Polymers have a reputation for several advantageous characteristics like chemical resistance, weight reduction, and simple form-giving processes. The rise of additive manufacturing technologies such as Fused Filament Fabrication (FFF) has introduced an even more versatile production process that supported new product design and material concepts. This led to new investigations and innovations driven by the individualization of customized products.
View Article and Find Full Text PDFWe present an analysis of dielectric spectra measured for a specially designed non-polymeric asymmetric binary glass former characterized by a large difference of the component's T (ΔT = 216 K). We cover the whole additive concentration range from 4% up to 90% (by mass). Two main relaxations α and α are identified, which are characterized by well separated time scales and are attributed to the dynamics associated with the high-T component (α) and the low-T component (α).
View Article and Find Full Text PDFA series of high-Tg glass formers with Tg values varying between 347 and 390 K and molar masses in the range of 341 and 504 g mol-1 are investigated by dielectric spectroscopy. They are compared to paradigmatic reference systems. Differently polar side groups are attached to a rigid non-polar core unit at different positions.
View Article and Find Full Text PDFThe glass transition temperature () of a molecular glass depends on its molar mass. However, the nature of intermolecular interactions also plays a major role in both the glass transition temperature and its glass-forming ability. In this context, we report on novel molecular glasses containing nitrile groups and investigate the influence of this highly polar group on and the glass-forming ability.
View Article and Find Full Text PDFAlignment of nanoparticles to hierarchical periodic structures is an emerging field in the development of patterned surfaces. Common alignment methods are based on templates that guide particle self-assembly. These can be formed using lithographic methods offering an almost free choice of the motif, while being expensive and time-consuming for large-scale production.
View Article and Find Full Text PDFControlled wrinkling is a rather simple method of fabricating surface topographies. The production process is based on the spontaneous formation of wrinkles upon compression of a hard film attached to a soft elastic substrate. Controlled wrinkling typically features large-scale wrinkled samples with a discrete wavelength and amplitude.
View Article and Find Full Text PDFA novel nanoimprint lithography technique based on the photofluidization effect of azobenzene materials is presented. The tunable process allows for imprinting under ambient conditions without crosslinking reactions, so that shrinkage of the resist is avoided. Patterning of surfaces in the regime from micrometers down to 100 nm is demonstrated.
View Article and Find Full Text PDFFast concentration-induced diffusion-limited lyotropic phase transitions can be studied in situ with millisecond time resolution using continuous flow microfluidics in combination with microfocus small-angle X-ray scattering. The method was applied to follow a classical self-assembly sequence where amphiphiles assemble into micelles, which subsequently assemble into an ordered lattice via a disorder/order transition. As a model system we selected the self-assembly of an amphiphilic block copolymer induced by the addition of a nonsolvent.
View Article and Find Full Text PDFIn this article we present several developed and improved combinatorial techniques to optimize processing conditions and material properties of organic thin films. The combinatorial approach allows investigations of multi-variable dependencies and is the perfect tool to investigate organic thin films regarding their high performance purposes. In this context we develop and establish the reliable preparation of gradients of material composition, temperature, exposure, and immersion time.
View Article and Find Full Text PDFStar block copolymers are demonstrated for their application as a high-performance resist material. This new resist material shows advanced progress in sensitivity and solubility contrast and is finally combinatorially optimized to achieve a 66 nm line/space pattern. The tailored molecular architecture of the star block copolymer is synthesized via core-first atom transfer radical polymerization (ATRP) and shows narrow polydispersity indices below 1.
View Article and Find Full Text PDFElectron beam lithography is a powerful technique for the production of nanostructures but pattern quality depends on numerous interacting process variables. Orthogonal gradients of resist composition, baking temperatures, and development time as well as dose variations inside writing fields are used to prepare ternary combinatorial libraries for an efficient stepwise optimization of a molecular glass negative tone resist system.
View Article and Find Full Text PDFPhotoresists based on molecular glasses are gaining more and more importance as resist material to replace polymer based photoresist. In addition environmental issues have to be considered in the long-term. Therefore the paper describes novel negative photoresists containing a ternary mixture of a glassy low molecular functional polyphenol where the film preparation is possible by solvent-free physical vapor deposition.
View Article and Find Full Text PDFIn this article we present a setup for the combinatorial vapor deposition of thin-film multilayer devices as well as methods for the fast and efficient analytic screening of the libraries obtained. The preparation setup is based on a commercially available evaporation chamber equipped with various evaporation sources for both organic and metallic materials. The combinatorial approach is realized by the combination of a rotation stage for the substrate, a five-mask sampler, and an additional mask whose position can be deliberately varied along one axis during the evaporation process.
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