Résultat de la recherche
7 résultat(s) recherche sur le tag 'FT-IR' 
Visionner les documents numériques
Affiner la recherche Générer le flux rss de la recherche
Partager le résultat de cette recherche Interroger des sources externes
Titre : Etude structurale et optique de matériaux composites Type de document : texte imprimé Auteurs : Mouloud Hemara, Auteur ; Zeineddine Ouili, Directeur de thèse Editeur : Constantine : Université Mentouri Constantine Année de publication : 2015 Importance : 75 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : composites nanocomposites oxyde niobium (Nb2O5 ) Czochralski DRX ?-Raman FT-IR absorption UV-Visible radioluminescence niobium oxide ( Nb2O5 ) XRD UV-Visible absorption ???????? ?????? ?????? ????? ????????? Nb2O5 ????? ???? ????? ?????? ???? ??? ????? ??????? ????? ??????? ???????? ?????? ?? ?????? ?????? ?????? ? ??? ???????? ????????? ??????? Index. décimale : 530 Physique Résumé : This work is the development of single crystals KBr and KCl pure and doped with Nb crystallites was carried out by the drawing method according to the principle of Czochralski growth .
The structural study and optical different matrices , alkali halides to know the effects of doping on their properties.
The structural analysis of the samples prepared was carried out by the X-ray diffraction and IR spectroscopy and micro -Raman .
XRD revealed the incorporation of Nb crystallite in the crystal matrix , and produces another Nano phase ( Nb2O5 ) .
The μ -Raman and FT-IR spectroscopy to confirm the results of the characterization by X-ray diffraction as regards the presence of the phase Nb2O5 and existed the Nb- O chemical bond in the crystal matrices KBr and KCl .
The optical absorption study for the nanocomposites prepared Nb / Nb and KBr / KCl show a transparent matrices in the Visible and Ultraviolet related field , When these matrices are doped with Nb2O5 nanocrystallites their optical gap decrease.
The optical characterization radioluminescence for samples prepared shown that this low-intensity luminescence in the visible range when excited by radiation X.
Diplôme : Magistère En ligne : ../theses/physique/HEM6747.pdf Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=9869 Etude structurale et optique de matériaux composites [texte imprimé] / Mouloud Hemara, Auteur ; Zeineddine Ouili, Directeur de thèse . - Constantine : Université Mentouri Constantine, 2015 . - 75 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : composites nanocomposites oxyde niobium (Nb2O5 ) Czochralski DRX ?-Raman FT-IR absorption UV-Visible radioluminescence niobium oxide ( Nb2O5 ) XRD UV-Visible absorption ???????? ?????? ?????? ????? ????????? Nb2O5 ????? ???? ????? ?????? ???? ??? ????? ??????? ????? ??????? ???????? ?????? ?? ?????? ?????? ?????? ? ??? ???????? ????????? ??????? Index. décimale : 530 Physique Résumé : This work is the development of single crystals KBr and KCl pure and doped with Nb crystallites was carried out by the drawing method according to the principle of Czochralski growth .
The structural study and optical different matrices , alkali halides to know the effects of doping on their properties.
The structural analysis of the samples prepared was carried out by the X-ray diffraction and IR spectroscopy and micro -Raman .
XRD revealed the incorporation of Nb crystallite in the crystal matrix , and produces another Nano phase ( Nb2O5 ) .
The μ -Raman and FT-IR spectroscopy to confirm the results of the characterization by X-ray diffraction as regards the presence of the phase Nb2O5 and existed the Nb- O chemical bond in the crystal matrices KBr and KCl .
The optical absorption study for the nanocomposites prepared Nb / Nb and KBr / KCl show a transparent matrices in the Visible and Ultraviolet related field , When these matrices are doped with Nb2O5 nanocrystallites their optical gap decrease.
The optical characterization radioluminescence for samples prepared shown that this low-intensity luminescence in the visible range when excited by radiation X.
