Download or read book Mat riaux hybrides organiques inorganiques pr par s par voie sol gel Origine et contr le de leur organisation written by Frédéric Ben and published by . This book was released on 2001 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mat riaux hybrides organo min raux written by Touria Jermoumi and published by . This book was released on 1994 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book SYNTHESE ET CARACTERISATION DE MATERIAUX HYBRIDES ORGANIQUES INORGANIQUES written by FRANCOISE.. SURIVET and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: DE NOUVELLES FORMULATIONS HYBRIDES ORGANIQUES/INORGANIQUES ONT ETE MISES AU POINT EN VUE D'APPLICATIONS OPTIQUES. LA NATURE DE LA SEQUENCE SOUPLE DE TYPE POLYBUTADIENE HYDROGENE OU POLYDIMETHYLSILOXANE CONFERE A CES NOUVEAUX MATERIAUX HYBRIDES DE BONNES PROPRIETES TELLES QU'UNE EXCELLENTE TENUE AUX UV ET UNE BONNE RESISTANCE A L'OXYDATION. DEVANT LA RELATIVE COMPLEXITE DES PHENOMENES, NOUS AVONS SUIVI LES REACTIONS D'HYDROLYSE ET DE CONDENSATION DES FONCTIONS ALCOXY-SILANE SUR DES MACROMERES MODELES. LA RESONANCE MAGNETIQUE NUCLEAIRE DU SILICIUM ET LA CHROMATOGRAPHIE PAR EXCLUSION DE TAILLE NOUS NOUS ONT PERMIS DE CARACTERISER COMPLETEMENT LES DIFFERENTS PRODUITS DE REACTION ET DE MODELISER LE SCHEMA REACTIONNEL. L'ETUDE DE CES REACTIONS A ETE COMPLETEE PAR DES ETUDES CONCERNANT LA GELIFICATION. LES REACTIONS D'HYDROLYSE ET DE CONDENSATION SONT TRES RAPIDES. PAR LA SUITE, LE RALENTISSEMENT DE LA REACTION POURRAIT ETRE ATTRIBUE D'UNE PART A LA DIMINUTION DE LA REACTIVITE DES GROUPEMENTS REACTIFS ET D'AUTRE PART A DES CHANGEMENTS DE PHASE ET/OU DE VITRIFICATION. LA STRUCTURE COMPLEXE DES CERAMERES A ETE ETUDIEE EN CONFRONTANT DEUX TECHNIQUES D'ANALYSE, L'ANALYSE MECANIQUE DYNAMIQUE ET LA DIFFUSION DES RAYONS X AUX PETITS ANGLES. NOUS AVONS AINSI MONTRE QUE LA NATURE CHIMIQUE ET LA MASSE MOLAIRE DE L'OLIGOMERE, AINSI QUE LES DIFFERENTS TRAITEMENTS THERMIQUES AFFECTENT LA STRUCTURE DES RESEAUX. LA MISCIBILITE DES SEQUENCES URETHANE-UREE AVEC L'OLIGOMERE DE DEPART SEMBLE EGALEMENT JOUER UN ROLE IMPORTANT QUANT A LA MORPHOLOGIE DES CERAMERES

