Fig. 2. (a) DLS data of the 1 mg ml⁻¹ lignin solution and the lignin solution after addition of 1.5 ml of HCl. Both of the samples were kept at room temperature for one week before DLS measurement. (b) Addition of 1.5 ml of water to 5 ml of 1 mg ml⁻¹ lignin solutions which were kept at room temperature for 0.5 h and one week, respectively. Both of the samples were kept at room temperature for 6 h after addition of anti-solvents before DLS measurement.