Diplôme : Magistère En ligne : ../theses/physique/HEM6747.pdf Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=9869 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité HEM/6747 HEM/6747 Thèse Bibliothèque principale Thèses Disponible Elaboration et caractérisation de matériaux composites à base des nanoparticules du semi-conducteur CuO et de l’oxyde de terre rare Dy2O3 dispersées dans les matrices diélectriques KBr, KCl et NaCl. / Samiya Addala
Titre : Elaboration et caractérisation de matériaux composites à base des nanoparticules du semi-conducteur CuO et de l’oxyde de terre rare Dy2O3 dispersées dans les matrices diélectriques KBr, KCl et NaCl. Type de document : texte imprimé Auteurs : Samiya Addala, Auteur ; O. Halimi, Directeur de thèse Editeur : Constantine : Université Mentouri Constantine Année de publication : 2015 Importance : 106 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : NaCl KCl KBr semiconducteur (CuO) oxyde de terre rare (Dy2O3) Czochralski DRX FT-IR µ-Ramn MEB-EDX UV-Visible photoluminescence semiconductor (CuO) rare earth oxide (Dy2O3) XRD IR ?-Ramn Uvi-Vis ???????? ??????????? ??? ?????? )CuO( ??????)Dy2O3) ????? ????????? ?????? ???? X ????????
?????? ???? ????? ? ?????? ?? ??? ??????? ?????? ?????????? ?????? MEBIndex. décimale : 530 Physique Résumé : Elaboration and characterization of composite materials based on nanoparticles of the semiconductor CuO and the rare earth oxide Dy2O3 dispersed in the dielectric matrix of KBr, KCl and NaCl In this work copper oxide (CuO) and dysprosium oxide (Dy2O3) nanocrystals doped KBr, KCl and NaCl single crystals have been grown by Czochralski (Cz) method.
The effects of doping on the structural and optical properties of the host matrices have been studied.
The structural studies of samples were performed by XRD, μ-Raman, IR spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX).The treatment of XRD spectrum confirms the existence of crystallites of dopants (Sb2O3 and Y2O3) in the nanometer regime;Studies by μ-Raman and IR confirmed the
presence of chemical bonds Dy—Oand Cu—O in the different matrices.
The morphological study using the scanning electron microscope (SEM) shows that the micron grains scattered on the surface. The microscopic size of these aggregates is due to the fact that the nanocrystals have a tendency to reduce its free energy (Gibbs energy) of surface. The energy dispersive X-ray analysis (EDX) spectrum indicates that
the NaCl:CuO single crystal has a very high purity.
The optical absorption and photoluminescence shows that the optical gaps of the crystallites (CuO and Dy2O3) have been shifted to the high energy due to the quantum confinement effect of the charges.
The samples have important intense luminescence properties in the ultraviolet range. This feature makes these materials candidates which might come in the manufacture of components for optical systems using shorter wavelengths.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/ADD6746.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=9870 Elaboration et caractérisation de matériaux composites à base des nanoparticules du semi-conducteur CuO et de l’oxyde de terre rare Dy2O3 dispersées dans les matrices diélectriques KBr, KCl et NaCl. [texte imprimé] / Samiya Addala, Auteur ; O. Halimi, Directeur de thèse . - Constantine : Université Mentouri Constantine, 2015 . - 106 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : NaCl KCl KBr semiconducteur (CuO) oxyde de terre rare (Dy2O3) Czochralski DRX FT-IR µ-Ramn MEB-EDX UV-Visible photoluminescence semiconductor (CuO) rare earth oxide (Dy2O3) XRD IR ?-Ramn Uvi-Vis ???????? ??????????? ??? ?????? )CuO( ??????)Dy2O3) ????? ????????? ?????? ???? X ????????
?????? ???? ????? ? ?????? ?? ??? ??????? ?????? ?????????? ?????? MEBIndex. décimale : 530 Physique Résumé : Elaboration and characterization of composite materials based on nanoparticles of the semiconductor CuO and the rare earth oxide Dy2O3 dispersed in the dielectric matrix of KBr, KCl and NaCl In this work copper oxide (CuO) and dysprosium oxide (Dy2O3) nanocrystals doped KBr, KCl and NaCl single crystals have been grown by Czochralski (Cz) method.
The effects of doping on the structural and optical properties of the host matrices have been studied.
