Photothermal Miniemulsion Polymerization by Amphiphilic Gold Nanoclusters

Gold nanoclusters (AuNCs), which are approximately 2 nm in size, exhibit distinctive photophysical and catalytic properties, but their performance is often compromised by environmental factors. To mitigate these challenges, attempts have been made to incorporate AuNCs into polymer matrices to enhance their stability. Miniemulsion polymerization has proven to be an effective method for fabricating organic-inorganic composites. Here, we present a facile photothermal-assisted method for miniemulsion polymerization utilizing AuNCs, which serve as co-stabilizers of the emulsion and photothermal conversion agents. By grafting tryptamine onto hydrophilic AuNCs, the amphiphilic AuNCs were spontaneously adsorbed at the styrene/water interfaces, resulting in stable nanoemulsions. Taking advantage of the photothermal properties of surface-bounded AuNCs, rapid polymerization of styrene within the nanoemulsion was successfully initiated by external laser irradiation. The prepared nanocomposites inherited the photothermal activity of AuNCs and exhibited good photothermal stability and repeatability. This approach not only facilitates remote control of chemical reactions, but also optimizes the distribution of AuNCs within the final polymer matrix, thereby enabling the efficient synthesis of nanocomposites while exploiting the unique photofunctionality of AuNCs.