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Durable and self-healing superhydrophobic surfaces for building materials
Accepted Manuscript Durable and Self-Healing Superhydrophobic Surfaces for Building Materials Usama Zulfiqar, Muhammad Awais, Syed Zajif Hussain, Irshad Hussain, S.Wilayat Husain, Tayyab Subhani PII: DOI: Reference:
S0167-577X(17)30079-4 http://dx.doi.org/10.1016/j.matlet.2017.01.070 MLBLUE 22023
To appear in:
Materials Letters
Received Date: Revised Date: Accepted Date:
8 November 2016 13 January 2017 17 January 2017
Please cite this article as: U. Zulfiqar, M. Awais, S.Z. Hussain, I. Hussain, S.Wilayat Husain, T. Subhani, Durable and Self-Healing Superhydrophobic Surfaces for Building Materials, Materials Letters (2017), doi: http:// dx.doi.org/10.1016/j.matlet.2017.01.070
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Durable and Self-Healing Superhydrophobic Surfaces for Building Materials Usama Zulfiqar*a, Muhammad Awais a, Syed Zajif Hussain b, Irshad Hussainb, S.Wilayat Husain a and Tayyab Subhania a Composite Research Center, Department of Materials Science and Engineering, Institute of Space Technology, Islamabad, Pakistan. b Department of Chemistry, SBA-School of Science and Engineering, Lahore University of Management Sciences, DHA, Lahore Cantt 54792, Pakistan. Abstract The large-scale industrial applications of superhydrophobic surfaces are restricted by their poor mechanical properties. We present a facile method to produce a mechanically durable superhydrophobic surface on building materials, which has the added feature to restore its properties after severe abrasion. These superhydrophobic surfaces were fabricated, from hydrophobic silica nanoparticles and commercially available spray adhesive, on three commercially available construction materials i.e. bricks, marble and glass. The prepared surfaces were able to sustain the impact of sand particles traveling at a speed of 11.26 Km/h, and also revamp their superhydrophobic character by simple acetone treatment upon receiving severe damages from emery paper and knife scratches. Keywords: Superhydrophobic; Nanoparticles; Adhesion; Self-healing *Corresponding author: Tel: +923347064887; E-mail address: [email protected] Introduction From artificial intelligence to kingfisher-inspired bullet trains, nature has always been the source of scientific innovations. Indeed, improved understanding and advanced technology have now made it possible for scientists to derive motivation from nature’s perfect architecture to resolve challenging engineering problems. Superhydrophobic surfaces is one of such examples branded for its water-repellent quality [1, 2]. The applications of this technology have now stretched into a variety of engineering fields such as building materials, electronic devices, microfluidic devices, biomaterials and oil/water separation [3-8]. The detrimental effects of moisture for construction industry are not concealed to mankind as the absorption of moisture deteriorates building materials via physical and chemical processes [5, 6]. One of the solutions is to coat the building structures with novel materials to render their surfaces superhydrophobic. It is known that the wettability of superhydrophobic surfaces can be controlled by tailoring their roughness and chemical nature. The roughness level of a surface can be controlled by constructing hierarchical structures providing excellent water-repellent properties but the control over their mechanical properties is still a serious challenge. Despite the importance of durability in daily life applications, this aspect has attained less
1
attention so far. However, very recently durable superhydrophobic surfaces are being prepared by silica nanoparticles in combination with different materials including polydimethylsiloxane [9], epoxy [10] and benzoxazine [11]. In addition to good mechanical strength, the durability of wear-resistant superhydrophobic surfaces is another requisite. A self-healing process is therefore required to be developed in artificial superhydrophobic surfaces, which could restore the original surface properties in case of external deterioration e.g. a self-healing coating prepared from polystyrene/silica nanoparticles and polydimethylsiloxane can repair deterioration upon heating or treating with tetrahydrofuran [12]. Another recent example is the self-healing fabrics, which retain their properties upon heating [13]. In this investigation, we have fabricated durable self-healing superhydrophobic coatings on brick, marble and glass substrates with the ability to convalesce with a simple acetone treatment even after severe abrasion. Following our previous work [4], bi-modal hydrophobic silica nanoparticles were synthesized from sodium silicate solution and utilized with a commercially available spray adhesive to form durable and self-healing superhydrophobic surfaces. Experimental Materials Sodium silicate solution (SSS) with Na2O= 7.5–8.5%, SiO2= 25.5–28.5% and pH range of 11.0–11.5, and trimethylchlorosilane (TMCS) were purchased from Merck Millipore while commercially available 3M Super 77 Multipurpose Spray Adhesive was used as binder. All other solvents and materials were purchased from local market. Method 25 mL of SSS was diluted with 300 mL of water followed by subsequent addition of 200 mL methanol in reaction vessel and aged for 1 h. Later, 30 mL of TMCS was added and resulted solution was left to stir for 2 h. On average, 8 g of hydrophobic silica nanoparticles (H-SiO2NPs) were retrieved by centrifugation and washing with ethanol. Afterwards, 3 wt% suspension of H-SiO2NPs was prepared in acetone via sonication for 1hr. The glass, marble and brick samples were sprayed with adhesive for 6 sec from a distance of 30 cm. After 5 min, 0.5 ml/cm2 of H-SiO2NPs suspension was dropped onto sprayed samples and left to dry for 1h at room temperature. The surfaces were rinsed in acetone to remove excessive particles and dried. For self-healing, the damaged samples were rinsed in acetone followed by drying at 50 °C.
