Interfacial Activity of Gold Nanoparticles Coated with a Polymeric Patchy Shell and the Role of Spreading Agents

Autor(es)

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

• Tipo de documento: Artigo Científico
• Fonte: ACS OMEGA; v. 1, n. 2, p. 311-317, AUG 2016.
• Citações Web of Science: 3

Resumo

Gold patchy nanoparticles (PPs) were prepared under surfactant-free conditions by functionalization with a binary ligand mixture of polystyrene and poly(ethylene glycol) (PEG) as hydrophobic and hydrophilic ligands, respectively. The interfacial activity of PPs was compared to that of homogeneous hydrophilic nanoparticles (HPs), fully functionalized with PEG, by means of pendant drop tensiometry at water/air and water/decane interfaces. We compared interfacial activities in three different spreading agents: water, water/chloroform, and pure chloroform. We found that the interfacial activity of PPs was close to zero (similar to 2 mN/m) when the spreading agent was water and increased to similar to 14 mN/m when the spreading agent was water/chloroform. When the nanoparticles were deposited with pure chloroform, the interfacial activity reached up to 60 mN/m by compression. In all cases, PPs exhibited higher interfacial activity than HPs, which were not interfacially active, regardless of the spreading agent. The interfacial activity at the water/decane interface was found to be significantly lower than that at the water/air interface because PPs aggregate in decane. Interfacial dilatational rheology showed that PPs form a stronger elastic shell at the pendant drop interface, compared to HPs. The significantly high interfacial activity obtained with PPs in this study highlights the importance of the polymeric patchy shell and the spreading agent. (AU)

• Processo FAPESP: 12/21930-3 - Controle de autoassociação de nanopartículas através das interações envolvendo surfactantes e polímeros
• Beneficiário: Ana Maria Percebom Sette da Silva
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 14/01807-8 - Preparação, autoassociação e comportamento interfacial de nanopartículas de ouro com caráter janus
• Beneficiário: Ana Maria Percebom Sette da Silva
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado