Non-Isothermal Crystallisation Kinetics of In Situ Prepared Poly(ɛ-caprolactone)/Surface-Treated SiO2 Nanocomposites

2007 ◽  
Vol 208 (4) ◽  
pp. 364-376 ◽  
Author(s):  
Alexandros A. Vassiliou ◽  
George Z. Papageorgiou ◽  
Dimitrios S. Achilias ◽  
Dimitrios N. Bikiaris
Keyword(s):  
Crystallisation Kinetics ◽  
Sio2 Nanocomposites ◽  
Isothermal Crystallisation ◽  
Kinetics Of

In situ quantification of crystallisation kinetics of plagioclase and clinopyroxene in basaltic magma: Implications for lava flow

2021 ◽  
Vol 568 ◽  
pp. 117016
Author(s):  
Nolwenn Le Gall ◽  
Fabio Arzilli ◽  
Giuseppe La Spina ◽  
Margherita Polacci ◽  
Biao Cai ◽  
...  
Keyword(s):  
Lava Flow ◽  
Basaltic Magma ◽  
Crystallisation Kinetics ◽  
Kinetics Of

Characterization and Crystallization Kinetics of in situ Prepared Poly(propylene terephthalate)/SiO2 Nanocomposites

2009 ◽  
Vol 211 (1) ◽  
pp. 66-79 ◽  
Author(s):  
Dimitris S. Achilias ◽  
Dimitrios N. Bikiaris ◽  
Efthimios Papastergiadis ◽  
Dimitris Giliopoulos ◽  
George Z. Papageorgiou
Keyword(s):  
Crystallization Kinetics ◽  
Sio2 Nanocomposites ◽  
Poly Propylene ◽  
Kinetics Of

Isothermal crystallisation kinetics of poly(3-hydroxybutyrate) using step-scan DSC

2006 ◽  
Vol 83 (2) ◽  
pp. 313-319 ◽  
Author(s):  
L M W K Gunaratne ◽  
R A Shanks
Keyword(s):  
Crystallisation Kinetics ◽  
Isothermal Crystallisation ◽  
Kinetics Of

scholarly journals Physical Properties and Non-Isothermal Crystallisation Kinetics of Primary Mechanically Recycled Poly(l-lactic acid) and Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3396
Author(s):  
Luboš Běhálek ◽  
Jan Novák ◽  
Pavel Brdlík ◽  
Martin Borůvka ◽  
Jiří Habr ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Physical Properties ◽  
Structural Changes ◽  
The Other ◽  
Half Time ◽  
Crystallisation Kinetics ◽  
Isothermal Crystallisation ◽  
Melt Crystallisation ◽  
Kinetics Of ◽  
Crystallisation Rate

The physical properties and non-isothermal melt- and cold-crystallisation kinetics of poly (l-lactic acid) (PLLA) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) biobased polymers reprocessed by mechanical milling of moulded specimens and followed injection moulding with up to seven recycling cycles are investigated. Non-isothermal crystallisation kinetics are evaluated by the half-time of crystallisation and a procedure based on the mathematical treatment of DSC cumulative crystallisation curves at their inflection point (Kratochvil-Kelnar method). Thermomechanical recycling of PLLA raised structural changes that resulted in an increase in melt flow properties by up to six times, a decrease in the thermal stability by up to 80 °C, a reduction in the melt half-time crystallisation by up to about 40%, an increase in the melt crystallisation start temperature, and an increase in the maximum melt crystallisation rate (up to 2.7 times). Furthermore, reprocessing after the first recycling cycle caused the elimination of cold crystallisation when cooling at a slow rate. These structural changes also lowered the cold crystallisation temperature without impacting the maximum cold crystallisation rate. The structural changes of reprocessed PHBV had no significant effect on the non-isothermal crystallisation kinetics of this material. Additionally, the thermomechanical behaviour of reprocessed PHBV indicates that the technological waste of this biopolymer is suitable for recycling as a reusable additive to the virgin polymer matrix. In the case of reprocessed PLLA, on the other hand, a significant decrease in tensile and flexural strength (by 22% and 46%, respectively) was detected, which reflected changes within the biobased polymer structure. Apart from the elastic modulus, all the other thermomechanical properties of PLLA dropped down with an increasing level of recycling.

