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LGP2 - Ph.D. thesis defended in 2016

Jennifer MARCON

December 15, 2016 - Fluid Mechanics, Energy, Processes
Ph.D. title
Lignocellulosic pulp: study of a new bleaching sequence with low environmental impact.
Supervision
Gérard MORTHA, Professor, Grenoble INP-Pagora / LGP2 ♦♦ Nathalie MARLIN, Associate Professor, Grenoble INP-Pagora / LGP2
Abstract
Chlorine dioxide is the most widely used bleaching agent for the production of bleached chemical pulps. However, its main drawback is the formation of chlorate, which decreases the delignification efficiency, and the reject of COD and toxic chloro-organic molecules (AOX) in mill effluents.
This study focused on the development of a new bleaching stage using chlorine dioxide (D stage) in non-conventional conditions, to reduce the environmental impact and production costs. The work was carried out on several softwood kraft pulps after cooking, taken at different stages of the bleaching sequence. The best results of the novel D stage were obtained for pulps at low kappa number, i.e. at the end of the bleaching sequence. The D stage was optimized and coupled with hydrogen peroxide addition. The same brightness and average degree of polymerization as for conventional D bleaching were obtained. Interestingly, a very important decrease of pollution load (70% of AOX and 20% of COD) was obtained, accompanied by a significant gain of productivity and energy saving (lower temperature and reaction time).
Chemical investigations on the reaction mechanism, carried out by different techniques (ESR, NMR and FTIR spectroscopies, HPAEC-PAD chromatography), allowed to reveal the main features of the reaction mechanism of chlorine dioxide and highlight the structural modifications brought to the pulp residual lignin during the novel unconventional D bleaching stage.
Other members of the jury
Anne-Laurence DUPONT, CNRS Researcher, CRC, Paris ♦♦ Dimitry EVTUGUIN, Professor, University of Aveiro (Portugal) ♦♦ Hervé GALLARD, Professor, University of Poitiers ♦♦ Auphélia BURNET, R&D Engineer, Centre Technique du Papier, Grenoble ♦♦ Lucie BOIRON, R&D Engineer, Munksjö, Apprieux

Jordan PERRIN

December 14, 2016 - Fluid Mechanics, Energy, Processes [Thesis online]
Ph.D. title
Production of pure cellulose from wood by green purification and bleaching process with ozone, for textile and chemical application.
Supervision
Dominique LACHENAL, Professor, Grenoble INP-Pagora / LGP2 ♦♦ Christine CHIRAT, Associate Professor, Grenoble INP-Pagora / LGP2
Abstract
Bleaching of wood pulp is still an environmental issue. A new ozone-based TCF bleaching sequence made it possible to produce a bleached dissolving pulp whose properties were comparable to those of a pulp bleached with a conventional bleaching sequence using chlorine dioxide (ECF).
It was noticed that the TCF bleached pulp had better brightness stability. The origin of yellowing is still poorly understood. It was studied here by the implementation of several analytical methods including EPR spectroscopy, UV-Raman spectroscopy for the analysis of aromatic and quinone residues and also fluorescence spectroscopy for the measurement of carbonyl and carboxyl groups. It was shown that the carbonyl groups present on the cellulose are detrimental to the brightness stability, both during accelerated ageing and mercerization. They can be partly eliminated by an alkaline treatment, which in return improves the brightness stability. Addition of hydrogen peroxide allows for a further increase of the brightness stability, but without any extra carbonyl removal. Hydrogen peroxide would have an effect on some conjugated residual chromophores, mainly quinones, involved in the yellowing mechanism. The TCF pulp would possess less quinones than a ECF pulp.
The thesis was supported by ADEME, the French Environmental Agency, and two major players in ozone generation (Xylem and Degremont-Ozonia)
Other members of the jury
Yves QUENEAU, Research Director, INSA Lyon ♦♦ Carlos PASCOAL NETO, Professor, University of Aveiro (Portugal) ♦♦  Ute HENNIGES, Associate Professor, Boku University (Austria)

Julie CHAPELAIN

December 8, 2016 - Fluid Mechanics, Energy, Processes
Ph.D. title
Dispersed air flotation foams for radioactive decontamination of land.
Supervision
Davide BENEVENTI, CNRS Researcher, Grenoble INP-Pagora / LGP2

