Properties Of Nanophosphors Research Articles

Fabrication and characterization of YVO4:Eu3+ nanomaterials by the micro-wave technique

Fabrication and characterization of YVO4:Eu3+ nanophosphors prepared by microwave (MW) irradiation assisted soft template synthesis were reported. The effects of synthesis conditions such as different powers of MW irradiation, pH values and concentration of reaction materials on properties of nanophosphor were also investigated to obtain the controllable size, morphology and high luminescence efficiency. Morphology, crystalline structure, and optical properties were characterized by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) and fluorescence spectroscopy, respectively. The results showed that YVO4:Eu3+ nanophosphors were obtained by using diethyleneglycol (DEG) as soft template, with pH values in the range of 4 to 12, upon microwave irradiation from 300 to 900 W, at temperature of 80 °C. The high fluorescent YVO4:Eu3+ nanocrystals obtained with size from 15 nm down to 8 nm are more effective to develop an ultrahigh sensitive fluorescent label for biomolecule, cell and tissue.

Hydrothermal Synthesis and Photoluminescent Properties of YBO3:Eu3+ Nanophosphor Under Ultraviolet and Vacuum Ultraviolet Excitation

YBO3:Eu3+ Nanophosphors were prepared by hydrothermal reaction (HR) with different reaction times. When the reaction times increased, the grain sizes of phosphor did not change obviously, but the particle size, morphology, and aggregation state were different. This transformation has influenced luminescent properties. The change trends of luminescent intensity under ultraviolet (UV) and vacuum ultraviolet (VUV) excitation are almost contrary: the nanophosphor that has better intensity in UV region is lower in the VUV region and vice versa. The emission under UV excitation decreases first and increases later as time increases. However, the emission under VUV excitation increases first and decreases later. In the UV region, orange emissions (at 592 nm) are higher than red emissions (at 611 nm), but in VUV regions, red emissions are higher. All results indicated that luminescence properties of nanophosphors in VUV regions differ greatly from those of nanophosphors in UV regions. In a certain nanoscale, the decreased particle size will lead to enhanced luminescence under VUV excitation but weaker luminescence under UV excitation. The related phenomena and possible explanations are also discussed.

Development of Autoluminescent Surfacings for Concrete Pavements

“Nanotechnology” is the term used to cover the design, construction, and use of functional structures with at least one characteristic dimension measured in nanometers. Although the technology initially developed in the fields of electronics, physics, and chemistry, more recent developments emerged in the engineering field. The focus is on a specific potential application of nanotechnology in pavement engineering where the properties of nanophosphors are used to develop an autoluminescent pavement or structure. A brief background is provided on potential applications of nanotechnology in pavement engineering, followed by a discussion on the specific research conducted. Data obtained from scanning electron microscope images and luminescence measurements of typical infrastructure materials with nanophosphors embedded are shown and discussed. An example is demonstrated in which the application of nanotechnology in pavement engineering may potentially lead to the provision of a safer and more economical transportation experience to the traveling public. Some remaining challenges for the current project are discussed and conclusions are made, showing that nanotechnology can play a role in improving the understanding and service delivery in pavement engineering.