Süperhidrofobik ve hidrofobik yüzeyler üzerinde sıvı damlası gaz kabarcığı ve sıvı jeti dinamiğinin incelenmesi

Yıl 2016, Cilt: 22 Sayı: 7, 613 - 619, 21.12.2016

Ali Kibar

Öz

Bu çalışmada, hidrofobik
ve süperhidrofobik yüzeylerin hidrofilik yüzeylerden farklılıkları ve bu
yüzeyler üzerinde sıvı damlası, gaz kabarcığı ve sıvı jeti dinamiği
incelenmiştir. Hidrofobik yüzeyler üzerinde sıvı/su damlası yüksek temas açısı
ile durmasına karşılık gaz/hava kabarcığı yüzeyde yayılmaktadır.
Süperhidrofobik yüzeyler için Cassie ve Wenzel olmak iki farklı durum
mevcuttur. Her iki durumda da yüzeyin temas açısı yüksek olmasına karşılık
Cassie durumda temas açısı histerezisi düşük Wenzel durumda ise yüksek
olmaktadır. Cassie durum süperhidrofobik yüzeyler üzerindeki sıvı damlası
yüzeyle çok az noktalardan temas etmesi sayesinde küçük bir dış kuvvet
etkisiyle yüzeyden uzaklaştırılabilmektedir. Süperhidrofobik yüzeyler sıvı
içerisine daldırıldıklarında etrafı ince bir hava filmi ile kaplanmaktadır. Bu
şekildeki yüzeye alttan gönderilen hava kabarcığı yüzeydeki hava filmine nüfuz
ederek kaybolmaktadır. Yüzey üzerindeki kabarcık ise yüzeyde yayılmaktadır.
Süperhidrofobik yüzeyler donma/buzlanmasının önlenmesi, film/damla yoğuşmanın
kontrolü, kaynamada oluşan hava kabarcık dinamiğinin kontrolü gibi birçok
alanlarda uygulama alanları bulunmaktadır.

Anahtar Kelimeler

Süperhidrofobik yüzey, Temas açısı, Temas açısı histerezisi, Sıvı jeti, Sıvı damlası, Gaz kabarcığı

