Fig. 4: Gelation induced by salt addition.

Inverted CNC suspensions (initial (a) and fractionated (b,c)) between crossed polarizers, with different CNC mass fractions w but a constant sodium ion concentration \(c_{Na^ + } \approx c_{Na^ + }^g\), adjusted by the addition of NaCl. The samples stood upside down for 2 weeks after reaching gelation by the addition of NaCl