2
Characterization Fourier transform-infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and goniometer were respectively used for investigating the functional groups, morphology, particle size and contact angle measurements of H-SiO2NPs and prepared surfaces. The spray adhesive forms a non-uniform layer which may affect the contact angle readings. That’s why contact angle was recorded from several points and an average value is used. Still, the variation from superhydrophobic behavior (<150º) is discernible throughout this work. Abrasion resistance was determined by sand abrasion, emery paper abrasion and knife scratch test. An emery paper of grit size 320 with 200g weight was displaced through the sample for 50mm. The test was repeated for 5 cycles and contact angle after each cycle was noted. For sand abrasion test, three different loads of sand (15, 30, 60g) were impacted on the superhydrophobic coatings with a speed of 11.26Km/h. Results and Discussion Spherical H-SiO2NPs (Diameter 321±38nm and 113±17 nm) were produced by hydrolysis and condensation of diluted sodium silicate in methanol while the surface of H-SiO2NPs was covered with methyl group by reacting with TMCS as is evidenced from their FTIR spectra (Fig. 1 a). The produced particles exhibited excellent superhydrophobic behavior as they form a hierarchical structure due to the diversity of particle sizes as discussed in our previous study [4] (Fig. 1 b). Fig. 2 shows the hierarchical structure formed by adhesive and H-SiO2NPs on brick, marble and glass substrate. The achieved multiscale roughness is the key to water-repellent properties of these surfaces. It can be seen that H-SiO2NPs have covered the entire area and they are embedded in the adhesive coatings. The surface chemistry of H-SiO2NPs, combined with micro- and nano-scale features formed by adhesive and nanoparticles, construct an ideal superhydrophobic surface while adhesive layer provides strength to these coating. The contact angles recorded for brick, marble and glass substrates are 168º±5º, 166º±5º and 163º±2º, respectively (Fig. 3 d). The abrasion tests were performed to check the durability and mechanical performance of these coatings (Fig. 3 a and c). It is evident from the results that the surfaces are superhydrophobic even after 5 cycles of abrasion (Fig. 3 d). However, excessive mechanical damage was experienced in case of glass as compared to brick and marble substrates, which sustained the abrasion without appreciable damage to the coating.
