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Partager le résultat de cette recherche Interroger des sources externesCaractérisations physico-chimiques et cinétique de bioactivité des biomateriaux / Fatima-Zohra Mezahi
Titre : Caractérisations physico-chimiques et cinétique de bioactivité des biomateriaux : hydroxyapatite & verre bioactif 54S4 élaboré par fusion et par voie sol-gel Type de document : texte imprimé Auteurs : Fatima-Zohra Mezahi ; Univ. de Constantine, Éditeur scientifique ; A. Harabi, Directeur de thèse Année de publication : 2009 Importance : 177 f. Note générale : 01 Disponible à la salle de recherche 02 Disponibles au magazin de la B.U.C. 01 CD Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : Verre Hydroxyapatite Voie fusion Procédé sol-gel Bioactivité Solution physiologique Glass Melting process Sol gel process Bioactivity الهيدروكسيدأباتيت والزجاج طريقة الإنصهار سائل-هلام النشاط الحيوي السائل فيزيولوجي Index. décimale : 530 Physique Résumé : This work has been devoted to study the bioactive materials:
- The natural and synthetic hydroxyapatite.
- Quaternary glass 52S4: 52% SiO2- 30% CaO -14% Na2O- 4% P2O5 (wt%).
Among the main techniques used for both physical and chemical characterizations of these biomaterials are: the Induced Coupled Plasma (ICP-OES), X- Ray Diffraction (XRD), Scanning Electron Microscopy (SEM-EDS), Infra-Red spectroscopy (IR) and Nuclear Magnetic
Resonance (NMR).
The obtained results show that the hydroxyapatite bioactivity is controlled by several factors such as the density, trace elements and the second phase formation. In addition, mechanical properties optimization by adding inert oxides (ZrO2, TiO2 and Al2O3) is not always
accompanied by HA bioactivity improvement. It has been found that the presence of certain foreign oxides in the HA matrix inhibits “bone-like apatite” formation at the immerged HA surface in a Simulated Body Fluid (SBF).
As far as glasses are concerned, two synthesis routes have been used: the melting and sol-gel processes, which allow to obtain a porous glass with a large specific area. The immersion of these glasses in SBF and Phosphor Buffered Solution (PBS) has allowed to conclude that:
- the glasses synthesised by melting and sol-gel processes are bioactive, - the bioactivity kinetic is very sensitive to several factors, such as porosity, the dissolution kinetics of glasses and the ion concentrations of the immersion solution.
These work results confirm that glasses are more reactive than hydroxyapatite by carbonated apatite formation on its surface, in a very short time.Diplôme : Doctorat en sciences En ligne : ../theses/physique/MEZ5504.pdf Permalink : index.php?lvl=notice_display&id=3430 Caractérisations physico-chimiques et cinétique de bioactivité des biomateriaux : hydroxyapatite & verre bioactif 54S4 élaboré par fusion et par voie sol-gel [texte imprimé] / Fatima-Zohra Mezahi ; Univ. de Constantine, Éditeur scientifique ; A. Harabi, Directeur de thèse . - 2009 . - 177 f.
01 Disponible à la salle de recherche 02 Disponibles au magazin de la B.U.C. 01 CD
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : Verre Hydroxyapatite Voie fusion Procédé sol-gel Bioactivité Solution physiologique Glass Melting process Sol gel process Bioactivity الهيدروكسيدأباتيت والزجاج طريقة الإنصهار سائل-هلام النشاط الحيوي السائل فيزيولوجي Index. décimale : 530 Physique Résumé : This work has been devoted to study the bioactive materials:
- The natural and synthetic hydroxyapatite.
- Quaternary glass 52S4: 52% SiO2- 30% CaO -14% Na2O- 4% P2O5 (wt%).
Among the main techniques used for both physical and chemical characterizations of these biomaterials are: the Induced Coupled Plasma (ICP-OES), X- Ray Diffraction (XRD), Scanning Electron Microscopy (SEM-EDS), Infra-Red spectroscopy (IR) and Nuclear Magnetic
Resonance (NMR).
The obtained results show that the hydroxyapatite bioactivity is controlled by several factors such as the density, trace elements and the second phase formation. In addition, mechanical properties optimization by adding inert oxides (ZrO2, TiO2 and Al2O3) is not always
accompanied by HA bioactivity improvement. It has been found that the presence of certain foreign oxides in the HA matrix inhibits “bone-like apatite” formation at the immerged HA surface in a Simulated Body Fluid (SBF).
