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Hierarchically organized functional nanomaterials are of interest for potential use in electrochemical, catalytic and gas-sensing applications due to their unique structural organization defined on different length scales. Here we present the application of the aerosol processing route in generation of hierarchically organized nanostructured TiO2 particles. Particles are obtained by the thermal decomposition of aerosol generated by atomization of colloidal TiO2 solution with a low-intensity ultrasound generator operating at the high frequency of 1.7 MHz. By a proper choice of the precursors type and concentration, as well as processing parameters (temperature of aerosol decomposition and the residence time of droplet/particle), fine control over both the submicron- and nanometer-length scales of spherically structured TiO2 was achieved. The median diameter and the crystallite size of titania particles were found to be tunable from 350 to 450 nm and from 2.5 to 50 nm, respectively. Moreover, it was shown that the structural complexity of the particles synthesized at the lower processing temperatures might be further extended by their surface sensitization with several bidentate ligands. The results obtained demonstrate advantages of ultrasonic spray pyrolysis route in synthesis of hierarchically organized functional nanomaterials.

Hierarchical structures, which refers to the materials that have more than one length scale, organized as the assemblage of primary units with high surface-to-volume ratio, play an important role in advanced materials design. Especially, the building of complex hierarchical structures exhibiting the hybrid organic-inorganic interfaces might be of special importance for the creation of advanced nanostructured materials having either improved or novel characteristics that bridges various scientific areas for the future diverse technological applications in catalysis, optics, energy, life science etc. Applying the bottom-up building blocks approaches, it is possible to create the hierarchical structures in a controlled manner having different morphologies, starting from aqueous, organic or colloidal precursor solutions. Among the diversity of the “bottom-up” chemical approaches, synthesis through dispersion phase (aerosol) enables generation of ultrafine, either single or complex structures with controlled stoichiometry, chemical and phase content. The opportunities of the hot wall aerosol processing, provided by high heating and cooling rates, short residence time and high surface reaction, refers to the synthesis of spherical three-dimensional (3D), hierarchically organized nanostructured particles with uniformly distributed components and phases. The particles composite inner structure, representing an assembly of nanosized primary particles, opens the possibility for particle surface modification and functionalization emphasizing their application in photovoltaics, energy transfer and bioimaging. This versatile technique has been used for the successful synthesis of hierarchically organized submicronic titanium (IV) oxide or Y2O3 up-conversion phosphor particles having the diverse levels of structural, morphological and functional complexity explored by means of appropriate selection of different precursor solutions, either true or colloid, surface modification and

Hierarchically organized functional nanomaterials are of interest for potential use in electrochemical, catalytic and gas-sensing applications due to their unique structural organization defined on different length scales. Here we present the application of the aerosol processing route in generation of hierarchically organized nanostructured TiO2 particles. Particles are obtained by the thermal decomposition of aerosol generated by atomization of colloidal TiO2 solution with a low-intensity ultrasound generator operating at the high frequency of 1.7 MHz. By a proper choice of the precursors type and concentration, as well as processing parameters (temperature of aerosol decomposition and the residence time of droplet/particle), fine control over both the submicron- and nanometer-length scales of spherically structured TiO2 was achieved. The median diameter and the crystallite size of titania particles were found to be tunable from 350 to 450 nm and from 2.5 to 50 nm, respectively. Moreover, it was shown that the structural complexity of the particles synthesized at the lower processing temperatures might be further extended by their surface sensitization with several bidentate ligands. The results obtained demonstrate advantages of ultrasonic spray pyrolysis route in synthesis of hierarchically organized functional nanomaterials.

