Pub Date : 2019-01-14DOI: 10.4172/2324-8777.1000264
K. König, Fabian Langensiepen, G. Seide, Jonas Daenicke, D. Schubert
In this paper, the feasibility of fabricating polypropylene (PP) nanofibers was investigated using conductive additives such as sodium stearate (NaSt), sodium oleate (NaOl) and Irgastat during melt electro spinning with a single nozzle lab and a 600- nozzle pilot scale device. Varying PP grades of high melt flow indices (MFI=450-1200 g/10 min) were used with different amounts of additives. The effects of the additives on the fiber diameters, thermal properties, electrical conductivity and polymer degradation were investigated. On a lab scale, fiber diameters of less than 500 nm were achieved with the compound of PP HL712FB, 4 wt% NaSt and 2 wt% Irgastat. The lab scale device was extended by a heatable spinning chamber, which affects fiber diameter reduction. The fabrication of nanofibers was in principle attributed to the increase in electrical conductivity with the introduction of the additives. On a pilot scale, the smallest fiber diameter of 6.64 μm could be achieved with PP HL508FB and 2 wt% NaSt. The comparison between the production of the fibers with a single nozzle and the pilot scale plant has revealed that a transfer of results is not possible without further ado. Due to the higher dwell time in the nozzle, a strong thermal degradation of the polymer could be detected with the high temperature size exclusion chromatography, whereby NaOl had the strongest influence on the thermal degradation. The high melt flow PP HL712FB and its compounds could not be processed with the pilot scale device due to its low viscosity, resulting in an insufficient pressure built up within the spinneret. Another reason for the non-spinnability of the material is the higher thermal and mechanical stress caused by the preceding melts preparation in an extrusion step. Further adjustments to the pilot plant are necessary to ensure a constant temperature distribution in the nozzle plate to achieve uniform fiber cross sections. The implementation of an uneven collector has successfully led to an even deposition of the fibers to obtain an isotropic non-woven fabric.
{"title":"From Lab to Pilot Scale: Melt Electrospun Nanofibers of Polypropylene with Conductive Additives","authors":"K. König, Fabian Langensiepen, G. Seide, Jonas Daenicke, D. Schubert","doi":"10.4172/2324-8777.1000264","DOIUrl":"https://doi.org/10.4172/2324-8777.1000264","url":null,"abstract":"In this paper, the feasibility of fabricating polypropylene (PP) nanofibers was investigated using conductive additives such as sodium stearate (NaSt), sodium oleate (NaOl) and Irgastat during melt electro spinning with a single nozzle lab and a 600- nozzle pilot scale device. Varying PP grades of high melt flow indices (MFI=450-1200 g/10 min) were used with different amounts of additives. The effects of the additives on the fiber diameters, thermal properties, electrical conductivity and polymer degradation were investigated. On a lab scale, fiber diameters of less than 500 nm were achieved with the compound of PP HL712FB, 4 wt% NaSt and 2 wt% Irgastat. The lab scale device was extended by a heatable spinning chamber, which affects fiber diameter reduction. The fabrication of nanofibers was in principle attributed to the increase in electrical conductivity with the introduction of the additives. On a pilot scale, the smallest fiber diameter of 6.64 μm could be achieved with PP HL508FB and 2 wt% NaSt. The comparison between the production of the fibers with a single nozzle and the pilot scale plant has revealed that a transfer of results is not possible without further ado. Due to the higher dwell time in the nozzle, a strong thermal degradation of the polymer could be