Épinal, France
Épinal, France

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Szczurek A.,CNRS Jean Lamour Institute | Amaral-Labat G.,CNRS Jean Lamour Institute | Fierro V.,CNRS Jean Lamour Institute | Pizzi A.,University of Lorraine | And 2 more authors.
Carbon | Year: 2011

Tannin-formaldehyde carbon aerogels were prepared based on organic gels obtained by sol-gel polymerisation of tannin with formaldehyde that have been dried with supercritical acetone and pyrolysed at 900 °C. Tannins drastically reduce the cost of the gels, typically by a factor five, and polymerise in a wide range of pHs, leading to porous carbonaceous materials whose mesopore fraction ranges from 57% to 78%. The surface area and the total porosity can be as high as 715 m2 g-1 and 95%, respectively. Pore volumes and micro-mesopore-size distributions are similar to those of much more expensive carbon aerogels derived from resorcinol- formaldehyde resin. However, more easily adjustable pore textures may be obtained using tannins as precursors. © 2011 Elsevier Ltd. All rights reserved.


Amaral-Labat G.,CNRS Jean Lamour Institute | Szczurek A.,CNRS Jean Lamour Institute | Fierro V.,CNRS Jean Lamour Institute | Masson E.,CRITT Bois | And 3 more authors.
Microporous and Mesoporous Materials | Year: 2012

The effects of supercritical drying of diluted resorcinol-formaldehyde (RF) gels in CO 2 and in acetone are compared. We show that, for both processes, depressurizing rate of the autoclave after drying has a significant influence on the resultant shrinkage, and hence on resultant bulk density, surface area and pore volumes. At depressurizing rates below 2 MPa/min, acetone leads to much lower shrinkage than does CO 2, and is 1000 times cheaper. However, supercritical drying with CO 2 remains interesting because it is faster, easier to control, less sensitive to the experimental conditions and cleaner. We indeed show that acetone is degraded and leads to various compounds that might partly remain in the porosity of the dried RF gels. Supercritical CO 2 also clearly leads to the highest surface areas and micropore volumes, whereas supercritical acetone is in favour of higher mesopore volumes, especially at high depressurizing rates. © 2011 Elsevier Inc. All rights reserved.


Amaral-Labat G.,CNRS Jean Lamour Institute | Szczurek A.,CNRS Jean Lamour Institute | Fierro V.,CNRS Jean Lamour Institute | Pizzi A.,University of Lorraine | And 2 more authors.
Microporous and Mesoporous Materials | Year: 2012

New carbon aerogels have been prepared from urea-branched phenol-resorcinol-formaldehyde resin. Such material, called "blue glue" and used as cold-set adhesive for wood, has been modified in order to obtain highly porous organic gels. The latter were prepared at different pH (5, 7 and 9), dried with supercritical methanol, and carbonised at two different heating rates (2.5 and 5 °C min -1). FTIR analysis confirmed the expected chemical structure of the gel, and GC-MS analysis of the solvent condensed after supercritical drying suggested a slight chemical degradation of the gels during the drying process. However, low-density (0.15-0.31 g cm -3), monolithic, carbon gels could be successfully derived from these materials, having high BET surface areas (900-1300 m 2 g -1) and high mesopore fractions (60-80%). These ranges of values originate from the conditions tested for preparing the materials. Such carbon aerogels are two times cheaper than their traditional resorcinol-formaldehyde- based counterparts and present similar, if not more developed, porous structures. © 2012 Elsevier Inc. All rights reserved.


Szczurek A.,CNRS Jean Lamour Institute | Amaral-Labat G.,CNRS Jean Lamour Institute | Fierro V.,CNRS Jean Lamour Institute | Pizzi A.,University of Lorraine | And 3 more authors.
Materials Chemistry and Physics | Year: 2011

Organic and carbon aerogels have been prepared from resorcinol-formaldehyde resin diluted with various amounts of water. Water was exchanged by acetone or ethanol, and the gels were subsequently dried with supercritical acetone or with supercritical ethanol. We showed that the nature of the solvent with which water was exchanged only had a minor impact on the porosity of the resultant aerogels. In contrast, the same solvents used as drying fluids in the supercritical state led to significant differences, but only in the case of diluted gels. When the initial dilution was low, similar results were indeed obtained with both solvents. Ethanol was shown to lead to higher shrinkages and higher bulk densities than acetone. A higher chemical degradation of the resin during the drying process was also observed when ethanol was used. © 2011 Elsevier B.V. All rights reserved.


