Icephobic Behaviour and Thermal Stability of Flame-Sprayed Polyethylene Coating: The Effect of Process Parameters
- 179 Downloads
The present work investigates the effect of different process parameters on the production of low-density polyethylene (LDPE) coatings by flame spray technology. Previously, flame spraying of polymers has been successfully performed to obtain durable icephobic coatings, providing an interesting solution for applications facing icing problems, e.g. in marine, aviation, energy, and transportation industry. However, the fine tailoring of the process parameters represents a necessary strategy for optimising the coating production due to the unique thermal properties of each polymer. For this purpose, we vary the heat input of the process during flame spraying of the coating, by changing the transverse speed and the spraying distance. The results show that the variation in the process parameters strongly influenced the quality of the polymer coating, including its areal roughness, thickness, chemical composition, thermal stability, and degree of crystallinity. Furthermore, we demonstrate that these properties significantly affect the icephobic behaviour of the surface within the spray window of the chosen parameters. In conclusion, the relationship between the thermal degradation of the polymer and the icephobicity of the surface was defined. This highlights the importance of process parameter optimisation in order to achieve the desired icephobic performance of the LPDE coatings.
Keywordsflame spraying ice adhesion strength icephobic surface polymer coating thermal degradation
The accumulation of ice and snow on outdoor structures represents a serious problem in Nordic regions as well as in several countries in both hemispheres (Ref 1). In fact, the atmospheric ice strongly adheres to bare surfaces and its accumulation contributes to compromising the effectiveness and efficiency of different applications, for example, power lines and electrical conductors during winter storms (Ref 2). Moreover, ice accretion on aircraft surfaces produces severe changes in their aerodynamic properties (Ref 3). Since the accumulation of ice represents an adverse impact on both safety and structure performances (Ref 4, 5), different strategies are developed to prevent ice adhesion on outdoor surfaces. Several active and passive methods have been adopted to avoid ice accumulation and reduce safety issues. On one hand, active methods include processes involving the mechanical removal of ice by scraping and vibrating the structure, the use of de-icing chemical fluids, and thermal heating above the freezing point (Ref 6). Unfortunately, these active methods produce environmental pollution, energy consumption, and ineffective manual operations. On the other hand, passive methods represent a smart strategy, which aims to develop efficient and durable anti-ice solutions. These methods consist of using icephobic material to coat the ice-exposed surfaces, preventing ice accumulation and consequent safety issues. Theoretically, the surface is considered as icephobic when it effectively reduces the adhesion strength of ice and prevents ice accumulation (Ref 7). In particular, the adhesion forces should be low in order to practically shed the ice off from the surface (Ref 8). However, only a few coatings have been achieved this, withstanding their durability (Ref 9).
The research and development of icephobic surfaces have been achieved a considerable interest in the speciality of coating design, during the last two decades (Ref 10, 11). Different coating technologies have been used for the production of icephobic surfaces, mainly chemical synthesis (Ref 12), sol–gel methods (Ref 13), and other laboratory-scale coating and painting processes. However, these methods generally require extended processing time, a large waste of chemicals, and controlled environmental conditions. Therefore, thermal spray technology represents a valid alternative to the chemical synthesis for the production of smart coatings (Ref 14). This technique aims to improve the performance of a component by adding a functionalised coating to the surface (Ref 15). Anti-corrosion (Ref 16-19), low friction and wear resistance (Ref 20-23), chemical and weathering resistance (Ref 24, 25), and antifouling (Ref 26, 27) represent some of the applications of the thermally sprayed coatings. In particular, flame spraying represents one of the thermal spray techniques used for the production of polymer coatings. In this process, the material in the form of powder is fed into a spray gun. The powder is injected into a combustion flame, which is used to melt the thermoplastic polymers during spraying. The melted particles hit the substrate, spread, and coalesce within each other to form a coating (Ref 28). The main advantage of flame spraying is that the melting and the consolidation of the polymer happen almost simultaneously during a single-step spraying process. Consequently, additional post-treatments are not necessary after the material deposition for the coating consolidation, such as post-curing at room temperature, ultraviolet radiation, or oven treatment, which are needed in some other surface technologies (Ref 9, 12). However, the temperature of the flame in thermal spraying is much higher than the melting temperature of polymers (Ref 29). Although specific equipment is available for flame spraying of polymers, a certain degree of material degradation always takes place during the flame processes (Ref 29). Therefore, fine tailoring of the process parameters is necessary to avoid the thermal degradation of the material, consisting of polymer chain scission, oxidation, surface embrittlement (Ref 30), and decrease in mechanical properties (Ref 29).
