Fanch Cherhal

Herve Bizot

Bernard Cathala

Isabelle Capron

come

Cellulose nanocrystals as amphiphilic particles for the interface.

Cellulose nanocrystals as amphiphilic particles for the interface.

F. Cherhal, H. Bizot, B. Cathala and I. Capron INRA, UR1268 Biopolymères, Interactions et Assemblages, 44300 Nantes, France.

Isabelle.capron@nantes.inra.fr

Increasing environmental awareness is prompting scientists and industrialists to develop strategies for environmental sustainability by using processes and materials with low cost, energy consumption and toxicity, together with high biodegradability. There is strong motivation within this context to replace petroleum-based polymers with polymers from renewable resources. Emulsions are used in large application domains such as food, cosmetics, pharmaceutical or coatings. These emulsions usually use surfactants issued from the petro-chemical industry. For example, in 2001, surfactants represented 11 million tons among which only 20% was of vegetal origin. In a same time, it is referred that a lot of vegetal wastes, notably in the wood industry, will have to find new developments in the coming period.

In a recent study, we showed that it was possible to obtain highly stable oil-in-water Pickering emulsions stabilized only by unmodified Cellulose NanoCrystals (CNC) 1 . The amazing properties of these systems in terms of stability and mechanical behaviour for encapsulation of any oil, including vegetable oils, are due both to their anisotropic shape and to the irreversible nature of such particles adsorption 2 . Furthermore, the CNC preparation by enzymatic or acid hydrolysis, or oxidation process, may introduce charged groups at the surface. This provides good colloidal stability thanks to charge repulsions but can prevent stabilizing ability. We used this original ability of the nanocrystals to stabilise oil/water interface to study the influences of surface charge on their amphiphilic properties 3 . Furthermore, according to the process and the botanic origin, the CNCs may provide naturally a large range of particles from 200 nm to several microns in length leading to variable aspect ratios. This was used to develop various formulations leading to stable fluid or interconnected emulsions 4 . As a result, CNC appears as a stiff anisotropic versatile plateform with amphiphilic contrasted surfaces that develop hydrogen bonds, van der Waals, electrostatic, and hydrophobic interactions. These properties make it a good renewable and biocompatible candidate for petroleum derivatives alternative in numerous interfacial applications.

Conversion of lignocellulosic biomass

Pre-treatment, deconstruction and conversion of lignocellulosic biomass to chemical platforms or transportation (renewables : wood, corns, beets…) Conversion of carbohydrates to higher value added chemicals

Conversion of vegetable oils, derivatives and by-products Conversion of vegetable oils

Reactions involving (unsaturated) fatty acids/esters, glycerol or minor compounds (esterification, transesterification, oxidation, metathesis, hydroformylation, hydrogenation, ...)

Valorisation of by-products (including CO2), waste and recycling Chemical valorization of waste All processes involving biogas and more generally agricultural waste Chemical valorization of CO2

Eco-efficient processes Design of energy (and atoms)-saving processes for the rational conversion of renewable carbon Chemical and physical pre-treatments of biomass, green solvents, alternative media, catalysis, process design, process intensification...

Catalytic materials specifically dedicated to innovative processes incorporating biobased materials

Preparation and characterization of materials for the selective conversion of biomass : eco-design, green synthesis, bio-sourced precursors, ...

Environmental impact of all actions implemented

All works evaluating the ecological impact of chemicals and processes on the environment.


The different tree components: When measuring the tree dimensions: circumference measured every 1 -2 m; indicate where to cut the tree components along the tree; measure, tree height, crown diameter etc.

When logging the tree: take necessary precautions; cut the liana; prepare a path to escape.

etc When cutting the tree components: -3-5 cm disk are collected; -Distance between samples depends on the strategy adopted.

When separating the branches and the leaves: -Per class of diameters (e.g. >20, 20-7, 7-4 and <4cm) if difficult to collect all leaves, use sub-sampling; -For the big branches it is more convenient to use the same strategy as for the trunk.

