Grain Shapes and Growth Kinetics of the Cylinder Phase in a Block Copolymer Solution

2004 ◽  
Vol 37 (13) ◽  
pp. 4891-4899 ◽  
Author(s):  
Thomas Q. Chastek ◽  
Timothy P. Lodge
2014 ◽  
Vol 70 (a1) ◽  
pp. C1176-C1176
Author(s):  
Ezzeldin Metwalli

Dispersed metal nanoparticles (nps) in a polymer matrix are essential for many technological applications, including biological imaging, thin film technology, magnetic recording media, optoelectronics and sensors. Real time investigation of the evolution of nps size and shape during the in-situ metal deposition on polymer thin films enables a fine tune of magnetic and electric properties. Metals in their atomic state are deposited on several homopolymer and block copolymer films by DC magnetron system (Metwalli et al., 2013, Metwalli et al., 2008, Buffet et al., 2011). With the unprecedented time resolution of 10 milliseconds, the growth kinetics of the metal nps on the polymer surfaces is monitored using in-situ GISAXS. An exponential growth of nps size on all polymer surfaces is observed. Below a certain critical nps size, an initial fast particle growth is due to high particle mobility. A slower kinetics at concentrated metal dispersion is due to the strong metal-metal interactions. The metal growth kinetics study for many chemically different homopolymer films explains the long-time debated high selectivity characteristics of metals towards one block in block copolymer based nano-templates.


Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization


1998 ◽  
Vol 536 ◽  
Author(s):  
E. M. Wong ◽  
J. E. Bonevich ◽  
P. C. Searson

AbstractColloidal chemistry techniques were used to synthesize ZnO particles in the nanometer size regime. The particle aging kinetics were determined by monitoring the optical band edge absorption and using the effective mass model to approximate the particle size as a function of time. We show that the growth kinetics of the ZnO particles follow the Lifshitz, Slyozov, Wagner theory for Ostwald ripening. In this model, the higher curvature and hence chemical potential of smaller particles provides a driving force for dissolution. The larger particles continue to grow by diffusion limited transport of species dissolved in solution. Thin films were fabricated by constant current electrophoretic deposition (EPD) of the ZnO quantum particles from these colloidal suspensions. All the films exhibited a blue shift relative to the characteristic green emission associated with bulk ZnO. The optical characteristics of the particles in the colloidal suspensions were found to translate to the films.


2016 ◽  
Vol 58 (5) ◽  
pp. 418-421
Author(s):  
Fatma Ünal ◽  
Ahmet Topuz

RSC Advances ◽  
2021 ◽  
Vol 11 (30) ◽  
pp. 18493-18499
Author(s):  
Sergio Sánchez-Martín ◽  
S. M. Olaizola ◽  
E. Castaño ◽  
E. Urionabarrenetxea ◽  
G. G. Mandayo ◽  
...  

Impact of deposition parameters, microstructure and growth kinetics analysis of ZnO grown by Aerosol-assisted Chemical Vapor Deposition (AACVD).


Author(s):  
Phillip Mark Rodger ◽  
Caroline Montgomery ◽  
Giovanni Costantini ◽  
Alison Rodger

The formation and stability of diphenylalanine fibres are studied by combining molecular dynamics simulations with microscopy and spectroscopy experiments, quantitatively detailing their morphology, energetics and growth kinetics.


Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 259 ◽  
Author(s):  
Pablo A. Ruiz-Trabolsi ◽  
Julio Cesar Velázquez ◽  
Carlos Orozco-Álvarez ◽  
Rafael Carrera-Espinoza ◽  
Jorge A. Yescas-Hernández ◽  
...  

Boride layers are typically used to combat the wear and corrosion of metals. For this reason, to improve our knowledge of the boriding process, this research studied the effect of the size of the treated material on the kinetics of the growth of the boride layers obtained during a solid diffusion process. The purpose was to elucidate how the layers’ growth kinetics could be affected by the size of the samples since, as the amount of matter increases, the amount of energy necessary to make the process occur also increases. Furthermore, the level of activation energy seems to change as a function of the sample size, although it is considered an intrinsic parameter of each material. Six cylindrical samples with different diameters were exposed to the boriding process for three different exposure times (1.5, 3, and 5 h). The treatment temperatures used were 900, 950, and 1000 °C for each size and duration of treatment. The results show that the layer thickness increased not only as a function of the treatment conditions but also as a function of the sample diameter. The influence of the sample size on the growth kinetics of the boride layers is clear, because the growth rate increased even though the treatment conditions (time and temperature) remained constant.


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