title: Influence of nanoparticle surface functionalization on the thermal stability of colloidal polystyrene films.
abstract: The installation of large scale colloidal nanoparticle thin films is of great interest in sensor technology or data storage. Often, such devices are operated at elevated temperatures. In the present study, we investigate the effect of heat treatment on the structure of colloidal thin films of polystyrene (PS) nanoparticles in situ by using the combination of grazing incidence small-angle X-ray scattering (GISAXS) and optical ellipsometry. In addition, the samples are investigated with optical microscopy, atomic force microscopy (AFM), and field emission scanning electron microscopy (FESEM). To install large scale coatings on silicon wafers, spin-coating of colloidal pure PS nanoparticles and carboxylated PS nanoparticles is used. Our results indicate that thermal annealing in the vicinity of the glass transition temperature T(g) of pure PS leads to a rapid loss in the ordering of the nanoparticles in spin-coated films. For carboxylated particles, this loss of order is shifted to a higher temperature, which can be useful for applications at elevated temperatures. Our model assumes a softening of the boundaries between the individual colloidal spheres, leading to strong changes in the nanostructure morphology. While the nanostructure changes drastically, the macroscopic morphology remains unaffected by annealing near T(g).
authors.affiliation: HASYLAB at DESY, Notkestr. 85, D-22607 Hamburg, Germany. gerd.herzog@desy.de
authors.forename: Gerd
authors.initials: G
authors.lastname: Herzog
authors.forename: Mottakin M
authors.initials: MM
authors.lastname: Abul Kashem
authors.forename: Gunthard
authors.initials: G
authors.lastname: Benecke
authors.forename: Adeline
authors.initials: A
authors.lastname: Buffet
authors.forename: Rainer
authors.initials: R
authors.lastname: Gehrke
authors.forename: Jan
authors.initials: J
authors.lastname: Perlich
authors.forename: Matthias
authors.initials: M
authors.lastname: Schwartzkopf
authors.forename: Volker
authors.initials: V
authors.lastname: Körstgens
authors.forename: Robert
authors.initials: R
authors.lastname: Meier
authors.forename: Martin A
authors.initials: MA
authors.lastname: Niedermeier
authors.forename: Monika
authors.initials: M
authors.lastname: Rawolle
authors.forename: Matthias A
authors.initials: MA
authors.lastname: Ruderer
authors.forename: Peter
authors.initials: P
authors.lastname: Müller-Buschbaum
authors.forename: Wilfried
authors.initials: W
authors.lastname: Wurth
authors.forename: Stephan V
authors.initials: SV
authors.lastname: Roth
mesh_terms: D003102:Colloids / Q000737:chemistry; D008567:Membranes, Artificial; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D011137:Polystyrenes / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature
chemical_list: D003102:Colloids; D008567:Membranes, Artificial; D011137:Polystyrenes