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

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 manipulated. 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. Overall, this work provides insight into a quantitative pathway by which in situ interfacial reactions may be performed and monitored in real time, with complete alteration of the interfacial activity of the molecule.