J. Svoboda, K. Drdlíková, D. Drdlík, A. Kroupa, J. Michalička, K. Maca
The preparation of a transparent ultra-fine-grained doped ceramics requires a homogeneous dopant distribution in a matrix. In the present work, two thermodynamical phenomena allowing the preparation of such ceramics (the dissolution of the dopant and the formation of undesirable secondary phases) were experimentally and theoretically studied. A general thermodynamic-kinetic model was developed for dopant dissolution, which was verified for the experimental conditions used in this work. The model and experiment showed that Mn3O4 dopant with overall concentration of 1 at.% and particle size of 50 nm is dissolved and homogenized in a fine-grained alumina matrix within less than one hour at a temperature of 1220 ?C. For the purposes of the study of the formation of undesired secondary phase, the phase diagram of the Al2O3-Mn3O4 system was calculated using the CALPHAD approach. Detailed STEM observations combined with EDX and EELS chemical analyses showed that the data used for the calculation of the phase diagram need some modifications because they overestimate the solubility of Mn in the alumina and underestimate the solubility of Mn in the MnAl2O4 spinel.
{"title":"Doping of alumina ceramics by manganese - thermodynamical and experimental approach","authors":"J. Svoboda, K. Drdlíková, D. Drdlík, A. Kroupa, J. Michalička, K. Maca","doi":"10.2298/pac2201013s","DOIUrl":"https://doi.org/10.2298/pac2201013s","url":null,"abstract":"The preparation of a transparent ultra-fine-grained doped ceramics requires a homogeneous dopant distribution in a matrix. In the present work, two thermodynamical phenomena allowing the preparation of such ceramics (the dissolution of the dopant and the formation of undesirable secondary phases) were experimentally and theoretically studied. A general thermodynamic-kinetic model was developed for dopant dissolution, which was verified for the experimental conditions used in this work. The model and experiment showed that Mn3O4 dopant with overall concentration of 1 at.% and particle size of 50 nm is dissolved and homogenized in a fine-grained alumina matrix within less than one hour at a temperature of 1220 ?C. For the purposes of the study of the formation of undesired secondary phase, the phase diagram of the Al2O3-Mn3O4 system was calculated using the CALPHAD approach. Detailed STEM observations combined with EDX and EELS chemical analyses showed that the data used for the calculation of the phase diagram need some modifications because they overestimate the solubility of Mn in the alumina and underestimate the solubility of Mn in the MnAl2O4 spinel.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68579486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Ochoa-Muñoz, M. Álvarez‐Láinez, J. Rodríguez-Páez, D. Mejía
In this work, the most suitable conditions were determined for shaping ceramic bodies of the MSnO3 system (M = Ba, Zn, Ca), using submicron particles of these perovskites synthesized by a chemical route. For this, the rheological behaviours of colloidal suspensions of the MSnO3 powders (M = Ba, Zn, Ca) were studied considering the effects of solid content and concentration of ammonium polyacrylate (APA). The results indicated that the optimal solids contents for stable suspensions in each system were 13.8 (BaSnO3), 19.4 (ZnSnO3), and 21.5 vol.% (CaSnO3). The suspensions containing BaSnO3 and ZnSnO3 showed large reductions in viscosity, approximately 87%, when APA (0.5-0.8wt.%) was added. In contrast, the CaSnO3 suspension did not show significant changes after addition of APA. Slip casting of the stable suspensions allowed formation of porous green bodies, which were subsequently sintered in the range 1000-1500 ?C. Considering their potential use as gas sensors, a preliminary study of the sintered bodies showed high detection responses (Ra/Rg) toward 80 ppm reducing gas at operating temperature of 270 ?C, especially ZnSnO3 to acetone and ethanol vapours, BaSnO3 to ethanol vapour and CaSnO3 to toluene vapour.
