Ice adhesion tests are widely used to assess the performance of potential icephobic surfaces and coatings. A great variety of test designs have been developed and used over the past decades due to the lack of formal standards for these types of tests. In many cases, the aim of the research was not only to determine ice adhesion values, but also to understand the key surface properties correlated to low ice adhesion surfaces. Data from different measurement techniques had low correspondence between the results: Values varied by orders of magnitude and showed different relative relationships to one another. This study sought to provide a broad comparison of ice adhesion testing approaches by conducting different ice adhesion tests with identical test surfaces. A total of 15 test facilities participated in this round-robin study, and the results of 13 partners are summarized in this paper. For the test series, ice types (impact and static) as well as test parameters were harmonized to minimize the deviations between the test setups. Our findings are presented in this paper, and the ice- and test-specific results are discussed. This study can improve our understanding of test results and support the standardization process for ice adhesion strength measurements.

In this study, we assessed the effects of ice types, test parameters, and surface properties on measurement data of the ice adhesion centrifuge test. This method is often used for the evaluation of low ice adhesion surfaces, although no test standard has been defined yet. The aim of this paper is to improve the understanding of the relevant test parameter and identify crucial criteria to be considered in harmonization and standardization efforts. Results clearly indicate that the ice type (static vs. impact ice) has the greatest impact on the test results, with static ice delivering higher values in a broader data span. This is beneficial for material developers as it eases the evaluation process, but it contradicts the technical efforts to design tests that are as close as possible to realistic technical environments. Additionally, the selected ice type has a significant impact on the relevance of the surface properties (roughness, wettability). Despite the complexity of interactions, a trend was observed that the roughness is the determining surface parameter for high impact velocity ice (95 m/s). In contrast, for tests with static ice, the wettability of the test surface is of higher relevance, leading to the risk of overestimating the icephobic performance of structured surfaces. The results of this paper contribute to the demanding future tasks of defining well-founded test standards and support the development of icephobic surfaces.

Significant progress in the field of icephobic coatings has raised a demand for evaluation criteria to assess and monitor the related icephobic effects and their durability. The initial coating performance in preventing ice formation and reducing ice adhesion needs to be proven over a given period by withstanding technically relevant stressors. In this study, silanized polyurethane (PUR) coatings are assessed in conjunction with a standardized accelerated ultraviolet (UV)-ageing procedure in order to identify potential monitoring tools that are also applicable during in-service inspections. Wettability and roughness parameters are recorded after pre-defined ageing intervals, compared with the ice adhesion strength, and tested using a modified centrifuge. Correlation assessments indicate that the chosen parameters cannot generally be used for the monitoring of icephobic effects for the selected material class. It is more likely that specific coating parameter sets need to be defined for in-service monitoring, as an important step towards the integration of icephobic coatings into technical applications.

Organically modified layered silicates can be used as barrier pigments in organic coating systems to reduce the permeation of water vapor and gases, e.g., oxygen as well as harmful gases that promote corrosion. Unmodified layered silicates are not sufficient to reduce the permeation significantly. However, the arrangement and orientation of the particles have an enormous impact on the later performance in the barrier film. In organic solvents or non‐aqueous polymer matrices the non‐modified layered silicates cannot exfoliate adequately. The organic modification influences the layer spacing and the compatibility to organic solvents. Layered silicates are modified with dodecylamine to enhance the spacing layer. The spacing layer is enhanced by 55% caused by the organic modification as it is commonly known. In contrast to previous work freeze drying of the organically modified layered silicates improved the particle distribution and by this barrier properties significantly. The modified particles reduce the diffusion of water and oxygen by ≈99.6% and 97.2%, respectively. The corrosive gas test of electronic circuit boards shows no growth of dendrites and no failure of the electronics in contrast to protective coating without the layered silicates.