Download or read book ETUDE DE MATERIAUX HYBRIDES ORGANIQUES INORGANIQUES A BASE DE POLYBUTADIENE HYDROGENE RELATION VOIE DE SYNTHESE GELEFICATION MORPHOLOGIE FINALE written by HAMID.. KADDAMI and published by . This book was released on 1995 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: L'ETUDE CONSISTE EN L'ELABORATION DES MATERIAUX HYBRIDES ORGANIQUESINORGANIQUES A BASE DE POLYBUTADIENE HYDROGENE ET D'ALCOXYDES DE SILICIUM (APS, IPS ET TEOS) SUIVANT TROIS VOIES DE SYNTHESE DIFFERENTES: HPBD/DIISOCYANATE IPDI/APS ; HPBD/IPS ET HPBD/TEOS. EN ETUDIANT LA GELIFICATION ET LA MORPHOLOGIE FINALE EN FONCTION DES CONDITIONS DE REACTION, NOUS CONCLUONS: * LA VARIATION DE LA VOIE D'ELABORATION ENTRAINE DANS UNE ETAPE INTERMEDIAIRE LA FORMATION DE MACROMONOMERES FONCTIONNALISES ALCOXYSILANE DE STRUCTURES CHIMIQUES, PRESENTANT L'ENCOMBREMENT DIFFERANT DES GROUPEMENTS REACTIFS ALCOXYSILANE. CES DIFFERENCES ENTRAINERONT PAR LA SUITE DES ECARTS IMPORTANTS DES DEGRES DE CONVERSION FINAUX. * L'ETUDE DE LA RETICULATION A MONTRE QUE CES SYSTEMES ONT DES MODES DE GELIFICATION DIFFERENTS. EFFECTIVEMENT, POUR LES SYSTEMES HPBDIPS, LA VITRIFICATION DE ZONES RICHES EN COMPOSES INORGANIQUES, SE PRODUISANT EN MEME TEMPS QUE LA GELIFICATION DU SYSTEME, EST MISE EN EVIDENCE POUR TOUTES LES CONDITIONS EXPERIMENTALES (QUANTITE DE CATALYSEUR ET TEMPERATURE DE REACTION). CEPENDANT, POUR LES SYSTEMES HPBD/IPDI/APS LA VITRIFICATION DES ZONES INORGANIQUES SE MANIFESTE SEULEMENT LORSQUE LE GEL EST ATTEINT RAPIDEMENT. * LUNE ETUDE MORPHOLOGIQUE A MONTRE QUE, POUR TOUTES LES QUANTITES DE CATALYSEUR UTILISEES, LES MATERIAUX HYBRIDES ORGANIQUES-INORGANIQUES HPBD/IPS ET HPBD/TEOS, ONT DES MORPHOLOGIES VOISINES: ZONES INORGANIQUES DE FAIBLE TAILLE (NANOMETRIQUE) ET DE FORT RAPPORT FONCTIONNALITE/TAILLE DANS UNE MATRICE ORGANIQUE. CETTE MORPHOLOGIE EST IDENTIQUE A CELLE DES SYSTEMES HPBD/IPDI/APS AVEC DE FORTES QUANTITES DE CATALYSEUR. CEPENDANT, POUR LES FAIBLES QUANTITES DE CATALYSEUR ACIDE, UNE MORPHOLOGIE DIFFERENTE EST REVELEE: EN PLUS DE ZONES INORGANIQUES DE TAILLE FAIBLE, UNE PHASE MIXTE DE GRANDE TAILLE ET DE FAIBLE RAPPORT FONCTIONNALITE/TAILLE EST FORMEE ENTRAINANT UNE CHUTE DES PROPRIETES MECANIQUES DES MATERIAUX. LA FORMATION DE CES DERNIERES ZONES S'EXPLIQUE PAR LA MISCIBILITE PARTIELLE DES CHAINES ORGANIQUES AVEC LES ALCOXYSILANES PARTIELLEMENT CONDENSES

