{Fabrication of superhydrophobic surfaces by laser surface texturing and autoxidation:} http://dx.doi.org/10.5599/jese.1260 639 J. Electrochem. Sci. Eng. 12(4) (2022) 639-649; http://dx.doi.org/10.5599/jese.1260 1 2 Open Access : : ISSN 1847-9286 3 www.jESE-online.org 4 Original scientific paper 5 Fabrication of superhydrophobic surfaces by laser surface 6 texturing and autoxidation 7 Vijay Kumar, Rajeev Verma and Harish Kumar Bairwa 8 Industrial and Production Engineering Department, Dr B R Ambedkar National Institute of 9 Technology Jalandhar, Punjab, India-144011 10 Corresponding author: vknitj94@gmail.com 11 Received: January 7, 2022; Accepted: March 11, 2022; Published: May 4, 2022 12 13 Abstract 14 The creation of superhydrophobic surfaces (SHS) has received exceptional thought from the 15 entire research community due to its notable application in varied fields such as anti-icing, 16 self-cleaning, drag reduction, anti-bacterial, and oil-water separation. The superhy-17 drophobic (SH) conditions for a surface can be attained through the consolidation of a low 18 surface energy surface with appropriate micro/nano-surface roughness through texturing. 19 Motivated by the SH nature of lotus leaf and petal effect, microstructures have been 20 prepared in this work on a metal surface by a fiber laser marking machine at 35 W. The 21 textured surfaces with a different pitch to diameter (p/d) ratio (2.0-0.70) have been turned 22 into hydrophobic and finally SH, after storing in an ambient environment for a few days due 23 to oxide layer deposition on the textured surface. In this study, the maximum contact angle 24 achieved by textured geometry after 30 days of auto-oxidation was 158.6 o. Further, test 25 results showed that the fabricated surfaces have a high potential to maintain their SH 26 nature even after the harsh condition of applications. 27 Keywords 28 Antibacterial; oxide layer deposition; texturing; micro/nano-structure; self-cleaning 29 30 Introduction 31 Recently, the transformation in the wettability condition of metallic surfaces from hydrophilic to 32 superhydrophobic (SH) has received considerable attention from researchers due to its numerous 33 applications such as an anti-bacterial layer, anti-frosting, self-cleaning, and drag-reducing over-34 lay [1]. The micro/nanostructures of insect wings and plants leaf have been saved as biomedical 35 bodies for researchers to create such surfaces on metallic/alloy surfaces primarily to reduce 36 maintenance costs. They show unique wetting behaviours such as SH and oil-water separation 37 properties. The wettability behaviour of SHS is likely to be influenced by the micro/nano dual 38 structure as well as the surface chemistry of the substrate surface [2]. 39 http://dx.doi.org/10.5599/jese.1260 http://dx.doi.org/10.5599/jese.1260 http://www.jese-online.org/ mailto:vknitj94@gmail.com J. Electrochem. Sci. Eng. 12(4) (2022) 639-649 FABRICATION OF SUPERHYDROPHOBIC SURFACES 640 The surface wettability can be categorized into three categories: hydrophilic, hydrophobic, and 40 SH properties, which depend on the water contact angle (WCA) of the surface [3]. That is, the surface 41 with WCA less than 90o is a hydrophilic surface, WCA lies between 90 to 150o for a hydrophobic 42 surface, whereas WCA greater than 150o is referred to as SHS. The above states of the surface are 43 highly influenced by the surface interface energy of water droplets and solid surfaces. The 44 wettability of surfaces has been studied by three states: the Wenzel state, the Cassie-Baxter (CB) 45 state, and the metastable state [4,5]. The Wenzel model considers water droplets seeping between 46 surface asperities, while the CB model discusses water droplets settling onto irregularities and 47 trapped air in the rough surface irregularities [6]. The schematic diagram of the above three 48 categories is shown in Figure 1. Among the above three infiltration states, the CB state is more 49 appropriate for the investigation of the SHS [7,8] since it is valid for rough and chemically 50 homogeneous surfaces and to air entrapment inside the irregularities of rough surfaces. 