{"title":"Formation of ceramic bodies using submicron msno3 (m = ba, zn, ca) particles and evaluation of their electric behaviour in different atmospheres","authors":"Y. Ochoa-Muñoz, M. Álvarez‐Láinez, J. Rodríguez-Páez, D. Mejía","doi":"10.2298/pac2203237o","DOIUrl":"https://doi.org/10.2298/pac2203237o","url":null,"abstract":"In this work, the most suitable conditions were determined for shaping ceramic bodies of the MSnO3 system (M = Ba, Zn, Ca), using submicron particles of these perovskites synthesized by a chemical route. For this, the rheological behaviours of colloidal suspensions of the MSnO3 powders (M = Ba, Zn, Ca) were studied considering the effects of solid content and concentration of ammonium polyacrylate (APA). The results indicated that the optimal solids contents for stable suspensions in each system were 13.8 (BaSnO3), 19.4 (ZnSnO3), and 21.5 vol.% (CaSnO3). The suspensions containing BaSnO3 and ZnSnO3 showed large reductions in viscosity, approximately 87%, when APA (0.5-0.8wt.%) was added. In contrast, the CaSnO3 suspension did not show significant changes after addition of APA. Slip casting of the stable suspensions allowed formation of porous green bodies, which were subsequently sintered in the range 1000-1500 ?C. Considering their potential use as gas sensors, a preliminary study of the sintered bodies showed high detection responses (Ra/Rg) toward 80 ppm reducing gas at operating temperature of 270 ?C, especially ZnSnO3 to acetone and ethanol vapours, BaSnO3 to ethanol vapour and CaSnO3 to toluene vapour.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68581754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the present study, densification, mechanical properties (elastic modulus, hardness, flexural strength) and stored elastic energy-fragmentation of the pure Al2O3 and Al2O3-Cr2O3 ceramics with different Cr2O3 volume content (0.5, 1, 3, 5, 10 and 20 vol.%) were investigated. The fragmentation behaviour was interpreted from the point of armour application as larger fragments are required for higher penetration resistance. The equibiaxial flexural strength test method was used to measure the fracture strength values. A similar densification behaviour was obtained for the pure Al2O3 and the Al2O3-Cr2O3 ceramic specimens with 0.5, 10 and 20 vol.% Cr2O3 with the obtained relative densities of around 97%TD. The elastic modulus of the pure Al2O3 and Al2O3-Cr2O3 ceramic specimens showed consistent values with the densification except for the Al2O3-Cr2O3 ceramics containing 20 vol.% Cr2O3. All Al2O3-Cr2O3 ceramics have lower flexural strength values than the pure Al2O3. The pure Al2O3 had the smallest crack surface area accompanying the largest fragment size for given fracture energy. This indicates that the pure Al2O3 will break into larger pieces in case of a possible impact.
{"title":"Investigation of mechanical properties and stored elastic energy-fragmentation of Al2O3-Cr2O3 ceramic system with increasing Cr2O3 content","authors":"Betül Kafkaslıoğlu Yıldız, Y. Tür","doi":"10.2298/pac2204351k","DOIUrl":"https://doi.org/10.2298/pac2204351k","url":null,"abstract":"In the present study, densification, mechanical properties (elastic modulus, hardness, flexural strength) and stored elastic energy-fragmentation of the pure Al2O3 and Al2O3-Cr2O3 ceramics with different Cr2O3 volume content (0.5, 1, 3, 5, 10 and 20 vol.%) were investigated. The fragmentation behaviour was interpreted from the point of armour application as larger fragments are required for higher penetration resistance. The equibiaxial flexural strength test method was used to measure the fracture strength values. A similar densification behaviour was obtained for the pure Al2O3 and the Al2O3-Cr2O3 ceramic specimens with 0.5, 10 and 20 vol.% Cr2O3 with the obtained relative densities of around 97%TD. The elastic modulus of the pure Al2O3 and Al2O3-Cr2O3 ceramic specimens showed consistent values with the densification except for the Al2O3-Cr2O3 ceramics containing 20 vol.% Cr2O3. All Al2O3-Cr2O3 ceramics have lower flexural strength values than the pure Al2O3. The pure Al2O3 had the smallest crack surface area accompanying the largest fragment size for given fracture energy. This indicates that the pure Al2O3 will break into larger pieces in case of a possible impact.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68582051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ceramic composites consisting of a boron carbide (B4C) matrix and titanium diboride (TiB2) secondary phase were obtained by reactive sintering from boron carbide powder with 40 and 50wt.% of titanium dioxide (TiO2) additive. The same sintering temperature of 1850?C and pressure of 35MPa, but different sintering times from 15 to 60min, were applied during reactive hot pressing of the composites in vacuum. The effects of TiO2 content and sintering time on phase compositions, microstructures and mechanical properties of the composites were studied. The TiO2 additive enhanced densification of the B4C-TiB2 ceramic composites. Both Vickers hardness and the fracture toughness of the composites increased with prolongation of sintering time. The highest hardness of 29.8GPa was achieved for the composite with 29.6 vol.% of TiB2 obtained by sintering of the precursor with 40wt.% of TiO2 additive for 60min. The fracture toughness reached a maximum value of 7.5MPa?m1/2 for the composite containing 40.2 vol.% of TiB2, which was fabricated by reactive sintering of the precursor with 50wt.% of TiO2 additive for 60min.
