Abstract
Block copolymer micelles mediate PbBr(2) complexation through two distinct pathways: an architecture-dependent interfacial process under static conditions and a shear-dominated mechanism under dynamic mixing. This study reveals how the polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) asymmetry governs the chain adsorption conformations (trains, loops, and tails) on PbBr(2) surfaces and its complexation outcome. Under static conditions, the process is kinetically limited by micellar diffusion. Upon reaching the PbBr(2) surface, the strong pyridine-Pb(2+) coordination induces a restructuring of the micelle core. For asymmetric PS-b-P2VP with long P2VP blocks, a thin PS shell allows the P2VP core to deform and spread onto the surface, creating a large adsorption footprint. The long-tethered P2VP chains form multiple train-loop segments, maximizing the number of coordination sites per micelles and enabling efficient PbBr(2) dissociation into [PbBr(3)](-) complexes. Conversely, the thick PS shells of symmetric copolymers act as a steric barrier. This shield prevents interfacial restructuring and hinders complexation. Dynamic mixing introduces an energy-driven mechanism that circumvents these architectural constraints. Shear forces simultaneously fragment PbBr(2) monoliths into nanoparticles, accelerating complexation independently of copolymer architecture. UV-vis and dynamic light scattering (DLS) analyses show that micelle dimensions and chain conformations dictate the efficiency of PbBr(2) complexation. By correlating micelle architecture with mixing conditions, this work establishes key design principles for PbBr(2) complexation. We reveal a critical mechanistic switch. Under static conditions, the process is architecture-dependent. In contrast, dynamic mixing creates a shear-dominated, architecture-independent process. This finding provides fundamental insight into controlling lead halide precursor solutions.