Studies of isothermal crystallisation kinetics of sunflower hard stearin-based confectionery fats

2013 ◽  
Vol 139 (1-4) ◽  
pp. 184-195 ◽  
Author(s):  
Miguel A. Bootello ◽  
Richard W. Hartel ◽  
Madeline Levin ◽  
Jose M. Martínez-Blanes ◽  
Concepción Real ◽  
...  
Keyword(s):  
Crystallisation Kinetics ◽  
Confectionery Fats ◽  
Isothermal Crystallisation ◽  
Kinetics Of

ChemInform Abstract: Isothermal in situ Reduction Kinetics of CoCl2-SiO2 Gels to Co-SiO2 Nanocomposites.

ChemInform ◽  
2010 ◽  
Vol 30 (20) ◽  
pp. no-no
Author(s):  
A. Basumallick ◽  
G. C. Das ◽  
S. Mukherjee
Keyword(s):  
Reduction Kinetics ◽  
In Situ Reduction ◽  
Sio2 Nanocomposites ◽  
Kinetics Of

Non-Isothermal Crystallisation Kinetics of Polyamide 6/Mesoporous Silica Nanocomposites

2007 ◽  
Vol 15 (7) ◽  
pp. 561-567
Author(s):  
Qingyuan Hu ◽  
Xiangling Ji ◽  
Yunfeng Lu
Keyword(s):  
Differential Scanning Calorimetry ◽  
Mesoporous Silica ◽  
Polyamide 6 ◽  
Nucleating Agents ◽  
Scanning Calorimetry ◽  
Crystallisation Kinetics ◽  
Silica Nanocomposites ◽  
Crystallisation Process ◽  
Isothermal Crystallisation ◽  
Kinetics Of

Non-isothermal crystallisation kinetics of a polyamide 6/mesoporous silica nanocomposite (PA6-MS) has been investigated by differential scanning calorimetry (DSC) at different cooling rates. Mandelkern, Jeziorny-Ziabicki and Ozawa methods were applied to describe this crystallisation process. The analyses show that the mesoporous silica particles act as nucleating agents in the composite and that the Avrami exponent n varies from 3.0 to 4.6. The addition of mesoporous silica influenced the mechanism of nucleation and the growth of polyamide 6 (PA 6) crystallites.

Highly explosive basaltic eruptions: magma fragmentation induced by rapid crystallisation

2020 ◽  
Author(s):  
Fabio Arzilli ◽  
Giuseppe La Spina ◽  
Mike R. Burton ◽  
Margherita Polacci ◽  
Nolwenn Le Gall ◽  
...  
Keyword(s):  
Ex Situ ◽  
Explosive Eruptions ◽  
In Situ Observation ◽  
Sudden Increase ◽  
Crystallisation Kinetics ◽  
Magma Fragmentation ◽  
Crystallization Experiments ◽  
Basaltic Magmas ◽  
Kinetics Of

<p>Basaltic eruptions are the most common form of volcanism on Earth and planetary bodies. The low viscosity of basaltic magmas generally favours effusive and mildly explosive volcanic activity. Highly explosive basaltic eruptions occur less frequently and their eruption mechanism still remains subject to debate, with implications for the significant hazard associated with explosive basaltic volcanism. Particularly, highly explosive eruptions require magma fragmentation, yet it is unclear how basaltic magmas can reach the fragmentation threshold.</p><p>In volcanic conduits, the crystallisation kinetics of an ascending magma are driven by degassing and cooling. So far, the crystallisation kinetics of magmas have been estimated through ex situ crystallization experiments. However, this experimental approach induces underestimation of crystallization kinetics in silicate melts. The   crystallization experiments reported in this study were performed in situ at Diamond Light Source (experiment EE12392 at the I12 beamline), Harwell, UK, using basalt from the 2001 Etna eruption as the starting material. We combined a bespoke high-temperature environmental cell with fast synchrotron X-ray microtomography to image the evolution of crystallization in real time. After 4 hours at sub-liquidus conditions (1170 °C and 1150 °C) the system was perturbed through a rapid cooling (0.4 °C/s), inducing a sudden increase of undercooling. Our study reports the first in situ observation of exceptionally rapid plagioclase and clinopyroxene crystallisation in trachybasaltic magmas. We combine these constraints on crystallisation kinetics and viscosity evolution with a numerical conduit model to show that exceptionally rapid syn-eruptive crystallisation is the fundamental process required to trigger basaltic magma fragmentation under high strain rates. Our in situ experimental and natural observations combined with a numerical conduit model allow us to conclude that pre-eruptive temperatures <1,100°C can promote highly explosive basaltic eruptions, such as Plinian volcanism, in which fragmentation is induced by fast syn-eruptive crystal growth under high undercooling and high decompression rates. This implies that all basaltic systems on Earth have the potential to produce powerful explosive eruptions.</p>

Sign in / Sign up

Export Citation Format

Share Document