Continuous citrate?capped gold nanoparticle synthesis in a two?phase flow reactor

Abstract A continuous manufacturing platform was developed for the synthesis of aqueous colloidal 10–20 nm gold nanoparticles (Au NPs) in a flow reactor using chloroauric acid, sodium citrate and citric acid at 95 o C 2.3 bar(a) pressure. The use two-phase system – heptane as phase prevented fouling on walls, while improving residence time distribution. Continuous syntheses up to 2 h demonstrated its potential application manufacturing, live quality control established online UV-Vis photospectrometry that monitored particle size process yield. stable reproducible over precursor concentration above 0.23 mM (after mixing), resulting average between 12 15 nm. hydrophobic membrane separator provided successful separation organic phases collection Au NPs flow. Process yield increased higher inlet rates (from 70 % almost 100 %), due lower solution less PTFE membrane. This study addresses challenges translation from batch provides tools development nanoparticles. Graphical abstract