Fanny HOENG

October 14, 2016 - Materials, Mechanical, Civil Engineering, Electrochemistry
Ph.D. title
Potential of nanocellulose for conductive ink preparation.
Supervision
Julien BRAS, Associate Professor, Grenoble INP-Pagora / LGP2 ♦♦ Aurore DENNEULIN, Associate Professor, Grenoble INP-Pagora / LGP2
Abstract
This project aims at developing new conductive inks based on nanocellulose and silver nanowires for transparent and conductive applications. Nanocellulose are nanoparticles extracted from the cellulose and two kinds currently exist : the cellulose nanocrystals (CNC) and the cellulose nanofibrils (CNF).
This project have evaluated on one hand the ability of using tubular rigid CNC as template for producing silver nanorods, prior their formulation into conductive inks. On the other hand, the ability of using flexible and entangled CNF to stabilize commercial silver nanowires, usually unstable in suspension, was investigated.
The results of this project lead to the patented formulation and commercialization of one low silver content conductive ink based on silver and CNC and two conductive transparent ink based on CNF and silver nanowires. Physico-chemical interactions and colloidal stability of such hybrid suspension have been scientifically studied meanwhile printing process adapted formulation have been successfully designed and tested at laboratory scale but also industrial scale.
Other members of the juryBernard CATHALA, Research Director, INRA ♦♦ Orlando ROJAS, Professor, Aalto University, Finland ♦♦ David GETHIN, Professor, Swansea University, United Kingdom ♦♦ Charles NEUMAN, CEO, Poly-Ink

Nagalakshmaiah MALLADI

September 23, 2016 - Fluid Mechanics, Energy, Processes
Ph.D. title
Melt processing of cellulose nanocrystals: thermal, mechanical and rheological properties of polymer nanocomposites.
Supervision
Nadia EL KISSI, CNRS Research Director, Laboratoire Rhéologie et Procédés, Grenoble  ♦♦ Alain DUFRESNE, Professor, Grenoble INP-Pagora / LGP2
Abstract
The low thermal stability and irreversible agglomeration issues are limiting the processing of polymer nanocomposites using cellulose nanocrystals as the reinforcing phase. In this context, thermally stable and highly dispersed cellulose nanocrystals were prepared by green processes (aqueous based methods) like physical adsorption and surface modification. These two different extrudable cellulose nanocrystals were used to reinforce hydrophobic polymers. Ensuing polymer nanocomposites had a positive impact on the storage modulus, tensile strength and Young’s modulus.
Importantly, no evidence of micro aggregates in the matrix was observed in the scanning electron microscopy images contrary to non-treated cellulose nanocrystals.
Both the surface modification and adsorption are water based methods and are industrially viable solutions.
Other members of the jury
Claire BARRES, Associate Professor, INSA Lyon ♦♦ Lazhar BENYAHIA, Professor, Université du Maine, Le Mans-Laval ♦♦  Bruno VERGNES, Research Director, CEMEF, Nice

Marcos MARIANO

September 22, 2016 - Materials, Mechanical, Civil Engineering, Electrochemistry [Thesis online]
Ph.D. title
Applications of cellulose nanocrystals: thermal, rheological and mechanical properties of new materials.
Supervision
Alain DUFRESNE, Professor, Grenoble INP-Pagora / LGP2 ♦♦ Nadia EL KISSI, CNRS Research Director, LRP, Grenoble
Abstract
The preparation of composites based on cellulose nanocrystals (CNC) is normally performed using techniques such as melt processing or casting/evaporation. In the last one, impressive mechanical properties can be reached due to the creation of a particle 3D network that is based on new hydrogen bonds between the cellulose nanorods. This process of new H-bond formation normally takes time and is dependent of the nanoparticle size and its volume fraction. Besides, the quality of filler dispersion into the polymeric matrix is also an important parameter to provide the highest surface area and provides an ideal structure for the rigid structure.
This thesis proposes different preparation methods and characterizations to obtain nanocomposites with a simple preparation either by casting-evaporation or melt processing. Nanocomposites materials based on cellulose nanocrystals and amorphous or semi-crystalline polymer as matrix were prepared and characterized. Most of the work has focused on the optimization of their properties and the impact of the processing method, in particular by extrusion or injection molding. The impact of the nanofiller-induced crystallization of the matrix, and the possibility of reorganization of the nanocrystals after processing, were notably addressed.
Other members of the jury Yves GROHENS, Professor, Université de Bretagne Sud, Lorient ♦♦ Christian CARROT, Professor, Université Jean Monnet, Saint-Etienne ♦♦ Jannick DUCHET-RUMEAU, Professor, INSA Lyon