3
To further evaluate the mechanical performance of coatings, sand abrasion test was performed (Fig.3 c). After the impact from 15 g of sand, the contact angles of surfaces on brick, marble, and glass dropped to 167º, 164º, and 162º from 168º, 166º and 163º respectively (Fig.3 e). A significant decrease in contact angles was observed to;149º, 148º, and 146º after the impact with 30 g of sand and 103º, 123º, and 137º after increasing sand weight to 60 g. The acetone treatment effectively restored the superhydrophobicity of the affected samples and the contact angle jumped to 164º, 163º and163º, respectively (Fig.3 e). To further investigate this effect, the brick sample was subjected to abrasion with 60g of sand for three time followed by healing with acetone after each cycle. It was found that acetone treatment was very effective to repair damaged surfaces (Fig. 4 a). After the first abrasion cycle, the contact angle was reduced to 142º, which restored to 167º after acetone treatment. Similar recovery effects were observed in following two abrasion cycles: the contact angle first dropped to 123º and 125º and then restored to 156º and 146º after acetone treatment, respectively. For the final assessment of self-healing capability, a glass slide sample with superhydrophobic coating was subjected to emery paper abrasion, 60 g sand abrasion and knife scratches (Fig 4 b). After acetone treatment, the sample showed excellent superhydrophobic properties with water contact angle of 161º (Fig 4 c). It can be inferred from the results that a mechanically durable H-SiO2NPs based superhydrophobic coatings can be developed using commercially available spray adhesives for a variety of substrates having self-healing properties after mechanical damages. As observed from experimental results and microscopic observations (Fig 4 d and e), the acetone treatment helps the coating to remove surface bound sand particles and rearrange the mixture of H-SiO2NPs and adhesive in damaged area. The adhesive is soluble in acetone which helps in healing the superhydrophobic coatings. Conclusions A durable and self-healing superhydrophobic coating was developed on building materials including brick, marble, and glass. The deterioration of prepared superhydrophobic surfaces was evaluated by sand impact abrasion, emery paper abrasion, and knife scratch tests. The combination of hydrophobic silica nanoparticles and adhesive protected the surfaces from external damage without significant decrease in superhydrophobicity. The self-healing characteristic of the damaged surfaces was achieved by simple acetone treatment. The produced surface has the ability to recover from the outdoor deterioration as experienced by building materials.
4
Figures
Figure 1: (a) FTIR spectrum and (b) SEM image of hydrophobic silica nanoparticles
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Figure 2: SEM images of superhydrophobic coatings on (a) brick, (b) marble and (c) glass substrates
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Figure 3: (a) Schematic of emery paper abrasion test, (b) photographic image of marble and brick surfaces containing water droplets, (c) schematic of sand abrasion test, and graphical representation of contact angles after (d) emery paper abrasion (d) and sand abrasion tests
Figure 4: (a) Graphical representation of contact angles after healing cycles, (a) mechanically damaged superhydrophobic surface, (c) superhydrophobic surface after acetone treatment, and (d and e) SEM images of acetone treated surface
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References [1] X. Guo, X. Li, Materials Letters 186 (2017) 357-360. [2] J.-W. Lee, W. Hwang,Materials Letters 168 (2016) 83-85. [3] J. Li, D. Li, W. Li, H. She, H. Feng, D. Hu, Materials Letters 171 (2016) 228-231. [4] U. Zulfiqar, S.Z. Hussain, M. Awais, M.M.J. Khan, I. Hussain, S.W. Husain, T. Subhani, Colloids and Surfaces A: Physicochemical and Engineering Aspects 508 (2016) 301-308. [5] L.A. Carrascosa, D.S. Facio, M.J. Mosquera, Nanotechnology 27(9) (2016) 095604. [6] D. Kronlund, A. Bergbreiter, M. Lindén, D. Grosso, J.-H. Colloids and Surfaces A: Physicochemical and Engineering Aspects 483 (2015) 104-111. [7] J. Seo, S.-K. Lee, J. Lee, J.S. Lee, H. Kwon, S.-W. Cho, J.-H. Ahn, T. Lee, Scientific reports 5 (2015). [8] E.J. Falde, S.T. Yohe, Y.L. Colson, M.W. Grinstaff, Biomaterials 104 (2016) 87-103. [9] P. Wang, M. Chen, H. Han, X. Fan, Q. Liu, J. Wang, Journal of Materials Chemistry A 4(20) (2016) 7869-7874. [10] T. Simovich, A.H. Wu, R.N. Lamb, Thin Solid Films 589 (2015) 472-478. [11] Z. Wang, H. Zhu, N. Cao, R. Du, Y. Liu, G. Zhao, Materials Letters 186 (2017) 274-278. [12] C.-H. Xue, Z.-D. Zhang, J. Zhang, S.-T. Jia, Journal of Materials Chemistry A 2(36) (2014) 15001-15007. [13] Y. Li, B. Ge, X. Men, Z. Zhang, Q. Xue, Composites Science and Technology 125 (2016) 55-61.