detected with the high temperature size exclusion chromatography, whereby NaOl had the strongest influence on the thermal degradation. The high melt flow PP HL712FB and its compounds could not be processed with the pilot scale device due to its low viscosity, resulting in an insufficient pressure built up within the spinneret. Another reason for the non-spinnability of the material is the higher thermal and mechanical stress caused by the preceding melts preparation in an extrusion step. Further adjustments to the pilot plant are necessary to ensure a constant temperature distribution in the nozzle plate to achieve uniform fiber cross sections. The implementation of an uneven collector has successfully led to an even deposition of the fibers to obtain an isotropic non-woven fabric.","PeriodicalId":16457,"journal":{"name":"Journal of Nanomaterials & Molecular Nanotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80827342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.4172/2324-8777.1000272
F. Gharib, I. M. Zeid, S. Ghazi, E. Ahmed
The present study describes the synthesis and rapid production of selenium nanoparticles (SeNPs) by reducing selenate in the presence of Ascorbic Acid (AA) as a reductant, coating, and stabilizing agent. The formation of nanosized selenium at 10 mm sodium selenate (Na2SeO4) and 1.5% AA was confirmed by the appearance of the characteristic surface plasmon absorption peak at 296 nm in UV-vis spectra. Transmission Electron Microscopy (TEM) indicates that SeNPs was mostly spherical with a mean diameter of approximately 33.4 nm. X-RAY Diffraction (XRD) pattern confirmed crystalline shape indicating particle size of approximately 42.92 nm. The particle size distribution of SeNPs was approximately 45.9 nm by Dynamic Light Scattering (DLS). Fourier Transform Infrared (FTIR) spectroscopic analysis indicates the coating of selenium nanoparticles with ascorbic acid bonding of SeNPs with the COO˗ group of ascorbic acid. A pot experiment at the Experimental Farm of Helwan University, Cairo, Egypt during the season of 2016 was performed to evaluate the effects of foliar applications of both Na2SeO4 and chemically synthesized SeNPs (≈ 33.4 nm) each at 0.0, 6.25, 12.5, 25 and 50 µM on vegetative growth, yield and some physiological activities of cowpea (Vigna unguiculata L) plants. Foliar application of Na2SeO4 and SeNPs up to 25 µM significantly increased growth criteria (i.e. length of roots and stem, the root, stem and leaves fresh and dry weights, No of leaves and total leaves area cm2/plant), weight and quality of seed compared to the corresponding untreated control plants. Application of Na2SeO4 and SeNPs, especially at 6.25 µM concentration increased the Total Photosynthetic Pigments (TPP), Total Carbohydrate (TC), total soluble proteins (TSP), and different minerals in leaves accompanied by decrease in Total Soluble Sugars (TSS). SeNPs at 6.25 µM increased the levels of the growth hormones Indole Acetic Acid (IAA), Gibberellic Acid (GA3) and Cytokinins (CKs) of cowpea leaves, with a relatively lower Abscisic Acid (ABA) content and higher GA3/ABA ratios, followed by Na2SeO4 at 6.25 µM which explains the increase in growth parameters and seed weight in SeNPs and Na2SeO4 treated plants compared to control plants. Atomic Absorption Spectroscopy (AAS) study unveiled the residual accumulation of selenium nanoparticles in leaves and seeds of cowpea plants at 50 µM. Transmission electron microscopy showed small, dark deposits in leaf cells exposed to SeNPs, which probably originated from the nanoparticles absorbed onto the leaves and transferred to seeds. In conclusion, application of SeNPs and Na2SeO4 at 6.25 µM improved vegetative growth, seed weight, nutritional value and quality of cowpea plants and seeds.
