Computer-aided phase modulated flow birefringence experiment on polystyrene solutions

Park, O Ok; Hwang, Chang Ik; Lim, Tai Jun

doi:10.1007/bf02698107

Cited by 13 publications

(1 citation statement)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, nicotinamide (3-pyridine carboxylic acid amide, commonly known as vitamin B 3 ) is a reactive moiety of the coenzyme nicotinamide adenine dinucleotide [8,9].…”

Section: Introductionmentioning

confidence: 99%

FT-IR spectra, vibrational assignments, and density functional calculations of imidazo[1,2-a]pyridine molecule and its Zn(II) halide complexes

Yurdakul

Badoğlu

2009

Struct Chem

View full text Add to dashboard Cite

The geometry, frequency, and intensity of the vibrational bands of imidazo[1,2-a]pyridine (which is abbreviated as impy) were obtained by the density functional theory (DFT) calculations with BLYP, B3LYP, and B3PW91 functionals and 6-31G(d) basis set. The optimized geometric bond lengths and bond angles are in good agreement with the available X-ray data. The infrared spectrum of imidazo[1,2-a]pyridine was computed by the DFT method in order to reproduce the vibrational wavenumbers and intensities with an accuracy, which allows reliable vibrational assignments. Total energy distribution and isotopic shifts have been calculated in order to help for the perfect assignment of the vibrational modes. The zinc halide complexes Zn(impy) 2 X 2 [X = Cl, Br, and I] have also been synthesized. The compounds were characterized using the elemental analysis, FT-IR spectra, and quantum chemical calculations. The geometry optimization of Zn(impy) 2 X 2 yields distorted tetrahedral environment around Zn ion.

show abstract

“…For example, nicotinamide (3-pyridine carboxylic acid amide, commonly known as vitamin B 3 ) is a reactive moiety of the coenzyme nicotinamide adenine dinucleotide [8,9].…”

Section: Introductionmentioning

confidence: 99%

FT-IR spectra, vibrational assignments, and density functional calculations of imidazo[1,2-a]pyridine molecule and its Zn(II) halide complexes

Yurdakul

Badoğlu

2009

Struct Chem

View full text Add to dashboard Cite

show abstract

Crystallization kinetics of poly(ethylene terephthalate): Cmemory effect of shear history

Kim

1993

Polymer Engineering & Sci

View full text Add to dashboard Cite

The memory effect of shear history was studied with poly(ethylene terephthalate) (PET) prepared under different shear conditions of 11.7 to 1168 s−1 in a capillary rheometer. The shear history of PET resin led to a memory effect, which in turn affected the crystallization kinetics. The crystallization rate increased with increasing shear rate. Double peaks of heating crystallization exotherms and a low value of Avrami exponent appeared at low shear rates, which was attributed to the existence of crystallization processes with different rates; one was the fast process involving the disentangled molecules that persisted during melting, and the other was the slow process involving the highly entangled molecules. The change of instantanenous Avrami exponent and overall crystallization rate constant was in good agreement with the expected trends assuming coexistence of the two crystallization processes. The crystallization kinetics of PET with shear history could be regarded as a growth rate decrease problem to be interpreted by the modified Avrami equation, 1 − Vc = exp[− K·f(t)n], when the fast process dominated the overall crystallization. The effect of shear history was reduced because of the relaxation process as the holding time in melt state before crystallization was increased.

show abstract

Birefringence measurement on the liquid crystal by phase modulation technique

Yoon

Park

Kim

1990

Korean J. Chem. Eng.

View full text Add to dashboard Cite

Computer-aided phase modulated flow birefringence experiment on polystyrene solutions

Cited by 13 publications

References 15 publications

FT-IR spectra, vibrational assignments, and density functional calculations of imidazo[1,2-a]pyridine molecule and its Zn(II) halide complexes

FT-IR spectra, vibrational assignments, and density functional calculations of imidazo[1,2-a]pyridine molecule and its Zn(II) halide complexes

Crystallization kinetics of poly(ethylene terephthalate): Cmemory effect of shear history

Birefringence measurement on the liquid crystal by phase modulation technique

Contact Info

Product

Resources

About