scholarly journals Aggregation of Cyanine Dye in Bilayer Vesicles of Phospholipids

2005 ◽  
Vol 4 (3) ◽  
Author(s):  
Casey McCullough ◽  
Matthew Heywood ◽  
Hussein Samha
Keyword(s):  
Aqueous Solution ◽  
Equilibrium Constant ◽  
Room Temperature ◽  
Aggregation Number ◽  
Cyanine Dye ◽  
Molar Ratio ◽  
Isosbestic Point ◽  
Dye Molecules ◽  
Vis Spectroscopy ◽  
J Aggregates

The effect of phospholipid, 1,2-Dipalmitoyl-sn-glycero-3-Phosphocholine (DPPC) on the spectroscopy of the cyanine dye, 1-ethyl-1’-octadecyl-2,2’-cyanine iodide (PIC-18), has been investigated using UV-Vis spectroscopy. Vesicles of DPPC containing PIC-18 in the molar ratio of 1:3 (dye/phospholipids) were prepared in aqueous solution. J-aggregates of PIC-18 were detected in the bilayer wall of the vesicles. When an aqueous solution of mixed PIC-18/DPPC vesicles is treated with excess DPPC vesicles that are prepared separately, the dye molecules in the mixed vesicles underwent a rapid (aggregate)n' n(monomer) equilibrium as the appearance of only one isosbestic point in the absorbance of the dye indicates. The equilibrium constant was calculated at room temperature (Keq = 6.7x10-2). An aggregation number of 4 was calculated for the dye in the bilayer vesicles.

scholarly journals J-Aggregates of Cyanine Dyes in Aqueous Solution of Polymers: A Quantitative Study

2004 ◽  
Vol 3 (3) ◽  
Author(s):  
Wesley Tillmann ◽  
Hussein Samha
Keyword(s):  
Aqueous Solution ◽  
Quantitative Study ◽  
Aggregation Number ◽  
Cyanine Dyes ◽  
Cyanine Dye ◽  
Isosbestic Point ◽  
Maximum Capacity ◽  
Vis Spectroscopy ◽  
J Aggregates

The effect of polyvinylsulfate (PVS) on the spectroscopy of the cyanine dye, 1,1’-diethyl-2,2’-cyanine iodide (PIC), has been investigated using UV-vis spectroscopy. J-aggregates of the PIC dye were formed upon addition of PVS to the monomers of the dye in solution. The appearance of only one isosbestic point in the UV-vis spectra suggests that the dye monomers are quantitatively converted to J-aggregates and equilibrium was reached. Using Benisi-Hildebrand kinetics, aggregation number of 4 was calculated for the dye. In addition, a 1:2 mole ratio of PIC/PVS was calculated at the maximum capacity of the polymer.

scholarly journals Crystal structure of the new hybrid material bis(1,4-diazoniabicyclo[2.2.2]octane) di-μ-chlorido-bis[tetrachloridobismuthate(III)] dihydrate

2015 ◽  
Vol 71 (11) ◽  
pp. 1384-1387
Author(s):  
Marwen Chouri ◽  
Habib Boughzala
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Hydrogen Bonds ◽  
Room Temperature ◽  
Molar Ratio ◽  
Water Molecules ◽  
Site Symmetry ◽  
Two Dimensional ◽  
Slow Evaporation ◽  
Solution Ph

The title compound bis(1,4-diazoniabicyclo[2.2.2]octane) di-μ-chlorido-bis[tetrachloridobismuthate(III)] dihydrate, (C6H14N2)2[Bi2Cl10]·2H2O, was obtained by slow evaporation at room temperature of a hydrochloric aqueous solution (pH = 1) containing bismuth(III) nitrate and 1,4-diazabicyclo[2.2.2]octane (DABCO) in a 1:2 molar ratio. The structure displays a two-dimensional arrangement parallel to (100) of isolated [Bi2Cl10]4−bioctahedra (site symmetry -1) separated by layers of organic 1,4-diazoniabicyclo[2.2.2]octane dications [(DABCOH2)2+] and water molecules. O—H...Cl, N—H...O and N—H...Cl hydrogen bonds lead to additional cohesion of the structure.

