Droplet-Flow Photopolymerization Aided by Computer: Overcoming the Challenges of Viscosity and Facilitating the Generation of Copolymer Libraries

Abstract

Continuous-flow chemistry represents a robust setting for photochemical reactions. We have developed the first computer-aided droplet-flow platform for photocontrolled radical polymerization. This method allows precise and scalable living polymerizations of monomers at high concentrations in flow, even when solids are generated. The consistent good performance of polymerization during the programmed change of reaction conditions demonstrates the reliability and utility of this method. Furthermore, the droplet-flow approach not only streamlines an automated high-throughput living polymerization (275 droplets of samples in 11 min), which enables the rapid generation of copolymer libraries for low-cost structure–property relationship screening, but also allows on-line switching to desirable reaction conditions for the scale-up (co)­polymerization purpose.

Machine Learning-Guided Discovery of 19F MRI Agents Enabled by Automated Copolymer Synthesis

“…Droplet-based flow systems manipulate discrete volumes of reaction mixtures that are separated by an immiscible inert fluid. 56,[65][66][67] As our lab demonstrated previously, polymerization in droplets reduces the residence time distribution and improves control of polymer composition, molar mass (Mn), and dispersity. 61 For this application, nitrogen gas was used as the immiscible fluid between large reaction droplets, or slugs.…”

“…We identified continuous-flow chemistry as an ideal experimental platform for the iterative synthesis of novel copolymer materials due to its ease of automation, reproducible control of reaction conditions, potential for closed looped optimization between synthesis and analysis, and simple translation to manufacturing scales. [55][56][57][58][59][60][61][62] A majority of previously reported high throughput copolymer synthesis systems polymerize one sample at a time and, thus, require extremely short reaction times to achieve a high sample throughput. For example, Hedrick and coworkers developed a flow reactor capable of synthesizing 100 unique block copolymers in 8 minutes, but the technology relied on ring-opening polymerizations with reaction times of <1 second.…”

Computer‐Aided Living Polymerization Conducted under Continuous‐Flow Conditions†

“…Thanks to the rapid progress of computer science, the computer‐aided living flow polymerizations have recently emerged as a new and highly promising direction to further boost precise polymer synthesis. [ 46‐52 ] The substance‐creating research fields, which have historically relied on the manual designs and operations, have benefitted from advancements in mechanical automation, algorithms and other hardware. [ 53‐56 ] A variety of groups worldwide are seeking avenues to merge computer science with polymerizations using flow techniques as an effective breakthrough point, owing to the ease of connections via the compatible ports on both computers and flow devices.…”

“…[ 53‐56 ] A variety of groups worldwide are seeking avenues to merge computer science with polymerizations using flow techniques as an effective breakthrough point, owing to the ease of connections via the compatible ports on both computers and flow devices. [ 46‐52 ] Those contributions have not only offered powerful platforms to achieve on‐line monitoring of propagation, preparation of series of polymers through programs, generation of target polymers via algorithm optimizations, but also created new opportunities to improve polymerization from a different dimension based on frontier techniques.…”

A Recommender System for Inverse Design of Polycarbonates and Polyesters

“…[6][7][8][9][10][11][12] In this context, new automated synthesis platforms for polymeric materials are critical and offer significant benefits by enabling programmatic control over polymer properties such as monomer conversion (MC), the degree of polymerization (DP), dispersity (Ð), and resulting architecture of the polymeric materials. [13][14][15][16][17] Additionally, these systems can be merged with in-line characterization to enable real-time feedback and optimization of polymer characteristics. 14,15 Coupling of these systems with advances in predictive models for polymer properties will undoubtedly afford immense progress towards rapid development and commercialization of new materials with improved performance characteristics.…”