Comparison of the interfacial activity between homogeneous and Janus gold nanoparticles by pendant drop tensiometry Fernández Rodríguez, Miguel Ángel Song, Yang Rodríguez Valverde, Miguel Ángel Chen, Shaowei Cabrerizo Vílchez, Miguel Ángel Hidalgo Álvarez, Roque Isidro This study was supported by the Junta de Andalucía (projects P09-FQM-4698 and P10-FQM-5977), the Ministerio de Economía y Competitividad (project MAT2011-23339) and the U.S. National Science Foundation (DMR-0804049). The interfacial activity of 3.5 nm homogeneous (HPs) and amphiphilic Janus gold nanoparticles (JPs) was characterized by pendant drop tensiometry for water/air and water/decane interfaces. This technique requires a smaller quantity of nanoparticles than the traditional Langmuir balance technique. The direct deposition at the interface of the nanoparticles dispersed in a spreading solvent also requires smaller quantities of sample than does adsorption from the bulk. From the growing and shrinking of the pendant drops, the interfacial activity of the nanoparticles can be evaluated and compared within a wide range of area per particle. In this work, the JPs exhibited a higher interfacial activity than did the HPs in all cases. A hard disk model fits the piecewise compression isotherm of the HPs, yet this model underestimates the interactions between the JPs adsorbed at the interface. 2024-02-26T11:47:49Z 2024-02-26T11:47:49Z 2014 journal article Published version: Fernández Rodríguez, Miguel Ángel et al. Comparison of the interfacial activity between homogeneous and Janus gold nanoparticles by pendant drop tensiometry. Langmuir 2014, 30, 7, 1799–1804 Publication Date:February 3, 2014. https://doi.org/10.1021/la404194e https://hdl.handle.net/10481/89582 10.1021/la404194e eng http://creativecommons.org/licenses/by-nc-sa/4.0/ open access Atribución-NoComercial-CompartirIgual 4.0 Internacional