Papers by Keyword: Fluorescent Dye

Abstract: Homopolymer PHB and copolymer PHB/HV containing granules were isolated from Azotobacter chroococcum cells and used for latexes formation. Composite latex films were formed from the PHB and PHB/HV latexes with different content of poly (vinyl alcohol) and glycerol and a hydrophobic fluorescent benzanthrone derivated dye 3-piperidinobenzanthrone, possessed high fluorescence intensity in a system with PHA granules. Fluorescence based methods were used for characterization of the elaborated latex film by their stability at high temperature and for visualization of the film surfaces PHA granules distribution. Film stability in phosphate buffered saline was evaluated by dye migration activity in the solution. The results of mechanical testing of the latex films were compared with the stability testing and surface visualization results. The data obtained allow a better understanding the difference of the mechanical and physical properties of the investigated films.

Abstract: Fluorescent dyes based on 3-(2'-benzothiazolyl)coumarin were synthesized by a simple condensing reaction in this study. The chemical structures of synthesized compounds were subjected to FT-IR, 1H-NMR, Mass and UV/Vis analysis for color characteristics. Polyester fabrics dyed with the compounds were evaluated by color strength and color fastness to washing, perspiration and light of ISO. The results showed that all dyes decide after identified by IR, MS and ¹H-NMR the structure is correct. And then all dyes were used to the dyeing of polyester fabrics. It was clearly that color strength increased with the increasing of the amount of carbon in the 7-position of coumarin ring. The level of color fastness to washing and perspiration were 4-5 or more, while the level of color fastness to light decreased with an increase of carbon chain length.

Abstract: This paper is dedicated to an impregnation technique for crack identification of uniaxial tensile behaviour of concrete samples. A method for crack identification in concrete after uniaxial tension tests was adopted for the observation of differences between various experiments which were conducted with and without the elimination of secondary flexure. During the procedure an epoxy resin containing fluorescent dye was infused into concrete samples by vacuum to expose cracks and defects. After impregnation the samples were sawed from the prism and pictures taken under ultraviolet light.

Abstract: The core-shell structure of dye-silica nanoparticle has been prepared. The dye-silica nanoparticle can be used as a substitute of fluorescent dye for bio analysis. The hybrid organicinorganic nanoparticle was prepared by sol-gel process using organic modified silane as the coupling agent for flourescent dye and silica. The size of the particle was about 50 nm, which was measured by DLS and confirmed by SEM photograph. The fluorescent dye (fluorescein-5-maleimide) was reacted with (3-mercaptopropyl) trimethoxy silane to produce dye-silane compound, followed by the sol-gel reaction with tetraethoxysilane(TEOS) and water to produce core-shell structure. The fluorescent spectrum showed that the fluorescent intensity of dye-silica nanoparticle was higher than that of fluorescent dye.