The structural studies of samples were performed by XRD, μ-Raman, IR spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX).The treatment of XRD spectrum confirms the existence of crystallites of dopants (Sb2O3 and Y2O3) in the nanometer regime;Studies by μ-Raman and IR confirmed the
presence of chemical bonds Dy—Oand Cu—O in the different matrices.
The morphological study using the scanning electron microscope (SEM) shows that the micron grains scattered on the surface. The microscopic size of these aggregates is due to the fact that the nanocrystals have a tendency to reduce its free energy (Gibbs energy) of surface. The energy dispersive X-ray analysis (EDX) spectrum indicates that
the NaCl:CuO single crystal has a very high purity.
The optical absorption and photoluminescence shows that the optical gaps of the crystallites (CuO and Dy2O3) have been shifted to the high energy due to the quantum confinement effect of the charges.
The samples have important intense luminescence properties in the ultraviolet range. This feature makes these materials candidates which might come in the manufacture of components for optical systems using shorter wavelengths.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/ADD6746.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=9870 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité ADD/6746 ADD/6746 Thèse Bibliothèque principale Thèses Disponible 
Titre : Elaboration et caractérisation structurale et optique des nanocristaux du semiconducteur Sb2O3 et de l'oxyde Y2O3 dispersés dans les matrices cristallines des halogénures alcalins KBr, KCl et NaCl Type de document : texte imprimé Auteurs : Lazhar Bouhdjer, Auteur ; M. Sebais, Directeur de thèse Editeur : constantine [Algérie] : Université Constantine 1 Année de publication : 2013 Importance : 93 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : semi-conducteur Sb2O3 oxyde de terre rare Y2O3 Czochralski DRX FT-IR ?-Ramn absorption UV-Visible photoluminescence semiconductor (Sb2O3) rare earth oxide (Y2O3) XRD IR ?-
Ramn Uvi-Vis ???????? ???????????
????? ????????? ???????? ?????? ???? ????? ? ?????? ?? ??? ??????? ?????? ?????????? ?????? MEB (Sb2O3)??? ?????? (Y2O3)??????
?????? ?????? XIndex. décimale : 530 Physique Résumé : Preparation and structural and optical characterization of semiconductor nanocrystals
of Sb2O3 and Y2O3 oxide dispersed in a crystalline matrices of alkali halides KBr, KCl
and NaCl.
In this work antimony oxide (Sb2O3) and yttrium oxide (Y2O3) nanocrystals doped KBr, KCl and NaCl single crystals have been grown by Czochralski (Cz) method.
The effects of doping on the structural and optical properties of the host matrices have
been studied.
The structural studies of samples were performed by XRD, μ-Raman, IR spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). The treatment of XRD spectrum confirms the existence of crystallites of dopants (Sb2O3 and Y2O3) in the nanometer regime; on the other hand, the existence of the stable monoclinic phase crystallites (Y2O3) under atmospheric conditions reconfirms presence of (Y2O3) in nanoscale.
Studies by μ-Raman and IR confirmed the presence of chemical bonds Y—O and Sb—O in the different matrices.
The morphological study using the scanning electron microscope (SEM) shows that the micron grains scattered on the surface. The volume of these aggregates is due to the fact that the nanocrystals have a tendency to reduce its free energy (Gibbs energy) of surface.
The optical absorption and photoluminescence shows that the optical gaps of the crystallites (Sb2O3 and Y2O3) have been shifted to the high energy due to the quantum confinement effect of the charges.
The samples have important intense luminescence properties in the ultraviolet range. This feature makes these materials candidates which might come in the manufacture of components for optical systems using shorter wavelengths.Diplôme : Doctorat en sciences En ligne : ../theses/physique/BOU6378.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=9379 Elaboration et caractérisation structurale et optique des nanocristaux du semiconducteur Sb2O3 et de l'oxyde Y2O3 dispersés dans les matrices cristallines des halogénures alcalins KBr, KCl et NaCl [texte imprimé] / Lazhar Bouhdjer, Auteur ; M. Sebais, Directeur de thèse . - constantine (Route ain el bey, Algérie) : Université Constantine 1, 2013 . - 93 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : semi-conducteur Sb2O3 oxyde de terre rare Y2O3 Czochralski DRX FT-IR ?-Ramn absorption UV-Visible photoluminescence semiconductor (Sb2O3) rare earth oxide (Y2O3) XRD IR ?-
Ramn Uvi-Vis ???????? ???????????