Place 3 Place 4

Place 5

Place 6

When collecting samples:

-At different location to ensure consideration of the variation of the moisture content & wood density ; more than 3 samples for each tree components;

When weighting the tree components:

to perform quickly (avoid moisture content loss); -Adapt the spring balance depending on the size of the samples. Vitellaria paradoxa: main tree species, used to make butter (karité), and fodder during the « soudure »period.

1. CONTEXT Information on the trees to be logged were obtained form the logging company Trees were georeferenced in order to minimize the transport and facilitate the measurements Damaged trees close to the road were also considered (mainly for the small trees because trees cannot be logged under a certain minimum diameter, generally around 50 cm of dbh) Sampling method varies depending on the size of the tree roots; In some ecosystems (e.g. agroforestry), it is preferable to develop ratio/ha

UN-REDD

P R O G R A M M E UN-REDD P R O G R A M M E

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  Destructive measurements (Eucalyptus plantation in Congo) Semi-destructive field measurements for Vitellaria paradoxa parkland in North Cameroon Destructive measurements for trees in tropical rainforests in Ghana Destructive measurements for root biomass assessment Conclusion: methodologies have to be adapted to the financial and technical means, the social and biophysical contexts 2. Destructive measurements (Eucalyptus plantation in Congo) Saint-André, L., A. T. M'Bou, et al. (2005). "Age-related equations for above and below ground biomass of a Eucalyptus hybrid in Congo." Forest Ecology and Management 205(1-3): 199-214 Rivoire, M., Genet, A., Didier, S., Nys, C., Legout, A., Longuetaud, F., Cornu, E., Freyburger, C., Motz, A., Bouxiero, N. et Saint-André, L., 2009. Protocole. d'acquisition de données volume-biomasse-minéralomasse, Bure. Rapport technique, INRA, Nancy, France.In order to be the most cost-efficient you need to: -Prepare the equipment; prepare the field data sheets; -Prepare the bags to transport the samples; -Well explain to the different technicians their role and tasks.Potential distribution of the tasks between technicians:

  , M., Besnard, A., Asante, W.A., Eshun, J., Adu-Bredu, S., Valentini, R., Bernoux, M., Saint-André, L., 2010. Wood density, phytomass variations within and among trees, and allometric equations in a tropical rainforest of Africa Forest Ecology and Management 260, 1375-1388. UN-REDD P R O G R A M M E 1. CONTEXT Geographic localisation: Western region, hilly landscape, precipitation (1750-2155mm), moist or wet evergreen forest (FAO ecological zone), dense forest (few logging activities 40 years ago) Hawthorne, W.D., 1995. Ecologcial Profiles of Ghanaian Forest Trees. Oxford Forestry, Institute, Dept. of Plant Sciences, Forestry Dept., Republic of Ghana, Overseas, Development Admin, Oxford Floristic composition: >150 tree species per hectare, three main plant functional types (Shade bearer, Pioneer and Non-Pioneer Light Demander)=> existing classification Social aspects: logging concession (about 140 ha), logging operations focusing on few tree species Use of the trees: timber Legal aspects: only trees identified by the Forest Commission and identified in the concession plan can be logged (only commercial trees) functional types (PFT) -Diameter classes from 2 to 200 cm of diameter -Logging activities and timber demand -Geographical position and risks Sampling strategy depended on: Target: Three trees per PFT and per diameter class (10 cm)

  t r e s s l e n g t h ( L b ) Width (Wb) 1. Log the trees 2. Design tree architecture (segment of 2m for the trunk and 1m length for the branches) up to 10cm of DBH. 3. Branches less than 10cm of diameter are cut and weighted 4. Three branch samples are selected to measure the leaves separately 5. The trunk and branch volume is measured (up to 10cm of diameter) 6. The stump is measured 7. Wood (1 stump, 1 middle of the trunk, 3 branches) and leaves (

  Destructive measurements for root biomass assessment Levillain, J., Thongo M'Bou, A., Deleporte, P., Saint-André, L. et Jourdan, C., 2011. Is the simple auger coring method reliable for below-ground standing biomass estimation in Eucalyptus forest plantations? Annals of Botany, 108(1): 221-230.

