Preparation, assembly and interfacial behavior of Janus gold nanoparticles

• Grant number: 14/01807-8
• Support type: Scholarships abroad - Research Internship - Post-doctor
• Effective date (Start): May 04, 2014
• Effective date (End): April 30, 2015
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal researcher: Watson Loh
• Grantee: Ana Maria Percebom Sette da Silva
• Supervisor abroad: Luis M. Liz-Marzán
• Home Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Research place: Centre for Cooperative Research in Biomaterials (CIC biomaGUNE), Spain
• Associated to the scholarship: 12/21930-3 - Nanoparticles self-assembly controlled by interactions involving surfactants and polymers, BP.PD

Abstract

Janus or double-faced nanoparticles (JanusNP) may behave similarly to surfactant molecules but in a different length scale. It means that the interparticle interactions can lead to NP assembly in bulk solvents and interfaces. This behavior can be especially important for systems formed by noble-metallic nanoparticles due to the possibility of control properties related to the phenomena of Localized Surface Plasmon Resonance (LSPR) and Surface Enhanced Raman Spectroscopy (SERS). The present project aims to achieve selective coating each hemisphere of gold nanoparticles with polymers of antagonistic chemical nature (hydrophobic vs. hydrophilic) to generate JanusNP. In some cases, thermosensitive systems will be prepared by using polymers exhibiting a phase transition upon mild heating (e.g. poly(N-isopropylacrylamide at 32 ºC)). After obtaining JanusNP, the goal is to study their self-assembly in bulk of different solvents, as well as investigate the arrangement at the air/liquid interface, preparing arrays by using a Langmuir trough. Finally, several techniques will be used to characterize the structure of the nanoparticles, the self-assembled structures and the obtained arrays, and to analyze and explore their resulting properties. Among them, we can mention UV-Vis spectroscopy, Dynamic Light Scattering (DLS), interfacial tension measurements, Nuclear Overhauser Effect Spectroscopy by Nuclear Magnetic Resonance (NOESY NMR), Raman Scattering, and Transmission and Scanning Electron Microscopy (TEM and SEM). (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

FERNANDEZ-RODRIGUEZ, MIGUEL A.; PERCEBOM, ANA M.; GINER-CASARES, JUAN J.; RODRIGUEZ-VALVERDE, MIGUEL A.; CABRERIZO-VILCHEZ, MIGUEL A.; LIZ-MARZAN, LUIS M.; HIDALGO-ALVAREZ, ROQUE. Interfacial Activity of Gold Nanoparticles Coated with a Polymeric Patchy Shell and the Role of Spreading Agents. ACS OMEGA, v. 1, n. 2, p. 311-317, AUG 2016. Web of Science Citations: 3.

PERCEBOM, ANA M.; GINER-CASARES, JUAN J.; CLAES, NATHALIE; BALS, SARA; LOH, WATSON; LIZ-MARZAN, LUIS M. Janus gold nanoparticles obtained via spontaneous binary polymer shell segregation. CHEMICAL COMMUNICATIONS, v. 52, n. 23, p. 4278-4281, 2016. Web of Science Citations: 20.