the knowledge base in the area and to help proliferation of the ozone bleaching technology for a more sustainable pulp industry. It has been established that incorporating an ozone stage in an ECF bleaching sequence of eucalyptus and Pinus radiata kraft pulps is a straightforward way to reduce the chemical cost with a possibility of having higher brightness ceiling. Bleaching with ozone results in a substantial decrease of the pulp viscosity which is shown to have no consequence on the main strength properties and fibre morphology of the pulp. Other advantages of the ozone containing ECF sequence are the smaller content in residual extractives, the savings in the beating energy and the lower water retention value.
Other members of the jury
Bernard de JESO, Professor, Université Bordeaux 1 ♦♦ Monica EK, Professor, KTH (Sweden) ♦♦ Jean-Christophe HOSTACHY, Pulp & Paper Director, ITT Water & Wastewater ♦♦ Serge KOCIMSKI, Ozone Paper Pulp Manager, Degremont Technologies

Date of update May 18, 2018

Grenoble INP Institut d'ingénierie Univ. Grenoble Alpes