Download or read book Mat riaux hybrides organo min raux labor s partir de pr curseurs mol culaires liaison Si C Caract risation et r activit written by Philippe Thepot and published by . This book was released on 1993 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: DES MATERIAUX AMORPHES HYBRIDES ORGANO-MINERAUX DE TYPE SILSESQUIOXANE RSIO#1#,#5 ONT ETE ELABORES, PAR LA VOIE SOL-GEL, A PARTIR DE MONOMERES ORGANOSILICIES POLYFONCTIONNELS. LES SOLIDES OBTENUS SONT MICROPOREUX ET PRESENTENT DE GRANDES SURFACES SPECIFIQUES. LES CARACTERISTIQUES PHYSIQUES ET MORPHOLOGIQUES DEPENDENT PLUS DES CONDITIONS EXPERIMENTALES QUE DE LA STRUCTURE ET DE LA GEOMETRIE DES PRECURSEURS MOLECULAIRES SIMPLES ETUDIES. L'INFLUENCE D'INTERACTIONS ENTRE LES MOLECULES DE PRECURSEUR SUR L'ELABORATION DU SOLIDE A EGALEMENT ETE MISE EN EVIDENCE. LA FORMATION DE GELS A PARTIR DE PRECURSEURS OLEFINIQUES EST CATALYSEE PAR DES SELS DE PD#I#I. LA COORDINATION DE MOLECULES DE PRECURSEUR SUR LE METAL ACCELERE NOTABLEMENT LA POLYCONDENSATION ET CONDUIT A DES SOLIDES DE TRES FAIBLE POROSITE OU SURFACE SPECIFIQUE. UN GEL HYBRIDE CONTENANT DES UNITES COMPLEXE DE TRANSFERT DE CHARGE TERTHIOPHENE/TCNQ A ETE CARACTERISE. CE SOLIDE PRESENTE DES CARACTERISTIQUES TRES DIFFERENTES DE CELLES DE GELS ANALOGUES OBTENUS EN L'ABSENCE DE TCNQ. L'OXYDATION DE LA LIAISON SI-C DANS DES GELS A PONTS THIOPHENYLENE A PERMIS DE METTRE EN EVIDENCE LA FORMATION DE POLYTHIOPHENE AU SEIN DU SOLIDE AMORPHE. CE COUPLAGE OXYDANT A ETE ETENDU AUX MONOMERES SILYLES EN SOLUTION. L'OXYDATION ANODIQUE PERMET D'OBTENIR DES POLYTHIOPHENES DONT LES CARACTERISTIQUES IR ET RAMAN REVELENT DES LONGUEURS DE CONJUGAISON TRES ELEVEES. ENFIN, LA LIAISON SI-C LABILE DANS DES GELS HYBRIDES CONTENANT DES MOTIFS 1,3-BUTADIYNE A PERMIS L'ELIMINATION DU MOTIF ORGANIQUE DANS DES CONDITIONS DOUCES, OUVRANT AINSI DES PERSPECTIVES POUR L'ELABORATION CONTROLEE DE GELS INORGANIQUES A PARTIR DE MATERIAUX HYBRIDES

Download or read book Elaboration et tude de mat riaux hybrides organiques inorganiques written by Olivier Porcherie and published by . This book was released on 2003 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mat riaux hybrides organiques inorganiques lamellaires base de phosphate de zirconium et de complexes organiques de terres rares written by Shanez Tlemsani and published by . This book was released on 2003 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ce travail présente la synthèse, la caractérisation et l'étude des propriétés optiques de composés hybrides organiques-inorganiques lamellaires à base de phosphate de zirconium, activés par l'europium trivalent. Des techniques de synthèse organique multi-stades ont permis l'élaboration de ligands organiques dérivés de la 1,3-diphényle-1,3-propanedione(dibenzoyleméthane), par création d'une fonction amine terminale. Les complexes de terres rares associés ont été obtenus avec les ions Y3+, Eu3+ et Tb3+. L'insertion de ces complexes dans les feuillets minéraux de phosphate de zirconium a nécessité au préalable des étapes de pré-intercalation, conduisant à un écartement du réseau minéral par l'éthanol et la p-méthoxyaniline (PMA). De nombreuses conditions opératoires ont été mises en jeu afin d'obtenir les matériaux hybrides les mieux structurés. La caractérisation des complexes organiques et des matériaux hybrides correspondants a été conduite par analyses élémentaire et thermique, spectroscopie infrarouge, diffraction des rayons X, EXAFS et RMN. La diffraction des rayons X a permis de confirmer le maintien d'une structure lamellaire pour les matériaux hybrides élaborés. La stectroscopie infrarouge et la RMN ont aussi démontré l'interaction existant entre les composantes organique et minérale, par le biais de liaisons hydrogène résultant d'interactions acide-base entre les fonctions amines des molécules organiques et les groupements P-OH des feuillets minéraux. Les propriétés optiques ont permis d'identifier les centres absorbants et émetteurs, de préciser les niveaux électroniques mis en jeu et d'appréhender les chemins de désexcitation et de recombinaison active. L'incorporation des complexes d'europium dans le réseau minéral est à l'origine d'un accroissement de la symétrie ponctuelle, voire même d'une orientation vers la symétrie plus axiale, probablement liée à une configuration plane de ceux-ci. L'influence du réseau hôte en terme de champ cristallin subi Eu3+ est aussi visible dans les matériaux hybrides. Les cinétiques de désexcitation et de tranfert ont été interprétées et discutées sur la base du modèle ATE (Absorption-Transfert-Emission)

