Figure 2.

Effective charge of PNIPAM molecules at 10 mM monomeric concentration in water without salt (▲) and with 10 mM (■) or 50 mM added salt (●), all at 20.0 °C. The obtained effective charge of PNIPAM with one carboxylate end group per polymer (blue △) and the effective charge values with 50 mM LiClO₄ (○) and N(CH₃)₄ClO₄ (red △) are also indicated. The error bars indicate precision as derived from triplicate experiments. The effective charge values with no salt, with NaF and with Na2SO4 were all within the ±0.04 range.