{"title":"The Response of Cowpea (Vigna unguiculata L) Plants to Foliar Application of Sodium Selenate and Selenium Nanoparticles (SeNPs)","authors":"F. Gharib, I. M. Zeid, S. Ghazi, E. Ahmed","doi":"10.4172/2324-8777.1000272","DOIUrl":"https://doi.org/10.4172/2324-8777.1000272","url":null,"abstract":"The present study describes the synthesis and rapid production of selenium nanoparticles (SeNPs) by reducing selenate in the presence of Ascorbic Acid (AA) as a reductant, coating, and stabilizing agent. The formation of nanosized selenium at 10 mm sodium selenate (Na2SeO4) and 1.5% AA was confirmed by the appearance of the characteristic surface plasmon absorption peak at 296 nm in UV-vis spectra. Transmission Electron Microscopy (TEM) indicates that SeNPs was mostly spherical with a mean diameter of approximately 33.4 nm. X-RAY Diffraction (XRD) pattern confirmed crystalline shape indicating particle size of approximately 42.92 nm. The particle size distribution of SeNPs was approximately 45.9 nm by Dynamic Light Scattering (DLS). Fourier Transform Infrared (FTIR) spectroscopic analysis indicates the coating of selenium nanoparticles with ascorbic acid bonding of SeNPs with the COO˗ group of ascorbic acid. A pot experiment at the Experimental Farm of Helwan University, Cairo, Egypt during the season of 2016 was performed to evaluate the effects of foliar applications of both Na2SeO4 and chemically synthesized SeNPs (≈ 33.4 nm) each at 0.0, 6.25, 12.5, 25 and 50 µM on vegetative growth, yield and some physiological activities of cowpea (Vigna unguiculata L) plants. Foliar application of Na2SeO4 and SeNPs up to 25 µM significantly increased growth criteria (i.e. length of roots and stem, the root, stem and leaves fresh and dry weights, No of leaves and total leaves area cm2/plant), weight and quality of seed compared to the corresponding untreated control plants. Application of Na2SeO4 and SeNPs, especially at 6.25 µM concentration increased the Total Photosynthetic Pigments (TPP), Total Carbohydrate (TC), total soluble proteins (TSP), and different minerals in leaves accompanied by decrease in Total Soluble Sugars (TSS). SeNPs at 6.25 µM increased the levels of the growth hormones Indole Acetic Acid (IAA), Gibberellic Acid (GA3) and Cytokinins (CKs) of cowpea leaves, with a relatively lower Abscisic Acid (ABA) content and higher GA3/ABA ratios, followed by Na2SeO4 at 6.25 µM which explains the increase in growth parameters and seed weight in SeNPs and Na2SeO4 treated plants compared to control plants. Atomic Absorption Spectroscopy (AAS) study unveiled the residual accumulation of selenium nanoparticles in leaves and seeds of cowpea plants at 50 µM. Transmission electron microscopy showed small, dark deposits in leaf cells exposed to SeNPs, which probably originated from the nanoparticles absorbed onto the leaves and transferred to seeds. In conclusion, application of SeNPs and Na2SeO4 at 6.25 µM improved vegetative growth, seed weight, nutritional value and quality of cowpea plants and seeds.","PeriodicalId":16457,"journal":{"name":"Journal of Nanomaterials & Molecular Nanotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90590598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-10-31DOI: 10.4172/2324-8777.S6-003
C. Pellegrino, A. Volpe, R. Juris, M. Menna, V. Calabrese, F. Sola, C. Barattini, A. Ventola
We present a one-pot synthesis of core-shell silica nanoparticles (SiNPs) as a novel fluorescent probe for biological applications. SiNPs were doped with a different number of dyes to ensure high efficiency Fluorescence Resonance Energy Transfer (FRET). Dyes are individually entrapped in the silica core without a covalent bonding between them. The strong interconnection achieved inside the core, a FRET with efficiency up to 86% was obtained. Nanoparticles called NTB530, NTB575 and NTB660 contain two, three and four different dyes respectively. Nanoparticles can be excited with a common blue laser and characterized by a long Stokes Shift up to the near-IR emission. Photostability, tested under continuous irradiation with a mercury lamp, showed higher stability of our Nanoparticles compared to commercial dyes like Fluorescein and R-Phycoerythrin. To prove the potential application of our Nanoparticle in flow-cytometry, they were conjugated with Anti-Human CD8 antibody and tested in comparison with commercial ones.
