Fig. 4. (a) The gelation time and (b) the recovery rates of gelator GAA-2 in aromatics solvents/water ratios of 1 : 100 (0.1 mL : 10 mL) upon the addition of different amounts of GAA-2. Rheological studies of gels formed by spreading 30 mg of gelator GAA-2 powders over the crude oil surface (0.1 mL) in 10 mL of water. (c) Frequency sweep. G′ = storage modulus, G′′ = loss modulus. (d) The yield stress of gelator GAA-2 in different aromatics solvents.