????? ????????? ???????? ?????? ???? ????? ? ?????? ?? ??? ??????? ?????? ?????????? ?????? MEB (Sb2O3)??? ?????? (Y2O3)??????
?????? ?????? XIndex. décimale : 530 Physique Résumé : Preparation and structural and optical characterization of semiconductor nanocrystals
of Sb2O3 and Y2O3 oxide dispersed in a crystalline matrices of alkali halides KBr, KCl
and NaCl.
In this work antimony oxide (Sb2O3) and yttrium oxide (Y2O3) nanocrystals doped KBr, KCl and NaCl single crystals have been grown by Czochralski (Cz) method.
The effects of doping on the structural and optical properties of the host matrices have
been studied.
The structural studies of samples were performed by XRD, μ-Raman, IR spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). The treatment of XRD spectrum confirms the existence of crystallites of dopants (Sb2O3 and Y2O3) in the nanometer regime; on the other hand, the existence of the stable monoclinic phase crystallites (Y2O3) under atmospheric conditions reconfirms presence of (Y2O3) in nanoscale.
Studies by μ-Raman and IR confirmed the presence of chemical bonds Y—O and Sb—O in the different matrices.
The morphological study using the scanning electron microscope (SEM) shows that the micron grains scattered on the surface. The volume of these aggregates is due to the fact that the nanocrystals have a tendency to reduce its free energy (Gibbs energy) of surface.
The optical absorption and photoluminescence shows that the optical gaps of the crystallites (Sb2O3 and Y2O3) have been shifted to the high energy due to the quantum confinement effect of the charges.
The samples have important intense luminescence properties in the ultraviolet range. This feature makes these materials candidates which might come in the manufacture of components for optical systems using shorter wavelengths.Diplôme : Doctorat en sciences En ligne : ../theses/physique/BOU6378.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=9379 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BOU/6378 BOU/6378 Thèse Bibliothèque principale Thèses Disponible Documents numériques
texte intégraleAdobe Acrobat PDF
Titre : Synthèse, réactivité et étude structurale des complexes organométallocarbonyles mononucléaires, marqueurs de molécules biologiquement actives Type de document : texte imprimé Auteurs : Salah Merniz, Auteur ; M. Mokhtari, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2015 Importance : 105 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
ChimieTags : Complexes fer carbonyle Marquage Activité antibactérienne FT-IR RX Carbonyl Iron complexes labelling Antibacterial activity ???? ?????? ?????????? ???? ?????? ?????????? Index. décimale : 540 Chimie et sciences connexes Résumé : The objective of this work is the use of the organometallo-carbonyl as biological molecules markers. In fact, such molecules marked constitute easily detectable probes using IR spectroscopy because of the specific signals associated with the carbonyls ligands related to metal in the 1800-2200 cm-1 region.
In this domain, our contribution consists of the preparation and the structural study of new tricarbonyles iron obtained by covalent coupling between the cation [tricarbonyl (1-5-h- cyclohexa-1,3-diene) iron] tetrafluoroborate and the three biologically active molecules : the N-acetyl histamine, the imidazolidine-2-thione and the 2-aminothiazole. The labeled complexes have been purified and characterized by the spectroscopically (IR, RMN 1H)
methods.
Three complexes structure [Tricarbonyl (1-4-h–5- N-acetyl histaminio cyclohexa-1,3- diene) iron] 2, [Tricarbonyl (1-4-h-5-N-imidazolidinio-2-thione cyclohexa-1,3-diene) iron] 3 and [Tricarbonyl (1-4-h–5-N-2-aminothiazolio cyclohexa-1,3-diene) iron] 4 have been determined by X-ray crystallography revealing the exo enantiomer existence for 2 and for 4
and for dimer 3.
The biological activity of two free ligands imidazolidine-2-thione and the 2- aminothiazole showed an important antibacterial activity .After labeling them (3 and 4 respectively), this activity has decreased for the complex 3 and increased for the complex 4.
