A composition for treating a formation includes a surfactant including an amphiphilic block copolymer having a first block and a second block and an acid. The amphiphilic block copolymer is a reaction product of a first monomer and a second monomer via a reversible addition-fragmentation chain transfer polymerization (RAFT) in a two-step reaction using a chain transfer agent (CTA) and a radical initiator. The surfactant favors adsorption onto a surface of the formation such that a temporary barrier is formed, thereby attenuating a reaction rate between the acid and the formation.