Hierarchical structures, which refers to the materials that have more than one length scale, organized as the assemblage of primary units with high surface-to-volume ratio, play an important role in advanced materials design. Especially, the building of complex hierarchical structures exhibiting the hybrid organic-inorganic interfaces might be of special importance for the creation of advanced nanostructured materials having either improved or novel characteristics that bridges various scientific areas for the future diverse technological applications in catalysis, optics, energy, life science etc. Applying the bottom-up building blocks approaches, it is possible to create the hierarchical structures in a controlled manner having different morphologies, starting from aqueous, organic or colloidal precursor solutions. Among the diversity of the “bottom-up” chemical approaches, synthesis through dispersion phase (aerosol) enables generation of ultrafine, either single or complex structures with controlled stoichiometry, chemical and phase content. The opportunities of the hot wall aerosol processing, provided by high heating and cooling rates, short residence time and high surface reaction, refers to the synthesis of spherical three-dimensional (3D), hierarchically organized nanostructured particles with uniformly distributed components and phases. The particles composite inner structure, representing an assembly of nanosized primary particles, opens the possibility for particle surface modification and functionalization emphasizing their application in photovoltaics, energy transfer and bioimaging. This versatile technique has been used for the successful synthesis of hierarchically organized submicronic titanium (IV) oxide or Y2O3 up-conversion phosphor particles having the diverse levels of structural, morphological and functional complexity explored by means of appropriate selection of different precursor solutions, either true or colloid, surface modification and

Theoretical and experimental investigation of the particle formation during processing of colloidal nanoparticles in aerosol laminar flow reactor is presented. Simple analytical model taking into consideration all important process parameters, such as physico-chemical properties of the colloidal solution, initial droplet size, residence time and temperature, is developed in order to predict the final particle morphology. The formation of spherical, hierarchically organized, ~450 nm sized TiO2 particles has been followed at 150°C starting from colloidal TiO2 nanoparticle (~4.5 nm) solution as precursor. It has been shown that the final particle morphology is formed in the evaporation/drying stage through the self assembly processes of colloidal nanoparticles collision and aggregation. The dimensionless numbers Re, Nu, Pr and Bi, were used in modeling to briefly describe the transport properties in dispersed system and heat and mass transport phenomena. The predicted particle size and morphology is confirmed by using scanning electron microscopy (SEM/FESEM) and laser diffraction particle size analyzer (LPS). Additionally, closer morphological investigation is performed with transmission electron microscopy (TEM) and nanotomography. Correspondingly, theoretical analysis under this study presents a simple procedure to predict the final morphology and mean particle size during aerosol processing.

The low-temperature (T=150oC) aerosol route, representing a feasible bottom-up technique for nano materials processing in disperse system, was applied for the synthesis of spherical, non-agglomerated, hierarchically organized titanium dioxide (TiO2) nano-particles. The diverse levels of structural, morphological and functional complexity were explored simply by means of appropriate selection of different colloidal precursor solutions of either nearly spherical nano-particles[1] (a), surface modified nano-particles with dopamine (b) or nano-tubes (c). The detailed structural and morphological investigations were done by X-ray powder diffraction (XRPD), laser particle size (LPS) analysis, scanning and field emission electron microscopy (SEM/FESEM) and transmission electron microscopy (TEM). Spherical, submicronic, soft and grained TiO2 particles with the mean size from ~350 to ~450nm and with clustered inner structure, composed of primary nanocrystals (<10nm), were obtained. The optical properties and surface structure were analyzed by UV-Vis diffusive reflectance (UV-Vis DRS) and Fourier transform infrared (FTIR) spectroscopy. The obtained results offer a general route for the synthesis of self-assemblies with tunable morphology and optical properties. A significant decrease of the effective band gap values (1.7 to 1.9eV) for the processed TiO2 nanoparticles, compared to the band gap of bulk material (3.2eV), was achieved. Such hierarchical nano-structured powders, are expected to have potential application not only in the field of photovoltaic technologies[3] but also in various aspects of photo catalysis.[4] References: [1] Dugandžić I.M., Jovanović D.J., Mančić L.T., Zheng N., Ahrenkiel S.P., Milošević O.B., Šaponjić Z.V. and Nedeljković J.M., 2012 Surface modification of submicronic TiO2 particles prepared by ultrasonic spray pyrolysis for visible light absorption, J. Nanopart. Res., 14 (10) 1157 (DOI10.1007/s11051-012-1157-1) [3] Zhang Q., Myers D., Lan J., Jene

The opportunities of the hot wall aerosol synthesis, i.e. conventional spray pyrolysis (CSP) method are demonstrated for the generation of highly spherical three-dimensional (3D) nanostructured phosphor particles with uniformly distributed components, phases and nano-clustered inner structure. With the presumption that certain particle morphology is formed during the evaporation/drying stage, the aerosol transport properties and powder generation are correlated with the particles structural and morphological features. With the help of various analyzing techniques like Field Emission Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy (TEM) coupled with energy dispersive X-ray Analysis and STEM mode (TEM/EDS), X-ray Powder Diffraction (XRPD) and fluorescence measurements the feasible processing of up-conversion rare-earth Y2O3:Er, Yb phosphors powders are discussed.