Download or read book Elaboration de mat riaux hybrides organiques inorganiques propri t s optiques written by Eric Besson and published by . This book was released on 2004 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synth se et caract risation de gels de silice dans les milieux amphiphiles organis s Application l laboration de mat riaux texture anisotrope ou porosit ordonn e et modulable written by Thierry Dabadie and published by . This book was released on 1994 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: UNE NOUVELLE TECHNIQUE DE STRUCTURATION DE MATERIAUX INORGANIQUES PAR VOIE SOL-GEL A ETE MISE AU POINT. CERTAINS TENSIO-ACTIFS PERMETTENT LA PREPARATION DE CRISTAUX LIQUIDES LYOTROPES EN PHASE LAMELLAIRE OU HEXAGONALE. DE TELLES STRUCTURES SONT SUSCEPTIBLES D'ETRE FIGEES LORS DE LA GELIFICATION ET DE LA FORMATION DU RESEAU INORGANIQUE. DANS LE CAS DES GELS HUMIDES, CETTE TECHNIQUE PEUT GENERER UNE ORIENTATION ET UNE ANISOTROPIE DU RESEAU INORGANIQUE LORS DE L'APPLICATION D'UN CISAILLEMENT. DANS LE CAS DE GELS TRAITES THERMIQUEMENT, IL S'AVERE POSSIBLE D'OBTENIR UNE POROSITE ORDONNEE ET MODULABLE APRES ELIMINATION DE LA MESOPHASE STRUCTURANTE. DES COUCHES MINCES SONT PREPAREES ET APPLIQUEES A LA REALISATION DE MEMBRANES SEPARATIVES MICROPOREUSES. CES MEMBRANES SONT TESTEES EN PERVAPORATION

Download or read book Relation entre la structure et les propri t s m caniques de films minces hybrides organiques inorganiques pr par s par voie sol gel written by Fayna Mammeri and published by . This book was released on 2003 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ICREEC 2019 written by Ahmed Belasri and published by Springer Nature. This book was released on 2020-06-10 with total page 659 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights peer reviewed articles from the 1st International Conference on Renewable Energy and Energy Conversion, ICREEC 2019, held at Oran in Algeria. It presents recent advances, brings together researchers and professionals in the area and presents a platform to exchange ideas and establish opportunities for a sustainable future. Topics covered in this proceedings, but not limited to, are photovoltaic systems, bioenergy, laser and plasma technology, fluid and flow for energy, software for energy and impact of energy on the environment.

Download or read book Encapsulations written by Alexandru Grumezescu and published by Academic Press. This book was released on 2016-05-27 with total page 926 pages. Available in PDF, EPUB and Kindle. Book excerpt: Encapsulations, a volume in the Nanotechnology in the Agri-Food Industry series,presents key elements in establishing food quality through the improvement of food flavor and aroma. The major benefits of nanoencapsulation for food ingredients include improvement in bioavailability of flavor and aroma ingredients, improvement in solubility of poor water-soluble ingredients, higher ingredient retention during production process, higher activity levels of encapsulated ingredients, improved shelf life, and controlled release of flavor and aroma. This volume discusses main nanoencapsulation processes such as spray drying, melt injection, extrusion, coacervation, and emulsification. The materials used in nanoencapsulation include lipids, proteins, carbohydrates, cellulose, gums, and food grade polymers. Applications and benefits of nanoencapsulation such as controlled release, protections, and taste masking will be explained in detail. Includes the most up-to-date information on nanoencapsulation and nanocontainer-based delivery of antimicrobials Presents nanomaterials for innovation based on scientific advancements in the field Provides control release strategies to enhance bioactivity, including methods and techniques for research and innovation Provides useful tools to improve the delivery of bioactive molecules and living cells into foods

Download or read book Materials Syntheses written by Ulrich Schubert and published by Springer Science & Business Media. This book was released on 2008-11-23 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: Materials syntheses are more complex than syntheses of inorganic or organic compounds. Materials synthesis protocols often suffer from unclarities, irreproducibility, lack in detail and lack in standards. The need to change this situation is the main motivation for this book. It collects a number of detailed protocols, ranging from organic polymers to carbonaceous and ceramic materials, from gels to porous and layered materials and from powders and nanoparticles to films.

