Abstract
We develop a new gas-phase quantitative approach for in-situ characterization of hybrid nanomaterial colloids using the concept of ion mobility instrumentation coupling. Electrospray-differential mobility analysis (ES-DMA), a gas-phase electrophoretic method, is used for quantifying particle size distributions and number concentrations of nanomaterial colloids. Aerosol particle mass analyzer (APM) and aerosol electrometer coupled to ES-DMA are used for in-situ measuring particle mass and surface area of size-classified aerosolized nanomaterial colloids, respectively. Transmission electron microscopy is employed complementary to provide the imagery of hybrid nanomaterial colloid. Combining the information of the mobility size distribution, aerosol surface area measurement, and the aerosol mass-based distribution, we can quantify (1) the kinetics of aggregation and surface dissolution of silver nanoparticles (AgNPs) conjugated with thiolated polyethylene glycol (SH-PEG) under an acidic environment; (2) The lateral size, surface area of the synthesized graphene oxide (GO) colloid prior to hybridization; (3) The electrostatic-directed assembly of AgNP@GO colloids and the corresponding stability. This study demonstrates a facile, prototype methodology to determine important formulation factors relevant to the formation of hybrid nanomaterial colloids and the performance in a variety of nanotechnological and bio-nanotechnological applications.