Diplôme : Doctorat en sciences En ligne : ../theses/chimie/MER6682.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=9945 Synthèse, réactivité et étude structurale des complexes organométallocarbonyles mononucléaires, marqueurs de molécules biologiquement actives [texte imprimé] / Salah Merniz, Auteur ; M. Mokhtari, Directeur de thèse . - [S.l.] : جامعة الإخوة منتوري قسنطينة, 2015 . - 105 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ChimieTags : Complexes fer carbonyle Marquage Activité antibactérienne FT-IR RX Carbonyl Iron complexes labelling Antibacterial activity ???? ?????? ?????????? ???? ?????? ?????????? Index. décimale : 540 Chimie et sciences connexes Résumé : The objective of this work is the use of the organometallo-carbonyl as biological molecules markers. In fact, such molecules marked constitute easily detectable probes using IR spectroscopy because of the specific signals associated with the carbonyls ligands related to metal in the 1800-2200 cm-1 region.
In this domain, our contribution consists of the preparation and the structural study of new tricarbonyles iron obtained by covalent coupling between the cation [tricarbonyl (1-5-h- cyclohexa-1,3-diene) iron] tetrafluoroborate and the three biologically active molecules : the N-acetyl histamine, the imidazolidine-2-thione and the 2-aminothiazole. The labeled complexes have been purified and characterized by the spectroscopically (IR, RMN 1H)
methods.
Three complexes structure [Tricarbonyl (1-4-h–5- N-acetyl histaminio cyclohexa-1,3- diene) iron] 2, [Tricarbonyl (1-4-h-5-N-imidazolidinio-2-thione cyclohexa-1,3-diene) iron] 3 and [Tricarbonyl (1-4-h–5-N-2-aminothiazolio cyclohexa-1,3-diene) iron] 4 have been determined by X-ray crystallography revealing the exo enantiomer existence for 2 and for 4
and for dimer 3.
The biological activity of two free ligands imidazolidine-2-thione and the 2- aminothiazole showed an important antibacterial activity .After labeling them (3 and 4 respectively), this activity has decreased for the complex 3 and increased for the complex 4.
Diplôme : Doctorat en sciences En ligne : ../theses/chimie/MER6682.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=9945 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité MER/6682 MER/6682 Thèse Bibliothèque principale Thèses Disponible
Titre : Elaboration et caractérisation de nanocomposites hybrides : Oxydes métalliques/polymères Type de document : texte imprimé Auteurs : Bariza Troudi, Auteur ; Ouahiba Halimi, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2017 Importance : 121 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : Synthèse hydrothermale Nanocomposites Films minces CuO/PS CuO/PVC PbO/PS PbO/PVC DRX FT-IR Raman AFM Absorption UV-Visible photoluminescence Hydrothermal synthesis thin films UV-Visible Absorption ?????? ?????? ????? ????? ???????? ??? ????????- ???? ???????? ?????? Index. décimale : 530 Physique Résumé : Thin films of metal oxides/polymers nanocomposites were deposited on glass substrates by Spin-Coating and Dip-Coating techniques. The nanocomposites were elaborated by inserting, in the matrices of polystyrene (PS) and polyvinyl chloride (PVC) polymers, of nanoparticles of metal oxides such as copper oxide (CuO) and lead oxide (PbO). The nanoparticles of semiconductor CuO and PbO were synthesized beforehand by the hydrothermal method. The xray diffraction characterization of the obtained powders have revealed a monoclinic phase for CuO crystallites and an orthorhombic phase for PbO. The size of the crystallites of the two semiconductors is of a nanometic order. Calcul the of gap energy indicate a shift towards high energies compared to massive crystals. This shift is due to the effect of the quantum confinement induced by the nanometric size of the crystallites of the semiconductors. These nanocrystals are used for the preparation of the nanocomposites of CuO/PS, CuO/PVC, PbO/PS and PbO/PVC by
simple insertion of CuO and PbO nanoparticles in the PS and PVC polymers. The analysis of the elaborated nanocomposites by X-ray diffraction has allowed to notice the incorporation of the CuO and PbO crystallites into the PS and PVC polymers matrixes and analysis by Raman and infrared spectroscopies has confirmed the presence of CuO and PbO crystallites in the PS and PVC matrixes by revealing specific vibration modes to the Cu-O and Pb-O bonds. The surface morphology and topography of thin films of nanocomposites were highlighted with the help of atomic force microscopy (AFM) and have shown homogeneous dispersion of CuO and PbO crystallites and a low surface roughness. the characterization by measurement of the optical absorption in the UV-Visible domain allows to observe the increase in optical absorption which is attributed to CuO and PbO nanocrystallites because PS and PVC are optically transparent in the UV-Visible domain. A shift of the gap energy of the nanocomposites compared with the gap energy of the pure polymers and the massive crystallites of CuO and PbO was observed. This variation in gap energy is the result of the new optical behavior of the prepared nanocomposites.