Synthesis, Characterization and Photocatalytic Activity of Nb-Doped TiO2 Nanoparticles

2012 ◽  
Vol 455-456 ◽  
pp. 110-114 ◽  
Author(s):  
Xuan Dong Li ◽  
Xi Jiang Han ◽  
Wen Ying Wang ◽  
Xiao Hong Liu ◽  
Yan Wang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Doped Tio2 ◽  
X Ray ◽  
Vis Spectroscopy

Nb-doped TiO2 powders with different concentrations of Nb have been synthesized by a sol-gel method and characterized by a series of technologies including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-vis spectroscopy. The photocatalytic activity of Nb-doped TiO2 is evaluated by degradation efficiency of methyl orange in aqueous solution. The results indicate that the photocatalytic activity of Nb-doped TiO2 synthesized with a Nb/Ti molar ratio of 5% is higher than that of TiO2 under the visible light.

scholarly journals Molecular Distribution Behavior of Cyanine Dyes in Aqueous Solution

2009 ◽  
Vol 7 (4) ◽  
Author(s):  
David Baumann ◽  
Bryan Clark ◽  
Jared Garlick ◽  
Hussein Samha
Keyword(s):  
Aqueous Solution ◽  
Narrow Band ◽  
Ammonium Phosphate ◽  
Emission Spectra ◽  
Cyanine Dye ◽  
Concentrated Solutions ◽  
Molecular Distribution ◽  
J Aggregates ◽  
Absorption And Emission Spectroscopy ◽  
Distribution Behavior

The molecular distribution of the cyanine dye (5-chloro-2-[3-[5-chloro-3-(4-sulfobutyl)-2(3H)-benzothiazolylidine]-1-propenyl]-3-(4-sulfobutyl)-benzothiazolium hydroxide triethylamine salt, NK-3796) in aqueous solution was investigated using absorption and emission spectroscopy. Dimers of the dye are formed in concentrated solutions, while monomers dominate more diluted solutions. J aggregates are formed in solutions containing electrolytes such as sodium chloride, calcium chloride, and di-hydrogen ammonium phosphate. The dye readily forms J aggregates upon mixing with electrolyte. The J aggregates formation was followed spectroscopically by the appearance of a red-shifted narrow band centered at 653 nm in the absorption spectra. A similar shift is also observed in the emission spectra. The absorbance bandwidth is dependent on the charge of the cation of the electrolyte. This suggests different ground-state conformations for the J aggregates in solution.

Synthesis of C60-Doped Polyaniline Nanoshuttles

2011 ◽  
Vol 284-286 ◽  
pp. 1010-1013 ◽  
Author(s):  
Qi Guan Wang ◽  
Su Min Wang ◽  
Jian Ping Li ◽  
Hiroshi Moriyama
Keyword(s):  
Interfacial Reaction ◽  
Supramolecular Structure ◽  
Significant Interaction ◽  
Room Temperature ◽  
Oxidative Polymerization ◽  
Molar Ratio ◽  
Ammonium Peroxydisulfate ◽  
Vis Spectroscopy ◽  
Amorphous Powders ◽  
Doped Polyaniline

Polyaniline–C60nanoshuttle composites have been successfully synthesized by the oxidative polymerization of aniline with ammonium peroxydisulfate in the presence of C60using an interfacial reaction at room temperature, in which the molar ratio of oxidant to monomer was kept at 0.25:1. The influence of initial C60/aniline molar ratio on the supramolecular structure of the composites was studied. It was found that at low molar ratio (0.01:1) amorphous powders could be synthesized, while the as-synthesized products at the higher molar ratio (0.04:1) were shuttle-like superstructures. FTIR and UV-vis spectroscopy confirmed the presence of C60in the resultant nanocomposite and suggested significant interaction of polyaniline with C60. The evolution of supramolecular structure of polyaniline nanoshuttle–C60nanocomposites was discussed.

scholarly journals Self Assembly of Cyanine Dye on Clay Nanoparticles

2005 ◽  
Vol 3 (4) ◽  
Author(s):  
Andrew Dixon ◽  
Clint Duncan ◽  
Hussein Samha
Keyword(s):  
Aqueous Solutions ◽  
Self Assembly ◽  
Montmorillonite Clay ◽  
Cyanine Dye ◽  
Clay Particles ◽  
Clay Nanoparticles ◽  
Charged Surfaces ◽  
Successive Addition ◽  
Vis Spectroscopy ◽  
J Aggregates

The effect of Ca-montmorillonite (clay) on the aggregation behavior of the cyanine dye, 1,1’-diethyl-2,2’-cyanine iodide (PIC), in aqueous solutions has been investigated using UV-vis spectroscopy. The absorbance of the monomeric dye in aqueous solutions is compared with the absorbance of the aggregates formed after adding the clay. The appearance of a sharp “red-shifted” band centered at 574 nm, after the addition of clay to the aqueous solutions of the dye, indicates the formation J-aggregates on the charged surfaces of the clay particles. The spontaneous and quantitative transformation of monomers into J-aggregates was controlled by the concentration of the clay in the solution. Successive addition of clay to the dye solution causes an increase in the absorbance intensity of the J-band and consequently, a decrease in the absorbance intensity of the monomer. These changes occur linearly which suggests that the dye monomers are quantitatively being converted to J-aggregates.