{"title":"Multiple Dye Doped Core-Shell Silica Nanoparticles: Outstanding Stability and Signal Intensity Exploiting FRET Phenomenon for Biomedical Applications","authors":"C. Pellegrino, A. Volpe, R. Juris, M. Menna, V. Calabrese, F. Sola, C. Barattini, A. Ventola","doi":"10.4172/2324-8777.S6-003","DOIUrl":"https://doi.org/10.4172/2324-8777.S6-003","url":null,"abstract":"We present a one-pot synthesis of core-shell silica nanoparticles (SiNPs) as a novel fluorescent probe for biological applications. SiNPs were doped with a different number of dyes to ensure high efficiency Fluorescence Resonance Energy Transfer (FRET). Dyes are individually entrapped in the silica core without a covalent bonding between them. The strong interconnection achieved inside the core, a FRET with efficiency up to 86% was obtained. Nanoparticles called NTB530, NTB575 and NTB660 contain two, three and four different dyes respectively. Nanoparticles can be excited with a common blue laser and characterized by a long Stokes Shift up to the near-IR emission. Photostability, tested under continuous irradiation with a mercury lamp, showed higher stability of our Nanoparticles compared to commercial dyes like Fluorescein and R-Phycoerythrin. To prove the potential application of our Nanoparticle in flow-cytometry, they were conjugated with Anti-Human CD8 antibody and tested in comparison with commercial ones.","PeriodicalId":16457,"journal":{"name":"Journal of Nanomaterials & Molecular Nanotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77386171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-10-31DOI: 10.4172/2324-8777.S6-002
G. Wakefield, M. Gardener, M. Stock, M. Adair
Titanium oxide is a photoactive material that generates hydroxyl free radicals via water splitting. When doped with rare earth ions titanium oxide nanoparticles are activated by X-rays and X-ray generated electrons and are used to enhance radiotherapy treatment of solid tumours. As the nanoparticles generate free radicals by water splitting the presence of molecular oxygen is not required and aggressive hypoxic tumours may be targeted. A clonogenic assay of radio resistant pancreatic cancer (PANC- 1) cells shows a radiotherapy dose enhancement factor of 1.9 at clinically relevant nanoparticle loadings. A fast growing oropharyngeal cancer (FaDu) xenograft demonstrates that rare earth doped titanium oxide nanoparticles delivered by intratumoural injection disperse throughout the tumour, being taken up by cancer cells and undergoing passive accumulation in the Golgi apparatus. Incident radiotherapy activates the nanoparticles to produce hydroxyl free radicals, destroying the Golgi apparatus, and inducing tumour cell apoptosis. This results in a reduction in proliferating cancer cells and a consequent reduction in tumour regrowth rate by a factor of 3.8. There is no increase in systemic toxicity when using nanoparticles in addition to radiotherapy. Rare earth doped titanium oxide nanoparticles therefore represent a novel approach to tumour treatment via destruction of the cells Golgi apparatus during radiotherapy.