8
Highlights Durable superhydrophobic surfaces have been fabricated on building materials. The surfaces are resistant to several abrasion cycles and demonstrate self-healing. The produced surfaces have ability to self-heal with a simple acetone treatment.
9
S0167-577X(17)30079-4 http://dx.doi.org/10.1016/j.matlet.2017.01.070 MLBLUE 22023
To appear in:
Materials Letters
Received Date: Revised Date: Accepted Date:
8 November 2016 13 January 2017 17 January 2017
Please cite this article as: U. Zulfiqar, M. Awais, S.Z. Hussain, I. Hussain, S.Wilayat Husain, T. Subhani, Durable and Self-Healing Superhydrophobic Surfaces for Building Materials, Materials Letters (2017), doi: http:// dx.doi.org/10.1016/j.matlet.2017.01.070
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Durable and Self-Healing Superhydrophobic Surfaces for Building Materials Usama Zulfiqar*a, Muhammad Awais a, Syed Zajif Hussain b, Irshad Hussainb, S.Wilayat Husain a and Tayyab Subhania a Composite Research Center, Department of Materials Science and Engineering, Institute of Space Technology, Islamabad, Pakistan. b Department of Chemistry, SBA-School of Science and Engineering, Lahore University of Management Sciences, DHA, Lahore Cantt 54792, Pakistan. Abstract The large-scale industrial applications of superhydrophobic surfaces are restricted by their poor mechanical properties. We present a facile method to produce a mechanically durable superhydrophobic surface on building materials, which has the added feature to restore its properties after severe abrasion. These superhydrophobic surfaces were fabricated, from hydrophobic silica nanoparticles and commercially available spray adhesive, on three commercially available construction materials i.e. bricks, marble and glass. The prepared surfaces were able to sustain the impact of sand particles traveling at a speed of 11.26 Km/h, and also revamp their superhydrophobic character by simple acetone treatment upon receiving severe damages from emery paper and knife scratches. Keywords: Superhydrophobic; Nanoparticles; Adhesion; Self-healing *Corresponding author: Tel: +923347064887; E-mail address: [email protected] Introduction From artificial intelligence to kingfisher-inspired bullet trains, nature has always been the source of scientific innovations. Indeed, improved understanding and advanced technology have now made it possible for scientists to derive motivation from nature’s perfect architecture to resolve challenging engineering problems. Superhydrophobic surfaces is one of such examples branded for its water-repellent quality [1, 2]. The applications of this technology have now stretched into a variety of engineering fields such as building materials, electronic devices, microfluidic devices, biomaterials and oil/water separation [3-8]. The detrimental effects of moisture for construction industry are not concealed to mankind as the absorption of moisture deteriorates building materials via physical and chemical processes [5, 6]. One of the solutions is to coat the building structures with novel materials to render their surfaces superhydrophobic. It is known that the wettability of superhydrophobic surfaces can be controlled by tailoring their roughness and chemical nature. The roughness level of a surface can be controlled by constructing hierarchical structures providing excellent water-repellent properties but the control over their mechanical properties is still a serious challenge. Despite the importance of durability in daily life applications, this aspect has attained less
1
attention so far. However, very recently durable superhydrophobic surfaces are being prepared by silica nanoparticles in combination with different materials including polydimethylsiloxane [9], epoxy [10] and benzoxazine [11]. In addition to good mechanical strength, the durability of wear-resistant superhydrophobic surfaces is another requisite. A self-healing process is therefore required to be developed in artificial superhydrophobic surfaces, which could restore the original surface properties in case of external deterioration e.g. a self-healing coating prepared from polystyrene/silica nanoparticles and polydimethylsiloxane can repair deterioration upon heating or treating with tetrahydrofuran [12]. Another recent example is the self-healing fabrics, which retain their properties upon heating [13]. In this investigation, we have fabricated durable self-healing superhydrophobic coatings on brick, marble and glass substrates with the ability to convalesce with a simple acetone treatment even after severe abrasion. Following our previous work [4], bi-modal hydrophobic silica nanoparticles were synthesized from sodium silicate solution and utilized with a commercially available spray adhesive to form durable and self-healing superhydrophobic surfaces. Experimental Materials Sodium silicate solution (SSS) with Na2O= 7.5–8.5%, SiO2= 25.5–28.5% and pH range of 11.0–11.5, and trimethylchlorosilane (TMCS) were purchased from Merck Millipore while commercially available 3M Super 77 Multipurpose Spray Adhesive was used as binder. All other solvents and materials were purchased from local market. Method 25 mL of SSS was diluted with 300 mL of water followed by subsequent addition of 200 mL methanol in reaction vessel and aged for 1 h. Later, 30 mL of TMCS was added and resulted solution was left to stir for 2 h. On average, 8 g of hydrophobic silica nanoparticles (H-SiO2NPs) were retrieved by centrifugation and washing with ethanol. Afterwards, 3 wt% suspension of H-SiO2NPs was prepared in acetone via sonication for 1hr. The glass, marble and brick samples were sprayed with adhesive for 6 sec from a distance of 30 cm. After 5 min, 0.5 ml/cm2 of H-SiO2NPs suspension was dropped onto sprayed samples and left to dry for 1h at room temperature. The surfaces were rinsed in acetone to remove excessive particles and dried. For self-healing, the damaged samples were rinsed in acetone followed by drying at 50 °C.