Our previous studies (Ref 31, 32) have demonstrated the icephobic property of thermally sprayed polymer coatings. For instance, polyethylene coatings showed potential icephobicity with ice adhesion value of 54 kPa for the polished surface (69 kPa for the as-sprayed surface). In addition, good coating durability was achieved for high-velocity impact test and particle erosion tests (Ref 31). Moreover, lubricant-infused porous coating (slippery liquid impregnated porous surface, SLIPS) showed extremely low ice adhesion (21 kPa for Thermally Sprayed SLIPS) and enhanced water repellency (Ref 32). However, further research is needed to optimise the manufacturing process of thermally sprayed icephobic coatings. Therefore, investigations are necessary on the effect of flame spraying parameters on the icephobicity of the surface. In particular, the process parameters strongly influence the performance of the coating (Ref 33). In addition, we have noticed that the chemical and thermal characterisations of the polymer coatings are essential in order to optimise the spray process for the selected purposes and coating requirements. Therefore, this study aims the optimisation of the process parameters to obtain an icephobic coating with preserved mechanical and structural properties. The influence of the process parameters on the coating properties was investigated by varying transverse speed and spraying distance of the spray gun for the polyethylene material. These parameters affect the heat input on the material during the process and thus the coating properties and its possible thermal degradation. In addition, the relationship between the icephobicity and the degradation of the coating is investigated, referring to the chemical and thermal characteristics of the flame-sprayed polymer coatings.
Materials and Methods
Material and Coating Fabrication
Microstructural and Surface Characterisation
The microstructure of the coating was analysed by a scanning electron microscope (SEM, Jeol, IT-500, Japan), investigating the presence of defects within the coating structure, such as voids and contaminations. In addition, energy dispersive x-ray spectroscopy (SEM/EDS) was used to obtain a semi-quantitative elemental composition (oxygen and carbon mass percentage, in the case of our material) in very specific locations of the cross section for coatings sprayed with different process parameters. For this test, the cross sections of the sample were coated by both carbon and gold sputtering to enhance the surface conductivity. The analysis was carried out by using an acceleration voltage of 10 kV in high vacuum by using a back-scattered electrons detector. This permitted the analysis of the coating chemical composition for different process parameters. Moreover, an optical microscope (Leica DM2500 M, Germany) was used to measure the thickness of the coating as an average of nine measurements in different points along the width of the specimen. The areal roughness (Sa) was measured with an optical profilometer (Alicona Infinite Focus G5, Alicona Imaging GmbH, Austria) by using 20× objective magnification in the areas of 2 × 2 mm2, according to ISO 4288 procedure. The texture of the surface was analysed by using 5× objective magnification in areas of approximately 30 × 30 mm2.
Ice Accretion and Ice Adhesion
Parameters of the icing wind tunnel
− 10 °C
The wettability of the surfaces was examined using a droplet shape analyser (DSA100, Krüss, Germany) to evaluate the static contact angle and the roll-off angle of the water droplets on the coating surface. The experiments were performed by pouring 6 µl water droplets of ultra-high purity water (MilliQ, Millipore Corporation, United States) onto the surfaces. The tendency of the water droplet to roll off from the surface was investigated by tilting experiment. In particular, the angle of inclination of the sample was measured when the droplet rolled off from the coating surface. The values were evaluated as an average of five measurements in different areas of the same coating surface at 21 °C and 60% relative humidity.
Chemical and Thermal Characterisations
Polymers are well-known heat-sensitive materials, and consequently, their structure is strongly influenced by the temperature reached by the material during flame spraying. This is mainly related to the time that the material spends in contact with the flame. In fact, the heat input of the process increases as the transverse speed and the spraying distance decreases (longer time process), producing possible oxidation and physical degradation of the sprayed polymer (Ref 34). For this reason, a thermal-processing window is recommended for each polymer to prevent excessive thermal degradation and consequently to ensure the quality of the coating. Therefore, chemical and thermal analyses of both the feedstock material and the coating were performed to analyse the possible thermal degradation produced by the process parameters, influencing the performance of the coating.
