Tailored Surfaces
Functional layers via photonic processes — efficient and at low temperatures
We develop coating processes based on light-induced reactions. By using (V)UV radiation, functional coatings can be produced in a targeted manner at atmospheric pressure and low temperatures, which is particularly suitable for temperature-sensitive materials.
Photon-based coating at low temperatures
- Use of (V)UV radiation to initiate polymerization and conversion processes
- Deposition of organic, inorganic, and hybrid layers
- Processing at atmospheric pressure and low process temperatures
- Suitable for sensitive substrates such as polymers and functional coating systems
Control of coating properties via process parameters
- Investigation of photon-excited reaction and excitation mechanisms
- Establishment of parameter-effect relationships
- Targeted adjustment of structure, composition, and functionality
- Combination of process development and material characterization
Applications and industrial implementation
- Functional layers for barrier technologies, energy, mobility, and packaging
- Development of processes for temperature-sensitive materials and flexible systems
- Validation in feasibility studies and transfer to production-ready processes
Contribution to scalable coating technologies
- Coating at atmospheric pressure as an advantage for industrial integration
- Energy-efficient processes through low temperatures and photonic activation
- Basis for large-scale and cost-effective applications
- Close collaboration with industry partners for practical implementation
Projects
Accelerator – Accelerated aging of complex polymer barrier materials for the energy sector
Complex polymer materials used in lightweight components for the hydrogen economy or photovoltaics must often withstand demanding physical stresses in addition to the required chemical stability. One example is gas barrier layers, which can be deposited even on thermally sensitive substrates using light-driven coating technologies. The goal of the project is to better understand which structural properties of these materials enable them to be used safely over long periods of time. Gas barrier layers will be deposited on polymer and metallic substrates using UV-assisted coating processes and specifically exposed to application-relevant aging scenarios. The structural and chemical analysis of the material changes is intended to generate insights into material-structure relationships that can also be utilized by companies in Saxony’s economy. As a prerequisite for such investigations, experimental setups and methods for targeted material aging will be established and used to study coating systems.
Funded by the Free State of Saxony (SAB) as part of EFRE/JTF 2021–2027 with EU co-financing
Flexible Ceramic Barrier Coatings on Paper
The joint project “Glass-Meets-Paper,” a collaboration between the PTS Institute for Fibers & Paper and the Leibniz Institute of Surface Engineering (IOM), is developing novel barrier layers for paper. The goal is to apply highly effective, purely inorganic SiOₓ and hybrid barriers to flexible paper substrates. To achieve this, liquid precursor compounds are applied to the paper via a wet chemical process and then converted into functional barrier layers using high-energy UV radiation, known as excimer radiation. Since the process does not require a vacuum, it offers good prospects for subsequent integration and scaling up on paper machines.
Funded by IGF
Accelerator – Accelerated aging of complex polymer barrier materials for the energy sector
Complex polymer materials used in lightweight components for the hydrogen economy or photovoltaics must often withstand demanding physical stresses in addition to the required chemical stability. One example is gas barrier layers, which can be deposited even on thermally sensitive substrates using light-driven coating technologies. The goal of the project is to better understand which structural properties of these materials enable them to be used safely over long periods of time. Gas barrier layers will be deposited on polymer and metallic substrates using UV-assisted coating processes and specifically exposed to application-relevant aging scenarios. The structural and chemical analysis of the material changes is intended to generate insights into material-structure relationships that can also be utilized by companies in Saxony’s economy. As a prerequisite for such investigations, experimental setups and methods for targeted material aging will be established and used to study coating systems.
Funded by the Free State of Saxony (SAB) as part of EFRE/JTF 2021–2027 with EU co-financing
Publication highlights
P.C. With, T. Pröhl, J.W. Gerlach, A. Prager, A. Konrad, F. Arena, U. Helmstedt
Hydrogen permeation through uniaxially strained SiOx barrier thin films photochemically prepared on PET foil substrates
Int. J. Hydrogen Energy 81 (2024) 405-410, https://doi.org/10.1016/j.ijhydene.2024.07.249
Hydrogen permeation through uniaxially strained thin SiOx gas barrier films - which were prepared at room temperature and ambient pressure on PET film substrates via UV photochemical conversion (photoconversion) - was investigated using a specialized measurement system. The hydrogen permeation measurements were performed as a function of the number of laminated individual SiOx barrier films, the sample temperature, and the uniaxial mechanical stress applied to the samples. The results show a significant overall improvement in hydrogen barrier properties for both individual SiOx barrier films on PET and laminated individual SiOx barrier films on PET. Under strain, the hydrogen barrier properties decrease due to stress-induced cracking in the barrier films. This deterioration is most pronounced in stressed individual SiOx barrier films; however, it can be significantly reduced by laminating individual SiOx barrier films.
M. Rudolph, P. Birtel, T. Arnold, A. Prager, S. Naumov, U. Helmstedt, A. Anders, P.C. With
Low‐temperature atmospheric pressure plasma conversion of polydimethylsiloxane and polysilazane precursor layers to oxide thin films
Plasma Process Polym. (2023) e2200229, https://doi.org/10.1002/ppap.202200229
This work investigates the conversion of PDMS and polysilazane layers into SiOx films using an atmospheric pressure plasma. The process enables the production of high-quality oxide thin films at low temperatures, which is particularly relevant for coating temperature-sensitive polymer substrates.
P.C. With, U. Helmstedt, L. Prager
Flexible Transparent Barrier Applications of Oxide Thin Films Prepared by Photochemical Conversion at Low Temperature and Ambient Pressure
Frontiers Mater. 7 (2020) 200, https://doi.org/10.3389/fmats.2020.00200
This review article describes the potential of photochemically synthesized oxide layers for use as transparent gas barriers in flexible applications. The focus is on cost-effective photochemical synthesis at room temperature and atmospheric pressure, which enables their use on flexible polymer films for encapsulating displays or solar cells.
P.C. With, U. Helmstedt, S. Naumov, A. Sobottka, A. Prager, U. Decker, R. Heller, B. Abel, L. Prager
Low-Temperature Photochemical Conversion of Organometallic Precursor Layers to Titanium(IV) Oxide Thin Films
Chem. Mater. 28 (2016) 7715, https://doi.org/10.1021/acs.chemmater.6b02757
This article describes the synthesis of thin titanium(IV) oxide films at low temperature and ambient pressure through the photochemical conversion of organometallic precursors. By avoiding high temperatures, functional oxide films can be deposited on various substrates, including thermally sensitive polymer films.
Equipment
- MECADI Hydrogen permeation measurement system
- MOCON Oxygen transmission measurement system
- MOCON Water vapor transmission measurement system
- VM 502 VUV Spectrophotometer
- Various VUV and UV light sources for surface activation and UV curing of polymers