51 52 Figure 1. Infiltration states in Wenzel, CB and metastable states 53 SHS has the potential application to reduce corrosion behavior and is advantageous in self-54 cleaning and offers antiseptic environments [9]. There are two essential aspects to enhancing the 55 SH behaviour of a surface that is low surface energy treatment and the creation of micro/nano-56 hierarchical structure. To improve the intrinsic SH behaviour of the surface, laser surface texturing 57 has been a relatively new technique for creating a dual structure on metallic surfaces, which is 58 responsible for the making surface non-sticky. So far, to produce such micro/nano-dual scale 59 structures on a surface, a great effort has been made lately by researchers and this has been a 60 motivation to discover a newer technique, which is easy and eco-friendly [10]. Previously, several 61 techniques have been proposed and investigated to achieve high WCA and low CA hysteresis, such 62 as chemical etching [11], plasma etching [12], shot blasting [13], machining [14], lithographic 63 patterning [15], sol-gel technique [16], electrodeposition [17], and plasma fluorination technique 64 [18]. However, the previously reported techniques have some disadvantages that limit their 65 application, for example, the intricate processing steps and low durability. To create SHS, some 66 chemical modifications such as coating of fluorosilane and fluoropolymer are used as the top layer, 67 which significantly improves the hydrophobic behavior of the surface [19]. However, these 68 fluorinated coatings are harmful to the environment and also may be easily peeled off from the 69 substrate interface due to poor mechanical interlocking and thermal stability. To overcome the 70 above shortcomings, laser surface texturing has emerged as one of the best techniques to produce 71 a hierarchical structure with well-defined surface roughness as a requisite favorable condition for 72 attaining SH behavior. Laser texturing produces required surface roughness and spontaneous 73 hydrophobization and carbon absorption onto the textured surfaces with a multimodal roughness 74 that looks passive, environmentally friendly, and naturally reproducible [20]. Recently, Ma et al. 75 fabricated SHS by creating a circular texturing pattern of different p/d ratios, which were highly 76 durable [21]. Moreover, creating an SHS by optimizing p/d ratios for different materials became an 77 interesting area for researchers due to its high durability and eco-friendly nature. 78 Wenzel state CB state Metastable state V. Kumar et al. J. Electrochem. Sci. Eng. 12(4) (2022) 639-649 http://dx.doi.org/10.5599/jese.1260 641 Very little literature has been reported on the fabrication of SHS by direct laser treatment on 79 steel surfaces. The fabrication of superhydrophobic or hydrophobic surfaces by direct laser texturing 80 (DLT) eliminates the use of any hazardous chemical treatment. The creation of SHS by DLT and 81 deposition of oxide layer due to heat-treatment during texturing (autoxidation) is highly responsible 82 for better durability and maintaining their behavior against harsh environmental conditions. 83 In this work, the fiber laser marking machine of 50W was employed to create a micro/nano-84 hierarchical structure on AISI 420 steel substrate. To attain a stable SH condition, the textured 85 surfaces of different p/d ratios such as 2.0, 1.0, 0.95, 0.90, 0.80, and 0.70 were left in an open 86 environment for a few days. The surface characterization through scanning electron microscopy 87 analysis, tape peel test, and sandpaper abrasion test were employed to evaluate the soundness of 88 the developed SHS. 89 Experimental 90 Surface preparation 91 The AISI 420 steel plate was procured from the local market of Jalandhar and its chemical 92 composition was evaluated by spectroscopic analysis at the Central Institute of Hand Tools, 93 Jalandhar, Punjab, India (Table 1). To perform micro-texturing on the AISI 420 steel sheet was 94 sectioned to the size of 40405 mm. Subsequently, the sectioned surface was polished with 95 abrasive sandpaper of P200, P400, P800, P1200, and P1500 followed by washing with ethanol and 96 deionized water. Before laser texturing, all samples were dried in an electric oven at 80 oC for 30 97 minutes to remove moisture from the surfaces. 98 Table 1. Spectroscopic analysis of AISI 420 steel 99 Element C Cr Mn Si P S Fe Content, wt.% 0.13 12.60 0.85 0.73 0.03 0.05 Balance Laser surface texturing 100 The fiber laser marking machine (Figure 2) with a 50 W laser source was applied to micro-texture 101 the circular pattern of diameter 100 μm and pitch varying from 200 to 70 μm as tabulated in Table 2. 