Elisa Zeno

Centre Technique du Papier, Grenoble | CTP

The twin-screw extrusion (TSE) process has recently been investigated for the production of cellulose nanofibrils (CNF). The main advantage of this process is the production of CNF at high solid content (around 20 wt% suspensions) and lower energy consumption. Typically, studies focus on the quality of the extruded material (i.e., CNF) by comparing...

Nowadays, drug encapsulation and drug release from cellulose nanofibrils systems are intense research topics, and commercial grades of cellulose nanomaterials are currently available. In this work we present an ester-containing prodrug of metronidazole that is covalently bound to cellulose nanofibrils in aqueous suspension through a two-step immobi...

La rentrée scolaire de septembre 2020 en France, en pleine pandémie de COVID-19, a été accompagnée de débats sur l’intérêt du port du masque à l’école primaire. Ce travail discute l’intérêt du port du masque dès 6 ans, à la lumière des connaissances scientifiques actualisées jusqu’à début novembre 2020 et des spécificités françaises. La littérature...

The biocompatibility and very high specific area of cellulose nanofibrils (CNF) are properties of high interest for the development of active substrates for new medical device development. Enzyme pretreated CNF (CNF-e) can be self-organized into nanostructured membranes that are suitable for active principle ingredients (API) encapsulation through...

Cellulose nanofibrils (CNF) are renewable bio-based materials with high specific area, which makes them ideal candidates for multiple emerging applications including for instance on-demand drug release. However, in-depth chemical and structural characterization of the CNF surface chemistry is still an open challenge, especially for low weight perce...

Herein, we report on the preparation of novel cellulose-PEG biohybrid papers with wet strength properties. The biohybrid paper sheets are obtained using a two-step procedure where ω- or α, ω-azide functionalized PEG chains are anchored onto alkyne-functionalized wood fibers through CuAAC ligation in mild and aqueous conditions. The incorporation of...

High and uncontrolled surface active substances (SAS) concentrations in deinking line process waters strongly disturb flotation deinking. Indeed, their adsorption at air/water and ink/water interfaces stabilizes air bubbles and ink particles, reducing ink collection during flotation. In addition, foam stabilization promoted by SAS reduces froth dra...

Today, recovered papers deinking by froth flotation represents the reference technology for the removal of inks and hydrophobic contaminants (i.e., stickies, pitches, wood extracts) from recovered paper slurries, and the production of deinked pulps with high optical properties. High ink removal efficiency and process yield are the key factors that...

This study presents a rapid method for nanopaper production by spray deposition of high concentration microfibrillated cellulose (MFC) slurries on a nylon fabric and their subsequent filtration dewatering. The filtration time for the consolidation of a wet MFC mat was of 15 and 90 s for sheets with basis weight of 13.7 and 124 g m−2, respectively....

A methacrylate based plasticised polymer electrolyte membrane is prepared via a rapid and facile UV curing process, the major concerns of mechanical integrity are overcome by simply using appropriately modified cellulose handsheet laden with nano-sized acidic alumina particles as a reinforcement. The use of the cellulose handsheets greatly enhances...

A novel UV-induced procedure, in the presence of glycidyl acrylate and proper radical/cationic photoinitiators, is here proposed to promote the in situ grafting of a methacrylic polymer network to the surface of natural cellulose fibers. As a result, composite polymer membranes reinforced by cellulose handsheets are obtained and demonstrate excelle...

Methacrylic-based thermo-set gel-polymer electrolytes obtained by the easy and reliable photo-polymerisation process and mechanically reinforced by a cellulose handsheet (paper) for flexible lithium batteries application are here presented. Adhesion between cellulose and polymer is improved by "in situ" grafting supported by benzophenone; the ionic...

Fully-solid methacrylic-based thermo-set polymer electrolyte membranes reinforced with nanoscale micro-fibrillated cellulose (MFC) fibres are here presented. The preparation is carried out in water and the membrane is obtained by an easy and reliable UV-induced polymerisation via a free radical mechanism; thus, the overall process is highly energy...

Alkyne-functionalized cellulose fibers have been generated through etherification under basic water or hydroalcoholic conditions (NaOH/H2O/Isopropanol). For a given NaOH content, the medium of reaction and more particularly the water/IPA ratio, was shown to be of crucial importance to derivatize the fibers without altering their integrity and their...

This dissertation describes the chemical modification of cellulosic fibers by organosilanes. The reactions of silanes bearing various functional groups were carried out in pure aqueous solution and followed in-situ by nuclear magnetic resonance spectrometry. The effect of pH, concentration, and temperature on the reaction kinetics was studied. Amin...