  of root biomass: Identify a certain area for sampling: e.g. Voronoï space Hypothesis: roots entering (other trees) = roots outside (considered tree) area can be divided into joint triangular Left: Sampling methods (Voronoï diagram) (picture: C. Jourdan), right: excavation of big roots / rubber plantation in Thailand The methods to develop tree biomass allometric equations depend on André, L., A. T. M'Bou, et al. (2005). "Age-related equations for above and below ground biomass of a Eucalyptus hybrid in Congo." Forest Ecology and Management 205(1-3): 199-214 • Henry, M., Besnard, A., Asante, W.A., Eshun, J., Adu-Bredu, S., Valentini, R., Bernoux, M., Saint-André, L., 2010. Wood density, phytomass variations within and among trees, and allometric equations in a tropical rainforest of Africa Forest Ecology and Management 260, 1375-1388. • Peltier, R., C. F. Njiti, et al. (2007). "Evaluation du stock de carbone et de la productivité en bois d'un parc à Karités du Nord-Cameroun." Bois et forêt des tropiques 294(4): 39-50. • Rivoire, M., Genet, A., Didier, S., Nys, C., Legout, A., Longuetaud, F., Cornu, E., Freyburger, C., Motz, A., Bouxiero, N. et Saint-André, L., 2009. Protocole. d'acquisition de données volume-biomasse-minéralomasse, Bure. Rapport technique, INRA, Nancy, France. • Levillain, J., Thongo M'Bou, A., Deleporte, P., Saint-Andr´e, L. et Jourdan, • C., 2011. Is the simple auger coring method reliable for below-ground standing biomass References

METHOD 3. 1. INFORMATION


Marie-Anne Auger-Rozenberg

Alain Roques

Systématique moléculaire des insectes du genre Megastigmus ravageurs de graines de Cupressacées: une espèce d'insecte par espèce d'hôte?

come

Une étude moléculaire, effectuée sur des individus appartenant aux différentes espèces actuellement décrites ou en cours de description (incluant des espèces nouvelles pour la science), a été réalisée par séquençage de fragments d'ADN mitochondrial et d'ADN nucléaire, afin d'étudier les relations phylogénétiques existant au sein des espèces inféodées aux Cupressacées, de retracer l'histoire évolutive du genre et mieux comprendre ses relations avec les hôtes-végétaux.

On s'est particulièrement intéressé au groupe d'espèces présentes sur les diverses espèces de genévriers sur le pourtour du Bassin Méditerranéen. Parmi elles, trois espèces ont été identifiées selon des critères morphologiques classiques : M. bipunctatus, rencontrée en Europe le plus souvent sur J. communis et observée aussi sur J. sabina, M. amicorum, présente sur les genévriers méditerranéens comme J. oxycedrus et J. phoenicea, et M. thuriferana qui s'attaque à J. thurifera dans les différentes zones isolées où ce genévrier est présent (France, Espagne, Maroc…).

Les analyses moléculaires montrent que les individus observés sur le genévrier thurifère appartiennent à une seule et même espèce, M. thuriferana, quelle que soit leur zone de collecte. En revanche, des différences ont été observées entre individus collectés sur J. oxycedrus et J. phoenicea. La présentation orale donnera plus d'éléments concernant le statut taxonomique de ces individus.

Systématique moléculaire des insectes du genre Megastigmus ravageurs de graines de Cupressacées: une espèce d'insecte par espèce d'hôte?

  radiation par hôte et même par groupe d'hôte pour ces insectes séminiphages. Les Megastigmus des Cupressacées, qui sont présents quasi-uniquement dans la zone paléarctique, forment un clade bien différencié, dans lequel on retrouve toutes les espèces associées aux graines des genres Juniperus et Cupressus. Contrairement à ce qui est observé pour les espèces associées aux graines de Pinaceae qui attaquent différentes espèces congénériques, on observe une tendance à ce qu'une espèce d'insecte s'attaque à une espèce d'hôte.