As far as glasses are concerned, two synthesis routes have been used: the melting and sol-gel processes, which allow to obtain a porous glass with a large specific area. The immersion of these glasses in SBF and Phosphor Buffered Solution (PBS) has allowed to conclude that:
- the glasses synthesised by melting and sol-gel processes are bioactive, - the bioactivity kinetic is very sensitive to several factors, such as porosity, the dissolution kinetics of glasses and the ion concentrations of the immersion solution.
These work results confirm that glasses are more reactive than hydroxyapatite by carbonated apatite formation on its surface, in a very short time.Diplôme : Doctorat en sciences En ligne : ../theses/physique/MEZ5504.pdf Permalink : index.php?lvl=notice_display&id=3430 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité MEZ/5504 MEZ/5504 Thèse Bibliothèque principale Thèses Disponible
Titre : Caractérisation phytochimique et évaluation des activités biologiques de Cleome arabica. Type de document : texte imprimé Auteurs : Aicha Madi, Auteur ; Abdelmalik Belkhiri, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2018 Importance : 146 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles. Langues : Français (fre) Catégories : Français - Anglais
BiologieTags : Cleome arabica ssp arabica HPLC/DAD/MS phénols totaux flavonoïdes bioactivité toxicité total phenols flavonoids bioactivity toxicity assays الفينولات الفلافونيدات النشاط البيولوجي تجارب السمية Index. décimale : 570 Sciences de la vie. Biologie Résumé : Cleome arabica ssp arabica, a threatened desert plant, has been subjected to the phytochemical and pharmacological screening.
Hydroalcoholic extracts from different parts (leaves, seeds and roots) of C. arabica have been tested for their antioxidant, analgesic and wound healing activities, as well as their toxic potential.
Quantitative evaluation of the total phenols, flavonoids and anthocyanidins contents of the different extracts were made and completed with chromatographic HPLC/DAD/SM analysis. The obtained results revealed that leaves extract was characterized by a highly content in phenolic compounds, compared to other extracts.
Hydroalcoholic extract of the three parts of plant were marked by the presence of flavonoids, specially of flavonols type (quercetin, keampferol, and isorhamnetin).
Phenolic acids content is marked by the presence in the seeds extract of ferulic acid, para-hydroxybenzoic acid, and para-coumaric acid, and in the roots extract of tricaffeoylquinic, gallic, ferulic, and vanillic acids.
Evaluation of antioxidant effect made by the three in vitro tests (DPPH, FRAP and Phosphomolybdenum) showed a highly antioxidant activity of the leaves extract compared to those of seeds and roots. A direct correlation was found between phenol total and flavonoids contents and antioxidant activity.
The effectives doses obtained by three pain tests, namely tail flick, hot plate and acetic acid test were 291,84mg/Kg, 848,53mg/Kg and 683,52mg/Kg respectively. Analgesic activity of the aerial part of C. arabica was found to be dose- dependent. The Hydroalcoholic extract displayed on excision and thermal healing activities
wounds. The wound healing effect of C.arabica was significantly more important than that of a commercial ointment used as a positive control (Cicatryl®).
Toxicity assays (acute toxicity, and hemolytic effect) have showed that Hydroalcoholic extract of aerial part of C. arabica is safe at the maximal described doses.
Diplôme : Doctorat en sciences En ligne : ../theses/biologie/MAD7196.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10767 Caractérisation phytochimique et évaluation des activités biologiques de Cleome arabica. [texte imprimé] / Aicha Madi, Auteur ; Abdelmalik Belkhiri, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2018 . - 146 f. ; 30 cm.
2 copies imprimées disponibles.
Langues : Français (fre)
Catégories : Français - Anglais
BiologieTags : Cleome arabica ssp arabica HPLC/DAD/MS phénols totaux flavonoïdes bioactivité toxicité total phenols flavonoids bioactivity toxicity assays الفينولات الفلافونيدات النشاط البيولوجي تجارب السمية Index. décimale : 570 Sciences de la vie. Biologie Résumé : Cleome arabica ssp arabica, a threatened desert plant, has been subjected to the phytochemical and pharmacological screening.
Hydroalcoholic extracts from different parts (leaves, seeds and roots) of C. arabica have been tested for their antioxidant, analgesic and wound healing activities, as well as their toxic potential.
