Testing of drying process model for acoustically levitated disaccharide aqueous solutions

The paper reports experimental results collected for testing a drying process model for acoustically levitated droplets. More specifically, the so-called D2 versus time law is tested on droplets of homologous disaccharide aqueous solutions. For assessing the validity of the model, the determination of the droplet diameter is performed by a direct video camera monitoring and by an OH/CH area ratio analysis of InfraRed spectra collected as a function of time. For such a test, aqueous solutions of trehalose and sucrose, which show different surface tension values, are investigated. The experimental findings, obtained by the two independent employed approaches, reveal, for both the samples, a good agreement with the theoretic model previsions for the initial time trend. Furthermore, in agreement with literature data, they furnish a value of the surface tension, which is higher for trehalose in respect to sucrose.