scholarly journals Studying the concentration dependence of the aggregation number of a micellar model system by SANS

Soft Matter ◽  
2015 ◽  
Vol 11 (21) ◽  
pp. 4208-4217 ◽  
Author(s):  
Matthias Amann ◽  
Lutz Willner ◽  
Jörg Stellbrink ◽  
Aurel Radulescu ◽  
Dieter Richter
Keyword(s):  
Aqueous Solution ◽  
Concentration Dependence ◽  
Aggregation Number ◽  
Model System ◽  
Polymer Micelles ◽  
P Concentration

Concentration dependence of the aggregation number of n-octacosanyl-PEO polymer micelles in aqueous solution determined by SANS experiments.

Impurity Concentration Dependence of Recrystallization Process of Phosphorus Implanted 4H-SiC(11-20)

2006 ◽  
Vol 527-529 ◽  
pp. 799-802
Author(s):  
Masataka Satoh ◽  
Tomoyuki Suzuki
Keyword(s):  
Ion Implantation ◽  
Concentration Dependence ◽  
Impurity Concentration ◽  
Annealing Temperature ◽  
Rutherford Backscattering Spectrometry ◽  
Amorphous Layer ◽  
Phosphorus Concentration ◽  
Recrystallization Process ◽  
Substitutional Impurity ◽  
P Concentration

The impurity concentration dependence of the recrystallization rate of phosphorus implanted 4H-SiC(11-20) has been investigated by means of Rutherford backscattering spectrometry in the annealing temperature range from 660 to 720 oC . The phosphorus ions were multiply implanted to form the implantation layer with the thickness of 200 nm and the phosphorus concentration of 1 x 1020, 4 x 1020, or 1 x 1021 /cm3, respectively. The recrystallization rate of the P ion implantation-induced amorphous layer in 4H-SiC(11-20) increases with an activation energy of 3.4 eV as does the case of the Ar ion implantation-induced amorphous layer in 6H-SiC(11-20) and (1-100). As the P concentration is increased from 1 x 1020 to 1 x 1021 /cm3, the recrystallization rate is enhanced from 3.5 to about 5nm/min, while the recrystallization rate for the Ar implantationinduced amorphous layer was 1.5 nm/min. It is suggested that the recrystallization process is enhanced by the presence of the substitutional impurity at the amorphous-crystalline interface during the recrystallization.

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.

The Raman Spectra and Conformational Change of Simple Sodium Alkylsulfates and Sodium Alkyisulfonates in Aqueous Solution

1983 ◽  
Vol 38 (9) ◽  
pp. 1046-1047 ◽  
Author(s):  
Teruki Ikeda ◽  
Tadayoshi Yoshida ◽  
Hirofumi Okabayashi
Keyword(s):  
Aqueous Solution ◽  
Concentration Dependence ◽  
Raman Spectra ◽  
Raman Line ◽  
Polar Group ◽  
Group Effect ◽  
Trans Form ◽  
Molecular Conformations ◽  
Sodium Alkylsulfates ◽  
Single Bonds

Abstract In order to study the polar group effect upon conformations about CH2-CH2 single bonds, the Raman spectra of simple sodium alkylsulfates and sodium alkyisulfonates were measured. The ethylsulfate ion (CH3-CH2-O-SO3-) in aqueous solution was found to take the trans form about the CH2 - O bond in 0.67-5.41 mol/1. For the n-propylsulfonate ion the Raman line due to the gauche form about the CH2 -CH2 bond was also observed, the trans form becoming predominant at higher concentrations. For the sulfate and sulfonate ions having butyl and hexyl chains, the concentration dependence of their molecular conformations was also investigated.

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