Nanoparticles in Block-Copolymer Films Studied by Specular and Off-Specular Neutron Scattering

Abstract

For the design of multicompositional materials with a spatially defined order of different components symmetric polystyrene(deuterated)-block-polybuthyl methacrylate P(Sd-b-BMA) lamellar thin films are used as a structure-directing matrix for the nanoparticle arrangement. A P(Sd-b-BMA) diblock-copolymer film spontaneously self-assembles upon annealing into a lamellar multilayer and orders the PS-coated nanoparticles, incorporated into the polymer solution prior to annealing, in a periodic lamellar structure. Specular reflection and off-specular neutron scattering were applied to determine the distribution of magnetite Fe3O4 nanoparticles in a symmetric P(Sd-b-BMA) film with a concentration of the nanoparticles of 7% of the volume fraction. From the experiments on neutron specular reflection and off-specular scattering, we obtained information about the distribution of the nanoparticles within the lamellae and about the distortion of the lamellar order of the copolymer matrix. LA026818A

Elastic torsion effects in magnetic nanoparticle diblock-copolymer structures

“…Lauter-Pasyuk et al examined the structure of thin lamellae forming diblock-copolymer films with incorporated polymer-coated nanoparticles. Due to polystyrene coating of the nanoparticles, a well controlled spatial distribution of the nanoparticles within the film was achieved [20,21]. Here we focus on thick diblock-copolymer films with a heterogeneous inner morphology.…”

“…The average nanoparticle diameter is d 0 = 10 nm as determined with scattering experiments. Since the nanoparticles are coated with polystyrene, they show an affinity to the polystyrene blocks [20,24]. Samples with nanoparticle weight concentrations of c = 0, 0.7, 2, 4, 8, 14, 16, 18, 20, 25 and 43 wt% were prepared by the solution casting technique to allow for an equilibration of the morphology.…”

Analysis of biosurfaces by neutron reflectometry: From simple to complex interfaces

“…90,91 A two-dimensional intensity map as a function of p i (p i ¼ 2p sin a i /k) and p f (p f ¼ 2p sin a f /k), where a i and a f are the angles of the incoming and outgoing neutrons, respectively, and k is the wavelength of the neutrons, clearly highlights the dominating intensity peak at p i À p f ¼ 0 corresponding to the specular reflection, but also allows for the visualization of the off-specular scattering. 92 The latter indicates the presence of surface and substrate roughness and nicely showcases any developments in in-plane fluctuations due to changing experimental conditions.…”

Hybrid Photovoltaics – from Fundamentals towards Application

“…[155,156] As a consequence, such block copolymers can be used to create well-defined microstructures and morphologies, either by sacrificial templating or as structure directing agents in a hybrid blend system. [157][158][159][160][161][162][163][164][165] Beyond the novel approaches, which are offered by the use of block copolymers, also the similar strategies as established in the usage of homopolymers can be applied when using block copolymers. Thus, a nanocomposite approach can be done to form the BHJ active layer or a pre-structuring of the inorganic materials followed by a backfilling with the organic one can be selected also when using block copolymers.…”