2
Characterization Fourier transform-infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and goniometer were respectively used for investigating the functional groups, morphology, particle size and contact angle measurements of H-SiO2NPs and prepared surfaces. The spray adhesive forms a non-uniform layer which may affect the contact angle readings. That’s why contact angle was recorded from several points and an average value is used. Still, the variation from superhydrophobic behavior (<150º) is discernible throughout this work. Abrasion resistance was determined by sand abrasion, emery paper abrasion and knife scratch test. An emery paper of grit size 320 with 200g weight was displaced through the sample for 50mm. The test was repeated for 5 cycles and contact angle after each cycle was noted. For sand abrasion test, three different loads of sand (15, 30, 60g) were impacted on the superhydrophobic coatings with a speed of 11.26Km/h. Results and Discussion Spherical H-SiO2NPs (Diameter 321±38nm and 113±17 nm) were produced by hydrolysis and condensation of diluted sodium silicate in methanol while the surface of H-SiO2NPs was covered with methyl group by reacting with TMCS as is evidenced from their FTIR spectra (Fig. 1 a). The produced particles exhibited excellent superhydrophobic behavior as they form a hierarchical structure due to the diversity of particle sizes as discussed in our previous study [4] (Fig. 1 b). Fig. 2 shows the hierarchical structure formed by adhesive and H-SiO2NPs on brick, marble and glass substrate. The achieved multiscale roughness is the key to water-repellent properties of these surfaces. It can be seen that H-SiO2NPs have covered the entire area and they are embedded in the adhesive coatings. The surface chemistry of H-SiO2NPs, combined with micro- and nano-scale features formed by adhesive and nanoparticles, construct an ideal superhydrophobic surface while adhesive layer provides strength to these coating. The contact angles recorded for brick, marble and glass substrates are 168º±5º, 166º±5º and 163º±2º, respectively (Fig. 3 d). The abrasion tests were performed to check the durability and mechanical performance of these coatings (Fig. 3 a and c). It is evident from the results that the surfaces are superhydrophobic even after 5 cycles of abrasion (Fig. 3 d). However, excessive mechanical damage was experienced in case of glass as compared to brick and marble substrates, which sustained the abrasion without appreciable damage to the coating.
