Temporal Fluctuations in Interparticle Interactions Drive the Formation of Transiently Stable Nanoparticle Precipitates
<p></p><p>The pH and ionic strength dependence of electrostatic interactions was explored to introduce temporal fluctuations in the strengths of interparticle interactions and choreograph a transient self-assembly response in plasmonic nanoparticles. The assembly process was triggered by the electrostatic attraction between positively-charged gold nanoparticles (AuNPs) and an aggregating agent, ethylenediaminetetraacetic acid (EDTA). The autonomous changes in the pH and ionic strength of the solution, under the influence of atmospheric CO<sub>2</sub>, weaken the aggregating ability of EDTA and initiate the complete disassembly of [+] AuNP - EDTA precipitates. The non-destructive way of disassembly minimizes the generation of waste, which helped in achieving some of the desirable feats in the area of dynamic self-assembly like easy removal of waste, transiently stable precipitates and negligible dampness. The chemical strategy adopted in the present work, to introduce transientness, can act as a generic tool in creating the next generation of complex matter.</p><br><p></p>