Fourier-Transform Infrared Spectroscopy (FTIR)
The chemical characterisation of the polymer powder and the variation in the chemical structure of the coatings were investigated by using Fourier-transform infrared spectroscopy (FTIR) (Bruker Tensor 27 FT-IR spectrometer, Bruker, Sweden). The FTIR spectra were measured at room temperature using an attenuated total reflection (ATR) spectrometer whereas the internal reflection element (IRE) was a diamond crystal. The degree of polymer oxidation was determined by monitoring the change in intensity of non-volatile carbonyl oxidation products. The intensity of the absorbance peak at 1713 cm−1 was taken as a measure of the concentration of carbonyl compounds derived by the polyethylene degradation (mainly carboxylic acids) (Ref 39, 40). All measurements were performed by using three samples taken from every coating surface.
Thermogravimetric Analysis (TGA)
The variations in the thermal stability of the coating within the spraying-process window were investigated by thermogravimetric analysis (TGA) (Netzsch TGA209F Tarsus, Netzsch, Germany). The specimen weight was approximately 10 mg and a dynamical heating was performed at 20 °C/min from 25 to 600 °C in nitrogen atmosphere. Firstly, the degradation temperature of the polymer powder was measured at the maximum deflection point of the TG curve. Secondly, the thermal stability of the coatings and their degradation degree were evaluated by comparing the temperatures at which the 2% (T98%), the 5% (T95%), and the 10% (T90%) of the mass of the coating were lost during the thermal heating (Ref 41). In particular, the lower these temperatures, the higher the degree of degradation of the polymer coating during flame spraying.
Differential Scanning Calorimetry (DSC)
Results and Discussion
Thermal spray technology, and especially flame spraying, represents a fast technique for the production of thermoplastic polymer coatings due to the advantage of the melting-consolidation transition of the polymer in one-step process. However, polymers are known to be heat-sensitive materials, and therefore, a thorough study is necessary to evaluate in detail the influence of the process parameters on the coating properties, such as thermal properties, mechanical performance, and durability. Moreover, the spray process parameters can influence the areal roughness of the coating, which has been considered as one of the main factors affecting the icephobicity of the surface (Ref 43, 44). For this reason, a compromise should be reached between the coating performances and the resulting surface properties affecting icephobicity, when selecting the process parameters.
Properties of LDPE powder
Particle size distribution
− 278 + 104 µm
Peak melting, T
Microstructural and Surface Properties of the Coatings
Icephobicity and Wettability of the Coating Surface
The results showed a strong influence of the process parameters on the icephobicity of the coating surfaces. Firstly, for the slowest transverse speed (from A0 to A2), ice adhesions represented the highest values obtained in this study. The ice adhesion decreased with decreasing areal roughness according to the previous research (Ref 37, 53, 54). In particular, samples A resulted in the highest ice adhesion here, despite they represented the smoothest surfaces in comparison with the other coatings. This indicates that other factors are affecting the icephobicity of the surface in addition to areal roughness. Secondly, with the medium transverse speed (B1 and B2), no clear relation was found between the ice adhesion and the areal roughness. Thirdly, the lowest ice adhesion is reached with the specimen C1 (32 ± 3 kPa), showing an optimal combination of parameters in the process window of this study.
The wettability properties of the polyethylene coatings
Water contact angle, °
Water roll-off angle, °
Chemical and Thermal Properties
In flame spraying, the combustion flame melts the polymer powder and the coating is formed by the molten particles hitting into the substrate surface (Ref 28). However, this flame causes the degradation of the polymer powder, especially for the smallest powder particles that do not withstand the flame temperature (they produce “sparks” in the flame). Moreover, the slowest transverse speed increases the time of the process, increasing the coating temperature (Ref 33). Consequently, degradation occurs by the mechanism of chain scission (producing short polymer chains and decreasing the molecular weight) and oxidation (Ref 29, 30, 58). The oxidation of thermally sprayed material is temperature and time-dependent process (Ref 28, 29, 59). The greater the time of exposition of the polymeric material to the flame, the higher the effect of the thermal oxidation in the deposited material. Two types of oxidation processes can be distinguished during the thermal spray process. Firstly, the oxidation process of the polymer powder occurs during the spraying of the powder passing the flame, known as in-flight oxidation. Secondly, the oxidation of the polymer splats, already deposited on the substrate, can happen during the coating formation. However, different researchers underlined the fundamental difficulty of separating the effect of these two stages of oxidation (Ref 28). The substrate temperature increases with increasing process time and decreased spraying distance (Ref 29, 60). For this reason, the chemical and thermal characterisations were needed for the flame-sprayed coatings to avoid the damage of mechanical properties, such as toughness and strength, and embrittlement of the coating surface (Ref 33).
