title: Self-assembly of soft nanoparticles with tunable patchiness.
abstract: Details of the forces between nanoparticles determine the ways in which the nanoparticles can self-assemble into larger structures. The use of directed interactions has led to new concepts in self-assembly such as asymmetric dendrons, Janus particles, patchy colloids and colloidal molecules. Recent models that include attractive regions or 'patches' on the surface of the nanoparticles predict a wealth of intricate modes of assembly. Interactions between such particles are also important in a range of phenomena including protein aggregation and crystallization, re-entrant phase transitions, assembly of nanoemulsions and the organization of nanoparticles into nanowires. Here, we report the synthesis of 6-nm nanoparticles with dynamic hydrophobic patches and show that they can form reversible self-assembled structures in aqueous solution that become topologically more connected upon dilution. The organization is based on guest-host supramolecular chemistry with the nanoparticles composed of a hydrophobic dendrimer host molecule and water-soluble hydrophilic guest molecules. The work demonstrates that subtle changes in hierarchal composition and/or concentration can dramatically change mesoscopic ordering.
authors.affiliation: Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, The Netherlands.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Hermans
authors.forename: Maarten A C
authors.initials: MA
authors.lastname: Broeren
authors.forename: Nikos
authors.initials: N
authors.lastname: Gomopoulos
authors.forename: Paul
authors.initials: P
authors.lastname: van der Schoot
authors.forename: Marcel H P
authors.initials: MH
authors.lastname: van Genderen
authors.forename: Nico A J M
authors.initials: NA
authors.lastname: Sommerdijk
authors.forename: George
authors.initials: G
authors.lastname: Fytas
authors.forename: E W
authors.initials: EW
authors.lastname: Meijer