The optical characterization by the measure of the photoluminescence has shown that the elaborated samples present intense luminescence bands in the visible range, hence the possibility of consider these matrices as optically active media and can be used for the making devices of specific optics properties.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/TRO7142.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10460 Elaboration et caractérisation de nanocomposites hybrides : Oxydes métalliques/polymères [texte imprimé] / Bariza Troudi, Auteur ; Ouahiba Halimi, Directeur de thèse . - [S.l.] : جامعة الإخوة منتوري قسنطينة, 2017 . - 121 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : Synthèse hydrothermale Nanocomposites Films minces CuO/PS CuO/PVC PbO/PS PbO/PVC DRX FT-IR Raman AFM Absorption UV-Visible photoluminescence Hydrothermal synthesis thin films UV-Visible Absorption ?????? ?????? ????? ????? ???????? ??? ????????- ???? ???????? ?????? Index. décimale : 530 Physique Résumé : Thin films of metal oxides/polymers nanocomposites were deposited on glass substrates by Spin-Coating and Dip-Coating techniques. The nanocomposites were elaborated by inserting, in the matrices of polystyrene (PS) and polyvinyl chloride (PVC) polymers, of nanoparticles of metal oxides such as copper oxide (CuO) and lead oxide (PbO). The nanoparticles of semiconductor CuO and PbO were synthesized beforehand by the hydrothermal method. The xray diffraction characterization of the obtained powders have revealed a monoclinic phase for CuO crystallites and an orthorhombic phase for PbO. The size of the crystallites of the two semiconductors is of a nanometic order. Calcul the of gap energy indicate a shift towards high energies compared to massive crystals. This shift is due to the effect of the quantum confinement induced by the nanometric size of the crystallites of the semiconductors. These nanocrystals are used for the preparation of the nanocomposites of CuO/PS, CuO/PVC, PbO/PS and PbO/PVC by
simple insertion of CuO and PbO nanoparticles in the PS and PVC polymers. The analysis of the elaborated nanocomposites by X-ray diffraction has allowed to notice the incorporation of the CuO and PbO crystallites into the PS and PVC polymers matrixes and analysis by Raman and infrared spectroscopies has confirmed the presence of CuO and PbO crystallites in the PS and PVC matrixes by revealing specific vibration modes to the Cu-O and Pb-O bonds. The surface morphology and topography of thin films of nanocomposites were highlighted with the help of atomic force microscopy (AFM) and have shown homogeneous dispersion of CuO and PbO crystallites and a low surface roughness. the characterization by measurement of the optical absorption in the UV-Visible domain allows to observe the increase in optical absorption which is attributed to CuO and PbO nanocrystallites because PS and PVC are optically transparent in the UV-Visible domain. A shift of the gap energy of the nanocomposites compared with the gap energy of the pure polymers and the massive crystallites of CuO and PbO was observed. This variation in gap energy is the result of the new optical behavior of the prepared nanocomposites.
The optical characterization by the measure of the photoluminescence has shown that the elaborated samples present intense luminescence bands in the visible range, hence the possibility of consider these matrices as optically active media and can be used for the making devices of specific optics properties.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/TRO7142.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10460 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité TRO/7142 TRO/7142 Thèse Bibliothèque principale Thèses Disponible
PermalinkPermalink