To compare the effect of process parameters on polymer degradation, the time the polymer is exposed to elevated temperatures was approximately estimated. The time of exposition of the in-flight particles to the flame can be considered of the same order for every produced coating, as the polymer particles passed through the same combustion flame with the same velocity. Therefore, the main effect of degradation would directly depend on the oxidation of the polymer splats on the substrate during the coating deposition. This oxidation mainly depends on the combination of process parameters chosen for the coating production, such as the transverse speed and the spraying distance. The transverse speed mostly influences the duration of the process and the spraying distance mainly controls the temperature reached by the substrate during the process. For a chosen spraying distance, the lower the transverse speed, the higher the degree of thermal oxidation experienced by the coating (see absorbance value between A1, B1, C1 and A2, B2, C2 in Fig. 8). Moreover, for a chosen transverse speed, the lower the spraying distance, the higher the temperature reached by the substrate, the higher the degree of oxidation of LPDE coatings (see absorbance value between A0, A1, A2 and B1, B2 in Fig. 8). Previously, FTIR analysis verified the increase in carbonyl and carboxyl compounds (containing oxygen element) limited at the coating surface for different spraying parameters. To support this, the energy dispersive x-ray spectroscopy (SEM/EDS) was used to evaluate the possible presence of carbonyl compounds (containing oxygen) in the coating structure. The mass percentage of oxygen was measured to be 14 ± 1 and 8 ± 0.5% for samples A0 and C2, respectively. These values corresponded to the average of three measurements analysed from the coating cross section. In particular, sample A0 showed a higher amount of oxygen in the coating structure, confirming the greater level of degradation produced during the process.
Results of the thermogravimetric analysis
For all the test samples, no relevant mass loss was measured below 150 °C, confirming the absence of moisture within the material and ensuring that the evaluated mass loss was referring only to the polymer chain degradation. Firstly, the results showed a good initial thermal stability of the powder that could withstand the temperature of 427 °C by evaporating only 2% of its total mass. In fact, the higher the value of T98%, the greater the thermal stability of the coating. Secondly, this good thermal stability was generally reduced for all the produced coatings. Therefore, the stability was decreased for the A specimens, confirming the highest degree of degradation for the sample sprayed with the closer distance, A0. For medium transverse speed (B1), the thermal stability of the coating slightly improved in comparison with the coatings sprayed with 500 mm/s. Moreover, even lower degradation was revealed for the sample C2, showing the loss of mass of 2% around 417 °C. This behaviour was reproduced for all the coating, also if we consider the temperatures at 5% mass loss (T95%) and 10% mass loss (T90%) in Table 4. These results strongly confirmed the decrease in thermal stability of the coating with the increased heat input on the polymer during the process. In fact, with decreasing transverse speed and spraying distance, the substrate can heat-up for a longer period of time, producing thermal degradation of the coating.
Melting temperatures and degree of crystallinity of LDPE powder and flame-sprayed coatings
The degree of crystallinity was strongly influenced by the heat input of the process for the samples A0, A1, and A2, increasing from 29 to 40%. A slightly further increase was revealed for samples B, and then, the degree of crystallinity was independent of the chosen process parameters for the coldest temperatures. We can generally conclude that the thermal degradation of the polymer negatively influenced its degree of crystallinity within the considered process window. Moreover, the variation in the degree of crystallinity due to thermal degradation strongly influenced the mechanical properties of the polyethylene, such as its tensile strength, ductility, stiffness, and toughness (Ref 62). In addition, the barrier properties of the coating, such as permeability to air and moisture, represent an important aspect in relation to the ice adhesion of the coating. The previous studies have shown that the permeability of thermally aged PE film increases for both moisture and air, showing a decrease in the barrier properties of the material (Ref 68). In fact, the higher permeability of water within the coating structure could be easily related to the tendency of supercooled droplets to penetrate the surface. However, these properties were not investigated in this study. Therefore, it cannot be excluded that they could be connected with the reduction in the icephobic behaviour of the surface with increasing thermal degradation. We can conclude that the thermal degradation of the polymer is correlated with the icephobicity of the surface, showing the higher ice adhesion strength for the most degraded polymer surfaces. However, further investigations are necessary to evaluate which aspect of thermal degradation, such as chain scission, oxidation, or surface embrittlement, directly influences the surface icephobicity.