{"title":"Nanoparticle Augmented Radiotherapy using Titanium Oxide Nanoparticles","authors":"G. Wakefield, M. Gardener, M. Stock, M. Adair","doi":"10.4172/2324-8777.S6-002","DOIUrl":"https://doi.org/10.4172/2324-8777.S6-002","url":null,"abstract":"Titanium oxide is a photoactive material that generates hydroxyl free radicals via water splitting. When doped with rare earth ions titanium oxide nanoparticles are activated by X-rays and X-ray generated electrons and are used to enhance radiotherapy treatment of solid tumours. As the nanoparticles generate free radicals by water splitting the presence of molecular oxygen is not required and aggressive hypoxic tumours may be targeted. A clonogenic assay of radio resistant pancreatic cancer (PANC- 1) cells shows a radiotherapy dose enhancement factor of 1.9 at clinically relevant nanoparticle loadings. A fast growing oropharyngeal cancer (FaDu) xenograft demonstrates that rare earth doped titanium oxide nanoparticles delivered by intratumoural injection disperse throughout the tumour, being taken up by cancer cells and undergoing passive accumulation in the Golgi apparatus. Incident radiotherapy activates the nanoparticles to produce hydroxyl free radicals, destroying the Golgi apparatus, and inducing tumour cell apoptosis. This results in a reduction in proliferating cancer cells and a consequent reduction in tumour regrowth rate by a factor of 3.8. There is no increase in systemic toxicity when using nanoparticles in addition to radiotherapy. Rare earth doped titanium oxide nanoparticles therefore represent a novel approach to tumour treatment via destruction of the cells Golgi apparatus during radiotherapy.","PeriodicalId":16457,"journal":{"name":"Journal of Nanomaterials & Molecular Nanotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83766173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-08-09DOI: 10.4172/2324-8777.1000246
Joy Sebastian Prakash Joseph Irudayaraj, Prakash Thanigainathan, M. Ramach, Karunanithi Rajamanickam
Cd/ZnSe quantum dots (QDs) were synthesized in a wet chemical method by using a stabilizing agent L-cysteine. This facile synthesis does not require any high temperature or inert gas atmosphere. The synthesized QDs were characterized by using UV-Vis spectrophotometer, spetrofluorometer, fourier transform infrared (FT-IR) spectrometer, Fluorescence lifetime spectrometer, thermogravimetric analysis (TGA), powder x-ray diffraction, transmission electron microscopy and scanning electron microscopy. The synthesized QDs are spherical in shape with an average diameter of 4.78 nm and are readily soluble in water, making them biologically compatible. Further, the carboxyl and amine functional groups are accessible on the QDs’ surface. Thus, these QDs can be used as molecular imaging probes by anchoring targeting molecules by using the functional groups available on the surface of the QDs.
{"title":"One-pot Chemical Synthesis and Characterization of Fluorescent Cd/Znse Quantum Dots Using L-Cysteine as Stabilizing Agent","authors":"Joy Sebastian Prakash Joseph Irudayaraj, Prakash Thanigainathan, M. Ramach, Karunanithi Rajamanickam","doi":"10.4172/2324-8777.1000246","DOIUrl":"https://doi.org/10.4172/2324-8777.1000246","url":null,"abstract":"Cd/ZnSe quantum dots (QDs) were synthesized in a wet chemical method by using a stabilizing agent L-cysteine. This facile synthesis does not require any high temperature or inert gas atmosphere. The synthesized QDs were characterized by using UV-Vis spectrophotometer, spetrofluorometer, fourier transform infrared (FT-IR) spectrometer, Fluorescence lifetime spectrometer, thermogravimetric analysis (TGA), powder x-ray diffraction, transmission electron microscopy and scanning electron microscopy. The synthesized QDs are spherical in shape with an average diameter of 4.78 nm and are readily soluble in water, making them biologically compatible. Further, the carboxyl and amine functional groups are accessible on the QDs’ surface. Thus, these QDs can be used as molecular imaging probes by anchoring targeting molecules by using the functional groups available on the surface of the QDs.","PeriodicalId":16457,"journal":{"name":"Journal of Nanomaterials & Molecular Nanotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83788752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-08-09DOI: 10.4172/2324-8777.1000251
S. Chen, C. Chen, L. Jiang, Y. Dan
Using different initiators, potassium persulphate (KPS) and azodiisobutyronitrile (AIBN), two conventional emulsifier-free emulsion polymerizations of the monomer tert-butyl acrylate (t-BA) in aqueous medium were carried out. The results of the measurements on the transmittance of the reaction system and the conversion of the monomer through UV-Vis absorption spectroscopy indicate that the polymerization processes of the t-BA initiated by KPS shows three stages while that initiated by AIBN behaves two stages. Investigations on the morphology and the average hydrodynamic diameter and its distribution of the obtained poly (t-BA) nano-microspheres by scanning electron microscope and dynamic light scattering techniques show that, during the polymerization, the poly(t-BA) nano-microspheres from AIBN initiated polymerization show a larger average hydrodynamic diameter and a steady diameter’s distribution. The results have prompted us to have a new insight in emulsifier-free emulsion polymerization and provide us a new idea and a convenient approach to synthesize polymeric nano-microspheres with a different hydrodynamic diameter by using initiator with required solubility in aqueous medium through free-radical polymerization.