Quantitative evaluation of the total phenols, flavonoids and anthocyanidins contents of the different extracts were made and completed with chromatographic HPLC/DAD/SM analysis. The obtained results revealed that leaves extract was characterized by a highly content in phenolic compounds, compared to other extracts.
Hydroalcoholic extract of the three parts of plant were marked by the presence of flavonoids, specially of flavonols type (quercetin, keampferol, and isorhamnetin).
Phenolic acids content is marked by the presence in the seeds extract of ferulic acid, para-hydroxybenzoic acid, and para-coumaric acid, and in the roots extract of tricaffeoylquinic, gallic, ferulic, and vanillic acids.
Evaluation of antioxidant effect made by the three in vitro tests (DPPH, FRAP and Phosphomolybdenum) showed a highly antioxidant activity of the leaves extract compared to those of seeds and roots. A direct correlation was found between phenol total and flavonoids contents and antioxidant activity.
The effectives doses obtained by three pain tests, namely tail flick, hot plate and acetic acid test were 291,84mg/Kg, 848,53mg/Kg and 683,52mg/Kg respectively. Analgesic activity of the aerial part of C. arabica was found to be dose- dependent. The Hydroalcoholic extract displayed on excision and thermal healing activities
wounds. The wound healing effect of C.arabica was significantly more important than that of a commercial ointment used as a positive control (Cicatryl®).
Toxicity assays (acute toxicity, and hemolytic effect) have showed that Hydroalcoholic extract of aerial part of C. arabica is safe at the maximal described doses.
Diplôme : Doctorat en sciences En ligne : ../theses/biologie/MAD7196.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10767 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité MAD/7196 MAD/7196 Thèse Bibliothèque principale Thèses Disponible
Titre : تحسين الخصائص الميكانيكية و البيوحيوية للهيدروكسيأباتيت الطبيعي Type de document : texte imprimé Auteurs : أسماء حرابي, Auteur ; عبد الحميد حرابي, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2016 Importance : 111ورقة. Format : 30 سم. Note générale : 2نسخ موجودة مكتبة المركزية
Langues : Arabe (ara) Catégories : Arabe
الفيزياءTags : علوم المواد:خزفيات الهيدروكسيابأتيت السائل الفسيولوجي النشاط الحيوي Hydroxyapatite β-TCP P2O5 B2O3 SBF Bioactivity Bioactivité Index. décimale : 530 الفيزياء Résumé : The main objective of this research is to study the hydroxyapatite (HA:
Ca10(PO4)6(OH)2,) which was extracted from cortical bovine. This latter because of both its abundance and high purity may be considered as an exciting starting material for cheap bioceramics production. The effect of milling time, sintring temperature and P2O5 and B203 additions on density, microhardness, bioactivity and compatibility of Hydroxyapatite have been studied. In order to accomplish the above objectives, many techniques have been used to study and characterize the chemical and physical properties of prepared samples. The most important of them are Scanning Electronic Microscope (SEM), Infra-Red (IR), X-ray Diffraction (XRD)
and the Induced Coupled Plasma (ICP-OES). In the first part the effect of milling time on the natural hydroxyapatite particles size has been studied. In addition, we studied the effect of sintring temperature on natural hydroxyapatite stability. and found that this latter is stable, so that at all temperatures the only phase present was Hydroxyapatite. Also, this latter has significant mechanical roperties. In addition, we studied the effect of the introduction of certain additives in Hydroxyapatite as P2O5 and B2O3 with a percentage of 3% at the following temperatures: 1050 ° C and 1250 ° C.. Although the introduction of the additions at 1050 ° C has not removed the percentage of sintering, but improved mechanical properties, in particular when B2O3 is added, where the value of microhardness increased to 0.96 GPa compared to 0.61 GPa obtained without additions and the value of the tensile strength increased from 6.7 MPa to 17 MPa. At 1250 ° C, the effect of additions was evident where the sintering percentage reached 93%, and the value of the tensile strength has jumped to 67 MPa in the samples containing 3% of B2O3 compared to a low value in the range of 13 MPa for samples without additions. these additives led to the transformation of the hydroxyapatite in ß-TCP, in different percentages. We can also observe that the ß-TCP percentage was higher when the sintering temperature is 1250 ° C. After the immersion of the different samples in SBF for different times, it was found that when the temperature is 1050 ° C, for the samples whithout additions and those containing P2O5 the apatite layer appears on the surface of samples after 14 days. But for samples containing B2O3 the appearance of the apatite layer was quicker, and that appears after only 3 days of immersion. While at the temperature 1250 ° C, any apatite layer has been observed on the surface of the different samples and this is due to the high relative density.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/AHAR4163.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10711 تحسين الخصائص الميكانيكية و البيوحيوية للهيدروكسيأباتيت الطبيعي [texte imprimé] / أسماء حرابي, Auteur ; عبد الحميد حرابي, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2016 . - 111ورقة. ; 30 سم.