102 103 Figure 2. Laser texturing machine and its texturing parameters (EzCad software) 104 http://dx.doi.org/10.5599/jese.1260 J. Electrochem. Sci. Eng. 12(4) (2022) 639-649 FABRICATION OF SUPERHYDROPHOBIC SURFACES 642 The scanning speed used was 50 mm/s, a frequency of 50 kHz, and a maximum power of 35 W 105 with a laser wavelength of 1064 nm. The same parameters were repeated three times for every 106 sample to achieve the surface roughness (Ra) between 8 and 14 μm, as seen in Table 2. From Table 2, 107 it has been observed that Ra values of the textured geometry increase with a decrease in p/d ratio, 108 which could be ascribed to the decrease in the flat area of the textured geometry. With the increase 109 of the p/d ratio, the untextured surface area (outside the cylinder) increases, and the mean surface 110 roughness decreases. 111 Table 2. Parameters of texturing pattern and its surface roughness values, d = 100 m 112 Sample No. p / μm p /d Ra / μm 1 200 2 9.10 2 100 1.00 9.15 3 95 0.95 9.79 4 90 0.90 10.23 5 80 0.80 11.02 6 70 0.70 11.29 Surface characterization 113 The surface morphology of the textured surface was characterized using scanning electron 114 microscopy (SEM). The wettability and durability of the texture geometry were investigated by 115 assessing the mechanical resistance by a small-scale laboratory testing, such as tape peeling, 116 abrasive paper abrasion, and contact angle hysteresis of water droplets deposited on the textured 117 surface. The droplet contact angle is defined as the angle at which the water-air interface intersects 118 the surface, which characterizes the wettability tendency of liquid droplets. The roll-off angle 119 represents the slope of a surface from that a drop starts rolling and eventually falls. Wettability 120 conditions of superhydrophobicity are usually accepted when the contact angle is greater than 150o 121 and also the roll angle is lower than 10o [22]. The WCA value has been measured for each experiment 122 and co-related with the SEM topography and the degree of hydrophobicity. We used a technique 123 like a sessile contact angle approach and for this purpose, an image was captured of liquid droplets 124 on the textured surface using a high-resolution (micro-lens) camera. Then the image processing was 125 carried out to assess the contact perspective as described above. Depending on the degree of rolling, 126 we incrementally tilted the samples to determine the angle when the drop started rolling off from 127 the surface. For this purpose, a drop of water of 10 μl volume was released from a micro-syringe 128 from a height of 10 mm, and the drop image was captured and analyzed using image analysis 129 software under ambient conditions (at 5-days interval). 130 Mechanical testing 131 Tape peel test 132 Generally, a tape peeling test is carried out to investigate the behavior of superhydrophobic 133 surfaces after being glued to other surfaces, which indicates the loss of a degree of wettability of 134 the SH surface. For the tape-peeling test, the highly adhesive and pressure-sensitive tape is used for 135 uniformity of adhesion. In this work, Cellofix test tapes were used for uniformly adhering to the 136 textured surface with the application of an external load of 80 g rolling onto the entire surface for 137 proper adherence with the SH surface. The glued tape was later lifted at an angle of 180o to the 138 surface [8,10,23]. The wettability of the surfaces was measured after every 10 repetitions of the 139 test. This test was measured until the SH surface showed very low wettability loss. 140 V. Kumar et al. J. Electrochem. Sci. Eng. 12(4) (2022) 639-649 http://dx.doi.org/10.5599/jese.1260 643 Sandpaper abrasion test 141 A sandpaper abrasion test was carried out to evaluate the durability of the SH surfaces against 142 the damage from abrasive particles, which shows the wettability changes after a number of abrasion 143 cycles. In this test, the sandpaper of grit size P800 was put on the SH surface to a length of 40 mm 144 facing abrasive particles towards the SH surface. Applied 100 g external load on top of the sandpaper 145 and sandpaper was pulled horizontally with a constant velocity of approximately 10 mm/s. This test 146 was repeated for 50 cycles and the WCA of abraded surfaces was measured at intervals of 10 147 abrasion cycles [24-26]. 