scholarly journals Effect of the Surface-Stimulated Mode on the Kinetics of Homogeneous Crystal Nucleation in Droplets

2008 ◽  
Vol 112 (29) ◽  
pp. 6592-6600 ◽  
Author(s):  
Y. S. Djikaev
Keyword(s):  
Crystal Nucleation ◽  
Homogeneous Crystal ◽  
Kinetics Of

Thermodynamics and kinetics of homogeneous crystal nucleation studied by computer simulation

2000 ◽  
Vol 62 (22) ◽  
pp. 14690-14702 ◽  
Author(s):  
H. E. A. Huitema ◽  
J. P. van der Eerden ◽  
J. J. M. Janssen ◽  
H. Human
Keyword(s):  
Computer Simulation ◽  
Crystal Nucleation ◽  
Thermodynamics And Kinetics ◽  
Homogeneous Crystal ◽  
Kinetics Of

scholarly journals New Insights into Crystallization of Heterophasic Isotactic Polypropylene by Fast Scanning Chip Calorimetry

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1683
Author(s):  
Daniela Mileva ◽  
Jingbo Wang ◽  
Markus Gahleitner ◽  
Katalee Jariyavidyanont ◽  
René Androsch
Keyword(s):  
Crystallization Kinetics ◽  
Isotactic Polypropylene ◽  
Crystallization Rate ◽  
Crystal Nucleation ◽  
Crystallization Time ◽  
Chip Calorimetry ◽  
The Matrix ◽  
Homogeneous Crystal ◽  
Kinetics Of ◽  
Fast Scanning Chip Calorimetry

The crystallization kinetics of metallocene-catalyzed heterophasic isotactic polypropylene composed of a matrix of isotactic polypropylene (iPP) and rubbery particles made of random ethylene–propylene copolymers (EPC), often denoted as heterophasic iPP copolymers, was analyzed as a function of the cooling rate and supercooling in nonisothermal and isothermal crystallization experiments, respectively. Fast scanning chip calorimetry (FSC) allowed assessing crystallization at processing-relevant conditions, and variation of the content (0–39 wt %) and composition (0–35 wt % propylene counits) of the EPC particles revealed qualitatively new insight about mechanisms of heterogeneous crystal nucleation. For neat iPP homopolymer, the characteristic bimodal temperature dependence of the crystallization rate due to predominance of heterogeneous and homogeneous crystal nucleation at high and low temperatures, respectively, is reconfirmed. At high temperatures, in heterophasic iPP, the here studied ethylene-(C2)-rich EPC particles accelerate crystallization of the iPP-matrix, with the acceleration or nucleation efficacy correlating with the EPC-particle content. The crystallization time reduces by more than half in presence of 39 wt % EPC particles. An additional nucleating effect of the EPC particles on iPP-matrix crystallization is detected after their crystallization, suggesting that liquid/rubbery particles are less effective than solid/semicrystalline particles in affecting crystallization of the surrounding iPP-matrix. At low temperature, homogeneous crystal nucleation in the iPP-matrix outpaces all heterogeneous nucleation effects, and the matrix-crystallization rate is independent of the sample composition. The obtained results lead to the conclusion that the crystallization kinetics of iPP can be affected significantly by the content and composition of EPC particles, even towards superfast crystallizing iPP grades.

scholarly journals Crystal nucleation and growth kinetics of NaF in photo-thermo-refractive glass

2013 ◽  
Vol 378 ◽  
pp. 115-120 ◽  
Author(s):  
I. Dyamant ◽  
A.S. Abyzov ◽  
V.M. Fokin ◽  
E.D. Zanotto ◽  
J. Lumeau ◽  
...  
Keyword(s):  
Growth Kinetics ◽  
Nucleation And Growth ◽  
Crystal Nucleation ◽  
Kinetics Of

scholarly journals Fast-Scanning Chip-Calorimetry Measurement of Crystallization Kinetics of Poly(Glycolic Acid)

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 891
Author(s):  
Yongxuan Chen ◽  
Kefeng Xie ◽  
Yucheng He ◽  
Wenbing Hu
Keyword(s):  
Crystallization Kinetics ◽  
Temperature Region ◽  
Glycolic Acid ◽  
Crystal Nucleation ◽  
Side Group ◽  
Half Time ◽  
Temperature Range ◽  
Chip Calorimetry ◽  
Kinetics Of ◽  
Fast Scanning Chip Calorimetry

We report fast-scanning chip-calorimetry measurement of isothermal crystallization kinetics of poly(glycolic acid) (PGA) in a broad temperature range. We observed that PGA crystallization could be suppressed by cooling rates beyond -100 K s−1 and, after fast cooling, by heating rates beyond 50 K s-1. In addition, the parabolic curve of crystallization half-time versus crystallization temperature shows that PGA crystallizes the fastest at 130 °C with the minimum crystallization half-time of 4.28 s. We compared our results to those of poly(L-lactic acid) (PLLA) with nearby molecular weights previously reported by Androsch et al. We found that PGA crystallizes generally more quickly than PLLA. In comparison to PLLA, PGA has a much smaller hydrogen side group than the methyl side group in PLLA; therefore, crystal nucleation is favored by the higher molecular mobility of PGA in the low temperature region as well as by the denser molecular packing of PGA in the high temperature region, and the two factors together decide the higher crystallization rates of PGA in the whole temperature range.

scholarly journals Impurities and Homogeneous Crystal Nucleation in Aqueous Solutions - An Overview

2019 ◽  
Vol 16 (3) ◽  
pp. 198-208
Author(s):  
C. K. Mahadevan
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Research Group ◽  
Present Author ◽  
Crystal Nucleation ◽  
Nucleation Process ◽  
Nucleation Parameters ◽  
The Past ◽  
Homogeneous Crystal ◽  
Made In

Nucleation process is the most important stage in the formation of a crystal and has attracted the attention of researchers due to its importance in many technological and biological contexts. As the presence of impurities affects the nucleation process significantly, several studies have been made in the past to understand it. In this article is presented an overview of various studies made to understand the effect of soluble impurities on the crystal nucleation parameters of certain important materials in aqueous solution focusing the results reported by the research group of the present author.

Heterogeneous and homogeneous crystal nucleation in colloidal hard-sphere like microgels at low metastabilities

Soft Matter ◽  
2011 ◽  
Vol 7 (23) ◽  
pp. 11267 ◽  
Author(s):  
Markus Franke ◽  
Achim Lederer ◽  
Hans Joachim Schöpe
Keyword(s):  
Hard Sphere ◽  
Crystal Nucleation ◽  
Homogeneous Crystal

Nucleation and Glass Formation

1985 ◽  
Vol 57 ◽  
Author(s):  
D. R. Uhlmann ◽  
M. C. Weinberg
Keyword(s):  
Glass Formation ◽  
Nucleation Theory ◽  
Crystal Nucleation ◽  
Oxide Glass ◽  
Classical Nucleation Theory ◽  
Nucleation Kinetics ◽  
Formation Behavior ◽  
Homogeneous Crystal ◽  
Exponential Factors

AbstractThe role of nucleation kinetics in affecting glass formation behavior is discussed. Also considered are measurements of homogeneous crystal nucleation in a variety of liquids. For a number of oxide glass-forming liquids, available data indicate pre-exponential factors which are larger than those predicted from classical nucleation theory by factors of 1017 to 1049. Possible sources of this discrepancy are discussed.

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