Tuning structural forces between silica surfaces by temperature-induced micellization of responsive block copolymers

Area of Science:

• Surface Science
• Materials Science
• Physical Chemistry

Background:

• Controlling surface interactions is crucial in various scientific and engineering fields.
• Responsive materials offer dynamic control over interfacial properties.

Purpose of the Study:

• To demonstrate a method for controlling surface interactions using a responsive solution.
• To investigate the effect of thermo-responsive Pluronics P85 block copolymers on silica surface forces.

Main Methods:

• Atomic Force Microscopy (AFM)-based force measurements were employed.
• Experiments were conducted between two silica surfaces immersed in an aqueous solution.
• The solution contained thermo-responsive Pluronics P85 block copolymers.

Main Results:

• A switchable surface interaction was achieved by altering temperature.
• Temperature changes induced micellization of block copolymers, leading to long-range structural forces.
• These forces oscillated between attractive and repulsive regimes, controlling surface interactions.

Conclusions:

• Thermo-responsive block copolymers provide a general method for reversibly controlling surface interactions via a temperature switch.
• Temperature-induced micellization is key to introducing tunable long-range forces.
• Surface nature plays a minor role as control is achieved through bulk solution changes.