{"title":"Microstructure and mechanical properties of b4c-tib2 composites reactive sintered from B4C + TiO2 precursors","authors":"P. Švec, Ľ. Čaplovič","doi":"10.2298/pac2204358s","DOIUrl":"https://doi.org/10.2298/pac2204358s","url":null,"abstract":"Ceramic composites consisting of a boron carbide (B4C) matrix and titanium diboride (TiB2) secondary phase were obtained by reactive sintering from boron carbide powder with 40 and 50wt.% of titanium dioxide (TiO2) additive. The same sintering temperature of 1850?C and pressure of 35MPa, but different sintering times from 15 to 60min, were applied during reactive hot pressing of the composites in vacuum. The effects of TiO2 content and sintering time on phase compositions, microstructures and mechanical properties of the composites were studied. The TiO2 additive enhanced densification of the B4C-TiB2 ceramic composites. Both Vickers hardness and the fracture toughness of the composites increased with prolongation of sintering time. The highest hardness of 29.8GPa was achieved for the composite with 29.6 vol.% of TiB2 obtained by sintering of the precursor with 40wt.% of TiO2 additive for 60min. The fracture toughness reached a maximum value of 7.5MPa?m1/2 for the composite containing 40.2 vol.% of TiB2, which was fabricated by reactive sintering of the precursor with 50wt.% of TiO2 additive for 60min.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68582142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. Ismail, Nurul Izzati Malek, A. Jani, M. Othman, N. Osman
Composite cathodes consisting of different compositional ratios of La0.6Sr0.4Co0.2Fe0.8O3-? (LSCF) and Ba(Ce0.6Zr0.4)0.9Y0.1O3-? (BCZY64), namely 100LSCF:0BCZY64 (L10B0), 70LSCF:30BCZY64 (L7B3), 50LSCF:50BCZY64 (L5B5) and 30LSCF:70BCZY64 (L3B7) were prepared via wet chemistry method. The symmetrical cell with a configuration of electrode|BCZY64|electrodewas fabricated using dry-pressingmethod for the electrolyte substrate and spin-coating technique for the cathode layer. The proton conduction in the composite cathode increases as the amount of proton-conducting phase increases as verified by the water uptake measurement performed via thermogravimetric analysis. The thickness of the composite cathode layer is about 15 ?m as observed by a scanning electron microscope and exhibits a well-connected particle network with sufficient porosity for oxidant diffusion (20-30%). The electrochemical performance of the symmetrical cell was investigated by electrochemical impedance spectroscopy in humidified air. The area-specific resistance (ASR) values of the tested cathodes follow the order of L7B3 < L10B0 < L5B5 < L3B7 and are 0.07 < 0.24 < 0.30 < 0.52W?cm2 at 700?C, respectively. The correlation between the cathode performance and cathode composition was investigated and the corresponding mechanism was systematically postulated.