2نسخ موجودة مكتبة المركزية
Langues : Arabe (ara)
Catégories : Arabe
الفيزياءTags : علوم المواد:خزفيات الهيدروكسيابأتيت السائل الفسيولوجي النشاط الحيوي Hydroxyapatite β-TCP P2O5 B2O3 SBF Bioactivity Bioactivité Index. décimale : 530 الفيزياء Résumé : The main objective of this research is to study the hydroxyapatite (HA:
Ca10(PO4)6(OH)2,) which was extracted from cortical bovine. This latter because of both its abundance and high purity may be considered as an exciting starting material for cheap bioceramics production. The effect of milling time, sintring temperature and P2O5 and B203 additions on density, microhardness, bioactivity and compatibility of Hydroxyapatite have been studied. In order to accomplish the above objectives, many techniques have been used to study and characterize the chemical and physical properties of prepared samples. The most important of them are Scanning Electronic Microscope (SEM), Infra-Red (IR), X-ray Diffraction (XRD)
and the Induced Coupled Plasma (ICP-OES). In the first part the effect of milling time on the natural hydroxyapatite particles size has been studied. In addition, we studied the effect of sintring temperature on natural hydroxyapatite stability. and found that this latter is stable, so that at all temperatures the only phase present was Hydroxyapatite. Also, this latter has significant mechanical roperties. In addition, we studied the effect of the introduction of certain additives in Hydroxyapatite as P2O5 and B2O3 with a percentage of 3% at the following temperatures: 1050 ° C and 1250 ° C.. Although the introduction of the additions at 1050 ° C has not removed the percentage of sintering, but improved mechanical properties, in particular when B2O3 is added, where the value of microhardness increased to 0.96 GPa compared to 0.61 GPa obtained without additions and the value of the tensile strength increased from 6.7 MPa to 17 MPa. At 1250 ° C, the effect of additions was evident where the sintering percentage reached 93%, and the value of the tensile strength has jumped to 67 MPa in the samples containing 3% of B2O3 compared to a low value in the range of 13 MPa for samples without additions. these additives led to the transformation of the hydroxyapatite in ß-TCP, in different percentages. We can also observe that the ß-TCP percentage was higher when the sintering temperature is 1250 ° C. After the immersion of the different samples in SBF for different times, it was found that when the temperature is 1050 ° C, for the samples whithout additions and those containing P2O5 the apatite layer appears on the surface of samples after 14 days. But for samples containing B2O3 the appearance of the apatite layer was quicker, and that appears after only 3 days of immersion. While at the temperature 1250 ° C, any apatite layer has been observed on the surface of the different samples and this is due to the high relative density.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/AHAR4163.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10711 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité حرا/4163 حرا/4163 Thèse Bibliothèque principale Thèses Disponible
Titre : تحضير و دراسة خصائص الانورثيت المحضر انطلاقا من الكاولان DD2والكلسيت Type de document : texte imprimé Auteurs : سمية زعيو, Auteur ; عبد الحمید حرابي, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2017 Importance : 118 ورقة. Format : 30 سم. Note générale : 2نسخ موجودة مكتبة المركزية
Langues : Arabe (ara) Catégories : Arabe
الفيزياءTags : Frittage Anorthite Na2CO3 Fe2O3 propriétés mécaniques Bioactivité Sintering sodium carbonate ferric oxide Mechanical properties Bioactivity Index. décimale : 530 الفيزياء Résumé : In this work, anorthite have a chemical formula (CaO.Al2O3.2SiO2) was prepared from local kaolin and calcium oxide (CaO) extracted from CaCO3. In the first stage, two different methods were followed. The second method shows more efficiency, it gives a good sintering percentage over 96 % of anorthite theoretical density.
The effect of different amounts of (Na2CO3) and (Fe2O3) on the anorthite sintering and crystallisation was studied, 3 wt% sodium carbonate addition increases the density to values greater than 97 % of theoretical. Moreover, the density of about 98 % of the theoretical was reached for samples containing 1.5 wt% Fe2O3 sintered at 900 °C for 1 h and promotes anorthite crystallisation at lower temperatures. The anorthite phase appeared earlier at 850°C.