The opportunities of the hot wall aerosol synthesis, i.e. conventional spray pyrolysis (CSP) method are demonstrated for the generation of highly spherical three-dimensional (3D) nanostructured phosphor particles with uniformly distributed components, phases and nano-clustered inner structure. With the presumption that certain particle morphology is formed during the evaporation/drying stage, the aerosol transport properties and powder generation are correlated with the particles structural and morphological features. With the help of various analyzing techniques like Field Emission Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy (TEM) coupled with energy dispersive X-ray Analysis and STEM mode (TEM/EDS), X-ray Powder Diffraction (XRPD) and fluorescence measurements the feasible processing of up-conversion rare-earth Y2O3:Er, Yb phosphors powders are discussed.

Poster presented at the conference Advanced Ceramics and Application II – Serbian Ceramic Society, Belgrade, September 30 – October 1, 2013

Spherical, submicronic TiO2 powder particles were prepared in the low temperature process of ultrasonic spray pyrolysis (150 °C) by using as a precursor aqueous colloidal solutions consisting of surface modified 45 Å TiO2 nanoparticles with dopamine. Detailed structural and morphological characterization of colored submicronic TiO2 spheres was performed by X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), laser particle size analysis and FTIR techniques. Also, optical characterization of both dopamine-modified TiO2 precursor nanoparticles and submicronic TiO2 powder particles was performed using absorption and diffuse reflectance spectroscopy, respectively. A significant decrease of the effective band gap (1.9 eV) in dopamine-modified TiO2 nanoparticles compared to the band gap of bulk material (3.2 eV) was preserved after formation of submicronic TiO2 powder particles in the process of ultrasonic spray pyrolysis under mild experimental conditions. Due to the nanostructured nature, surface-modified assemblage of TiO2 nanoparticles preserved unique ability to absorb light through charge transfer complex by photoexcitation of the ligand-to-TiO2 band, conventionally associated with extremely small TiO2 nanoparticles (d < 20 nm) whose surface Ti atoms, owing to the large curvature, have penta-coordinate geometry.

The aerosol route, representing a feasible bottom-up technique for nanomaterials processing in disperse system, was applied for the low-temperature (T=150 oC) synthesis of spherical, nonagglomerated, hierarchically organized titania and titanates nanostructures. The diverse levels of structural, morphological and functional complexity were explored by using appropriate colloidal precursors comprising either spherical nanoparticles or nanotubes. In both cases, spherical, grained, submicronic sized particles with the average diameter of ~350 nm for titania and ~ 450 nm for titanates were obtained. The detailed structural and morphological investigations were done according to X-ray powder diffraction (XRPD), scanning and field emission electron microscopy (SEM/FESEM), particle size distribution (PSD) and transmission electron microscopy (TEM) results. Results revealed that particles have clustered inner structure and are composed from primary nanounits in form of nanoparticles or nanotubes. Such hierarchically organized particles are expected to have potential application not only in the field of photovoltaics but also in various branches of photocatalysis.

The opportunities of the hot wall aerosol synthesis, i.e. conventional spray pyrolysis (CSP) method are demonstrated for the generation of highly spherical three-dimensional (3D) nanostructured phosphor particles with uniformly distributed components, phases and nano-clustered inner structure. With the presumption that certain particle morphology is formed during the evaporation/drying stage, the aerosol transport properties and powder generation are correlated with the particles structural and morphological features. With the help of various analyzing techniques like Field Emission Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy (TEM) coupled with energy dispersive X-ray Analysis and STEM mode (TEM/EDS), X-ray Powder Diffraction (XRPD) and fluorescence measurements the feasible processing of up-conversion rare-earth Y2O3:Er, Yb phosphors powders are discussed.