The kinetics of the hydrolysis and self-condensation reactions of 3-(2-amino-ethylamino)propyl-trimethoxysilane (DAMS) were investigated by in situ29Si NMR spectroscopy using pure water and an alcoholic (80:20 w/w ethanol/water) solvent mixture as reaction media. In both media, the reactivity of the silane was strongly influenced by the pH of the m...

Polypyrrole was chemically synthesised by using, for the first time, Birchwood xylan as additive, and ammonium peroxydisulfate (APS) as oxidant. The impact of additive concentration, polymerisation time and reagents concentration on PPy conductivity was studied. It was shown that, once fixed the pyrrole (Py)/APS and Py/xylan optimal ratios, the bes...

Methacrylic-based thermo-set gel-polymer electrolyte membranes obtained by a very easy, fast and reliable free radical photo-polymerisation process and reinforced with microfibrillated cellulose particles are here presented. The morphology of the composite electrolytes is investigated by scanning electron microscopy and their thermal behaviour (cha...

Methacrylic-based thermo-set gel-polymer electrolytes obtained by an easy and reliable free radical photo-polymerisation process demonstrate good behaviour in terms of ionic conductivity, interfacial stability with the Li-metal electrode and cyclability in lithium cells. Though the obtained membranes are flexible, self standing and easy to handle,...

Wood and cellulose derivatives, in both fibrous and water-soluble macromolecular form, are emerging as outstanding candidates for organic electronics applications due to their large-scale availability, low cost, and easy processability. Paper and wood fibre-based derivatives are considered to be materials of choice as supports for communication wor...

Residence time distribution (RTD) measurements performed in a small laboratory flotation column using an electrolyte tracer, showed that, without air injection, cellulose fibres induced a sizeable decrease in tracer average residence time, owing to the formation of stagnant zones. Bubble size, fibre flocculation level and gas hold-up were recorded...

The use of carboxymethylcellulose (CMC) in polypyrrole (PPy) synthesis and in the production of PPy freestanding films was investigated. PPy was synthesised by chemical oxidative polymerisation in aqueous solutions using ammonium persulfate (APS) as oxidant and CMC as conductivity enhancer (CMCd). CMCs with different molar weight, namely 90,000 and...

There is a need to monitor flotation deinking operations, in order to better control their efficiency, reduce losses, and save fiber resources. The objective of this work is to understand the variations of ink removal efficiency and flotation yield at industrial scale. A preflotation bank has been instrumented with air probes, and parameters releva...

The surface modification of cellulose opens the way towards almost infinite new applications, making it suitable for functional and sustainable materials. Additionally, it also represents a possibility for up-grading traditional products. In this work, we report about the photo-induced grafting onto cellulose substrates of a highly fluorinated acry...

Hydrophobisation treatment or sizing is conducted to limit the penetration of water or other liquids into papers, mainly for printing and writing or converting purposes. Internal sizing can be obtained through the addition of alkyl ketene dimer (AKD) into the pulp suspension. It is well known that AKD sizing efficiency depends on process parameters...

A laboratory flotation column equipped with Venturi aerators and an adjustable froth removal system was used to study the effect of calcium soap and a mixture of calcium soap/alkyl phenol ethoxylate surfactant on ink and fibres transfer during flotation de-inking of a 50% old newprint (ONP) / 50% old magazines (OMG) recovered papers mixture. Mass t...

PPy was synthesised by oxidative chemical polymerisation using xylan, CMC and NFC as additives. Conducting nanocomposite films were cast from aqueous slurries using doped PPy particles, CMC and NFC as the conducting and reinforcing phase, respectively. NFC‐based composites had higher conductivity and lower mechanical properties than CMC‐based homol...

Microfibrillated cellulose nanoparticles were used as binders for the aqueous processing of flexible electrodes for Li-ion batteries. Microfibrillated cellulose formed a nanostructured web-like network around graphite platelets conferring to the graphite anode a highly porous structure, excellent flexibility and good cycling performances. This work...

Polypyrrole (PPy) was chemically synthesised at two pH levels (pH = 2 and unadjusted pH, i.e. 6.6) using pre-formed carboxymethylcellulose-iron (CMC-Fe) complexes. The CMC-Fe complexes were prepared at a fixed CMC concentration, i.e. 5.5x10 -5 mol/L, and with an increasing FeCl 3 amount (from 4x10 -3 to 5x10 -2 mol/L). The quantity of iron bound to...