3
To further evaluate the mechanical performance of coatings, sand abrasion test was performed (Fig.3 c). After the impact from 15 g of sand, the contact angles of surfaces on brick, marble, and glass dropped to 167º, 164º, and 162º from 168º, 166º and 163º respectively (Fig.3 e). A significant decrease in contact angles was observed to;149º, 148º, and 146º after the impact with 30 g of sand and 103º, 123º, and 137º after increasing sand weight to 60 g. The acetone treatment effectively restored the superhydrophobicity of the affected samples and the contact angle jumped to 164º, 163º and163º, respectively (Fig.3 e). To further investigate this effect, the brick sample was subjected to abrasion with 60g of sand for three time followed by healing with acetone after each cycle. It was found that acetone treatment was very effective to repair damaged surfaces (Fig. 4 a). After the first abrasion cycle, the contact angle was reduced to 142º, which restored to 167º after acetone treatment. Similar recovery effects were observed in following two abrasion cycles: the contact angle first dropped to 123º and 125º and then restored to 156º and 146º after acetone treatment, respectively. For the final assessment of self-healing capability, a glass slide sample with superhydrophobic coating was subjected to emery paper abrasion, 60 g sand abrasion and knife scratches (Fig 4 b). After acetone treatment, the sample showed excellent superhydrophobic properties with water contact angle of 161º (Fig 4 c). It can be inferred from the results that a mechanically durable H-SiO2NPs based superhydrophobic coatings can be developed using commercially available spray adhesives for a variety of substrates having self-healing properties after mechanical damages. As observed from experimental results and microscopic observations (Fig 4 d and e), the acetone treatment helps the coating to remove surface bound sand particles and rearrange the mixture of H-SiO2NPs and adhesive in damaged area. The adhesive is soluble in acetone which helps in healing the superhydrophobic coatings. Conclusions A durable and self-healing superhydrophobic coating was developed on building materials including brick, marble, and glass. The deterioration of prepared superhydrophobic surfaces was evaluated by sand impact abrasion, emery paper abrasion, and knife scratch tests. The combination of hydrophobic silica nanoparticles and adhesive protected the surfaces from external damage without significant decrease in superhydrophobicity. The self-healing characteristic of the damaged surfaces was achieved by simple acetone treatment. The produced surface has the ability to recover from the outdoor deterioration as experienced by building materials.
4
Figures
Figure 1: (a) FTIR spectrum and (b) SEM image of hydrophobic silica nanoparticles
5
Figure 2: SEM images of superhydrophobic coatings on (a) brick, (b) marble and (c) glass substrates
6
Figure 3: (a) Schematic of emery paper abrasion test, (b) photographic image of marble and brick surfaces containing water droplets, (c) schematic of sand abrasion test, and graphical representation of contact angles after (d) emery paper abrasion (d) and sand abrasion tests
Figure 4: (a) Graphical representation of contact angles after healing cycles, (a) mechanically damaged superhydrophobic surface, (c) superhydrophobic surface after acetone treatment, and (d and e) SEM images of acetone treated surface
7
References [1] X. Guo, X. Li, Materials Letters 186 (2017) 357-360. [2] J.-W. Lee, W. Hwang,Materials Letters 168 (2016) 83-85. [3] J. Li, D. Li, W. Li, H. She, H. Feng, D. Hu, Materials Letters 171 (2016) 228-231. [4] U. Zulfiqar, S.Z. Hussain, M. Awais, M.M.J. Khan, I. Hussain, S.W. Husain, T. Subhani, Colloids and Surfaces A: Physicochemical and Engineering Aspects 508 (2016) 301-308. [5] L.A. Carrascosa, D.S. Facio, M.J. Mosquera, Nanotechnology 27(9) (2016) 095604. [6] D. Kronlund, A. Bergbreiter, M. Lindén, D. Grosso, J.-H. Colloids and Surfaces A: Physicochemical and Engineering Aspects 483 (2015) 104-111. [7] J. Seo, S.-K. Lee, J. Lee, J.S. Lee, H. Kwon, S.-W. Cho, J.-H. Ahn, T. Lee, Scientific reports 5 (2015). [8] E.J. Falde, S.T. Yohe, Y.L. Colson, M.W. Grinstaff, Biomaterials 104 (2016) 87-103. [9] P. Wang, M. Chen, H. Han, X. Fan, Q. Liu, J. Wang, Journal of Materials Chemistry A 4(20) (2016) 7869-7874. [10] T. Simovich, A.H. Wu, R.N. Lamb, Thin Solid Films 589 (2015) 472-478. [11] Z. Wang, H. Zhu, N. Cao, R. Du, Y. Liu, G. Zhao, Materials Letters 186 (2017) 274-278. [12] C.-H. Xue, Z.-D. Zhang, J. Zhang, S.-T. Jia, Journal of Materials Chemistry A 2(36) (2014) 15001-15007. [13] Y. Li, B. Ge, X. Men, Z. Zhang, Q. Xue, Composites Science and Technology 125 (2016) 55-61.
8
Highlights Durable superhydrophobic surfaces have been fabricated on building materials. The surfaces are resistant to several abrasion cycles and demonstrate self-healing. The produced surfaces have ability to self-heal with a simple acetone treatment.
9