148 Results and discussion 149 In the present experiment, we have successfully produced metal textured surfaces with uniform 150 SH properties using laser texturing (Figure 3). 151 152 Figure 3. Water droplets exhibiting uniform hydrophobic and SH properties of textured surfaces 153 after 19 days of exposure to the open environment 154 Influence of laser texturing on surface morphology 155 It has been well established that the morphology of the surface and the roughness have a strong 156 influence on surface wettability. In general, it has been reported in the literature that two states, 157 namely Wenzel and Cassie-Baxter (CB), are used to explain the liquid-solid interaction: (1) the liquid 158 fills the valleys of a rough solid surface known as the Wenzel state, and (2) air entering the valleys 159 of the rough solid surface called CB state. When processing line by line (two laser beams separated 160 by distance) during laser texturing, the laser beams move and remove material (ablation) from the 161 surface by melting and evaporating the metal, creating micro-patterned structures. To produce 162 metallic surfaces with SH properties, the surface must become one of three structures: 163 nanostructures, microstructures, or dual structures [27]. In this work, the circular-shaped texturing 164 with different p/d ratios (2.0-0.7) was fabricated on steel samples by a fibre laser texturing machine. 165 During pilot experimentation, SH behaviour on the samples was performed to optimize the p/d 166 ratio. From the study, it was found that textured geometry with a p/d ratio of 0.7 resulted in the 167 maximum WCA, demonstrating the most encouraging results, whereas textured geometry with a 168 p/d ratio 2 and more did not show many promising WCA results due to more flat surfaces present 169 on top of the sample. Based on this preliminary study, our further investigation was mainly focused 170 on textured geometry with a p/d ratio of 0.7, and a sample of texturing with a p/d ratio of 2 was 171 discarded from the further investigation. 172 A distribution of multi-model and regular pattern geometry has been produced after laser 173 texturing, as shown in the SEM image of the textured substrates at different magnification levels. 174 The laser-processed substrate surface produced a hierarchical structure, a nanostructure in micro-175 protrusion pores and depressions, due to the evaporation and inherent laser bulging effect. 176 http://dx.doi.org/10.5599/jese.1260 J. Electrochem. Sci. Eng. 12(4) (2022) 639-649 FABRICATION OF SUPERHYDROPHOBIC SURFACES 644 Figure 4 shows the SEM image of the texture pattern structure with a p/d ratio of 0.7 at 177 magnification levels of 200 and 500, respectively. The SEM images show the formulation of a coral-178 like surface structured with mushroom-like nano-protrusions on micro-cavities arranged in random 179 alignments. These uniform/deterministic micro-cavities-oriented structures consisted of tiny cavities 180 with dimensions in the micron to nano range that created an ultrafine porous structure [28]. Further 181 studies show that these structures were reproducible and well controllable by adjusting the laser 182 parameters. After the laser ablation process, the WCA on all textured geometries was measured and 183 left at ambient conditions to further study the wettability behaviour with time. Further investigation 184 of WCA ensured that the surface wettability of laser-ablated surfaces increases with time. 185 186 Figure 4. SEM images of a textured surface with a p/d ratio of 0.7 at different magnification levels 187 Effect of auto-oxidation on wettability 188 The topography of the textured surface depends on the laser power and the intensity of the beam. 189 It is well known that spatial depth and heat zone increase with increasing laser intensity. As the laser 190 intensity doubles, the heat-affected region lengthens three times. The result is that the texturing 191 pattern's size increased and a distorted type of heat-affected zone was created [2,29]. One advantage 192 of pattern distortion is that it creates a nano protrusion and a high heat-affected zone is highly 193 responsible for the oxide formation and carbon abstractions from the environment and surface 194 dissolution. After laser texturing on the specimens, WCA was measured on the textured patterns and 195 all specimens were subjected to exposure to an open environment for further wettability studies time 196 the contact angle was measured at time intervals of five days, as shown in Table 3. 