{"title":"Optimization of La0.6Sr0.4Co0.2Fe0.8O3-α - Ba(Ce0.6Zr0.4)0.9Y0.1O3-δ cathode composition for proton ceramic fuel cell application","authors":"I. Ismail, Nurul Izzati Malek, A. Jani, M. Othman, N. Osman","doi":"10.2298/pac2204374i","DOIUrl":"https://doi.org/10.2298/pac2204374i","url":null,"abstract":"Composite cathodes consisting of different compositional ratios of La0.6Sr0.4Co0.2Fe0.8O3-? (LSCF) and Ba(Ce0.6Zr0.4)0.9Y0.1O3-? (BCZY64), namely 100LSCF:0BCZY64 (L10B0), 70LSCF:30BCZY64 (L7B3), 50LSCF:50BCZY64 (L5B5) and 30LSCF:70BCZY64 (L3B7) were prepared via wet chemistry method. The symmetrical cell with a configuration of electrode|BCZY64|electrodewas fabricated using dry-pressingmethod for the electrolyte substrate and spin-coating technique for the cathode layer. The proton conduction in the composite cathode increases as the amount of proton-conducting phase increases as verified by the water uptake measurement performed via thermogravimetric analysis. The thickness of the composite cathode layer is about 15 ?m as observed by a scanning electron microscope and exhibits a well-connected particle network with sufficient porosity for oxidant diffusion (20-30%). The electrochemical performance of the symmetrical cell was investigated by electrochemical impedance spectroscopy in humidified air. The area-specific resistance (ASR) values of the tested cathodes follow the order of L7B3 < L10B0 < L5B5 < L3B7 and are 0.07 < 0.24 < 0.30 < 0.52W?cm2 at 700?C, respectively. The correlation between the cathode performance and cathode composition was investigated and the corresponding mechanism was systematically postulated.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68582370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The thermoelectric properties of ceramics with composition A0.98La0.02MnO3-? are anticipated to vary with the basicity and atomic portion of the alkaline earth metal, A. In the present investigation ceramic powder precursors with composition A0.98La0.02MnO3-? (A = Ca, Ba) were synthesized by the solid-state method and sintered in air at 1400?C. Seebeck coefficient, electrical and thermal conductivities were characterized for both materials from 100 to 900?C in air. The highest zT of 0.10 at 900?C was reached for Ca0.98La0.02MnO3-?. The high zT is attributed to the enhanced electronic conductivity (?90 S/cm at 900?C) due to La doping. zT for Ba0.98La0.02MnO3-? reached its highest value (0.02) at 800?C corresponding to a low electronic conductivity (?2 S/cm), while the thermal conductivity was significantly reduced compared to Ca0.98La0.02MnO3-? reaching ?1W/(m?K) combined with a high Seebeck coefficient, ?290 ?V/K. The present data represent a valuable basis for further development of these materials with respect to applications in thermoelectric devices.
