Fig. 2
Tuning the sizes of particles. a The size d = d1 = d2 of spherical CaCO3 particles was tuned by varying the stirring time t of the CaCl2 and Na2CO3 solutions at pH values of 5, 7, 9 in pure water solution with a sodium carbonate to calcium chloride ratio S = 1. b The size of the long axis d1 of ellipsoidal CaCO3 particles was tuned by varying the stirring time ts at certain salt concentration ratios S = 2.5 (black curve); 5 (red curve); and 10 (blue curve) in water/ethylene glycol = 1/5 solutions of pH = 9.5. c The aspect ratio R (d1/d2) of the CaCO3 particles as a function of S; R was tuned by varying the stirring time ts in different water and water/EG (ethylene glycol) mixtures at pH = 9.5. The vertical bars represent the standard deviation values.