PSI - Issue 40

I.A. Morozov et al. / Procedia Structural Integrity 40 (2022) 314–320 I.A. Morozov et al. / Structural Integrity Procedia 00 (2022) 000 – 000

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layer occurs) and then with the required modifier: a mixture of argon and acetylene for 30...120 seconds. As a result, a stiff heterogeneous nanocoating with a thickness of 1.5...3 nm was formed on the surface with contrasting structural-mechanical properties: areas of elevations and depressions with different stiffness. In the process of uniaxial fatigue loading, nanodefects (local nanocracks) originate and develop on the surfaces of treated materials. They become visible when the previously deformed material is stretched; in the unloaded state, folds appear in place of the cracks. One of the surfaces (treatment with 60 s in Ar/C 2 H 2 plasma) did not show cracking, which is related to the ratio of the elastic moduli of hard and relatively soft parts of the surface. These plasma-treated materials have increased wettability and surface free energy, which makes them promising for further development of deformable products for biomedical applications. Acknowledgements This work was supported by the Russian Science Foundation grant 17-79-20042. References Alves, P., Pinto, S., de Sousa, H.C., Gil, M.H., 2011. Surface modification of a thermoplastic polyurethane by low-pressure plasma treatment to improve hydrophilicity. Journal of Applied Polymer Science 122, 2302 – 2308. Barz, J., Haupt, M., Oehr, C., Hirth, T., Grimmer, P., 2019. Stability and water wetting behavior of superhydrophobic polyurethane films created by hot embossing and plasma etching and coating. Plasma Processes and Polymers 16, 1800214. Beliaev, A., Svistkov, A., Iziumov, R., Osorgina, I., Kondyurin, A., Bilek, M., McKenzie, D., 2016. Modelling of the mechanical behavior of a polyurethane finger interphalangeal joint endoprosthesis after surface modification by ion implantation. IOP Conference Series: Materials Science and Engineering 123, 012001. Carvalho, F.H.O., Vaz, A.R., Moshkalev, S., Gelamo, R.V., 2015. Syntesis of Carbon Nanostructures Near Room Temperature Using Microwave PECVD. Materials Research 18, 860 – 866. Cuong, N.K., Tahara, M., Yamauchi, N., Sone, T., 2003. Diamond-like carbon films deposited on polymers by plasma-enhanced chemical vapor deposition. Surface and Coatings Technology 174 – 175, 1024 – 1028. Kojio, K., Kugumiya, S., Uchiba, Y., Nishino, Y., Furukawa, M., 2009. The microphase-separated structure of polyurethane bulk and thin films. Polymer Journal 41, 118 – 124. López - García J., 2019. Wettability analysis and water absorption studies of plasma activated polymeric materials. In Non-Thermal Plasma Technology for Polymeric Materials. Elsevier, 261 – 285. Michelmore, A., Whittle, J.D., Short, R.D., 2015. The importance of ions in low pressure PECVD plasmas. Frontiers in Physics 3, Article #3. Morozov, I.A., Mamaev, A.S., Bannikov, M.V., Beliaev, A.Yu., Osorgina, I.V., 2018. The fracture of plasma-treated polyurethane surface under fatigue loading. Coatings 8, paper #75. Morozov, I.A., Kamenetskikh, A.S., 2019. Structural-mechanical AFM study of inhomogeneous stiff nanocoating of soft polymer substrate. IOP Conference Series: Materials Science and Engineering 699, 012031. Morozov, I.A., 2021. Atomic force microscopy nanoindentation kinetics and subsurface visualization of soft inhomogeneous polymer. Microscopy Research and Technique 84, 1959 – 1966. Ozdemir, Y., Hasirci, N., Serbetci, K., 2002. Oxygen plasma modification of polyurethane membranes. Journal of Materials Science: Materials in Medicine 13, 1147 – 1152. Tsougeni, K., Tserepi, A., Boulousis, G., Constantoudis, V., Gogolides, E., 2007. Control of nanotexture and wetting properties of polydimethylsiloxane from very hydrophobic to super-hydrophobic by plasma processing. Plasma Processes and Polymers 4, 398 – 405. Tsubone, D., Hasebe, T., Kamijo, A., Hotta, A., 2007. Fracture mechanics of diamond-like carbon (DLC) films coated on flexible polymer substrates. Surface and Coatings Technology 201, 6423 – 6430. Wilson, D.J., Rhodes, N.P., Williams, R.L., 2003. Surface modification of a segmented polyetherurethane using a low-powered gas plasma and its influence on the activation of the coagulation system. Biomaterials 24, 5069 – 5081.