197 Table 3. Wettability measurement on the laser texture AISI 420 steel 198 Time interval. day p / d 0.7 0.8 0.9 0.95 1.0 WCA, o 1 97.90 85.36 77.23 70.9 70.2 5 125..42 101.21 92.32 88.12 86.3 10 131.48 115.23 105.41 100.32 98.25 15 145.49 129.3 121.23 114 101 19 158.59 135.23 123 114.45 101 199 After 15 days, it was observed as 145.45o and after 19 days, the fabricated surface showed SH 200 behaviour with a contact angle of 158.6o in textured geometry with a p/d ratio of 0.7, whereas no 201 significant change in the contact angle was observed after 19 days, as shown in Figure 6. The 202 V. Kumar et al. J. Electrochem. Sci. Eng. 12(4) (2022) 639-649 http://dx.doi.org/10.5599/jese.1260 645 variation in wettability over time is due to a change in surface chemistry and a key factor could be 203 ascribed to the accumulation of carbon to the textured substrate with active magnetite, as shown 204 in Table 4 [30]. This accumulation of carbon particles from the air on the textured geometry and air 205 entrapment inside the texturing pattern creates low surface energy on the surfaces. As a result, 206 when a higher energy liquid is dropped on this surface, it is repelled from the surface and tries to 207 attain a spherical shape due to the dominant molecular cohesive forces among the water droplets. 208 Further, it was observed, that after a small surface inclination, the water droplets roll off easily from 209 the surfaces. The EDS analysis of textured geometry with a p/d ratio of 0.7 (Figure 5) after 19 days 210 shows an enormous chemical composition alteration of the surface, as shown in Table 4. The higher 211 chemical composition alteration especially carbon and oxygen, may be caused due to surface 212 burring due to ablation during laser texturing and oxidation due to heat treatment during texturing 213 followed by auto-oxidation. From Table 4, trends of increasing percentage composition of lower 214 melting points elements have been observed after laser texturing. This may be due to the lower 215 melting points element diffusing out to the surface by heat treatment during texturing due to high 216 laser fluence. The high increment of carbon composition and introduction of oxide formation on the 217 textured geometry could be accounted for by the creation of low surface energy. 218 219 Figure 5. Energy-dispersive X-ray spectroscopy (EDS) on the textured surface Table 4. Chemical composition of texture surface before and after texturing Before texturing After texturing Element Content, wt. % Element Content, wt. % C 0.13 C 6.35 P 0.035 P 0.33 S 0.026 S 0.44 Si 0.59 Si 4.58 Cr 13.68 Cr 9.67 Fe 84.56 Fe 59.61 O 17.47 Ca 1.55 Total 100.00 100.00 Micrographs of the SHS were examined by SEM and EDS analysis at 10 kV at the NITTR in 220 Chandigarh, India, to examine the surface morphology and chemical composition of the surfaces. 221 The ability of water repellence increases with decreasing p/d value of the laser-ablated surface due 222 to increased surface roughness and the same behaviour for the other values of the p/d ratio was 223 observed. There was no significant change in the contact angles of the irradiated surface with time 224 after a stable equilibrium was reached. The WCA of water droplets was calculated on laser irradiated 225 surfaces (p/d = 0.7, 0.8, 0.90, 0.95, and 1.0) ablated with the same laser fluence and left at ambient 226 conditions for 19 days. It could be acknowledged from the results obtained that the pulse 227 superposition implemented in the ablation process could play an essential role in the surface 228 topography produced by the laser texturing process. As the p/d ratio of the circular texture pattern 229 decreased from 1.0 to 0.7, the surface roughness (9.15 μm to 11.29 μm) also increased as shown in 230 Table 2. The increase of Ra value with dual structure is highly responsible for the improvement in 231 hydrophilic to SH behaviour. Further, with the increase of the p/d ratio from 0.7 to 2.0, the surface 232 microstructure becomes very flat and there are not many nano-scale multi-modal structures present 233 on the surface to offer hydrophobicity. The decrease in CAs and the high adhesive force of these 234 surfaces can be explained according to the Wenzel model. As illustrated in Figure 6, the lower WCA 235 http://dx.doi.org/10.5599/jese.1260 J. Electrochem. Sci. Eng. 12(4) (2022) 639-649 FABRICATION OF SUPERHYDROPHOBIC SURFACES 646 on textured geometry except/compared to p/d ratio 0.7 was due to the water droplet could get into 236 the groove of the rough solid surface partially or completely. 