The impact of natural polymeric dispersants, that is, carboxymethyl cellulose and guar gum, on the flotation selectivity was investigated on a flotation deinking pilot plant. Their effect on pulp flocculation, air bubble size, and gas hold-up was determined by implementing a fiber flocculation sensor, an automated bubble measurement device, and a g...

Biocide programs have become necessary in most fine paper manufacturing circuits, as drastic reduction of fresh water consumption in the industry enhances microbial development. Depending on their chemical nature, biocides may interfere with typical wet-end chemistry additives and furnish. A reference wet-end chemistry was set (including fixing aid...

One of the main drawbacks that restricts the practical application of gel-polymer electrolytes is the inferior mechanical performance compared to other available systems. In this work, we have reinforced UV-cured methacrylic membranes with cellulose. To enhance its compatibility with the polymer matrix, cellulose is modified by UV-grafting poly(eth...

In this work, the contribution of flotation deinking banks design on ink removal efficiency, selectivity, and specific energy consumption was simulated using a semiempirical approach. Single-stage with mixed tank/column cells, two-stage, and three-stage configurations were evaluated, and the total number of flotation units in each stage and their i...

Transport coefficients and correlations recently used to describe surfactant contribution to particle and water transport in a laboratory flotation column were used to simulate the impact of surfactant contamination on the flotation selectivity of industrial two-stage deinking lines. Simulation results showed that surfactants are slightly removed i...

The modification of cellulose fibers by grafting specific functions could improve their quality and allow their use for the development of new products. In this work we report about the functionalization of a cellulose fiber network (filters) with organo-polysilazane oligomers by UV-irradiation. Photo-induced grafting, as assessed by contact angle...

Transport coefficients and correlations recently used to describe surfactant contribution to particle and water transport in a laboratory flotation column were used to simulate the impact of surfactant contamination on the flotation selectivity of industrial two-stage deinking lines. Simulation results showed that surfactants are slightly removed in t...

L'objet de l'invention est une particule destinée à être ajoutée à une suspension de fibres cellulosiques, constituée par une matrice polymère encapsulant au moins un agent de collage. L'invention vise également un procédé de fabrication d'une telle particule ainsi qu'une composition l'incluant. Un autre objet de l'invention est son utilisation pou...

Surfactants are largely present in papermaking/recycling processes. They are added intentionally or come with raw materials or process/functional additives. Once they have reached the process, they build-up in the circuits and, depending on their surface activity and concentration, they can have adverse effects on deinking and on the whole papermak...

A laboratory flotation column equipped with Venturi aerators and an adjustable froth removal system was used to study the effect of an alkyl phenol ethoxylate surfactant on water, particle and surfactant transfer during flotation de-inking of recycled papers. Wash water was not used in order to emphasize the influence of surfactant concentration on...

Surfactants are largely present in the papermaking / recycling processes. They are added intentionally or they come with the raw-materials or process/functional additives. Once they reach the process, there are very few outlets and they can remain in the circuits, leading to a potentially adverse impact on the deinking and the papermaking processes...

A laboratory flotation column using Venturi aerators and a vacuum system to remove froth was used to investigate the contribution of gas flow, pulp flow, cell volume and froth retention time on the ink removal efficiency and on cellulose fibres and mineral fillers loss. The increase in the gas flow from 4 to 8 L/min gave a general rise of particle...

The effects of some surface active substances on the AKD sizing have been investigated, particularly the impact of fatty acids and of non-ionic surfactants, commonly found in a deinked pulp. The wetting and the absorption properties of AKD sized handsheets were studied as a function of the size dosage, of the surfactant presence and concentration i...

This work focuses onto the interactions between poly(ethylene oxide) (PEO) and fatty acids, in order to set their potential role of contaminants for PEO-based retention systems. Surface tension measurements were used to investigate PEO-fatty acid systems and they made it possible to clearly point out the interactions between the polymer and the sod...

This work focuses onto the interactions between poly(ethylene oxide) (PEO) and fatty acids, in order to set their potential role of contaminants for PEO-based retention systems. Surface tension measurements were used to investigate PEO–fatty acid systems and they made it possible to clearly point out the interactions between the polymer and the sod...

An original procedure is described which calls upon the heterogeneous grafting of bifunctional molecules onto a reactive polymeric surface, leaving one of the functions available for further exploitation. The principle of this strategy is to use reagents characterised by a rigid planar structure bearing the two active moieties at opposite sites of...

An original procedure is described which calls upon the heterogeneous grafting of bifunctional molecules onto a reactive polymeric surface, leaving one of the functions available for further exploitation. The principle of this strategy is to use reagents characterised by a rigid planar structure bearing the two active moieties at opposite sites of...