Rotational isomeric state models of sulphur and selenium chains. Part 3.—Large rings in liquid sulphur and the nature of Sπ

1968 ◽  
Vol 64 (0) ◽  
pp. 1396-1401 ◽  
Author(s):  
J. A. Semlyen
Keyword(s):  
Isomeric State ◽  
Rotational Isomeric State ◽  
Large Rings ◽  
Liquid Sulphur ◽  
State Models

Dipole moments and conformation energies for substituted ethanes

1982 ◽  
Vol 60 (16) ◽  
pp. 2049-2056 ◽  
Author(s):  
Victor M. S. Gil ◽  
António J. C. Varandas
Keyword(s):  
Simple Model ◽  
Potential Energy ◽  
Dipole Moments ◽  
Model Potential ◽  
Energy Functions ◽  
Electric Dipole Moments ◽  
Potential Energy Functions ◽  
Rotational Isomeric State ◽  
State Models ◽  
The Continuum

By using simple model potential energy functions for internal rotation of ethane derivatives (CH2X–CH2X and CHX2–CHX2), a comparison was made between the continuum and the rotational isomeric state models for obtaining conformation information (especially energy differences for the staggered conformers) from electric dipole moments. It is found that the results obtained by the two procedures may be appreciably different, depending on the features of the conformational energy function and on the temperature considered.

scholarly journals Application of Rotational Isomeric State Theory to Ionic Polymer Stiffness Predictions

2005 ◽  
Vol 20 (9) ◽  
pp. 2443-2455 ◽  
Author(s):  
Lisa Mauck Weiland ◽  
Emily K. Lada ◽  
Ralph C. Smith ◽  
Donald J. Leo
Keyword(s):  
Isomeric State ◽  
Mechanical Response ◽  
Physical Structure ◽  
State Theory ◽  
Chain Conformation ◽  
Ionic Polymer ◽  
Polymer Morphology ◽  
Rotational Isomeric State ◽  
Material Stiffness ◽  
Chain Lengths

Presently, rotational isomeric state (RIS) theory directly addresses polymer chain conformation as it relates to mechanical response trends. The primary goal of this work is to explore the adaptation of this methodology to the prediction of material stiffness. This multiscale modeling approach relies on ionomer chain conformation and polymer morphology and thus has potential as both a predictive modeling tool and a synthesis guide. The Mark–Curro Monte Carlo methodology is applied to generate a statistically valid number of end-to-end chain lengths via RIS theory for four solvated Nafion® cases. For each case, a probability density function for chain length is estimated using various statistical techniques, including the classically applied cubic spline approach. It is found that the stiffness prediction is sensitive to the fitting strategy. The significance of various fitting strategies, as they relate to the physical structure of the polymer, are explored so that a method suitable for stiffness prediction may be identified.

Sign in / Sign up

Export Citation Format

Share Document