237 238 Figure 6. WCA of textured AISI 420 steel specimens with different p/d ratios during 20 days interval 239 Mechanical test 240 To determine the functional working efficiency of the fabricated SHS, mechanical reliability is also 241 a critical parameter. In general, the SHS artificially produced by chemical methods are relative of 242 low durability and can lose their ability to repel water through scratching or abrasion, causing 243 excessive damage to the surface chemistry and structure [24]. Small scale laboratory tests prevalent 244 to ascertain the durability of SHS were conducted, namely sandpaper abrasion tests, tape peel tests, 245 and water repellency over time. In this study, SH surfaces show marginal loss of wettability after 50 246 test repetitions. It was observed that samples with a p/d ratio of 0.7 had exhibited some decreasing 247 trend of WCA during the first 40 test cycles of the tape peel test and a similar diminishing trend was 248 observed in the sandpaper abrasion test. A very small wettability change of the surface had been 249 observed in the first 10 cycles of the abrasive paper scratch test. Whiles, a sharp drop in WCA 250 (Figure 7) from 157.40 to 144.30 was observed between 10 to 50 cycles as the structure of the 251 textured substrate was damaged. The decreasing trends of WCA were observed after increasing the 252 number of testing cycles because when the number of cycles increases, the nano-protrusion over 253 micro-structures gets damaged after every repetition. However, the surface remains hydrophobic 254 after 50 cycles of test and it marginally lost its ability to repel water. 255 The promising results of the study show that these low water adhesion SHS can be used in many 256 engineering fields, such as the ‘mechanical hand’ to transfer small water droplets without any loss 257 or contamination for micro sample analysis. These SHS can also be used to store any type of liquid 258 solution in small volumes where no loss is required. Moreover, such surfaces can also be used to 259 transfer liquid droplets from low adhesion surface to high adhesion surface without any loss. 260 70 80 90 100 110 120 130 140 150 160 1 5 10 15 20 C o n ta ct a n g le , Time interval, day 0.7 0.8 0.9 0.95 1.0 Ra = 11.29 Ra = 11.02 Ra = 10.23 Ra = 9.79 Ra = 9.15 p/d: V. Kumar et al. J. Electrochem. Sci. Eng. 12(4) (2022) 639-649 http://dx.doi.org/10.5599/jese.1260 647 261 Figure 7. WCA measurement on the surface after mechanical testing (p/d = 0.70) 262 Conclusion 263 It has been shown that a compact and relatively inexpensive fiber laser texturing machine can be 264 used to produce SHS on AISI 420 steel substrates that exhibit hydrophobic properties immediately 265 after direct laser texturing under atmospheric conditions. The wettability of the ablated surface 266 enhances with time and the surfaces become SH after 19 days of autoxidation. To evaluate the 267 mechanical stability of the developed SHS, two different test methods were performed, the first 268 being the sandpaper abrasion test and the second being the tape-peel adhesion test. Following are 269 the main finding of the study: 270 • SEM and EDS analysis showed that laser texturing was mainly responsible for the changes in 271 surface morphology and scatting surface chemistry. The results showed that both the surface 272 chemistry and the pulse overlap could have a significant impact on the water repellency of 273 the AISI 420 steel surface. 274 • The superhydrophobicity of the laser-textured surface increased with decreasing p/d value 275 due to increased surface roughness. A circular texture pattern with a value of 0.7 p/d shows 276 excellent non-wetting behaviour due to increased surface roughness. The maximum WCA 277 achieved was 158.6o after 19 days of the sample stored at ambient conditions. 278 • After investigation, it has been found that an increase in carbon and oxidation percentage on 279 the textured surface over time was highly responsible for the SH behaviour. 