In this study, icephobic LDPE coatings were produced with flame spraying by varying the heat input during coating processing. This was done by changing the transverse speed and the spraying distance of the spray gun. The optimisation of the parameters for the icephobic application was achieved through the process window designed for the LDPE coatings. In particular, it was found that the process parameters strongly affected the areal roughness of the coatings and the heat input during the production process. This increased the thermal degradation of the polymer coating, compromising its thermal stability, degree of crystallinity, and consequently its icephobic behaviour. For this reason, the heat input should be monitored during flame spraying of polymeric material to avoid the decrease in the coating properties. Here, we found that the most icephobic coating (ice adhesion strength 32 ± 3 kPa) was produced by using 900-mm/s transverse speed and 250-mm spraying distance. The areal roughness affected the ice adhesion, but no clear relationship was established for these samples. However, the thermal effect was shown to represent the main factor influencing the icephobicity of the coating. The heat input of the process influences both on the areal roughness and the thermal degradation of the coating. The higher the processing temperature of the polymer, the smoother the surface produced and the greater the material degradation. Connections were found between the thermal properties of the LDPE coating and the icephobic characteristic of the surface. In particular, an increase in the coating degradation (intensity of the absorbance peak at 1713 cm−1) was strongly correlated with the decrease in the icephobicity for certain heat-input limit. After that, coatings achieve a relatively stable behaviour within the property deviation. Similarly, the degree of crystallinity increased as the degree of thermal degradation decreased and a good relationship was found with the decrease in ice adhesion until the limit. Moreover, this study showed that thermal stability is necessary for higher ice adhesion performance. This can be assumed to be one of the dominant factors in flame spraying of polymers. However, the coating degradation can be caused during both spraying and post-heating steps for these samples. Therefore, to understand better the effect of the process steps on the coating quality, further investigations will focus on their influence on the coating degradation and consequently on the icephobicity of the surface.
Authors thank the LubISS (Lubricant Impregnated Slippery Surfaces) project that has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant Agreement No. 722497. Mr. Anssi Metsähonkala of Tampere University is acknowledged for operating the flame spray process, M.Sc. Jarmo Laakso of Tampere University for the SEM/EDS analysis, and M.Sc. Matteo Orlandini of Millidyne Oy for the particle size analysis. M.Sc. Henna Niemelä-Anttonen and B.Sc. Enni Hartikainen of Tampere University are thanked for assisting the ice accretion and the ice adhesion testing.
- 4.X. Huang, N. Tepylo, V. Pommier-Budinger, M. Budinger, E. Bonaccurso, P. Villedieu, and L. Bennani, A Survey of Icephobic Coatings and Their Potential Use in a Hybrid Coating/Active Ice Protection System for Aerospace Applications, Prog. Aerosp. Sci., 2019, 105, p 74-97. https://doi.org/10.1016/j.paerosci.2019.01.002 CrossRefGoogle Scholar
- 15.N. Espallargas, Future Development of Thermal Spray Coatings: Types, Designs, Manufacture and Applications, Elsevier, Cambridge, 2015, https://doi.org/10.1016/B978-0-85709-769-9.00006-3 CrossRefGoogle Scholar
- 17.C.C. Berndt, D. Otterson, M.L. Allan, C.C. Berndt, and D. Otterson, Polymer Coatings for Corrosion Protection in Biochemical Treatment of Geothermal Residues, Geotherm. Resour. Counc. Trans., 1998, 22, p 425-429Google Scholar
- 19.X. Chen, J. Yuan, J. Huang, K. Ren, Y. Liu, S. Lu, and H. Li, Large-Scale Fabrication of Superhydrophobic Polyurethane/Nano-Al2O3 Coatings by Suspension Flame Spraying for Anti-Corrosion Applications, Appl. Surf. Sci., 2014, 311, p 864-869. https://doi.org/10.1016/j.apsusc.2014.05.186 CrossRefGoogle Scholar