	Marie-Anne Auger-Rozenberg (1), Alain Roques (1)
	1 INRA UR633 Zoologie Forestiere, 2163 Avenue de la Pomme de Pin, CS 40001 Ardon,
	45075 ORLEANS Cedex 2, France
	Une étude sur la phylogénie moléculaire des insectes du genre Megastigmus
	inféodés aux conifères (Auger-Rozenberg et al, 2006) a précédemment montré l'existence
	d'une


) despite its sensitivity to water 1 .

Fig. 1. SMP Programming

Shape recovery (>90%) is triggered by heating above Tg and water uptake.

Commonly used approach for modeling the thermomechanical behaviour of SMP is based on the theory of linear viscoelasticity 2,3 .

The time and temperature dependencies of linear viscoelastic behaviour of amorphous potato starch obtained by extrusion was investigated by dynamic thermomechanical analysis (DMA) in order to build a constitutive model that takes into account the dehydration effect occurring during DMA analysis.

A master curve of the relaxation modulus was built to describe the viscoelastic properties on a large time domain.

Objectives

1. Linear viscoelasticity behaviour of extruded potato starch was modelled using generalized Maxwell model.

2. Relaxation modulus was determined by tensile stress DMA in a wide range of time in function of temperature for different water content.

3. Relaxation modulus was obtained as continuous function of temperature and water content.

4. The glass transition temperature decreases with increasing water content following models of Gordon-Taylor and Couchman-Karasz. Figure

Conclusions

Relaxation modulus E(t)

Water loss during DMA experiments was evaluated by thermogravimetric analysis and Tg (by DSC) used as calibration curve (Fig. 1). E '(ω) and E'' (ω) were obtained as a function of the actual water content in the range of studied temperatures (Fig. 2). The principle of TTS, using the translation factor a T (T) was applied on the isotherms of E' (Fig. 3a) to obtain a master curve which then was modelled using generalized Maxwell model (Fig. 3b).

The principle of TTS, using the shift factor a T (T) allowed us to obtain master curves of storage and loss modulus for all water content. The storage modulus increases with the increasing frequency whereas the loss moduli exhibited a maxima (Fig. 4a). The shift factors a T (T) from all water content can be fitted by a WLF relation (Fig. 4b).

The modulus E(t) (Fig. 5a). was calculated from E'(ω) using the obtained parameters of generalized Maxwell model (Table 1). The obtained translation factor a T (T) allows us to compute E(t) at any temperature and, by interpolation, also its variation as a function of water content (Fig. 5b).

∑ = + + = n i i i i E E E 1 2 2 0 ) ( 1 ) ( ) ( ' ω τ ω τ ω ∑ = + = n i i i i E E 1 2 " ) ( 1 ) ( ω τ ω τ ω ∑ = - + = n i i i t E E t E 1 0 ) / exp( ) ( τ ) ( ) ( T R T a t E t E × =
Contact: magdalena.kristiawan@nantes.inra.fr

Perspectives

The results will lead to a dataset of material constitutive laws (relaxation modulus) for modeling and simulation of shape memory effect using FEM.

Material and Method

The DMA was performed in tensile mode (ε=0.05%

  Fig. 3a; 14% w.b.; ∆T=50°C 25°C

Figure 4 .

 4 Fig. 4a8% 10% 12% 14% 16%

  1. Véchambre C., Chaunier C., Lourdin D.; Macromolecular Materials Engineering 295, 115-122 (2010) 2. Diani J., Gilormini P., Frédy C., Rousseau I.; Int. J. Solids Structures 49, 793-799 (2012) 3. Nguyen T.D., Yakacki C.M, Brahmbhatt P.D., Chambers M.L.; Adv. Mater. 22, 3411-3423 (2010) 4. Ferry J.D., Viscoelastic properties of polymers, 3rd edition, John Wiley & Sons (1980)

  ) in frequency range (0.1-50 Hz) in function of initial water content (8-17% wet basis) and temperature(25-105°C)

Table 1 .

 1 Coefficients of the generalized Maxwell model, from Fig.3b

	References