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How does the chain extension of poly (acrylic acid) scale in aqueous solution? A combined study with light scattering and computer simulation

D. Reith·B. Mueller·F. Mueller-Plathe·S. Wiegand
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Abstract

This work adresses the question of the scaling behaviour of polyelectrolytes in solution for a realistic prototype: We show results of a combined experimental (light scattering) and theoretical (computer simulations) investigation of structural properties of poly (acrylic acid) (PAA). Experimentally, we determined the molecular weight (M_W) and the hydrodynamic radius (R_H) by static light scattering for six different PAA samples in aqueous NaCl-containing solution (0.1-1 mol/L) of polydispersity D_P between 1.5 and 1.8. On the computational side, three different variants of a newly developed mesoscopic force field for PAA were employed to determine R_H for monodisperse systems of the same M_W as in the experiments. The force field effectively incorporates atomistic information and one coarse-grained bead corresponds to one PAA monomer. We find that R_H matches with the experimental data for all investigated samples. The effective scaling exponent for R_H is found to be around 0.55, which is well below its asymptotic value for good solvents. Additionally, data for the radius of gyration (R_G) are presented.

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D. Reith, B. Mueller, F. Mueller-Plathe, S. Wiegand. 2001-03-15. How does the chain extension of poly (acrylic acid) scale in aqueous solution? A combined study with light scattering and computer simulation. https://doi.org/10.1063/1.1471901

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