Free-energy model of asymmetry in side-chain liquid-crystalline diblock copolymers

2001 ◽  
Vol 39 (21) ◽  
pp. 2671-2691 ◽  
Author(s):  
Mitchell Anthamatten ◽  
Paula T. Hammond
1994 ◽  
Vol 27 (21) ◽  
pp. 6225-6228 ◽  
Author(s):  
D. G. Walton ◽  
G. J. Kellogg ◽  
A. M. Mayes ◽  
P. Lambooy ◽  
T. P. Russell

Author(s):  
Dominic Di Toro ◽  
Kevin P. Hickey ◽  
Herbert E. Allen ◽  
Richard F. Carbonaro ◽  
Pei C. Chiu

<div>A linear free energy model is presented that predicts the second order rate constant for the abiotic reduction of nitroaromatic compounds (NACs). For this situation previously presented models use the one electron reduction potential of the NAC reaction. If such value is not available, it has been has been proposed that it could be computed directly or estimated from the electron affinity (EA). The model proposed herein uses the Gibbs free energy of the hydrogen atom transfer (HAT) as the parameter in the linear free energy model. Both models employ quantum chemical computations for the required thermodynamic parameters. The available and proposed models are compared using second order rate constants obtained from five investigations reported in the literature in which a variety of NACs were exposed to a variety of reductants. A comprehensive analysis utilizing all the NACs and reductants demonstrate that the computed hydrogen atom transfer model and the experimental one electron reduction potential model have similar root mean square errors and residual error probability distributions. In contrast, the model using the computed electron affinity has a more variable residual error distribution with a significant number of outliers. The results suggest that a linear free energy model utilizing computed hydrogen transfer reaction free energy produces a more reliable prediction of the NAC abiotic reduction second order rate constant than previously available methods. The advantages of the proposed hydrogen atom transfer model and its mechanistic implications are discussed as well.</div>


2007 ◽  
Vol 371 (5) ◽  
pp. 1405-1419 ◽  
Author(s):  
Bethany L. Kormos ◽  
Yulia Benitex ◽  
Anne M. Baranger ◽  
David L. Beveridge

2013 ◽  
Vol 130 (3) ◽  
pp. 2165-2175 ◽  
Author(s):  
Wuqiong Sun ◽  
Xiaohua He ◽  
Xiaojuan Liao ◽  
Shaoliang Lin ◽  
Wei Huang ◽  
...  

2018 ◽  
Vol 42 (16) ◽  
pp. 13581-13588
Author(s):  
Jianfeng Ban ◽  
Lulu Pan ◽  
Bo Shi ◽  
Hailiang Zhang

Influence of the weight fraction of PMT6S on the phase behaviors of diblock copolymers.


2005 ◽  
Vol 881 ◽  
Author(s):  
Sang-Joo Kim ◽  
Stefan Seelecke ◽  
Brian L. Ball ◽  
Ralph C. Smith ◽  
Chang-Hoan Lee

AbstractThe one-dimensional free energy model for ferroelectric materials developed in [1-3] is general-ized to two dimensions. The proposed two-dimensional energy potential consists of four energy wells corresponding to four variants of the material, four saddle points representing the barriers for 900 switching processes, and a local energy maximum across which 1800-switching processes take place. The free energy potential is combined with the evolution equations based on the theory of thermally activated processes. The prediction of the model is compared with the recent measurements on a Ba- TiO3 single crystalline ferroelectric in [4]. The responses of the model at various loading frequencies are calculated and the kinetics of 900 and 1800 switching processes are discussed.


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