A dispersing agent or dispersant formed as a block copolymer for use in surface coating compositions, such as architectural paint compositions, that can alter its properties as a result of changes in environmental conditions is provided. These stimuli-responsive copolymers are synthesized with properties that can be controlled based on number of blocks and block length and/or as a function of pH and temperature. The addition or these copolymers to coating compositions including other additives, such as pigments and/or fillers, can decrease settling rate, control viscosity, and control interfacial activity of the additives in the compositions.