Figure 7: The pH dependent variation of a) zeta potential ξ .for various biopolymers at room temperature. Arrows indicate pI values which is 9 and 5 for gelatin A and gelatin B molecules. Agar is a polyanion and chitosan is a polycation. b) Turbidity profiles are shown for various interacting biopolymers in their salt free solutions for measurements taken at room temperature. The alphabets A, B and C identify the locations on the curves where pHc, pHΦ and pHprep occur. For A-GB samples titrations were conducted from high to low pH whereas for other samples it was from low to high pH. See text for details. Reproduced with permission from Elsevier [95].