Ionic Association of Lithium Triflate in Glymes, Model Solvents, and High Molecular Weight Poly(Ethylene Oxide)

1994 ◽  
Vol 369 ◽  
Author(s):  
R. Frech ◽  
W. Huang ◽  
M. A. K. L. Dissanayake
Keyword(s):  
Molecular Weight ◽  
Ethylene Oxide ◽  
High Molecular Weight ◽  
Deformation Mode ◽  
Ionic Association ◽  
Lithium Triflate ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Solvent Molecules ◽  
High Molecular Weight Poly

AbstractIonic association in lithium trifluoromethanesulfonate (triflate) dissolved in glymes, glycols, model solvents, and high molecular weight poly(ethylene oxide) is studied by analysis of vibrational band structure. Surprisingly, the CF3 symmetric deformation mode is shown to be the most accurate measure of ionic association and the reasons for this are discussed. The nature of various associated lithium triflate species as deduced from ab initio calculations is supported by spectral data presented here. A weak interaction of the triflate anion with certain solvent molecules containing an alcohol OH group is observed. Finally the temperature dependence of ionic association in a complex of lithium triflate and high molecular weight poly(ethylene oxide) is described.

Shear-thickening behavior of high molecular weight poly(ethylene oxide) solutions

2011 ◽  
Vol 51 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Daniela Rivero ◽  
Laura M. Gouveia ◽  
Alejandro J. Müller ◽  
A. Eduardo Sáez
Keyword(s):  
Molecular Weight ◽  
Ethylene Oxide ◽  
High Molecular Weight ◽  
Shear Thickening ◽  
Poly Ethylene Oxide ◽  
Thickening Behavior ◽  
Poly Ethylene ◽  
High Molecular Weight Poly

Phase Separation in Al2O3 Sol-gel System Incorporated with High Molecular Weight Poly(ethylene oxide)

2007 ◽  
Vol 1007 ◽  
Author(s):  
Yasuaki Tokudome ◽  
Kazuki Nakanishi ◽  
Koji Fujita ◽  
Kiyotaka Miura ◽  
Kazuyuki Hirao
Keyword(s):  
Molecular Weight ◽  
Phase Separation ◽  
Ethylene Oxide ◽  
High Molecular Weight ◽  
Propylene Oxide ◽  
Bet Surface Area ◽  
Pure Alumina ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
High Molecular Weight Poly

ABSTRACTPure alumina monoliths with well-defined macropores and mesostructured skeleton have been synthesized via a spontaneous route from the aqueous and ethanolic solution of aluminum salts in the presence of propylene oxide and high molecular weight poly(ethylene oxide)(PEO). The addition of propylene oxide to the starting solution controls the gelation, while the addition of PEO induces the phase separation. Appropriate choice of the starting composition, with which the phase separation and gelation concur, produces large-dimension (10mm×10mm×10mm), bicontinuous macroporous Al2O3 monoliths. The mean size of the continuously connected pores is controlled in the micrometer range, depending on the PEO concentration and polarity of the solution. On the other hand, micropores and mesopores, originated from the interstices among primary particles, exhibit median pore size of about 2.6 nm and the BET surface area as high as 396 m2/g after dried temperature at 40 °C.

Sign in / Sign up

Export Citation Format

Share Document