scholarly journals Influence of Synthesis Parameters of FeNi3 Alloy Nanoparticles Obtained by Chemical Reduction Method in Aqueous Solution

2019 ◽  
Vol 70 (4) ◽  
pp. 1118-1124
Author(s):  
Teodora Malaeru ◽  
Eros Alexandru Patroi ◽  
Delia Patroi ◽  
Eugen Manta ◽  
Virgil Marinescu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Room Temperature ◽  
Chemical Reduction ◽  
Molar Ratio ◽  
Initial Reaction ◽  
Growth Promoter ◽  
Stoichiometric Ratio ◽  
Alloy Nanoparticles ◽  
Face Centered Cubic ◽  
Structural Morphology

This paper reports the synthesis of FeNi3 alloy nanoparticles by chemical reduction of the Fe2+ and Ni2+ ions, from the corresponding chlorides, with hydrazine (N2H4�H2O) as a reducing agent in aqueous solution at room temperature by modifying the molar ratio of the ions Fe2+: Ni2+, reaction time, with and without amine-type growth promoter, and reducing both, with or without ultrasonic aid. The FeNi3 alloy nanoparticles have been investigated by XRD, EDS spectrum analysis, SEM and VSM. When the molar ratio of Fe2+ and Ni2+ is equal to 1:3, reducing both, with or without ultrasonic aid, Fe2+ and Ni2+ were completely reduced into Fe and Ni, resulting FeNi3 alloy with a face-centered cubic (fcc) crystal structure. EDS analysis supported the presence of metal ions in atomic weight corresponding to the stoichiometric ratio of initial reaction. SEM analysis showed that nanoparticles of FeNi3 alloy have a spherical structural morphology. Hysteresis loop show a ferromagnetic behaviour of the FeNi3 alloy nanoparticles at room temperature.

scholarly journals AQUEOUS SOLUTIONS OF CHITOSAN: VISCOMETRIC AND FLOCCULATION PROPERTIES

2021 ◽  
Vol 2021 ◽  
pp. 123-130
Author(s):  
C.-E. Brunchi ◽  
L. Ghimici
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Zeta Potential ◽  
Aqueous Solutions ◽  
Room Temperature ◽  
Polymer Concentration ◽  
Pyrethroid Insecticides ◽  
Vis Spectroscopy ◽  
Insecticide Concentration ◽  
Maximum Removal

The hydrodynamic and flocculation properties of aqueous solution of chitosan (CS) were investigated at room temperature. The viscometric data of dilute CS solutions were discussed in terms of Wolf method as a function of polymer concentration, salt nature (NaCl, NaNO3, and CaCl2) and concentration. The flocculation properties in emulsions of some commercial pyrethroid insecticides (Fastac 10 EC (F), Decis (Dc) and Karate Zeon (KZ)) were evaluated. The viscosity measurements reveal that the experimental data fit well with the Wolf model and the [η] values decrease in salt aqueous solutions. For the same insecticide concentration (0.02%, v/v), UV-Vis spectroscopy measurements show maximum removal efficiency around 90% for Fastac 10EC and Decis and 80% for Karate Zeon. The residual KZ absorbance decreased with the increase of insecticide concentration in the initial emulsion, from 80% for the lowest concentration (0.02%, v/v) to around 90% for the highest one (0.06%, v/v). The supernatant zeta potential dependence on the chitosan dose pleads for the charge neutralization as the main mechanism for the flocculation of pyrethroid insecticide particles.

scholarly journals Photoluminescence characteristics of strontium titanate thin films prepared by spray pyrolysis

2014 ◽  
Vol 10 (2) ◽  
Author(s):  
S. Aisah Mat ◽  
Karim Deraman ◽  
R. Hussin ◽  
W. Nurulhuda W. Shamsuri ◽  
Bakar Ismail ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Aqueous Solution ◽  
Spray Pyrolysis ◽  
Strontium Titanate ◽  
Room Temperature ◽  
Band Gap Energy ◽  
Molar Ratio ◽  
Photoluminescence Spectra ◽  
Gap Energy

Strontium titanate, SrTiO3 thin films were successfully prepared by spray pyrolysis. The strontium titanate, STO precursor solid thin film were fabricated from an aqueous solution of Sr(NO3)2/[(CH3)2CHO]4Ti/HNO3 = 19:1:20 (molar ratio) at room temperature on a substrate. The as-deposited STO thin film with those annealed at different temperature were prepared. Photoluminescence spectra of thin films were obtained using Photoluminescence Spectrophotometer and optical properties were carried out by using Shimadzu Uv-Vis Spectrophotometer. In conclusion, the band gap energy and the bandwidth of thin films have been analysed.  ________________________________________GRAPHICAL ABSTRACT

Sign in / Sign up

Export Citation Format

Share Document