Kaynakça

• Neinhuis C, Barthlott W. "Characterization and distribution of water-repellent, self-cleaning plant surfaces". Annals of Botany, 79(6), 667-677, 1997.
• Young T. "An Essay on the cohesion of fluids". Philosohical Transactions of the Royal of London, 95, 65-87, 1804.
• Erbil HY, Demirel AL, Avci Y, Mert O. "Transformation of a simple plastic into a superhydrophobic surface". Science, 299(5611), 1377-1380, 2003.
• He Y, Jiang C, Cao X, Chen J, Tian W, Yuan W. "Reducing ice adhesion by hierarchical micro-nano-pillars". Applied Surface Science, 305, 589-595, 2014.
• Xu W, Choi CH. "From sticky to slippery droplets: Dynamics of contact line depinning on superhydrophobic surfaces". Physical Review Letters, 109(2), 1-5, 2012.
• Dorrer C, Rühe J. "Micro to nano: Surface size scale and superhydrophobicity". Beilstein Journal of Nanotechnol, 2, 327-332, 2011.
• Latthe SS, Terashima C, Nakata K, Sakai M, Fujishima A. "Development of sol-gel processed semi-transparent and self-cleaning superhydrophobic coatings". Journal of Materials Chemistry A, 2, 5548-5553, 2014.
• Blake TD. "The physics of moving wetting lines". Journal of Colloid and Interface Sciences, 299(1), 1-13, 2006.
• Aljallis E, Sarshar MA, Datla R, Sikka V, Jones A, Choi CH. "Experimental study of skin friction drag reduction on superhydrophobic flat plates in high Reynolds number boundary layer flow". Physics of Fluids, 25(2), 1-14, 2013.
• Merkle CL, Deutsch S. "Drag reduction in liquid boundary layers by gas injection. Viscous Drag Reduct Bound Layers". Washington, USA, Fluid Mechanics and Heat Transfer, A91-12688 02-34, 1990.
• Stephani KA, Goldstein DB. "An Examination of trapped bubbles for viscous drag reduction on submerged surfaces". Journal of Fluids Engineering, 132(4), 41303-41311, 2010.
• Zhang P, Lv FY. "A review of the recent advances in superhydrophobic surfaces and the emerging energy-related applications". Energy, 82, 1068-1087, 2015.
• Dotan A, Dodiuk H, Laforte C, Kenig S. "The relationship between water wetting and ice adhesion". Journal of Adhesion Sciences Technology, 23(15), 1907-1915, 2009.
• Gao L, McCarthy TJ. "Teflon is hydrophilic. Comments on definitions of hydrophobic, shear versus tensile hydrophobicity, and wettability characterization". Langmuir, 24(17), 9183-9188, 2008.
• Antonini C, Innocenti M, Horn T, Marengo M, Amirfazli A. "Understanding the effect of superhydrophobic coatings on energy reduction in anti-icing systems". Cold Regions Science and Technology, 67(1-2), 58-67, 2011.
• Bisetto A, Torresin D, Tiwari MK, Del Col D, Poulikakos D. "Dropwise condensation on superhydrophobic nanostructured surfaces: literature review and experimental analysis". Journal of Physics Conferences Series, 501, 1-10, 2014.
• Miljkovic N, Wang EN. "Condensation heat transfer on superhydrophobic surfaces". MRS Bulletion, 38(5), 397-406, 2013.
• Chen CH, Cai Q, Tsai C, Chen CL, Xiong G, Yu Y, et al. "Dropwise condensation on superhydrophobic surfaces with two-tier roughness". Applied Physics Letters, 90, 173108-173110, 2007.
• Khoufech A, Benali M, Saleh K. "Influence of liquid formulation and impact conditions on the coating of hydrophobic surfaces". Powder Technology, 270, 599-611, 2015.
• Richard D, Quéré D. "Bouncing water drops". Europhysics Letters, 50(6), 769-775, 2000.
• Yarin AL. "Drop impact dynamics: splashing, spreading, receding, bouncing". Annual Reviews of Fluid Mechanics, 38, 159-192, 2006.
• Craik ADD, Latham RC, Fawkes MJ, Gribbon PWF. "The circular hydraulic jump". Journal Fluid Mechanics, 112, 347-362, 1981.
• Kate RP, Das PK, Chakraborty S. "Hydraulic jumps due to oblique impingement of circular liquid jets on a flat horizontal surface". Journal of Fluid Mechanics, 573, 247-263, 2007.
• Maynes D, Johnson M, Webb BW. "Free-surface liquid jet impingement on rib patterned superhydrophobic surfaces". Physics of Fluids, 23(5), 52104, 2011.
• Prince JF, Maynes D, Crockett J. "On jet impingement and thin film breakup on a horizontal superhydrophobic surface". Physics of Fluids, 27(11), 112108, 2015.
• Kibar A, Karabay H, Yiǧit KS, Ucar IO, Erbil HY. "Experimental investigation of inclined liquid water jet flow onto vertically located superhydrophobic surfaces". Experiments in Fluids, 49(5), 1135-1145, 2010.
• Kibar A. "Experimental and numerical investigations of the impingement of an oblique liquid jet onto a superhydrophobic surface: energy transformation". Fluid Dynamics Research, 48, 015501, 2016.
• Kibar A. "Experimental and numerical investigation of liquid jet impingement on superhydrophobic and hydrophobic convex surfaces". Fluid Dynamics Research, 49, 015502, 2017.
• Mertens K, Putkaradze V, Vorobieff P. "Morphology of a stream flowing down an inclined plane. Part 1. Braiding". Journal of Fluid Mechanics, 531, 49-58, 2005.
• Ozbay R, Kibar A, Choi CH. Bubble adhesion to superhydrophilic surfaces. Editor: Mittal KL. Advances in. Contact Angle, Wettability and Cohesion, Vol. Two, 149-162, Hoboken, USA, Wiley-Scrivener, 2015.
• Sheng X, Zhang J. "Air layer on superhydrophobic surface underwater". Colloids and Surfaces A: Physicochemical and Engineering Aspects, 377(1-3), 374-378, 2011.
• Kibar A, Ozbay R, Sarshar MA, Kang YT, Choi CH. "Air bubble movement over and under hydrophobic surfaces in water". 8th International Conference on Multiphase Flow ICMF, Jeju, Korea, 26-31 May 2013.