Crystallization Behavior of a Ferri-Silicate α-Waste Glass

1985 ◽  
Vol 50 ◽  
Author(s):  
A. D. Stalios ◽  
R. De Batist
Keyword(s):  
Crystallization Behavior ◽  
Crystallization Process ◽  
Waste Glass ◽  
Avrami Equation ◽  
Two Dimensional ◽  
Diffusion Controlled ◽  
Instantaneous Nucleation ◽  
Dimensional Growth ◽  
And Diffusion

AbstractThe crystallization behavior of a ferri-silicate α-waste glass was studied by means of several experimental techniques. The main crystal phase showed a plate-like morphology and was identified as a monoclinic pyroxene. The Johnson-Mehl-Avrami equation was used for the determination of the kinetic parameters of the process. Following both isothermal and non-isothermal techniques, the Avrami exponent, n, was found to be nearly one. The activation energy for crystal growth is Eg = 356 kJ mole−1. The crystallization process is governed by instantaneous nucleation and diffusion controlled two dimensional growth.

Polarography of n-butylthioglycolate in aqueous media, methanol, and acetonitrile

1984 ◽  
Vol 62 (9) ◽  
pp. 1817-1821
Author(s):  
K. C. Gupta ◽  
Kalpana K. Sharma
Keyword(s):  
Aqueous Media ◽  
Mercury Electrode ◽  
Wave Characteristics ◽  
Anodic Wave ◽  
Diffusion Controlled ◽  
Dropping Mercury Electrode ◽  
Drop Time ◽  
And Diffusion ◽  
Mechanism Of The Reaction

The polarographic behaviour of n-butylthioglycolate (RSH) at the DME in aqueous media, methanol, and acetonitrile has been investigated in the presence of 0.1 M KNO3 and 0.01% thymol. The effect of pH, concentration of RSH, and drop time on the wave characteristics and the mechanism of the reaction occurring at the surface of the mercury drop have been studied. Well-defined reversible and diffusion-controlled anodic waves were obtained in aqueous media (pH 4.2), 40% methanol (pH 3.22), and 40% acetonitrile (pH 2.96). Mathematical and analytical evidence was obtained to show that the anodic wave of RSH at a dropping mercury electrode in aqueous media, 40% methanol, and 40% acetonitrile is due to the formation of the mercury complex RSHg. The dissociation constant (pK) of the mercapto group in n-butylthioglycolate is 9.6 and the diffusion coefficient in the different media are 1.17 × 10−6 cm2 s−1 (in aqueous media) 1.23 × 10−6 cm2 s−1 (in 40% methanol), and 2.43 × 10−6 cm2 s−1 (in 40% acetonitrile). The linearity of id with RSH concentration provides a rapid and precise method for the determination of RSH, down to 0.4 mM in aqueous media, methanol, and acetonitrile.

scholarly journals Determination of two dimensional growth conditions for Zn chalcogenides by the observation of RHEED intensity oscillation.

Hyomen Kagaku ◽  
1989 ◽  
Vol 10 (6) ◽  
pp. 429-434
Author(s):  
Katsuhiro UESUGI ◽  
Satomi KAMIYAMA ◽  
Masami FUJIMOTO ◽  
Ziqiang ZHU ◽  
Takafumi YAO
Keyword(s):  
Growth Conditions ◽  
Two Dimensional ◽  
Intensity Oscillation ◽  
Dimensional Growth

Isothermal Crystallization of PET/PTT-CNTs Composites

2013 ◽  
Vol 750-752 ◽  
pp. 191-194
Author(s):  
Fang Xie ◽  
Hao Liang ◽  
Xiao Jun Ren ◽  
Yi Fa Chen
Keyword(s):  
Isothermal Crystallization ◽  
Crystallization Behavior ◽  
Crystallization Process ◽  
Avrami Equation ◽  
Half Time

Isothermal crystallization behavior of PET/PTT-CNTs composites was investigated by DSC. The Avrami equation was employed to describe the isothermal crystallization process. The change of the half-time of crystallization t1/2 suggested that the addition of CNTs in the composites can accelerate the overall crystallization process.

EXPRESS: Two-Trace Two-Dimensional Correlation Spectroscopy (2T2D-COS) Study of the Crystallization Behavior of Bioplastics

2021 ◽  
pp. 000370282110141
Author(s):  
Isao Noda
Keyword(s):  
Crystallization Behavior ◽  
Crystallization Process ◽  
Correlation Spectroscopy ◽  
Two Dimensional ◽  
Difference Spectra ◽  
Amorphous Component ◽  
Fundamental Properties ◽  
Intensity Changes ◽  
Copolymer Poly ◽  
Primary Crystals

A pair of ATR IR spectra obtained during the crystallization of bioplastic copolymer poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] or PHBHx from the melt by spontaneous cooling were examined using the two-trace two-dimensional correlation spectroscopy (2T2D-COS) analysis. Unlike conventional difference spectra, 2T2D spectra showed unexpected details for the patterns of spectral intensity changes, clearly revealing the existence of two distinct populations of crystalline contributions, attributed to the well-ordered primary crystals and the less ordered secondary crystals, in addition to the amorphous component. The 2T2D spectrum sorts out highly overlapped bands associated with different constituents of the system, based on the fundamental properties and constraint imposed on a pair of spectra. Hetero-mode asynchronous 2T2D correlation analysis between the congested CH-stretching region and better resolved carbonyl-stretching region further indicates that the increase in the intensities of certain methyl and methylene bands during the crystallization process is mostly associated with the growth of the well-ordered primary crystals of PHBHx instead of the formation of the secondary crystals in the confined inter-lamellar space.

Determination of Diffusion Parameters of Solved Molecules by Measuring the Relaxation Kinetics on the Picosecond Time Scale

1981 ◽  
Vol 36 (12) ◽  
pp. 1323-1326 ◽  
Author(s):  
E. Heumann
Keyword(s):  
Kinetic Model ◽  
Probe Beam ◽  
Time Scale ◽  
Solvent Viscosity ◽  
Diffusion Parameters ◽  
Diffusion Controlled ◽  
Picosecond Time Scale ◽  
Excimer Formation ◽  
And Diffusion

AbstractPicosecond probe beam spectroscopy is used to measure the nonstationary contribution to diffusion controlled excimer formation in dependence on concentration and solvent viscosity. Utilizing a kinetic model, the effective encounter radius and diffusion parameters of pyrene molecules in different solvents have been determined.

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