Analysis of Small-Angle Neutron Scattering from Blends of Charged and Neutral Polymers Based on Rod–Coil Random Phase Approximation

lithium battery

AUTHORS

J. Lee, R. Jana, E. E. Abdo, C. Pratt, L. He, A. V. Dobrynin, N. P. Balsara

JOURNAL

ACS Macro Letters, 15, 1, 112–119

DATE

16th December 2025

PRODUCTS

ABSTRACT

Blends of charged and neutral polymers are of interest due to potential applications in rechargeable batteries. In this study, concentration fluctuations in blends of charged poly[lithium 3-(methacryloyloxy)propylsulfonyl-1-(trifluoromethanesulfonyl)imide] (PLiMTFSI) and neutral poly(ethylene oxide) (PEO) were investigated by small-angle neutron scattering (SANS). The scattering data were analyzed in the framework of the random phase approximation (RPA). Since ion dissociation can lead to stiffening, the charged polymers were approximated as rods, while the neutral polymers were assumed to be random coils. This approach works reasonably well at low weight fractions of charged polymers. For blends with higher weight fractions of the charged polymer, concentration fluctuations were highly suppressed, resulting in q-independent coherent structure factors that are inconsistent with the rod–coil RPA.

KEYWORDS

ions, neutron scattering, polyelectrolytes, polymers, scattering

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