The low-temperature (T=150oC) aerosol route, representing a feasible bottom-up technique for nano materials processing in disperse system, was applied for the synthesis of spherical, non-agglomerated, hierarchically organized titanium dioxide (TiO2) nano-particles. The diverse levels of structural, morphological and functional complexity were explored simply by means of appropriate selection of different colloidal precursor solutions of either nearly spherical nano-particles[1] (a), surface modified nano-particles with dopamine (b) or nano-tubes (c). The detailed structural and morphological investigations were done by X-ray powder diffraction (XRPD), laser particle size (LPS) analysis, scanning and field emission electron microscopy (SEM/FESEM) and transmission electron microscopy (TEM). Spherical, submicronic, soft and grained TiO2 particles with the mean size from ~350 to ~450nm and with clustered inner structure, composed of primary nanocrystals (<10nm), were obtained. The optical properties and surface structure were analyzed by UV-Vis diffusive reflectance (UV-Vis DRS) and Fourier transform infrared (FTIR) spectroscopy. The obtained results offer a general route for the synthesis of self-assemblies with tunable morphology and optical properties. A significant decrease of the effective band gap values (1.7 to 1.9eV) for the processed TiO2 nanoparticles, compared to the band gap of bulk material (3.2eV), was achieved. Such hierarchical nano-structured powders, are expected to have potential application not only in the field of photovoltaic technologies[3] but also in various aspects of photo catalysis.[4] References: [1] Dugandžić I.M., Jovanović D.J., Mančić L.T., Zheng N., Ahrenkiel S.P., Milošević O.B., Šaponjić Z.V. and Nedeljković J.M., 2012 Surface modification of submicronic TiO2 particles prepared by ultrasonic spray pyrolysis for visible light absorption, J. Nanopart. Res., 14 (10) 1157 (DOI10.1007/s11051-012-1157-1) [3] Zhang Q., Myers D., Lan J., Jene

The aerosol route, representing a feasible bottom-up technique for nanomaterials processing in disperse system, was applied for the low-temperature (T=150 oC) synthesis of spherical, nonagglomerated, hierarchically organized titania and titanates nanostructures. The diverse levels of structural, morphological and functional complexity were explored by using appropriate colloidal precursors comprising either spherical nanoparticles or nanotubes. In both cases, spherical, grained, submicronic sized particles with the average diameter of ~350 nm for titania and ~ 450 nm for titanates were obtained. The detailed structural and morphological investigations were done according to X-ray powder diffraction (XRPD), scanning and field emission electron microscopy (SEM/FESEM), particle size distribution (PSD) and transmission electron microscopy (TEM) results. Results revealed that particles have clustered inner structure and are composed from primary nanounits in form of nanoparticles or nanotubes. Such hierarchically organized particles are expected to have potential application not only in the field of photovoltaics but also in various branches of photocatalysis.

Spherical, submicronic TiO2 powder particles were prepared in the low temperature process of ultrasonic spray pyrolysis (150 °C) by using as a precursor aqueous colloidal solutions consisting of surface modified 45 Å TiO2 nanoparticles with dopamine. Detailed structural and morphological characterization of colored submicronic TiO2 spheres was performed by X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), laser particle size analysis and FTIR techniques. Also, optical characterization of both dopamine-modified TiO2 precursor nanoparticles and submicronic TiO2 powder particles was performed using absorption and diffuse reflectance spectroscopy, respectively. A significant decrease of the effective band gap (1.9 eV) in dopamine-modified TiO2 nanoparticles compared to the band gap of bulk material (3.2 eV) was preserved after formation of submicronic TiO2 powder particles in the process of ultrasonic spray pyrolysis under mild experimental conditions. Due to the nanostructured nature, surface-modified assemblage of TiO2 nanoparticles preserved unique ability to absorb light through charge transfer complex by photoexcitation of the ligand-to-TiO2 band, conventionally associated with extremely small TiO2 nanoparticles (d < 20 nm) whose surface Ti atoms, owing to the large curvature, have penta-coordinate geometry.

The opportunities of the hot wall aerosol synthesis, i.e. conventional spray pyrolysis (CSP) method are demonstrated for the generation of highly spherical three-dimensional (3D) nanostructured phosphor particles with uniformly distributed components, phases and nano-clustered inner structure. With the presumption that certain particle morphology is formed during the evaporation/drying stage, the aerosol transport properties and powder generation are correlated with the particles structural and morphological features. With the help of various analyzing techniques like Field Emission Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy (TEM) coupled with energy dispersive X-ray Analysis and STEM mode (TEM/EDS), X-ray Powder Diffraction (XRPD) and fluorescence measurements the feasible processing of up-conversion rare-earth Y2O3:Er, Yb phosphors powders are discussed.