Download or read book In Situ Gelling Polymers written by Xian Jun Loh and published by Springer. This book was released on 2014-10-01 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the research involving in situ gelling polymers and can be used as a guidebook for academics, industrialists and postgraduates interested in this area. This work summaries the academic contributions from the top authorities in the field and explore the fundamental principles of in situ gelling polymeric networks, along with examples of their major applications. This book aims to provide an up-to-date resource of in situ gelling polymer research.

Download or read book Flexoelectricity in Liquid Crystals written by Agnes Buka and published by World Scientific. This book was released on 2013 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book intends to give a state-of-the-art overview of flexoelectricity, a linear physical coupling between mechanical (orientational) deformations and electric polarization, which is specific to systems with orientational order, such as liquid crystals. Chapters written by experts in the field shed light on theoretical as well as experimental aspects of research carried out since the discovery of flexoelectricity. Besides a common macroscopic (continuum) description the microscopic theory of flexoelectricity is also addressed. Electro-optic effects due to or modified by flexoelectricity as well as various (direct and indirect) measurement methods are discussed. Special emphasis is given to the role of flexoelectricity in pattern-forming instabilities. While the main focus of the book lies in flexoelectricity in nematic liquid crystals, peculiarities of other mesophases (bent-core systems, cholesterics, and smectics) are also reviewed. Flexoelectricity has relevance to biological (living) systems and can also offer possibilities for technical applications. The basics of these two interdisciplinary fields are also summarized.

Download or read book Wood Adhesives written by Antonio Pizzi and published by CRC Press. This book was released on 2011-01-07 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wood adhesives are of tremendous industrial importance, as more than two-thirds of wood products in the world today are completely or partially bonded together using a variety of adhesives. Adhesive bonding offers many advantages over other joining methods for wood components, and there has been a great deal of R& D activity in devising new wood adhesives or improving the existing ones. The modern mantra in all industrial sectors is: "think green, go green," which has attracted much attention in the wood adhesive industry. Therefore, there is also a lot of research activity in synthesizing environmentally benign and human-friendly wood adhesives. This book is divided into four parts: Part 1: Fundamental Adhesion Aspects in Wood Bonding; Part 2: Synthetic Adhesives; Part 3: Environment-friendly adhesives; and Part 4: Wood Welding and General Paper. It addresses many different types of wood adhesives, as well as bonding (welding) of wood components without adhesives, a more recent development. The information contained in this book is valuable for individuals engaged in all aspects of wood adhesion and adhesives and, hopefully, will inspire new ideas in wood adhesives, a topic of vital industrial importance.

Download or read book X Ray and Neutron Reflectivity Principles and Applications written by Jean Daillant and published by Springer Science & Business Media. This book was released on 2003-07-01 with total page 347 pages. Available in PDF, EPUB and Kindle. Book excerpt: The reflection of and neutrons from surfaces has existed as an x-rays exp- imental for almost it is in the last technique fifty Nevertheless, only years. decade that these methods have become as of enormously popular probes This the surfaces and interfaces. to be due to of several appears convergence of intense different circumstances. These include the more n- availability be measured orders tron and sources that can over (so reflectivity x-ray many of and the much weaker surface diffuse can now also be magnitude scattering of thin films and studied in some the detail); growing importance multil- basic the realization of the ers in both and technology research; important which in the of surfaces and and role roughness plays properties interfaces; the of statistical models to characterize the of finally development topology its and its characterization from on roughness, dependence growth processes The of and to surface scattering experiments. ability x-rays neutro4s study four five orders of in scale of surfaces over to magnitude length regardless their and also their to ability probe environment, temperature, pressure, etc. , makes these the choice for buried interfaces often probes preferred obtaining information about the microstructure of often in statistical a global surfaces, the local This is manner to complementary imaging microscopy techniques, of such studies in the literature witnessed the veritable by explosion published the last few Thus these lectures will useful for over a resource years.