Fluorescent Material (fluorescent + material)

Distribution by Scientific Domains


Selected Abstracts


ChemInform Abstract: Synthesis and Properties of 1-(4-Aminophenyl)-2,4-dicyano-3-diethylamino-9,9-diethylfluorenes: Potential Fluorescent Material.

CHEMINFORM, Issue 43 2008
Xiao-Hang Chen
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


Morphology and photophysical properties of a thermally responsive fluorescent material based on a rod-coil tri-block copolymer

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008
Zhun Ma
Abstract A thermally responsive rod-coil poly[poly (N -isopropylacrylamide)- b -polyfluorene- b -poly(N -isopropylacrylamide)] triblock copolymer has been successfully synthesized by atom transfer radical polymerization from an end-functionalized macroinitiator. The thermochromic behavior and relevant morphology of this polymer were investigated by UV-vis spectra, DLS, and AFM, respectively, at various temperatures. A thermally responsive fluorescent material was achieved facilely by combining the optically active polyfluorene with temperature-responsive poly(N -isopropylacrylamide). All the measurements demonstrated that in the region of 25,45°C, the polymer underwent a phase transition and the corresponding change in optical properties in its water solution. However, the polymer did not show completely reversible behavior upon heating and cooling. On the basis of the comparison with two other thermally responsive conjugated polymers in literatures, a tentative mechanism has been proposed that ,,, interaction induced rigid segments to remain chain conformation and packing styles as in collapsed state. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]


Method for checking label accuracy in barn and free range eggs

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 9 2005
Neville G Gregory
Abstract The aim was to develop a method for testing whether eggs sold as either ,barn' or free range' were laid under cage conditions. The surface patterns on 11 520 eggs from cage, barn and free range production systems were examined under ultraviolet light for distinctive fluorescent marks associated with each production system. In addition, the effects of egg washing, egg size, condensation and cage dusting on the prevalence of the fluorescent patterns associated with the cage production system were examined. The prevalence of fluorescent white double parallel lines with 2.2,2.5 cm spacing was a distinguishing feature for eggs laid on wire floors in cages. If five or more eggs in a sample of 90 eggs have double fluorescent lines it can be concluded with greater than 999 in 1000 probability that the batch contains some cage-laid eggs. Dust from the egg collection area below the feed trough was the main source of the fluorescent material. Washing the eggs removed or obscured the double lines. Egg size and condensation had limited effects on the prevalence of double lines. Infrequent dusting of the wire floor did not reduce the value of the test. Copyright © 2005 Society of Chemical Industry [source]


Synthesis and photophysical behavior of a water-soluble coumarin-bearing polymer for proton and Ni2+ ion sensing

POLYMER INTERNATIONAL, Issue 6 2009
Bao-Yan Wang
Abstract BACKGROUND: In recent years, many fluorescent chemosensors with various macromolecular structures have been prepared for the detection of protons or metal cations in the environment. Most of this research is focused on polymer sensors with fluorescent recognition sites in the main chain. In this case, the fluorescent recognition sites are covalently bonded to the polymer chain, and thus the polymer shows photophysical properties as a chemosensor for protons and metal ions. RESULTS: An acrylic monomer bearing coumarin moieties, 7-hydroxy-4-methyl-8-(4,-acryloylpiperazin-1,-yl)methylcoumarin, was synthesized. This was then copolymerized with N -vinylpyrrolidone to obtain a blue fluorescent material. The fluorescent copolymer has good solubility in aqueous solution. Its main photophysical properties were determined in relation to its use as a sensor for protons and metal cations. It is an efficient ,off-on' switcher for pH between 3.02 and 12.08. Additionally, the polymer sensor is selective to Ni2+ ions, with the increase in the fluorescence intensity depending on Ni2+ ion concentrations in the range 0.33 × 10,5,7.67 × 10,5 mol L,1. CONCLUSION: The results suggest that this copolymer may offer potential as a reusable polymer sensor for protons and Ni2+ ions in aqueous solution. Copyright © 2009 Society of Chemical Industry [source]


Molecular Engineering of Blue Fluorescent Molecules Based on Silicon End-Capped Diphenylaminofluorene Derivatives for Efficient Organic Light-Emitting Materials

ADVANCED FUNCTIONAL MATERIALS, Issue 8 2010
Kum Hee Lee
Abstract Blue fluorescent materials based on silicone end-capped 2-diphenylaminofluorene derivatives are synthesized and characterized. These materials are doped into a 2-methyl-9,10- di -[2-naphthyl]anthracene host as blue dopant materials in the emitting layer of organic light-emitting diode devices bearing a structure of ITO/DNTPD (60,nm)/NPB (30,nm)/emitting layer (30,nm)/Alq3 (20,nm)/LiF (1.0,nm)/Al (200,nm). All devices exhibit highly efficient blue electroluminescence with high external quantum efficiencies (3.47%,7.34% at 20,mA,cm,2). The best luminous efficiency of 11.2,cd,A,1 and highest quantum efficiency of 7.34% at 20,mA,cm,2 are obtained in a device with CIE coordinates (0.15, 0.25). A deep-blue OLED with CIE coordinates (0.15, 0.14) exhibits a luminous efficiency of 3.70,cd,A,1 and quantum efficiency of 3.47% at 20,mA,cm,2. [source]


Tuning and Transcription of the Supramolecular Organization of a Fluorescent Silsesquioxane Precursor into Silica-Based Materials through Direct Photochemical Hydrolysis,Polycondensation and Micropatterning

ADVANCED FUNCTIONAL MATERIALS, Issue 3 2009
Xavier Sallenave
Abstract A new fluorescent silsequioxane precursor with tuned optical properties and controlled aggregation properties is designed. The two cyclohexyl moieties introduced in the molecular structure allow the formation of very good quality films. The J-aggregated structure is transcribed into the solid by photoacid-catalyzed hydrolysis,polycondensation. Aggregation of the chromophores is reduced and highly fluorescent materials are obtained. The photoacid generator lies on the surface of the homogeneous layer of the sol,gel precursor. This phase separation presents several advantages, including UV protection of the chromophore and easy removal of the PAG. The first example of chemical amplification in the photolithography of the conjugated silsesquioxane precursor is demonstrated. As hydrolysis,polycondensation could be achieved in a controlled way by UV exposure, chemically amplified photolithography is achieved by irradiating a composite film (,110,nm thick) on silicon wafer by using a copper TEM grid as shadow mask. The pattern is produced uniformly on a miscroscopic scale of 3,mm, the photopatterned pixels remaining highly fluorescent. The sizes of the photolithographed pixels correspond to the sizes of the rectangular holes of the 300,×,75 mesh grid (hole: 63,<$>,<$>m,×,204,<$>,<$>m). [source]


N-alkylated 3,5-bis(arylidene)-4-piperidones.

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2008
Synthetic approaches, X-ray structure, anticancer activity
In a search for cytotoxic fluorescent materials a series of N-alkylated and N,N-dialkylated 3,5-bis(arylidene)piperidones was synthesized. Alkylation of 3,5-bis(arylidene)-4-piperidone afforded quaternary salts only while condensation of N-alkyl-4-piperidones with substituted benzaldehydes was a convenient route to the corresponding N-alkylated compounds. Compounds and their pharmaceutically acceptable salts demonstrated high activity against resistant human lung carcinoma cell line A549 with IC50 values in the range of 0.3-6.5 ,M. [source]