280 References 281 [1] B. D. Rezgui, Surface Texturing for a Superhydrophobic Surface, in: The Effects of Dust and 282 Heat on Photovoltaic Modules: Impacts and Solutions, A. Al-Ahmed, Inamuddin, F.A. Al-283 Sulaiman, F. Khan (Eds.), Green Energy and Technology, Springer Cham, 2022, p. 113. 284 https://doi.org/10.1007/978-3-030-84635-0_5 285 [2] Z. Yang, C. Zhu, N. Zheng, D. Le, J. Zhou, Materials (Basel) 11(11) (2018) 2210. 286 https://doi.org/10.3390/ma11112210 287 [3] Y. Wang, J. Liu, M. Li, Q. Wang, Q. Chen, Applied Surface Science 385 (2016) 472-480. 288 https://doi.org/10.1016/j.apsusc.2016.05.117 289 [4] H. H. Nguyen, A. K. Tieu, S. Wan, H. Zhu, S. T. Pham, B. Johnston, Applied Surface Science 290 537 (2021) 147808. https://doi.org/10.1016/j.apsusc.2020.147808 291 157.4 156.0 152.0 150.0 146.2 144.3 140 142 144 146 148 150 152 154 156 158 160 0 10 20 30 40 50 60 C o n ta ct a n g le , Number of abrasion/tape peeling cycles Tape Peel Test Sandpaper Abrasion Test http://dx.doi.org/10.5599/jese.1260 https://doi.org/10.1007/978-3-030-84635-0_5 https://doi.org/10.3390/ma11112210 https://doi.org/10.1016/j.apsusc.2016.05.117 https://doi.org/10.1016/j.apsusc.2020.147808 J. Electrochem. Sci. Eng. 12(4) (2022) 639-649 FABRICATION OF SUPERHYDROPHOBIC SURFACES 648 [5] A. R. Esmaeili, N. Mir, R. Mohammadi, A Facile, Journal of Colloid and Interface Science 573 292 (2021) 317-327. https://doi.org/10.1016/j.jcis.2020.04.027 293 [6] Y. Cho, C.H. Park, RSC Advances 10(52) (2020) 31251-31260. 294 https://doi.org/10.1039/D0RA03137B 295 [7] V. Kumar, R. Verma, S. Kango, V.S. Sharma, Materials Today Communications 26 (2021) 296 101736. https://doi.org/10.1016/j.mtcomm.2020.101736 297 [8] V. Kumar, R. Verma, S. Kango, Transactions of the Indian Institute of Metals 73 (2020) 1025-298 1026. https://doi.org/10.1007/s12666-020-01918-8 299 [9] B. S. Yilbas, H. Ali, A. Al-Sharafi, N. Al-Aqeeli, Optics and Lasers in Engineering 102 (2018) 300 1-9. https://doi.org/10.1016/j.optlaseng.2017.10.014 301 [10] R. S. Sutar, S. S. Latthe, S. Nagappan, C.-S. Ha, K. K. Sadasivuni, S. Liu, R. Xing, A. K. Bhosale, 302 Journal of Applied Polymer Science 138(9) (2021) 49943. 303 https://doi.org/10.1002/app.49943 304 [11] J. Wu, J. Chen, J. Xia, W. Lei, B.-p. Wang, Advances in Materials Science and Engineering 305 2013 (2013) 232681. https://doi.org/10.1155/2013/232681 306 [12] K. Ellinas, A. Tserepi, E. Gogolides, Langmuir 27(7) (2011) 3960-3969. 307 https://doi.org/10.1021/la104481p 308 [13] G. Deep, V. Rajora, I. Singh, 3rd National Conference on Advancements in Simulation & 309 Experimental Techniques in Mechanical Engineering (NCASEme-2016), Proceedings, 310 Chandigarh University, Gharuan, Mohali, Punjab, India, 2016, p. 253-257. 311 [14] D-M. Chun, C.-V. Ngo, K.-M. Lee, CIRP Annals - Manufacturing Technology 65(1) (2016) 312 519-522. https://doi.org/10.1016/j.cirp.2016.04.019 313 [15] K. Ellinas, M. Chatzipetrou, I. Zergioti, A. Tserepi, E. Gogolides, Advanced Materials 27(13) 314 (2015) 2231-2235. https://doi.org/10.1002/adma.201405855 315 [16] X. Wu, V. V. Silberschmidt, Z.-T. Hu, Z. Chen, Surface and Coatings Technology 358 (2019) 316 207-214. https://doi.org/10.1016/j.surfcoat.2018.11.039 317 [17] H. M. Forooshani, M. Aliofkhazraei, H. Bagheri, Journal of Alloys and Compounds 784 (2019) 318 556-573. https://doi.org/10.1016/j.jallcom.2019.01.079 319 [18] D. Zhao, M. Pan, J. Yuan, H. Liu, S. Song, L. Zhu, Progress in Organic Coatings 138 (2020) 320 105368. https://doi.org/10.1016/j.porgcoat.2019.105368 321 [19] Y. Xiu, L. Zhu, D.W. Hess, C. P. Wong, Nano Letters 7(11) (2007) 3388-3393. 322 https://doi.org/10.1021/nl0717457 323 [20] L. B. Boinovich, A. M. Emelyanenko, K. A. Emelyanenko, A. G. Domantovsky, A. A. Shiryaev, 324 Applied Surface Science 379 (2016) 111-113. https://doi.org/10.1016/j.apsusc.2016.04.056 325 [21] Q. Ma, Z. Tong, W. Wang, G. Dong, Applied Surface Science 455 (2018) 748-757. 326 https://doi.org/10.1016/j.apsusc.2018.06.033 327 [22] S. Niu, B. Li, Z. Mu, M. Yang, J. Zhang, Z. Han, L. Ren, Journal of Bionic Engineering 12(2) 328 (2015) 170-189. https://doi.org/10.1016/S1672-6529(14)60111-6 329 [23] T. Wu, W.-hua Xu, K. Guo, H. Xie, J.-ping Qu, Chemical Engineering Journal 407 (2021) 330 127100. https://doi.org/10.1016/j.cej.2020.127100 331 [24] X. Gao, Z. Guo, Journal of Colloid and Interface Science 512 (2018) 239-248. 