We have demonstrated chemical transformation in single microscopic-sized aerosol droplets localised in optical tweezers. Droplets in situ are measured during chemical transformation processes of solvent exchange and solute transformation through an ion exchange reaction. Solvent exchange between deionised water and heavy water in aerosol droplets is monitored through observation of the OH and OD Raman stretches. A change in solute chemistry of aerosol is achieved through droplet coalescence events between calcium chloride and sodium carbonate to promote ion exchange. The transformation forming meta-stable and stable states of CaCO₃ is observed and analysed using Gaussian peak decomposition to reveal polymorphs.

Date Published: 25 August 2017
PDF: 11 pages
Proc. SPIE 10347, Optical Trapping and Optical Micromanipulation XIV, 1034728 (25 August 2017); doi: 10.1117/12.2273899

Published in SPIE Proceedings Vol. 10347:
Optical Trapping and Optical Micromanipulation XIV
Kishan Dholakia; Gabriel C. Spalding, Editor(s)