Facile preparation of gold nanoparticles through autoreduction of gold ions in the presence of fluoroalkyl end-capped cooligomeric aggregates: LCST-triggered sol–gel switching behavior of novel thermoresponsive fluoroalkyl end-capped cooligomeric nanocomp

Thermosensitive fluoroalkyl end-capped N-(1,1-dimethyl-3-oxobutyl)acrylamide – acryloylmorpholine cooligomer, which was prepared by the cooligomerization of fluoroalkanoyl peroxide with the corresponding monomers, was applied to the autoreduction of gold ions to afford the fluorinated cooligomeric nanocomposite-encapsulated gold nanoparticles under very mild conditions; although the corresponding non-fluorinated cooligomer was not able to afford the gold nanoparticles at all under similar conditions. These fluorinated cooligomeric nanocomposites exhibited a plasmon absorption band around 520 nm related to the formation of gold nanoparticles in their aqueous solutions. Interestingly, these fluorinated nanocomposite-encapsulated gold nanoparticles can exhibit the thermoswitchable sol–gel transition through the lower critical solution temperature (LCST)-triggered aggregation of the corresponding nanocomposites, and this sol–gel switching behavior is reversible during a heating and cooling cycle.

Graphical abstractRF-(DOBAA)x-(ACMO)y-RF/Au nanocomposites were prepared by the autoreduction of gold ions in the presence of RF-(DOBAA)x-(ACMO)y-RF cooligomer; although the corresponding non-fluorinated cooligomer was not able to afford the gold nanoparticles at all. These fluorinated nanocomposites can exhibit the thermoswitchable sol–gel transition through the lower critical solution temperature (LCST)-triggered aggregation of the corresponding nanocomposites.Figure optionsDownload full-size imageDownload high-quality image (67 K)Download as PowerPoint slideResearch highlights► Autoreduction of gold ions. ► Fluorinated cooligomer. ► Fluorinated cooligomeric gold nanocomposite. ► LCST-triggered sol-gel switching behavior.