In Situ Hydrolysis of Block Copolymers at the Water-Oil Interface

Angew Chem Int Ed Engl. 2022 Jun 20;61(25):e202201392. doi: 10.1002/anie.202201392. Epub 2022 Apr 26.

Abstract

In situ manipulation of the chemical composition of block copolymers at the fluid interfaces affords a route by which the interfacial tension, the packing of the copolymers, and the penetration of the blocks into the two liquids can be controlled. Here, a series of linear block copolymers of poly(solketal methacrylate-b-styrene) (PSM-b-PS) are used, converting hydrophobic PSM block into a hydrophilic glycerol monomethacrylate (GM) block, that results in a marked decrease in the liquid-liquid interfacial tension. The kinetics of the first-order hydrolysis reaction was analyzed by monitoring the time-dependent interfacial tension as a function of pH, polymer concentration, molecular weight, and composition. Fluorescence recovery after photobleaching (FRAP) was used to measure the in-plane dynamics of the copolymers before and after hydrolysis. This work provides insights into a quantitative pathway by which in situ interfacial reactions may be performed and monitored in real time, completely changing the interfacial activity of the molecule.

Keywords: Block Copolymers; In Situ Hydrolysis; Interfaces; Reconfiguration; Self-Assembly.