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Light-induced reversible hydrophobization of cationic gold nanoparticles via electrostatic adsorption of a photoacid.

ABSTRACT: The ability to switch the hydrophilicity/hydrophobicity of nanoparticles promises great potential for applications. Here we report a generic approach that allows hydrophobization of cationic surfaces by light-induced photoacid switching from the unbound zwitterionic form to the electrostatically bound anionic form. Importantly, this allows reversible assembly and disassembly of cationic AuNPs, with disassembly kinetics controlled by temperature. The AuNPs can be repeatedly transferred between aqueous and non-polar solvents using light, showing potential in purification processes. In the macroscopic scale, nontrivially, light triggers the in situ hydrophobization of a flat cationized gold surface. The current approach is generic and opens up a new way to control the surface properties and self-assembly of nanoparticles.

SUBMITTER: Zhang H

PROVIDER: S-EPMC8928170 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature

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Light-induced reversible hydrophobization of cationic gold nanoparticles via electrostatic adsorption of a photoacid.

Zhang Hang H Muhammad Junaid J Liu Kai K Ras Robin H A RHA Ikkala Olli O

Nanoscale 20190801 30

The ability to switch the hydrophilicity/hydrophobicity of nanoparticles promises great potential for applications. Here we report a generic approach that allows hydrophobization of cationic surfaces by light-induced photoacid switching from the unbound zwitterionic form to the electrostatically bound anionic form. Importantly, this allows reversible assembly and disassembly of cationic AuNPs, with disassembly kinetics controlled by temperature. The AuNPs can be repeatedly transferred between aq ...[more]

PMID: 31318006

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