332 https://doi.org/10.1016/j.jcis.2017.10.061 333 [25] Y. Zhang, L. Zhang, Z. Xiao, S. Wang, X. Yu, Chemical Engineering Journal 369 (2019) 1-7. 334 https://doi.org/10.1016/j.cej.2019.03.021 335 [26] R. S. Sutar, S. S. Latthe, A. M. Sargar, C. E. Patil, V. S. Jadhav, A. N. Patil, K. K. Kokate, A. K. 336 Bhosale, K. K. Sadasivuni, S. V. Mohite, S. Liu, R. Xing, Macromolecular Symposia 393(1) 337 (2020) 2000031. https://doi.org/10.1002/masy.202000031 338 [27] Y. Yoon, D. Kim, J.-B. Lee, Micro and Nano Systems Letters 2(1) (2014) 3. 339 https://doi.org/10.1186/s40486-014-0003-x 340 https://doi.org/10.1016/j.jcis.2020.04.027 https://doi.org/10.1039/D0RA03137B https://doi.org/10.1016/j.mtcomm.2020.101736 https://doi.org/10.1007/s12666-020-01918-8 https://doi.org/10.1016/j.optlaseng.2017.10.014 https://doi.org/10.1002/app.49943 https://doi.org/10.1155/2013/232681 https://doi.org/10.1021/la104481p https://doi.org/10.1016/j.cirp.2016.04.019 https://doi.org/10.1002/adma.201405855 https://doi.org/10.1016/j.surfcoat.2018.11.039 https://doi.org/10.1016/j.jallcom.2019.01.079 https://doi.org/10.1016/j.porgcoat.2019.105368 https://doi.org/10.1021/nl0717457 https://doi.org/10.1016/j.apsusc.2016.04.056 https://doi.org/10.1016/j.apsusc.2018.06.033 https://doi.org/10.1016/S1672-6529(14)60111-6 https://doi.org/10.1016/j.cej.2020.127100 https://doi.org/10.1016/j.jcis.2017.10.061 https://doi.org/10.1016/j.cej.2019.03.021 https://doi.org/10.1002/masy.202000031 https://doi.org/10.1186/s40486-014-0003-x V. Kumar et al. J. Electrochem. Sci. Eng. 12(4) (2022) 639-649 http://dx.doi.org/10.5599/jese.1260 649 [28] E. Liu, H.J. Lee, X. Lu, Applied Sciences (Switzerland) 10(8) (2020) 2678. 341 https://doi.org/10.3390/app10082678 342 [29] V. Kumar, R. Verma, V.S. Sharma, V. Sharma, Surface Topography: Metrology and 343 Properties, 9(4) (2022) 43003. https://doi.org/10.1088/2051-672X/ac4321 344 [30] Y. Liu, H. Gao, S. Li, Z. Han, L. Ren, Chemical Engineering Journal 337 (2018) 697-708. 345 https://doi.org/10.1016/j.cej.2017.12.139 346 347 ©2022 by the authors; licensee IAPC, Zagreb, Croatia. This article is an open-access article distributed under the terms and conditions of the Creative Commons Attribution license (https://creativecommons.org/licenses/by/4.0/) http://dx.doi.org/10.5599/jese.1260 https://doi.org/10.3390/app10082678 https://doi.org/10.1088/2051-672X/ac4321 https://doi.org/10.1016/j.cej.2017.12.139 https://creativecommons.org/licenses/by/4.0/) @Article{Kumar2022a, author = {Kumar, Vijay and Verma, Rajeev and Bairwa, Harish Kumar}, journal = {Journal of Electrochemical Science and Engineering}, title = {{Fabrication of superhydrophobic surfaces by laser surface texturing and autoxidation:}}, year = {2022}, issn = {1847-9286}, month = {may}, number = {4}, pages = {639--649}, volume = {12}, abstract = {The creation of superhydrophobic surfaces (SHS) has received exceptional thought from the entire research community due to its notable application in varied fields such as anti-icing, self-cleaning, drag reduction, anti-bacterial, and oil-water separation. The super­hy­drophobic (SH) conditions for a surface can be attained through the consolidation of a low surface energy surface with appropriate micro/nano-surface roughness through texturing. Motivated by the SH nature of lotus leaf and petal effect, microstructures have been prepared in this work on a metal surface by a fiber laser marking machine at 35 W. The textured surfaces with a different pitch to diameter (p/d) ratio (2.0-0.70) have been turned into hydrophobic and finally SH, after storing in an ambient environment for a few days due to oxide layer deposition on the textured surface. In this study, the maximum contact angle achieved by textured geometry after 30 days of auto-oxidation was 158.6 o. Further, test results showed that the fabricated surfaces have a high potential to maintain their SH nature even after the harsh condition of applications.}, doi = {10.5599/JESE.1260}, file = {:D\:/OneDrive/Mendeley Desktop/Kumar, Verma, Bairwa - 2022 - Fabrication of superhydrophobic surfaces by laser surface texturing and autoxidation.pdf:pdf;:05_jESE_1260.pdf:PDF}, keywords = {Anti, bacterial, cleaning, micro/nano, oxide layer deposition, self, structure, texturing}, publisher = {International Association of Physical Chemists (IAPC)}, url = {https://pub.iapchem.org/ojs/index.php/JESE/article/view/1260}, }