Theoretical and experimental investigation of the particle formation during processing of colloidal nanoparticles in aerosol laminar flow reactor is presented. Simple analytical model taking into consideration all important process parameters, such as physico-chemical properties of the colloidal solution, initial droplet size, residence time and temperature, is developed in order to predict the final particle morphology. The formation of spherical, hierarchically organized, ~450 nm sized TiO2 particles has been followed at 150°C starting from colloidal TiO2 nanoparticle (~4.5 nm) solution as precursor. It has been shown that the final particle morphology is formed in the evaporation/drying stage through the self assembly processes of colloidal nanoparticles collision and aggregation. The dimensionless numbers Re, Nu, Pr and Bi, were used in modeling to briefly describe the transport properties in dispersed system and heat and mass transport phenomena. The predicted particle size and morphology is confirmed by using scanning electron microscopy (SEM/FESEM) and laser diffraction particle size analyzer (LPS). Additionally, closer morphological investigation is performed with transmission electron microscopy (TEM) and nanotomography. Correspondingly, theoretical analysis under this study presents a simple procedure to predict the final morphology and mean particle size during aerosol processing.

Poster presented at the conference Advanced Ceramics and Application II – Serbian Ceramic Society, Belgrade, September 30 – October 1, 2013

Set of colloidal TiO2 nanoparticles solutions (TiO2 NPs) were surface modified with the different quantities of dopamine (DA) and then are used as precursors for the synthesis of DA modified submicronic TiO2 particles (DA-TiO2 SPs). Low temperature (150 oC) aerosol-assisted route (spray drying) is used for the generation of the un-agglomerated spherical particles with the mean size of 430 nm that are composited from much smaller crystalline sub-units. Detailed structural and morphological characterization of DA-TiO2 NPs and SPs were performed by X-ray powder diffraction (XRPD) analysis, scanning and transmission electron microscopy (SEM/TEM) and laser particle size (LPS) analysis. Particles surface structure and optical properties were followed using FT-IR and UV-Vis spectroscopy. Observed optical characteristics of both DA-TiO2 NPs and DA-TiO2 SPs expose narrowing of effective band gap for the same value of 1.3 eV implicating the preservation of colloidal nanoparticles characteristics in submicronic powders.

It is highly desirable to induce significant red-shift in the optical absorption edges of TiO2 phases so that this class of low-cost and environmentally friendly materials can be used as effective optical absorbing materials in photovoltaic cells. This work focuses on studying the formation of charge transfer (CT) complex, between TiO2 surface and dopamine as surface modifier, that induced significant red-shift of optical absorption in comparison to unmodified TiO2 particles. For that purpose, the submicronic sized TiO2 particles were synthesized at 150 0C by means of ultrasonic spray pyrolysis route using two different approaches for powder processing differing on how the precursor solution was made. In the first one, the colloidal source solution of unmodified TiO2 nanoparticles was used as precursor solution and the particles were additionally modified by dopamine after completing the synthesis procedure. In the second approach, the dopamine modification of source colloidal TiO2 nanoparticles preceded to powder processing. From Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) images it can be concluded that both groups of dopamine modified submicronic spheres have diameter of approximately 430 nm and contain small primary building units (Figure 1a and 1b). The surface structure and optical properties of resulting particles were analyzed using Fourier Transform Infrared (FT-IR) and UV-Vis spectroscopy investigations. The FT-IR measurements show that dopamine successfully formed CT complex at TiO2 surface. Based on the significant red shift on diffusive reflectance spectra (Figure 1c) it was estimated the effective band-gap value for all observed samples as to be ~1.3 eV.

