title: Wrinkle-assisted linear assembly of hard-core/soft-shell particles: impact of the soft shell on the local structure.
abstract: This article addresses wrinkle assisted assembly of core-shell particles with hard cores and soft poly-(N-isopropylacrylamide) shells. As core materials we chose silica as well as silver nanoparticles. The assembled structures show that the soft shells act as a separator between the inorganic cores. Anisotropic alignment is found on two length scales, macroscopically guided through the wrinkle structure and locally due to deformation of the polymer shell leading to smaller inter-core separations as compared to assembly on flat substrates without confinement. The structures were analysed by means of scanning electron microscopy. Radial distribution functions are shown, clearly highlighting the impact of confinement on nearest neighbour distances and symmetry. The observed ordering is directly compared to Monte-Carlo simulations for hard-core/soft-shell particles, showing that the observed symmetries are a consequence of the soft interaction potential and differ qualitatively from a hard-sphere situation. For the silver-poly-(N-isopropylacrylamide) particles, we show UV-vis absorbance measurements revealing optical anisotropy of the generated structures due to plasmon coupling. Furthermore, the high degree of order of the assembled structures on macroscopic areas is demonstrated by laser diffraction effects.
authors.affiliation: Physical Chemistry II, University of Bayreuth, Universitaetsstrasse 30, 95447 Bayreuth, Germany.
authors.forename: Mareen
authors.initials: M
authors.lastname: Müller
authors.forename: Matthias
authors.initials: M
authors.lastname: Karg
authors.forename: Andrea
authors.initials: A
authors.lastname: Fortini
authors.forename: Thomas
authors.initials: T
authors.lastname: Hellweg
authors.forename: Andreas
authors.initials: A
authors.lastname: Fery
mesh_terms: D000178:Acrylamides / Q000737:chemistry* / Q000493:pharmacokinetics; D000180:Acrylic Resins / Q000737:chemistry / Q000493:pharmacokinetics; D011232:Chemical Precipitation; D006244:Hardness / Q000502:physiology*; D008863:Microspheres; D055616:Microtechnology / Q000379:methods; D008954:Models, Biological; D008968:Molecular Conformation; D057145:Nanoshells / Q000737:chemistry*; D058105:Polymerization; D011108:Polymers / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013499:Surface Properties
chemical_list: D000178:Acrylamides; D000180:Acrylic Resins; D011108:Polymers; C052970:poly-N-isopropylacrylamide; D012822:Silicon Dioxide; C067295:N-isopropylacrylamide