In Situ Monitoring of RAFT Polymerization by Tetraphenylethylene‐Containing Agents with Aggregation‐Induced Emission Characteristics

Abstract

A facile and efficient approach is demonstrated to visualize the polymerization in situ. A group of tetraphenylethylene (TPE)-containing dithiocarbamates were synthesized and screened as agents for reversible addition fragmentation chain transfer (RAFT) polymerizations. The spatial-temporal control characteristics of photochemistry enabled the RAFT polymerizations to be ON and OFF on demand under alternating visible light irradiation. The emission of TPE is sensitive to the local viscosity change owing to its aggregation-induced emission characteristic. Quantitative information could be easily acquired by the naked eye without destroying the reaction system. Furthermore, the versatility of such a technique was well demonstrated by 12 different polymerization systems. The present approach thus demonstrated a powerful platform for understanding the controlled living radical polymerization process.

Visualization of Atom Transfer Radical Polymerization by Aggregation‐Induced Emission Technology

“…Recently, Tang et al. reported a facile and efficient approach to solve above issues ingeniously by using aggregation‐induced emission (AIE) technology . AIE materials have a weak fluorescent signal in solution, and the fluorescence is significantly enhanced in the aggregate state, which is contrary to the aggregation‐induced quenching (ACQ) behavior of the conventional dyes .…”

Aggregation‐Induced Emission for Visualization in Materials Science

“…Recently, visualization of the reversible addition fragmentation chain transfer (RAFT) polymerization has been realized by employing an initiator with TPE moieties . The mechanism was mainly based on the different fluorescent behaviors of AIE‐active molecules in the presence of varied viscosity.…”

“…(A) Reaction process, (B) fluorescence photos, and (C) fluorescent emission spectra for the polymer solutions at different conversions under 365 nm UV irradiation. (D) The relationship between the molecular weight of polymer and the reaction conversion …”

“…[54] Recently,v isualization of the reversible addition fragmentation chain transfer (RAFT) polymerization has been realized by employing an initiator with TPE moieties. [55] The mechanism was mainly based on the different fluorescent behaviors of AIE-activem olecules in the presence of varied viscosity.T he increasedv iscosity led to inhibited molecular motion and at urnon fluorescent emission for the AIE molecules.T hrough the selection of initiators with differentc onfigurations, the molecules in Figure 6A were employedf or the polymerization reaction. Figure 6B shows the fluorescent performances for the polymerization at different conversione fficiencies.…”

Chain End‐Functionalized Polymer Brushes with Switchable Fluorescence Response

“…Dye labeling of polymers at specific sites in the chain is a versatile method to follow various physicochemical and optical phenomena occurring at the nanoscale . For example, fluorescent dye‐labeled polymers have been used to study polymer chain dynamics in solution, local glass transition temperature of block copolymers, and structures of block copolymer micelles .…”