Poster presented at the conference Advanced Ceramics and Application I - Serbian Ceramic Society, Belgrade May 10-11, 2012

Poster presented at the Third International Conference on the Physics of Optical Materials and Devices (ICOM 2012), September 3-6, Belgrade, Serbia

Poster presented at the Third International Conference on the Physics of Optical Materials and Devices (ICOM 2012), September 3-6, Belgrade, Serbia

It is highly desirable to induce significant red-shift in the optical absorption edges of TiO2 phases so that this class of low-cost and environmentally friendly materials can be used as effective optical absorbing materials in photovoltaic cells. This work focuses on studying the formation of charge transfer (CT) complex, between TiO2 surface and dopamine as surface modifier, that induced significant red-shift of optical absorption in comparison to unmodified TiO2 particles. For that purpose, the submicronic sized TiO2 particles were synthesized at 150 0C by means of ultrasonic spray pyrolysis route using two different approaches for powder processing differing on how the precursor solution was made. In the first one, the colloidal source solution of unmodified TiO2 nanoparticles was used as precursor solution and the particles were additionally modified by dopamine after completing the synthesis procedure. In the second approach, the dopamine modification of source colloidal TiO2 nanoparticles preceded to powder processing. From Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) images it can be concluded that both groups of dopamine modified submicronic spheres have diameter of approximately 430 nm and contain small primary building units (Figure 1a and 1b). The surface structure and optical properties of resulting particles were analyzed using Fourier Transform Infrared (FT-IR) and UV-Vis spectroscopy investigations. The FT-IR measurements show that dopamine successfully formed CT complex at TiO2 surface. Based on the significant red shift on diffusive reflectance spectra (Figure 1c) it was estimated the effective band-gap value for all observed samples as to be ~1.3 eV.

Set of colloidal TiO2 nanoparticles solutions (TiO2 NPs) were surface modified with the different quantities of dopamine (DA) and then are used as precursors for the synthesis of DA modified submicronic TiO2 particles (DA-TiO2 SPs). Low temperature (150 oC) aerosol-assisted route (spray drying) is used for the generation of the un-agglomerated spherical particles with the mean size of 430 nm that are composited from much smaller crystalline sub-units. Detailed structural and morphological characterization of DA-TiO2 NPs and SPs were performed by X-ray powder diffraction (XRPD) analysis, scanning and transmission electron microscopy (SEM/TEM) and laser particle size (LPS) analysis. Particles surface structure and optical properties were followed using FT-IR and UV-Vis spectroscopy. Observed optical characteristics of both DA-TiO2 NPs and DA-TiO2 SPs expose narrowing of effective band gap for the same value of 1.3 eV implicating the preservation of colloidal nanoparticles characteristics in submicronic powders.

In order to preserve unique properties of TiO2 nanoparticles towards their surface modification, two different approaches of low temperature aerosol-assisted processing were performed. Both were based on colloid precursor atomization and subsequent spray drying at T=150 oC in a hot wall reactor. In the first case, pure TiO2 colloid precursor solution was atomized and produced submicronic particles are subsequently modified, while in the second one atomization of already modified colloid precursor solution were done. In both cases the TiO2 surface modification was achieved with 30 % of dopamine. Powders crystallinity and phase composition were studied by X-ray powder difraction (XRPD), while detailed powders morphological characterization was followed using scanning and transmission electron microscopy (SEM and TEM). Optical properties of the surface modified TiO2 particles were investigated using reflection spectroscopy while the binding structure between dopamine and the surface titanium atoms was investigated by FTIR spectroscopy.

Poster presented at the International Symposium on Advanced Complex Inorganic Nanomaterials (ACIN 2011), September 11-14, 2011 - Namur, Belgium

Poster presented at the International Symposium on Advanced Complex Inorganic Nanomaterials (ACIN 2011), September 11-14, 2011 - Namur, Belgium

In order to preserve unique properties of TiO2 nanoparticles towards their surface modification, two different approaches of low temperature aerosol-assisted processing were performed. Both were based on colloid precursor atomization and subsequent spray drying at T=150 oC in a hot wall reactor. In the first case, pure TiO2 colloid precursor solution was atomized and produced submicronic particles are subsequently modified, while in the second one atomization of already modified colloid precursor solution were done. In both cases the TiO2 surface modification was achieved with 30 % of dopamine. Powders crystallinity and phase composition were studied by X-ray powder difraction (XRPD), while detailed powders morphological characterization was followed using scanning and transmission electron microscopy (SEM and TEM). Optical properties of the surface modified TiO2 particles were investigated using reflection spectroscopy while the binding structure between dopamine and the surface titanium atoms was investigated by FTIR spectroscopy.