A0.98La0.02MnO3-?复合陶瓷的热电性能在本研究中，组成为A0.98La0.02MnO3-?的陶瓷粉末前驱体(A = Ca, Ba)采用固相法合成，在1400℃空气中烧结。对两种材料的塞贝克系数、电导率和导热率进行了表征，范围从100到900?C在空气中。最高zT为0.10，在900?Ca0.98La0.02MnO3-?得到C。高zT归因于增强的电子导电性(?90s /cm, 900°C)。Ba0.98La0.02MnO3-?在800℃时达到最高值(0.02)。C对应于低电子导电性(?2 S/cm)，导热系数较Ca0.98La0.02MnO3-?达到1W/(m?K)，塞贝克系数高达290v /K。目前的数据为进一步开发这些材料在热电器件中的应用提供了有价值的基础。
{"title":"The effect of alkaline earth metal substitution on thermoelectric properties of A0.98La0.02MnO3-δ (A=Ca,Ba)","authors":"S. Singh, N. Kanas, M. Einarsrud, K. Wiik","doi":"10.2298/pac2201078s","DOIUrl":"https://doi.org/10.2298/pac2201078s","url":null,"abstract":"The thermoelectric properties of ceramics with composition A0.98La0.02MnO3-? are anticipated to vary with the basicity and atomic portion of the alkaline earth metal, A. In the present investigation ceramic powder precursors with composition A0.98La0.02MnO3-? (A = Ca, Ba) were synthesized by the solid-state method and sintered in air at 1400?C. Seebeck coefficient, electrical and thermal conductivities were characterized for both materials from 100 to 900?C in air. The highest zT of 0.10 at 900?C was reached for Ca0.98La0.02MnO3-?. The high zT is attributed to the enhanced electronic conductivity (?90 S/cm at 900?C) due to La doping. zT for Ba0.98La0.02MnO3-? reached its highest value (0.02) at 800?C corresponding to a low electronic conductivity (?2 S/cm), while the thermal conductivity was significantly reduced compared to Ca0.98La0.02MnO3-? reaching ?1W/(m?K) combined with a high Seebeck coefficient, ?290 ?V/K. The present data represent a valuable basis for further development of these materials with respect to applications in thermoelectric devices.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"8 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68580334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fatemeh Bavarsiha, Saeideh Dadashian, M. Montazeri-Pour, Fardin Ghasemy-Piranloo, M. Rajabi
In this research, three magnetically separable photocatalysts, Fe3O4/SiO2/TiO2, SrFe12O19/SiO2/TiO2 and Fe3O4/SiO2/ZnO, with core/shell/shell structures were successfully prepared. In the first step, soft magnetic and hard magnetic Fe3O4 and SrFe12O19 powders were synthesized using carbon reduction and co-precipitation routes, respectively. In the second step, silica coating was performed by controlling the hydrolysis and con- densation of tetraethyl orthosilicate (TEOS) precursor on the magnetic cores. In the third step, a layer of TiO2 or ZnO photocatalytic shells was made on the as-prepared composites using titanium n-butoxide (TNBT) or zinc nitrate hexahydrate, respectively. The formation of the core/shell/shell structures was confirmed by FESEM and TEM analyses. The saturation magnetizations of the Fe3O4/SiO2/TiO2, SrFe12O19/SiO2/TiO2 and Fe3O4/SiO2/ZnO photocatalytic materials were 41.5, 33 and 49 emu/g, respectively. Photocatalytic activity was evaluated by degradation percentages of methylene blue (MB) under UV illumination, which were 88%, 83% and 62%, for the Fe3O4/SiO2/TiO2, SrFe12O19//TiO2 and Fe3O4/SiO2/ZnO composites, respectively. The first-, and second-order reaction kinetics were used to find out the suitable MB removal kinetics.
{"title":"Synthesis, characterization and photocatalytic efficiency of Fe3O4/SiO2/TiO2, SrFe12O19/SiO2/TiO2 and Fe3O4/SiO2/ZnO core/shell/shell nanostructures","authors":"Fatemeh Bavarsiha, Saeideh Dadashian, M. Montazeri-Pour, Fardin Ghasemy-Piranloo, M. Rajabi","doi":"10.2298/pac2203291b","DOIUrl":"https://doi.org/10.2298/pac2203291b","url":null,"abstract":"In this research, three magnetically separable photocatalysts, Fe3O4/SiO2/TiO2, SrFe12O19/SiO2/TiO2 and Fe3O4/SiO2/ZnO, with core/shell/shell structures were successfully prepared. In the first step, soft magnetic and hard magnetic Fe3O4 and SrFe12O19 powders were synthesized using carbon reduction and co-precipitation routes, respectively. In the second step, silica coating was performed by controlling the hydrolysis and con- densation of tetraethyl orthosilicate (TEOS) precursor on the magnetic cores. In the third step, a layer of TiO2 or ZnO photocatalytic shells was made on the as-prepared composites using titanium n-butoxide (TNBT) or zinc nitrate hexahydrate, respectively. The formation of the core/shell/shell structures was confirmed by FESEM and TEM analyses. The saturation magnetizations of the Fe3O4/SiO2/TiO2, SrFe12O19/SiO2/TiO2 and Fe3O4/SiO2/ZnO photocatalytic materials were 41.5, 33 and 49 emu/g, respectively. Photocatalytic activity was evaluated by degradation percentages of methylene blue (MB) under UV illumination, which were 88%, 83% and 62%, for the Fe3O4/SiO2/TiO2, SrFe12O19//TiO2 and Fe3O4/SiO2/ZnO composites, respectively. The first-, and second-order reaction kinetics were used to find out the suitable MB removal kinetics.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68581528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Kazuz, Ž. Radovanović, Djordje Veljovic, V. Kojić, D. Jakimov, Tamara Vlajic-Tovilovic, V. Miletic, R. Petrović, Djordje Janackovic