Elsa WALGER

July 22, 2016 - Fluid Mechanics, Energy, Processes [Thesis online]
Ph.D. title
Study of the activation of hydrogen peroxide by the copper(II)-phenanthroline complex for the color-stripping of recovered cellulosic fibers
Supervision
Gérard MORTHA, Professor, Grenoble INP-Pagora / LGP2  ♦♦ Nathalie MARLIN, Associate Professor, Grenoble INP-Pagora / LGP2
Abstract
Today, recovered papers are reused for the manufacture of bright paper after deinking and fiber bleaching, which generally starts with an alkaline hydrogen peroxide stage (H2O2). However, the efficiency of H2O2 is often limited due to its low reactivity on the azo groups of paper dyes contained in recovered papers. The goal of this study was to improve the removal of these azo dyes by H2O2.
The improvement of H2O2 bleaching has been studied thoroughly in the context of chemical pulp delignification. In particular, the activation or catalysis of H2O2 by copper(II)-phenanthroline complexes (Cu-Phen) was found to be very effective. This inspired a preliminary bleaching study on deinked pulp and dyed pulp, and resulted in significant improvement of dye removal, which gave birth to our project.
The purpose of this work was to determine to what extent copper(II)-phenanthroline could improve the hydrogen peroxide color-stripping of dyed cellulosic fibers, and how. To answer this question, three intermediate issues were addressed: (1) does Cu-Phen alone have an effect on the dye? (2) does Cu-Phen improve the color-stripping of a dyed pulp by H2O2? (3) how does the H2O2/Cu-Phen system enhance the dye-color-stripping efficiency?
This work was thus divided into three studies: (1) the selected dyes and the complex were characterized in the absence of any oxidant and the interactions between the two were examined, (2) the H2O2/Cu-Phen system was applied on two dyed pulps to assess their color-stripping potential and to attempt to optimize it, and (3) the oxidation mechanism was investigated via trials in aqueous solution, with and without cellulose.
Using several analytical techniques (NMR, FTIR, UV-vis and EPR spectroscopy; ESI-MS) and speciation calculations, this work proved that the Cu-Phen complex enhanced H2O2 for the color-stripping of azo dyes, with and without fibers. It also provided evidence that phenanthroline acted as a stabilizer to adjust the solubility, stability and redox potential of copper(II), but may not be indispensable. The substrate (dyes but also cellulose) was strongly degraded by the H2O2/Cu-Phen system. The results of the mechanistic study supported the hypothesis of substrate oxidation by radicals produced via decomposition of H2O2 rather than by hydrogen peroxide itself. This mechanism, strongly dependent on the pH, is probably part of a catalytic cycle.
Finally, along with further research proposed based on our conclusions, this thesis should contribute to the improvement of deinked pulp bleaching as well as wastewater treatment in the pulp and textile industries.
Other members of the jury
Stéphane GRELIER, Professor, Université de Bordeaux ♦♦ Bodo SAAKE Professor, Universität Hamburg, Germany ♦♦ Carole DUBOC, CNRS Research Directeur, Université Grenoble Alpes ♦♦ Béatrice TUCCIO-LAURICELLA, Associate Professor, Aix-Marseille Université

Fanny BARDOT

June 13, 2016 - Fluid Mechanics, Energy, Processes
Ph.D. title
Modification of lignins from lignocellulosic pulps in order to incorporate them into ink formulations
Supervision
Gérard MORTHA, Professor, Grenoble INP-Pagora / LGP2  ♦♦ Anne BLAYO, Lecturer-Researcher, Grenoble INP-Pagora / LGP2
Abstract
The originality of this work is to use lignin, an aromatic macromolecule from lignocellulosic biomass, in replacement of petroleum-based resins for the formulation of inks for food contact packaging applications. Different chemical modifications were carried out on commercial lignins, in order to make them compatible with the ink components. Used reagents and processes were chosen in order to limit the environmental impact of the whole value chain. Chemical modifications were monitored by several analytical techniques such as GPC SEC for the molar mass distribution and NMR and FTIR spectrometry for the monitoring of lignin functional groups. Ink properties were characterized by rheological and colorimetric (CIE L*a*b* system) measurements on printed samples.
Among the significant results, changes in hydrophilic/hydrophobic balance were particularly noticed. Furthermore, the colour gamut of modified lignin-based inks was enhanced, compared to the one of unmodified lignin-based inks. Two applications emerged from this work: (1) formulation of lignin-based bio-sourced inks, which meet most of the industrial requirements, and (2), development of a modified lignin-based coating which improved barrier properties of recycled paperboard.
Other members of the jury
Anne-Laurence DUPONT, CNRS Researcher, Centre de Recherche sur la Conservation ♦♦ Bernard KUREK, CNRS Research Director, INRA, Reims ♦♦ Stéphanie BAUMBERGER, Professor, AgroParisTech ♦♦ Charles BOUCHARD, Doctor, Siegwerk, France