{"title":"A New Insight for Synthesizing Polymeric Nano-Microspheres with Different Size by Using Different Initiators in the Conventional Emulsifier-Free Emulsion Polymerization","authors":"S. Chen, C. Chen, L. Jiang, Y. Dan","doi":"10.4172/2324-8777.1000251","DOIUrl":"https://doi.org/10.4172/2324-8777.1000251","url":null,"abstract":"Using different initiators, potassium persulphate (KPS) and azodiisobutyronitrile (AIBN), two conventional emulsifier-free emulsion polymerizations of the monomer tert-butyl acrylate (t-BA) in aqueous medium were carried out. The results of the measurements on the transmittance of the reaction system and the conversion of the monomer through UV-Vis absorption spectroscopy indicate that the polymerization processes of the t-BA initiated by KPS shows three stages while that initiated by AIBN behaves two stages. Investigations on the morphology and the average hydrodynamic diameter and its distribution of the obtained poly (t-BA) nano-microspheres by scanning electron microscope and dynamic light scattering techniques show that, during the polymerization, the poly(t-BA) nano-microspheres from AIBN initiated polymerization show a larger average hydrodynamic diameter and a steady diameter’s distribution. The results have prompted us to have a new insight in emulsifier-free emulsion polymerization and provide us a new idea and a convenient approach to synthesize polymeric nano-microspheres with a different hydrodynamic diameter by using initiator with required solubility in aqueous medium through free-radical polymerization.","PeriodicalId":16457,"journal":{"name":"Journal of Nanomaterials & Molecular Nanotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76729959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-08-09DOI: 10.4172/2324-8777.1000247
Napon Butrach, O. Thumthan, S. Noothongkaew
TiO2 nanostructures were prepared by anodization of Ti foils. The TiO2 nanostructure films were annealed at the temperature range of 500°C to 900°C for 2 h. The morphology, elemental composition, and crystallization of TiO2 nanostructures were analyzed by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Raman spectra, and X-ray spectroscopy (XPS), respectively. XRD and Raman spectra results confirm the presence of the anatase phase for TiO2 nanostructure films which were annealed at 500°C to 700°C. Furthermore, it found that anatase to rutile phase transition occurred at temperature above 700oC.
{"title":"Characterization of Anatase and Rutile Phase of TiO2 Nanostructures with Different Thermal Annealing","authors":"Napon Butrach, O. Thumthan, S. Noothongkaew","doi":"10.4172/2324-8777.1000247","DOIUrl":"https://doi.org/10.4172/2324-8777.1000247","url":null,"abstract":"TiO2 nanostructures were prepared by anodization of Ti foils. The TiO2 nanostructure films were annealed at the temperature range of 500°C to 900°C for 2 h. The morphology, elemental composition, and crystallization of TiO2 nanostructures were analyzed by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Raman spectra, and X-ray spectroscopy (XPS), respectively. XRD and Raman spectra results confirm the presence of the anatase phase for TiO2 nanostructure films which were annealed at 500°C to 700°C. Furthermore, it found that anatase to rutile phase transition occurred at temperature above 700oC.","PeriodicalId":16457,"journal":{"name":"Journal of Nanomaterials & Molecular Nanotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77368176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-08-09DOI: 10.4172/2324-8777.1000250
Jeena Tr, Raj Ame, M. Bououdina
In this paper, a report has been acclaimed on the structural, morphological and photoluminescence properties of the pure and Yb3+ (2, 5 and 10 wt %) doped gadolinium oxide nanophosphor, synthesized by the citrate-nitrate auto combustion method. The influence of doping concentration on the properties of the prepared phosphor was studied using different characterization techniques. Structural studies carried out using XRD revealed crystalline cubic phase for both the pure and doped Gd2O3 nanoparticles. The phase formation and purity were further confirmed from the FTIR spectra. Surface morphology was found using SEM analysis showed the clusters of tiny particles. Optical absorption measurements were recorded in the UV-Vis-NIR wavelength region and the optical band gap variations with dopant concentration were discussed. The probable mechanism for the visible PL emissions by Yb3+ doped Gd2O3 phosphors are explained by different transition phenomenon. Fluorescence lifetime along with energy transfer efficiency from Gd3+ to Yb3+ was determined.