The prepared samples show a tensile strength of 82 MPa for 3% of Na2CO3 addition which corresponds to a flexural strength of about 222 MPa, a Vickers micro-hardness of 8.7 GPa that were treated at 900°C.
Excellent values of tensile strength about 96 MPa which corresponding to a flexural strength of 259 MPa, a Vickers micro-hardness of 9.1 GPa for the simples with 1.5 % weight of Fe2O3 were also obtained.
Finally, the bioactivity of anorthite by the possibility of formation of apatite on the surface of anorthite immersed in simulated body fluid (SBF) was confirmed.Diplôme : Doctorat en sciences En ligne : ../theses/physique/AZAI4214.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10660 تحضير و دراسة خصائص الانورثيت المحضر انطلاقا من الكاولان DD2والكلسيت [texte imprimé] / سمية زعيو, Auteur ; عبد الحمید حرابي, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2017 . - 118 ورقة. ; 30 سم.
2نسخ موجودة مكتبة المركزية
Langues : Arabe (ara)
Catégories : Arabe
الفيزياءTags : Frittage Anorthite Na2CO3 Fe2O3 propriétés mécaniques Bioactivité Sintering sodium carbonate ferric oxide Mechanical properties Bioactivity Index. décimale : 530 الفيزياء Résumé : In this work, anorthite have a chemical formula (CaO.Al2O3.2SiO2) was prepared from local kaolin and calcium oxide (CaO) extracted from CaCO3. In the first stage, two different methods were followed. The second method shows more efficiency, it gives a good sintering percentage over 96 % of anorthite theoretical density.
The effect of different amounts of (Na2CO3) and (Fe2O3) on the anorthite sintering and crystallisation was studied, 3 wt% sodium carbonate addition increases the density to values greater than 97 % of theoretical. Moreover, the density of about 98 % of the theoretical was reached for samples containing 1.5 wt% Fe2O3 sintered at 900 °C for 1 h and promotes anorthite crystallisation at lower temperatures. The anorthite phase appeared earlier at 850°C.
The prepared samples show a tensile strength of 82 MPa for 3% of Na2CO3 addition which corresponds to a flexural strength of about 222 MPa, a Vickers micro-hardness of 8.7 GPa that were treated at 900°C.
Excellent values of tensile strength about 96 MPa which corresponding to a flexural strength of 259 MPa, a Vickers micro-hardness of 9.1 GPa for the simples with 1.5 % weight of Fe2O3 were also obtained.
Finally, the bioactivity of anorthite by the possibility of formation of apatite on the surface of anorthite immersed in simulated body fluid (SBF) was confirmed.Diplôme : Doctorat en sciences En ligne : ../theses/physique/AZAI4214.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10660 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité زعي/4214 زعي/4214 Thèse Bibliothèque principale Thèses Disponible
Titre : دراسة الخصائص الفيزيائية و النشاط الحيوي للهيدروكسيأباتيت الطبيعي Ca10(PO4)6(OH)2 Type de document : texte imprimé Auteurs : أسماء حرابي ; جامعة قسنطينة, Éditeur scientifique ; عبد الحميد حرابي, Directeur de thèse Année de publication : 2009 Importance : 100 ورقة Format : 30 سم Note générale : 02 نسخ موجودة في مخزن المكتبة المركزية 01 قرص مضغوط Langues : Arabe (ara) Catégories : Arabe
الفيزياءTags : فيزياء المواد:الخزفيات التلبيد الهيدروكسيأباتيت السائل الفيزيولوجي النشاط الحيوي hydroxyapatite sintring P2O5 B2O3 Bioactivity SBF frittage Bioactivité Index. décimale : 530 الفيزياء Résumé : The main objective of this research is to study the hydroxyapatite (HA:
Ca10(PO4)6(OH)2,) which was extracted from cortical bovine. This latter because of both its abundance and high purity may be considered as an exciting starting material for cheap bioceramics production. The effect of various experimental conditions and P2O5 et B203 additions on sintering, microhardness, bioactivity and compatibility of HA have also been taken into account. In order to accomplish the above objectives, many techniques have been used to study
