@inproceedings{RoeskenRohrbeckCatenaetal., author = {R{\"o}sken, Liz M. and Rohrbeck, Magdalena and Catena, Alberto and Wehner, Stefan and Fischer, Christian B. and Richter, Matthias and St{\"a}dter, Matthias and Schmeißer, Dieter}, title = {Characterization of diamond-like carbon (DLC) coatings on industrial polyethylene and polyoxymethylene by SEM, AFM and NEXAFS}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, abstract = {Diamond-like carbon (DLC) coatings are often utilized to change the base properties of raw materials, e. g. to gain robust or chemically inert surfaces. Here the deposition of hard DLC layers on soft polymers is tested. The common industrial polymers polyethylene (PE) and polyoxymethylene (POM) serve as model substrates in the present work. In order to examine the effect of the carbonaceous layers on PE and POM thin diamond-like carbon films were realized via PECVD. The topography of the different coatings was detected by AFM and SEM uncovering the different influence of the substrate material, e. g. interlayer formation for PE. The composition of the surface structures were analyzed in more detail by NEXAFS, showing the hybridization of carbon atoms in chemical different surroundings from the pure polymer to the carbon coating. The comparison of carbon coated PE- and POM-composites enables valuable insights into the interaction between soft substrates and hard coatings. For the chosen settings in PECVD, POM showed incomplete coating, while on PE a very stable and robust composite has formed.}, language = {en} } @misc{FischerRohrbeckWehneretal., author = {Fischer, Christian B. and Rohrbeck, Magdalena and Wehner, Stefan and Richter, Matthias and Schmeißer, Dieter}, title = {Interlayer formation of diamond-like carbon coatings on industrial polyethylene: Thickness dependent surface characterization by SEM, AFM and NEXAFS}, series = {Applied Surface Science}, journal = {Applied Surface Science}, number = {271}, issn = {0169-4332}, doi = {10.1016/j.apsusc.2013.01.210}, pages = {381 -- 389}, abstract = {The coating of materials with diamond-like carbon (DLC) is a very common way to change and improve their basic characteristics. Although DLC is used on several substrates, the chemical and physical properties throughout the coating process on plastics are yet sparsely investigated. Two types of protective coatings one sp3-enriched (robust, r-type) and one with more sp2-centers (flexible, f-type) have been realized on polyethylene by PECVD deposition. SEM and AFM analysis of coated samples of DLC types revealed diverse surface topographies on different scales and images appeared even differently smoothed by the carbonaceous deposits. Grains of both DLC types are platelet-shaped and nearly double in size for the robust type indicating fundamental differences in the epitaxial DLC growth. NEXAFS spectroscopy showed significant details of carbon centers in chemically different neighborhood displaying a characteristic fingerprint behavior. Comparison of deposition models revealed a mechanism of interlayer formation which is discussed in detail. Interlayer formation is clearly the appropriate explanation of the process for the current carbon deposition between these two unequal materials. An improved understanding of hard DLC and soft polyethylene assembly is given in the presented work.}, language = {en} } @inproceedings{FischerRohrbeckWehneretal., author = {Fischer, Christian B. and Rohrbeck, Magdalena and Wehner, Stefan and Richter, Matthias and St{\"a}dter, Matthias and Schmeißer, Dieter}, title = {Interlayer formation of Diamond-Like Carbon Coatings on Polyethylene Plastic Material}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, abstract = {The coating of materials with diamond-like carbon (DLC) is a very common way to further improve and modify surface specific properties. Although DLC is frequently used as a protective coating on several substrates, the chemical and physical properties throughout the coating process on plastics are yet sparsely investigated. Different layer thicknesses of two types of protective coatings one sp3-enriched (robust, r-type) and one with more sp2-centers (flexible, f-type) have been realized on polyethylene by PECVD. Microscopic analysis showed diverse surface topographies for the two DLC-types. NEXAFS spectroscopy revealed significant details of carbon centers in chemically different neighborhood displaying a characteristic fingerprint behavior. The appropriate explanation for the current carbon deposition process is obviously the formation of an interlayer between these unequal materials. An improved understanding of hard DLC and soft polyethylene assembly is part of the present work.}, language = {en} } @inproceedings{RohrbeckFischerWehneretal., author = {Rohrbeck, Magdalena and Fischer, Christian B. and Wehner, Stefan and Richter, Matthias and Schmeißer, Dieter}, title = {Diamond-Like Carbon Coatings on Industrial Polyethylene Surfaces}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 47}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 47}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, abstract = {Synthetic materials are used in a wide variety of fields. Depending on the intended application the plastic material must meet specific requirements. Since the material always interacts with its environment, particular attention is required regarding the surface. Possible damage of the plastic material and further risks could be caused by the adhesion of bacteria, biofilm formation and encrustations. Therefore, bacteria-repellent coatings and surface-modified materials that allow for an effective removal of adhered bacteria are of extremely high interest for many applications. In this study Polyethylene (PE) is chosen as simplest model for relevant plastic materials. Surface modification of PE samples is accomplished by plasma-deposited diamond-like carbon (DLC) coatings to achieve increased abrasion strength and bacterial resistance. Two types of nanometer-scaled DLC films with different layer thicknesses are compared by multiscale microscopic analysis. Further spectroscopic measurements with synchrotron radiation are performed. These results will provide an enhanced understanding of layer formation at the interface between the basic plastic material and the DLC coating and will possibly lead to optimal parameters for the surface coating to achieve improved product characteristics.}, language = {en} } @inproceedings{FischerRohrbeckWehneretal., author = {Fischer, Christian B. and Rohrbeck, Magdalena and Wehner, Stefan and Richter, Matthias and Schmeißer, Dieter}, title = {Diamond-Like Carbon Coatings on Selected Plastic Materials}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 47}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 47}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, abstract = {The manufacturing of synthetic materials and their wide range of use for daily life is accompanied by essential requirements. Besides the basic performance of materials such as flexibility, elasticity, fracture strength and chemical resistance, further determinants are long term stability or biocompatibility. To overcome mismatches in surface characteristics of optimal parent material they can be customized for their intended use resulting in suitable coatings for profitable applications. The determining factor for such modifications is the preservation of basic material performance in addition to the benefit of further advantages like changed adhesive, improved repellent or antibacterial behavior. Protective coatings of selected plastic materials have been realized by depositing a few layers of diamond-like carbon (DLC). The assembly of soft plastic material and robust DLC coating is important for the resulting material characteristics. The detailed understanding of materials interphasing between these unequal materials and the conjunction of carbon centers in chemically different neighborhood is part of the presented work. Results will be transferable to other plastic materials with diverse needs, e.g. energy storage devices, water treatments and coatings for everyday commodities or industrial parts.}, language = {en} }