Europium-doped (Y0.5Gd0.5)2O3 phosphor powder is synthesized via spray pyrolysis of polymeric precursor solution obtained by dissolving the stoichiometric amount of corresponding metal nitrates in ethylenediaminetetraacetic acid (EDTA) - ethylene glycol (EG) mixture. The 0.1M true stable solution is obtained after pH correction with NH4OH (final pH=8.7). Ultrasonically (1.3MHz) generated aerosol droplets are decomposed at 550 oC in argon atmosphere. Following the initial attempt for obtaining dense, nanostructured spherical particles of pure (Y0.5Gd0.5)2O3:Eu3+ phase, as-prepared dark-gray powder is additionally thermally treated for 12 h in air up to 1100 oC. The particle morphology is analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Phase identification is performed by X-ray powder diffraction (XRPD) based on which the structural refinement through Rietveld method was done. Particle chemical purity is confirmed through EDS analysis, while laser particle sizer is used for determination of the particle size distribution.

Poster presented at 12th Annual Conference of the Materials Research Society of Serbia - YUCOMAT 2010, Herceg Novi, Montenegro, September 6–10, 2010., Europium-doped (Y0.5Gd0.5)2O3 phosphor powder is synthesized via spray pyrolysis of polymeric precursor solution obtained by dissolving the stoichiometric amount of corresponding metal nitrates in ethylenediaminetetraacetic acid (EDTA) - ethylene glycol (EG) mixture. The 0.1M true stable solution is obtained after pH correction with NH4OH (final pH=8.7). Ultrasonically (1.3MHz) generated aerosol droplets are decomposed at 550 oC in argon atmosphere. Following the initial attempt for obtaining dense, nanostructured spherical particles of pure (Y0.5Gd0.5)2O3:Eu3+ phase, as-prepared dark-gray powder is additionally thermally treated for 12 h in air up to 1100 oC. The particle morphology is analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Phase identification is performed by X-ray powder diffraction (XRPD) based on which the structural refinement through Rietveld method was done. Particle chemical purity is confirmed through EDS analysis, while laser particle sizer is used for determination of the particle size distribution.

Europium-doped (Y0.5Gd0.5)2O3 phosphor powder is synthesized via spray pyrolysis of polymeric precursor solution obtained by dissolving the stoichiometric amount of corresponding metal nitrates in ethylenediaminetetraacetic acid (EDTA) - ethylene glycol (EG) mixture. The 0.1M true stable solution is obtained after pH correction with NH4OH (final pH=8.7). Ultrasonically (1.3MHz) generated aerosol droplets are decomposed at 550 oC in argon atmosphere. Following the initial attempt for obtaining dense, nanostructured spherical particles of pure (Y0.5Gd0.5)2O3:Eu3+ phase, as-prepared dark-gray powder is additionally thermally treated for 12 h in air up to 1100 oC. The particle morphology is analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Phase identification is performed by X-ray powder diffraction (XRPD) based on which the structural refinement through Rietveld method was done. Particle chemical purity is confirmed through EDS analysis, while laser particle sizer is used for determination of the particle size distribution.

Poster presented at 12th Annual Conference of the Materials Research Society of Serbia - YUCOMAT 2010, Herceg Novi, Montenegro, September 6–10, 2010., Europium-doped (Y0.5Gd0.5)2O3 phosphor powder is synthesized via spray pyrolysis of polymeric precursor solution obtained by dissolving the stoichiometric amount of corresponding metal nitrates in ethylenediaminetetraacetic acid (EDTA) - ethylene glycol (EG) mixture. The 0.1M true stable solution is obtained after pH correction with NH4OH (final pH=8.7). Ultrasonically (1.3MHz) generated aerosol droplets are decomposed at 550 oC in argon atmosphere. Following the initial attempt for obtaining dense, nanostructured spherical particles of pure (Y0.5Gd0.5)2O3:Eu3+ phase, as-prepared dark-gray powder is additionally thermally treated for 12 h in air up to 1100 oC. The particle morphology is analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Phase identification is performed by X-ray powder diffraction (XRPD) based on which the structural refinement through Rietveld method was done. Particle chemical purity is confirmed through EDS analysis, while laser particle sizer is used for determination of the particle size distribution.