- 20.R.A.X. Nunes, S. Wagner, and J.R.T. Branco, Atrito e Desgaste de Recobrimentos de PET, Politeraftalato de Etileno, Pós-Consumo Processados Por Aspersão Térmica (Friction and Wear of Polyethylene Terephthalate (PET) coating after consumption processed by thermal spraying), Polímeros Ciência e Tecnol., 2007, 17(3), p 244-249 ((In Portuguese))CrossRefGoogle Scholar
- 24.L.D. Stephenson, A.D. Beitelman, R.G. Lampo, A. Kumar, D. Neale, L. Clark, K. Palutke, M. Surratt, and D. Butler, Demonstration of Thermally Sprayed Metal and Polymer Coatings for Steel Structures at Fort Bragg, NC, No. ERDC/CERL TR-17-30, ERDC-CERL Champaign United States, 2017Google Scholar
- 25.P.J. Loustaunau and D. Horton, EMAA Thermoplastic Powder Coatings: Shop and Field Applications of Powder Coatings for Aggressive Environments, No. CONF.-94022-, NACE International, Houston, TX (United States), 1994. https://www.osti.gov/biblio/70079
- 26.Z. Jia, Y. Liu, Y. Wang, Y. Gong, P. Jin, X. Suo, and H. Li, Flame Spray Fabrication of Polyethylene-Cu Composite Coatings with Enwrapped Structures: A New Route for Constructing Antifouling Layers, Surf. Coat. Technol., 2017, 309, p 872-879. https://doi.org/10.1016/j.surfcoat.2016.10.071 CrossRefGoogle Scholar
- 27.M. Zhai, Y. Gong, X. Chen, T. Xiao, G. Zhang, L. Xu, and H. Li, Mass-Producible Hydrophobic per Fl Uoroalkoxy/Nano-Silver Coatings by Suspension Fl Ame Spraying for Antifouling and Drag Reduction Applications, Surf. Coat. Technol., 2017, 328, p 115-120. https://doi.org/10.1016/j.surfcoat.2017.08.049 CrossRefGoogle Scholar
- 32.H. Niemelä-Anttonen, H. Koivuluoto, M. Kylmälahti, J. Laakso, and P. Vuoristo, Thermally Sprayed Slippery and Icephobic Surfaces, ITSC2018-Proceedings of the International Thermal Spray Conference, F. Azarmi, K. Balani, T. Eden, T. Hussain, Y.-C. Lau, H. Li, and K. Shinoda, Ed., ASM International, Orlando, 2018, p 380-384 Google Scholar
- 35.H. Koivuluoto, C. Stenroos, R. Ruohomaa, G. Bolelli, L. Lusvarghi, and P. Vuoristo, Research on Icing Behavior and Ice Adhesion Testing of Icephobic Surfaces, Proceedings of 16th International Workshop on Atmospheric Icing of Structures-IWAIS XVI, Jun 28–Jul 3, (Uppsala, Sweden), 2015, p 6Google Scholar
- 38.C. Stenroos, P. Vuoristo, and H. Koivuluoto, “Properties of Icephobic Surfaces in Different Icing Conditions,” Master thesis, Tampere University Technology, Tampere, Finland, 2015Google Scholar
- 39.S. Therias, J.-L. Gardette, B. Pukánszky, T. Janecska, A. Perthue, M. Gardette, and E. Földes, Photo- and Thermal-Oxidation of Polyethylene: Comparison of Mechanisms and Influence of Unsaturation Content, Polym. Degrad. Stab., 2013, 98(11), p 2383-2390. https://doi.org/10.1016/j.polymdegradstab.2013.07.017 CrossRefGoogle Scholar
- 45.C. Laforte and J.-L.J. Laforte, Tensile, Torsional and Bending Strain at the Adhesive Rupture of an Iced Substrate, Proceedings of the 28th International Conference on Ocean, Offshore and Arctic Engineering - OMAE 2009, May 31–Jun 5, (Honolulu, Hawaii, USA), ASME, 2009, p 79–86Google Scholar
- 52.H. Niemelä-Anttonen, H. Koivuluoto, M. Tuominen, H. Teisala, P. Juuti, J. Haapanen, J. Harra, C. Stenroos, J. Lahti, J. Kuusipalo, J.M. Mäkelä, and P. Vuoristo, Icephobicity of Slippery Liquid Infused Porous Surfaces under Multiple Freeze-Thaw and Ice Accretion-Detachment Cycles, Adv. Mater. Interfaces, 2018, 5(20), p 1800828. https://doi.org/10.1002/admi.201800828 CrossRefGoogle Scholar
- 53.R.J. Scavuzzo and M.L. Chu, Structural Properties of Impact Ices Accreted on Aircraft Structures, NASA Cr-179580, NASA-Lewis Research Centre, Cleveland, 1987Google Scholar
- 59.R. Perrin and J.P. Scharff, Chimie Industrielle, 2nd ed., Industrial Chemistry, Masson, 1997 ((In French))Google Scholar
- 68.C. Li and S.L. Xiao, Effects on the Properties of Polyethylene Film Aging by Different Methods, Adv. Mater. Res., 2013, 830, p 49-52. https://doi.org/10.4028/www.scientific.net/AMR.830.49 CrossRefGoogle Scholar
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.