{"title":"Rare Earth Yb3+ Doped Gd2O3 Single Phase Nanophosphors: Structural, Morphological and Photoluminescence Studies","authors":"Jeena Tr, Raj Ame, M. Bououdina","doi":"10.4172/2324-8777.1000250","DOIUrl":"https://doi.org/10.4172/2324-8777.1000250","url":null,"abstract":"In this paper, a report has been acclaimed on the structural, morphological and photoluminescence properties of the pure and Yb3+ (2, 5 and 10 wt %) doped gadolinium oxide nanophosphor, synthesized by the citrate-nitrate auto combustion method. The influence of doping concentration on the properties of the prepared phosphor was studied using different characterization techniques. Structural studies carried out using XRD revealed crystalline cubic phase for both the pure and doped Gd2O3 nanoparticles. The phase formation and purity were further confirmed from the FTIR spectra. Surface morphology was found using SEM analysis showed the clusters of tiny particles. Optical absorption measurements were recorded in the UV-Vis-NIR wavelength region and the optical band gap variations with dopant concentration were discussed. The probable mechanism for the visible PL emissions by Yb3+ doped Gd2O3 phosphors are explained by different transition phenomenon. Fluorescence lifetime along with energy transfer efficiency from Gd3+ to Yb3+ was determined.","PeriodicalId":16457,"journal":{"name":"Journal of Nanomaterials & Molecular Nanotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76949633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-08-09DOI: 10.4172/2324-8777.1000249
Javishk Shah, J. Ort, M. Carreon
Background: There is an increasing interest to consider carbon dioxide as a resource and a business opportunity rather than a waste with a disposal cost. Among the several specific motivations to produce platform chemicals such as carbamates from CO2 are the low or zero cost of this feedstock and the potential to be a more economic efficient route. However, this pathway requires the development of materials with tunable morphologies and textural properties that display enhanced catalytic performance, distinctive structural and adsorption properties than those of conventional materials. Gallium oxide can be rationally engineered into crystalline porous materials which combine highly desirable properties, such as controlled morphology, uniform micropores, and high surface areas with exceptional chemical and thermal stability. Method: The synthesis was performed in a batch reactor with mesoporous gallium oxide as catalyst while n-octylamine and nproponal were the reactants. The reactor was pressured with CO2. The temperature of the reaction was at 200°C and the reaction time is 24 h. Results: High surface area γ-mesostructured gallium oxide was tested as a catalyst for the synthesis of carbamates from CO2. The mesostructured catalysts displayed a high conversion of ≈ 69%, much higher than their non-mesostructured counterparts. After recycling the catalysts the γ-gallium oxide phase was preserved and displayed only a slight decrease in catalytic activity. The selectivity of carbamates was higher at small pore diameters which can be attributed to the enhanced diffusion of the linear chain carbamate compared to the branched urea derivatives. Conclusion: The results from this work demonstrate the successful use of mesostructured gallium oxide for the synthesis of carbamates from CO2. The high conversion of the mesostructured γ-gallium oxide compared to the non-mesostructured catalysts can be attributed to the high surface area.
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