TY - JOUR
TI - Effect of Molecular Weight on the Mechanical and Electrical Properties of Block Copolymer Electrolytes
AU - Mohit Singh
AU - Omolola Odusanya
AU - Gregg M. Wilmes
AU - Hany B. Eitouni
AU - Enrique D. Gomez
AU - Amish J. Patel
AU - Vincent L. Chen
AU - Moon Jeong Park
AU - Panagiota Fragouli
AU - Hermis Iatrou
AU - Nikos Hadjichristidis
AU - David Cookson
AU - Nitash P. Balsara
JO - Macromolecules
PY - 2007
VL - 40
TODO - 13
SP - 4578--4585
PB - American Chemical Society (ACS)
SN - 0024-9297, 1520-5835
TODO - 10.1021/ma0629541
TODO - Lamellar grains;  Polystyrene-Wocfc-poly(ethylene oxide) copolymers;  Theological properties, Doping (additives);  Ionic conductivity;  Mechanical properties;  Molecular weight;  Morphology;  Polyethylene oxides, Polyelectrolytes
TODO - The relationship between ionic conductivity, morphology, and Rheological properties of polystyrene-Wocfc-poly(ethylene oxide) copolymers (SEO) doped with a lithium salt, Li[N(SO2CF3)2], is elucidated. We focus on lamellar samples with poly(ethylene oxide) (PEO) volume fractions, φ, ranging from 0.38 to 0.55, and PEO block molecular weights, M PEO, ranging from 16 to 98 kg/mol. The low-frequency storage modulus (G′) at 90 °C increases with increasing MPEO from about 4 × 105 to 5 × 107 Pa. Surprisingly, the conductivity of the SEO/salt mixtures with the molar ratio of Li to ethylene oxide moieties of 0.02 σ, also increases with increasing MPEO, from 6.2 × 10-5 to 3.6 × 10-4 S/cm at 90 °C. We compare σ with the conductivity of pure PEO/salt mixtures, σPEO. and find that σ/[(φσPEO] of our highest molecular weight sample is close to 0.67, the theoretical upper limit for transport through randomly oriented lamellar grains. © 2007 American Chemical Society.
ER -