Work

Micelle-Mediated PbBr 2 Complexation: Influence of Block Copolymer Architecture and Mixing Conditions

Year: 2025

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide 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.

Source: Langmuir

DOI: 10.1021/acs.langmuir.5c04107

Authors: Belda Amelia Junisu, Ya-Sen Sun

Institution: National Cheng Kung University

Language: English

Topic: Surfactants and Colloidal Systems

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,500

Funder: Institute for Information Industry, Ministry of Science and Technology, Taiwan