PubMed | Gabes University, CNRS Jean Lamour Institute and Critt bois
Type: | Journal: Environmental science and pollution research international | Year: 2016

Olive stones (OS) were submitted to hydrothermal carbonisation (HTC) in order to evaluate the possibility of producing high added-value products, mainly furfural (FU) and 5-hydroxymethylfurfural (5-HMF) on one hand and hydrochars and carbons on the other hand. Temperature (160-240C), residence time (1-8h), initial pH (1-5.5) and liquid/solid ratio (4-48 w/w) were systematically varied in order to study the main products and to optimise FU production. FU production yield up to 19.9%, based on the hemicellulose content, was obtained. Other minor, but valuable, compounds such as 5-methylfurfural (5-MF) and some phenolic compounds were also produced. The hydrochar was carbonised at 900C, and the resultant carbon material was highly ultramicroporous with a peak of pore size distribution centred on 0.5nm and a surface area as high as 1065m


Golpayegani A.S.,CIRAD - Agricultural Research for Development | Golpayegani A.S.,Montpellier University | Thevenon M.-F.,CIRAD - Agricultural Research for Development | Gril J.,Montpellier University | And 2 more authors.
Maderas: Ciencia y Tecnologia | Year: 2014

The health problems amongst musical instrument makers working on the White mulberry (Morus alba), lead to investigate the toxicity potential of wood extractives. Five solvents of different polarity and two methods of extractions were used to ensure a thorough, clear and classified compound removal. The compounds were identified using qualitative GC-mass and the toxicity were determined by studying their effect on termite survival (Reticulitermes flavipes). The results indicated the presence of different compound categories like phenols, higher hydrocarbons, fatty acids, sterols and aromatic components in the extractives. These compounds were not removable by just one solvent and the order of removal was polarity related. The extractives were found toxic towards termites. Resorcinol, which corresponded to the highest proportion of peaks in the GC-mass spectra, has been assigned as the possible compound responsible for the allergic reactions by the artisans.


Bessieres J.,CNRS Wood Materials Research Laboratory | Maurin V.,Upper Alsace University | George B.,CNRS Wood Materials Research Laboratory | Molina S.,CNRS Wood Materials Research Laboratory | And 2 more authors.
Wood Science and Technology | Year: 2013

The penetration depth into wood structure by different wood finishes (solvent-borne, waterborne or powder) was assessed using a non-destructive analysis method, that is, X-ray tomography. The coating thickness was also evaluated. The results obtained from the image analysis by two specific softwares, namely VGStudio MAX® and ImageJ®, are compared and discussed by taking into account the chemical properties and anatomy of wood materials and the nature of finishes. The degree of coating penetration is mainly determined by its ability to flow into capillaries, and it was observed that resin type, solid matter content and drying method influence this ability. © 2013 Springer-Verlag Berlin Heidelberg.


Omrani P.,University of Lorraine | Mansouri H.R.,University of Lorraine | Pizzi A.,University of Lorraine | Masson E.,CRITT Bois
European Journal of Wood and Wood Products | Year: 2010

Grain direction has some influence on linear wood welding, but such differences are smaller with a newer welding technology and furthermore can be overcome by different techniques. © 2009 Springer-Verlag.


A double climatic chamber based on the guarded hot box method was designed to study the hygrothermal behaviour of different compositions of timber walls. Equipment installed allows to reproduce in the climatic chamber hygrothermal conditions close to real climatic conditions and to assess the evolution of temperature and humidity profiles of the tested walls. This paper deals with the hygrothermal behaviour of a timber-framed wall including hygroscopic materials. The results showed that the ability of the experimental device to reproduce desired conditions made it possible to measure wall thermal properties during steady-state (thermal resistance) and transient conditions (decrement factor and time lag). The hygroscopic behaviour of tested materials was also observed during the tests. © AFM, EDP Sciences 2013.


Grant
Agency: European Commission | Branch: FP7 | Program: CSA-SA | Phase: REGIONS-2007-2-02;REGIONS-2007-2-01 | Award Amount: 241.10K | Year: 2008

PRO-WOOD is a project designed to support an emerging wood cluster in the County of Brasov-Covasna in Romania. The wood sector has a long tradition in business and R&D, and an economic potential that needs to be developed. A very successful tool to trigger such economic and knowledge-based environments are cluster initiatives (CIs). However CIs do not have a long tradition in Eastern European, so called transition countries. Therefore it is the challenge of PRO-WOOD to initiate a know how-transfer in order to structure the existing cluster elements. The know how-transfer will be based upon a fact finding analysis and will be harmonized with the special needs of the wood sector in Brasov-Covasna. The project resolves to achieve four objectives: (1) Establish an infrastructure for regular co-operation between the stakeholders of the wood sector in Brasov-Covasna. (2) Trigger and increase the role of R&D within the future cluster work. (3) Formulate a vision for the wood cluster, that indicates objectives and measurable results. (4) Release a web-based network platform. Beside the economic effects that an established wood cluster will have for the region Brasov-Covasna, it will support the integration of the region into the European Research Area. Eight partners from Romania, Finland, France and Germany have formed a consortium. This partnership comprises the needed stakeholders on the Romanian side and the knowledge about cluster policy tools, wood research and business on the other side.

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