and characterize the chemical and physical properties of prepared samples. The most important of them are Scanning Electronic Microscope (SEM), Infra-Red (IR) and X-ray Diffractio (XRD). The first result from this research is the effect of temperature and time of sintering on the properties of HA. Where there was a close correlation between the sintering temperature and mechanical properties of these samples. Indeed, the sintering time has a significant influence on the growth of grains. In addition, the effect of milling time on particle size has not been overlooked. Powders of sub-micron particle sizes have been obtained. The influence of P2O5 and B203 additions on HA properties was also studied. The addition of P2O5 decreased the sintering temperature to a maximum of 1200°C, where the rate of densification of about 93% is obtained for the various additions. As far as micro-hardness is concerned, a value of 5.2 GPa was obtained for 3 wt% P2O5 addition, under the same conditions. This value is much higher than that (2.1 GPa) obtained for samples without additions. A relatively higher tensile strength value of 67 MPa, was measured for samples with 3 wt% P2O5 addition, well above that (13 MPa) of samples without addition and sintered at 1250°C. In the case of the second addition type (B203), it has no positive effect on samples densification. Micro-hardness values of 4.97
and 5.68 GPa were measured for samples with 3 wt% P2O5 addition and sintered at 1250 and 1300°C, respectively. These values are also relatively higher than the 3.4 and 4.7 GPa, measured for samples without additions. Finally, it has also been found that Apatite formation on HA surface during its immersion in "Simulated Body Fluid (SBF), was confirmed. In addition, these samples resisted well to lactic acid (the weight loss ratio was relatively low).Diplôme : Magistère En ligne : ../theses/physique/AHAR2956.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=6617 دراسة الخصائص الفيزيائية و النشاط الحيوي للهيدروكسيأباتيت الطبيعي Ca10(PO4)6(OH)2 [texte imprimé] / أسماء حرابي ; جامعة قسنطينة, Éditeur scientifique ; عبد الحميد حرابي, Directeur de thèse . - 2009 . - 100 ورقة ; 30 سم.
02 نسخ موجودة في مخزن المكتبة المركزية 01 قرص مضغوط
Langues : Arabe (ara)
Catégories : Arabe
الفيزياءTags : فيزياء المواد:الخزفيات التلبيد الهيدروكسيأباتيت السائل الفيزيولوجي النشاط الحيوي hydroxyapatite sintring P2O5 B2O3 Bioactivity SBF frittage Bioactivité Index. décimale : 530 الفيزياء Résumé : The main objective of this research is to study the hydroxyapatite (HA:
Ca10(PO4)6(OH)2,) which was extracted from cortical bovine. This latter because of both its abundance and high purity may be considered as an exciting starting material for cheap bioceramics production. The effect of various experimental conditions and P2O5 et B203 additions on sintering, microhardness, bioactivity and compatibility of HA have also been taken into account. In order to accomplish the above objectives, many techniques have been used to study
and characterize the chemical and physical properties of prepared samples. The most important of them are Scanning Electronic Microscope (SEM), Infra-Red (IR) and X-ray Diffractio (XRD). The first result from this research is the effect of temperature and time of sintering on the properties of HA. Where there was a close correlation between the sintering temperature and mechanical properties of these samples. Indeed, the sintering time has a significant influence on the growth of grains. In addition, the effect of milling time on particle size has not been overlooked. Powders of sub-micron particle sizes have been obtained. The influence of P2O5 and B203 additions on HA properties was also studied. The addition of P2O5 decreased the sintering temperature to a maximum of 1200°C, where the rate of densification of about 93% is obtained for the various additions. As far as micro-hardness is concerned, a value of 5.2 GPa was obtained for 3 wt% P2O5 addition, under the same conditions. This value is much higher than that (2.1 GPa) obtained for samples without additions. A relatively higher tensile strength value of 67 MPa, was measured for samples with 3 wt% P2O5 addition, well above that (13 MPa) of samples without addition and sintered at 1250°C. In the case of the second addition type (B203), it has no positive effect on samples densification. Micro-hardness values of 4.97
and 5.68 GPa were measured for samples with 3 wt% P2O5 addition and sintered at 1250 and 1300°C, respectively. These values are also relatively higher than the 3.4 and 4.7 GPa, measured for samples without additions. Finally, it has also been found that Apatite formation on HA surface during its immersion in "Simulated Body Fluid (SBF), was confirmed. In addition, these samples resisted well to lactic acid (the weight loss ratio was relatively low).Diplôme : Magistère En ligne : ../theses/physique/AHAR2956.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=6617 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité حرا/2956 حرا/2956 Thèse Bibliothèque principale Thèses Disponible