?-Tricalcium phosphate/fluorapatite (?-TCP/FAp) mixed powders were prepared in order to obtain dental root canal filling cements. Different liquids for cement pastes have been investigated and the most suitable one for obtaining rheologically optimal pastes was chosen for further analysis. Morphological changes in the cement materials as a consequence of the formation of hydroxyapatite (HAp) after the immersion in a simulated body fluid (SBF), an influence on the cell viability, and final success of the filling were investigated by field emission scanning electron microscopy. Treatment of the ?-TCP/FAp mixtures in SBF at 37?C resulted in a complete transformation of ?-TCP into HAp after 10 days, while the exposure of MRC-5 human and L929 animal fibroblast cells to the cement showed complete absence of cytotoxicity. The root canal of an extracted tooth was filled with the ?-TCP/FAp cement containing 5 wt.% of FAp and relatively strong adhesion between the cement and dentine was observed after 48h. The same cement material was immersed during 10 days in SBF and after that both human and animal fibroblast cells during in vitro MTT tests showed higher cell viability compared to the control sample. These findings lead to a conclusion that the ?-TCP/FAp based cement demonstrates potential for further development towards dental cement application.
{"title":"α-tricalcium phosphate/fluorapatite-based cement - promising dental root canal filling material","authors":"A. Kazuz, Ž. Radovanović, Djordje Veljovic, V. Kojić, D. Jakimov, Tamara Vlajic-Tovilovic, V. Miletic, R. Petrović, Djordje Janackovic","doi":"10.2298/pac2201022k","DOIUrl":"https://doi.org/10.2298/pac2201022k","url":null,"abstract":"?-Tricalcium phosphate/fluorapatite (?-TCP/FAp) mixed powders were prepared in order to obtain dental root canal filling cements. Different liquids for cement pastes have been investigated and the most suitable one for obtaining rheologically optimal pastes was chosen for further analysis. Morphological changes in the cement materials as a consequence of the formation of hydroxyapatite (HAp) after the immersion in a simulated body fluid (SBF), an influence on the cell viability, and final success of the filling were investigated by field emission scanning electron microscopy. Treatment of the ?-TCP/FAp mixtures in SBF at 37?C resulted in a complete transformation of ?-TCP into HAp after 10 days, while the exposure of MRC-5 human and L929 animal fibroblast cells to the cement showed complete absence of cytotoxicity. The root canal of an extracted tooth was filled with the ?-TCP/FAp cement containing 5 wt.% of FAp and relatively strong adhesion between the cement and dentine was observed after 48h. The same cement material was immersed during 10 days in SBF and after that both human and animal fibroblast cells during in vitro MTT tests showed higher cell viability compared to the control sample. These findings lead to a conclusion that the ?-TCP/FAp based cement demonstrates potential for further development towards dental cement application.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68579581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To improve dielectric properties of SrTiO3-based materials and meet their development requirements in various scientific and technology fields, Mg-doped SrTiO3 nanowire films (with 0, 0.5, 1, 1.5 and 2mol% Mg) were fabricated by liquid phase deposition (LPD) process. The results showed that structural and dielectric properties of the prepared samples can be effectively affected by Mg doping. Thus, the SrTiO3 nanowire film doped with 1.5mol% Mg has high dielectric constant of 594.2, a low dielectric loss of 0.0167 and the highest breakdown strength of 463.1 kV/cm at 1 kHz, therefore resulting in a high energy density of 5.64 J/cm3, which is about 3.9 times higher than that of the pure SrTiO3 nanowire films (1.44 J/cm3). Based on findings in this research, it was shown that improvement of dielectric properties of SrTiO3 ceramic systems can be obtained with formation of one-dimensional structures and selecting reasonable Mg content for doping.