Awatef LAAROUSSI

April 13, 2016 - Fluid Mechanics, Energy, Processes [Thesis online]
Ph.D. title
Flexible biocathode manufacturing by printing processes for implantable enzymatic biofuel cells
Supervision
Naceur BELGACEM, Professor, Grenoble INP-Pagora / LGP2  ♦♦ Didier CHAUSSY, Professor, Grenoble INP-Pagora / LGP2  ♦♦ Nadège REVERDY-BRUAS, Associate Professor, Grenoble INP-Pagora / LGP2
Abstract
Enzymatic biofuel cells, capable of converting efficiently the glucose from extracellular fluid into electrical energy, are a power source for implantable devices. However, the power output generated by these cells is not sufficient to fulfill the energy required by implantable artificial organs. Therefore, a new packaging architecture design based on flexible materials derived from printing technologies has been explored in order to enhance the power output of this cell.
This work demonstrates the relevance of printing processes such as ultrasonic spray and gravure to develop homogeneous, thin and flexible biocathodes. During this work, a carbon nanotubes / surfactant suspensions were deposited on a hydrophobic flexible substrate (carbon paper). Despite the poor printability of the substrate, flexible active layers were obtained (thickness between 5 and 10 µm).
Other members of the jury
Philippe CINQUIN, Professor, Université Joseph Fourier, Grenoble ♦♦ Latifa BERGUEOUI, Professor, INSAT, Tunisia ♦♦ Roberta BONGIOVANNI, Professor, Politecnico di Torino, Italy ♦♦ Sophie TINGRY, CNRS Researcher, Institut Européen des Membranes, Montpellier

Fanny TRICOT

February 3, 2016 -
Ph.D. title
Rewritable films on flexible substrates
Supervision
Nathalie DESTOUCHES, Professor, Université Jean Monnet, Saint-Étienne ♦♦ Francis VOCANSON, Professor, Université Jean Monnet, Saint-Étienne ♦♦ Didier CHAUSSY, Professor, Grenoble INP-Pagora / LGP2
Résumé
Previous research conducted by the laboratory Hubert Curien developed photosensitive Ag: TiO2 films on glass as support for updatable or permanent patterns. An adaptation of this work to plastic and paper substrates is here proposed to expand the potential application areas at product secure labeling for example. Fabrication techniques of such Ag: TiO2 films compatible with studied substrates have therefore been developed. Two paths have been considered.
The first uses the combination of Sol-Gel chemistry with the EISA method. Deposition processes such as spin coating, inkjet or flexographic printing are used to form a mesoporous film of TiO2 on substrates. Treatments based on solvent extraction or infrared annealing have been devised to release the porosity of the film without damaging the supports. To make films on paper, a silver salt is added to the sol before its coating. In the case of films deposited on plastic, silver is incorporated by soaking the material in a silver salt solution.
The second developed option proposes formulating an aqueous ink jet ink of TiO2 nanoparticles and silver ions by adapting the composition of a commercial suspension of TiO2 with the requirements of the ink jet process. After printing, the ink is dried by infrared annealing. The photochromic behavior under UV and visible light exposures of fabricated films allows them coloring and bleaching reversibly. Sol-Gel films coated on plastic can also be a support for permanent colored patterns realized by irradiation with a visible light of certain intensity.
Autres membres du jury
Roberta BONGIOVANNI, Professor, Politecnico di Torino, Italie ♦♦ Thierry GACOIN, CNRS Research Director, École Polytechnique, Paris ♦♦ Naceur BELGACEM Professor, Grenoble INP-Pagora / LGP2 ♦♦ Philippe BELLEVILLE, Research Director, CEA, Le Ripault

Date of update May 18, 2018

Grenoble INP Institut d'ingénierie Univ. Grenoble Alpes