Heterogeneous nucleation
Structural Match of Heterogeneously Nucleated Mn(OH)2 (s) Nanoparticles on Quartz under Various pH Conditions
While heterogeneous nucleation of nanoparticles on mineral surfaces is remarkably important due to its natural abundance and reactivity, the limitations of analytic techniques pose major difficulties in understanding heterogeneous nucleation. Using synchrotron grazing incidence small angle X-ray scattering (GISAXS), atomic force microscope (AFM), and classical nucleation theory, I invented a new method for obtaining the contact angles of heterogeneously nucleated nanoparticles on a flat surface by analyzing lateral and vertical dimensions at nanoscale. The obtained information proved that faster nucleation (higher supersaturation) yields a poorer structural match (higher contact angle) between Mn(OH)2 (s) and quartz. The calculated structural matches also provided previously unknown interfacial energies between Mn(OH)2 (s) and quartz (γsn = 262–272 mJ/m2), and between Mn(OH)2 (s) and water (γnf = 71 ± 7 mJ/m2). Our findings provide a new underpinning for studying heterogeneous nucleation behavior, not only of Mn (hydr)oxide, but also of other minerals controlled by kinetics in environmental systems and materials syntheses.
Haesung Jung, Byeongdu Lee, and Young-Shin Jun, “Structural Match of Heterogeneously Nucleated Mn(OH)2 (s) Nanoparticles on Quartz under Various pH Conditions”, Langmuir, 2016, 32, 10735–10743.
Haesung Jung, and Young-Shin Jun, “Ionic Strength-controlled Mn (Hydr)oxide Nanoparticle Nucleation on Quartz: Effect of Aqueous Mn(OH)2”, Environmental Science & Technology, 2016, 50, 105–113.