{"title":"Enhanced dielectric properties and energy storage density of Mg-doped SrTiO3 nanowire films","authors":"Mahsa Harooni, A. Sadeghzadeh‐Attar","doi":"10.2298/pac2201055h","DOIUrl":"https://doi.org/10.2298/pac2201055h","url":null,"abstract":"To improve dielectric properties of SrTiO3-based materials and meet their development requirements in various scientific and technology fields, Mg-doped SrTiO3 nanowire films (with 0, 0.5, 1, 1.5 and 2mol% Mg) were fabricated by liquid phase deposition (LPD) process. The results showed that structural and dielectric properties of the prepared samples can be effectively affected by Mg doping. Thus, the SrTiO3 nanowire film doped with 1.5mol% Mg has high dielectric constant of 594.2, a low dielectric loss of 0.0167 and the highest breakdown strength of 463.1 kV/cm at 1 kHz, therefore resulting in a high energy density of 5.64 J/cm3, which is about 3.9 times higher than that of the pure SrTiO3 nanowire films (1.44 J/cm3). Based on findings in this research, it was shown that improvement of dielectric properties of SrTiO3 ceramic systems can be obtained with formation of one-dimensional structures and selecting reasonable Mg content for doping.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68579989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lai Xiao, Yu-de Xiao, Xiao-long Zhao, Xing Li, Lv Chen, T. Xuan, Ya Zhang, Z. Cai, Xiao Wang
The microstructure and oxidation behaviour of the pure AlON ceramics and 8 wt.% SiC-AlON composite were investigated at 700-1500?C. With increasing oxidation temperature, the surface morphology of two ceramics showed a change from acicular to flaky-like and then to granular features. With the addition of nanosized SiC particles, the oxidation resistance of the ceramics was remarkably enhanced above 1100?C. This is attributed to the formation of a dense oxide layer composed of Al2O3, SiO2 and mullite, which could cover the whole matrix and suppress further penetration of oxygen. Due to the dense oxide layer, the oxidation kinetics of the 8 wt.% SiC-AlON composites conformed to a parabolic law, while that of the pure AlON conformed to a linear law. After oxidation at 1500 ?C for 40 h, the weight gain of the 8 wt.% SiC-AlON composites was 3.07mg/cm2, which was only 22.5% of that of the pure AlON.
{"title":"Oxidation resistance performance of SiC-AlON ceramic composites at high temperature","authors":"Lai Xiao, Yu-de Xiao, Xiao-long Zhao, Xing Li, Lv Chen, T. Xuan, Ya Zhang, Z. Cai, Xiao Wang","doi":"10.2298/pac2202097x","DOIUrl":"https://doi.org/10.2298/pac2202097x","url":null,"abstract":"The microstructure and oxidation behaviour of the pure AlON ceramics and 8 wt.% SiC-AlON composite were investigated at 700-1500?C. With increasing oxidation temperature, the surface morphology of two ceramics showed a change from acicular to flaky-like and then to granular features. With the addition of nanosized SiC particles, the oxidation resistance of the ceramics was remarkably enhanced above 1100?C. This is attributed to the formation of a dense oxide layer composed of Al2O3, SiO2 and mullite, which could cover the whole matrix and suppress further penetration of oxygen. Due to the dense oxide layer, the oxidation kinetics of the 8 wt.% SiC-AlON composites conformed to a parabolic law, while that of the pure AlON conformed to a linear law. After oxidation at 1500 ?C for 40 h, the weight gain of the 8 wt.% SiC-AlON composites was 3.07mg/cm2, which was only 22.5% of that of the pure AlON.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68580483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：