Electrochemically Triggered Interfacial Deposition/Assembly of Aqueous‐Suspended Colloids

Abstract

Following our recent work on polyelectrolyte deposition on ferrocene‐terminated self‐assembled monolayers (Langmuir 2018, 34, 12776–12786), we seek in this study to answer the following question: How would aqueous‐suspended colloids respond to the same electrochemical trigger – ferrocene oxidation? Using carboxylic‐terminated polystyrene nano‐/microbeads as a model colloid, we confirm first their transfer to and deposition at such redox‐active surfaces. Key factors involved, including the starting electrode surfaces, colloid size, range/duration of applied potential, and small supporting electrolytes, are examined in detail. A particularly interesting finding among these is the superior efficiency of the electrochemically triggered assembly compared to the electrically driven process. Taking advantage of this feature, we demonstrate fast, high‐fidelity colloid micropattern formation on electrodes at the end.

Aqueous Polyelectrolyte Electrodeposition: The Effects of Alkyl Substitution and Varying Supporting Electrolyte Concentrations on the Deposition Efficiency

“…An electrochemical stimulus, which can be regarded as an intermediate between internal and external stimulus, is becoming increasingly important [3–6] . Such systems can be used for energy storage, [7–10] control of interfacial accessibility, [11,12] facilitated production of electrogenerated chemoluminescence, [13,14] switching the turbidity of smart windows, [15] actuation, [16–18] sensing, [19] modification of interfaces, [20,21] adjustment of the viscoelastic properties of thin films, [22] capture and release applications, [4,22–25] and on‐demand switching of emulsion stability [26] …”