Interfacial Activity and Contact Angle of Homogeneous, Functionalized, and Janus Nanoparticles at the Water/Decane Interface Fernández Rodríguez, Miguel Ángel Ramos, Jose Isa, Lucio Rodríguez Valverde, Miguel Ángel Cabrerizo Vílchez, Miguel Ángel Hidalgo Álvarez, Roque Isidro Interfacial activity FreSCA cryo-SEM Pendant drop tensiometry Janus nanopar-ticles Water/decane interface This work was supported by the Spanish MINECO (Projects MAT2011-23339 and MAT2013-44429-R), “Junta de Andalucía” and FEDER (Projects P10-FQM-5977 and P12-FQM-1443), and the COST Action “Smart and Green Interfaces” (STSM MP1106-14761). Lucio Isa acknowledges financial support from the Swiss National Science Foundation (Grant PP00P2-144646/1). Surface heterogeneity affects the behavior of nanoparticles at liquid interfaces. To gain a deeper understanding on the details of these phenomena, we have measured the interfacial activity and contact angle at water/decane interfaces for three different types of nanoparticles: homogeneous poly(methyl methacrylate) (PMMA), silica functionalized with a capping ligand containing a methacrylate terminal group, and Ag-based Janus colloids with two capping ligands of different hydrophobicity. The interfacial activity was analyzed by pendant drop tensiometry, and the contact angle was measured directly by freeze-fracture shadow-casting cryo-scanning electron microscopy. The silver Janus nanoparticles presented the highest interfacial activity, compared to the silica nanoparticles and the homogeneous PMMA nanoparticles. Additionally, increasing the bulk concentration of the PMMA and silica nanoparticles up to 100-fold compared to the Janus nanoparticles led to silica particles forming fractal-like structures at the interface, contrary to the PMMA particles that did not show any spontaneous adsorption. 2024-02-26T12:10:35Z 2024-02-26T12:10:35Z 2015 journal article Published version: Fernández Rodríguez, Miguel Ángel et al. Interfacial Activity and Contact Angle of Homogeneous, Functionalized, and Janus Nanoparticles at the Water/Decane Interface. Langmuir 2015, 31, 32, 8818–8823 Publication Date:July 24, 2015. https://doi.org/10.1021/acs.langmuir.5b02137 https://hdl.handle.net/10481/89588 10.1021/acs.langmuir.5b02137 eng http://creativecommons.org/licenses/by-nc-sa/4.0/ open access Atribución-NoComercial-CompartirIgual 4.0 Internacional