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Contact angle measurements of (a) Pt nanorods, (b) Teflon thin film, (c) Pt nanorods with glancing angle deposited (GLAD) Teflon tips for different deposition times of 1 and 5 min, and (d) Pt nanorods with normal incidence deposited Teflon capping for different deposition times of 20 s and 5 min.
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Introducing a hydrophobic property to vertically aligned hydrophilic metallic nanorods was investigated experimentally and theoretically. The platinum nanorod arrays were deposited on flat silicon substrates using a sputter glancing angle deposition technique (GLAD). Then a thin layer of Teflon (nanopatch) was partially deposited on the tips of pla...
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Context 1
... contact angle larger than 90 • denotes a hydrophobic surface and gets close to 180 • for superhydrophobic surfaces, resulting in a spherical water droplet. The contact angle measurements of Pt nanorods, Teflon thin film, and Pt nanorods coated with Teflon tips are shown in figure 4. It is well known that substances such as Pt and Teflon exhibit different behavior when their surfaces get in contact with a water droplet. ...
Context 2
... contact angle measurements of Pt nanorods, Teflon thin film, and Pt nanorods coated with Teflon tips are shown in figure 4. It is well known that substances such as Pt and Teflon exhibit different behavior when their surfaces get in contact with a water droplet. It was found that the average contact angle of Pt nanorods was about 52 • , as shown in figure 4(a), indicating a hydrophilic surface. This value is comparable with the previously reported contact angle of Pt nanorods [23]. ...
Context 3
... value is comparable with the previously reported contact angle of Pt nanorods [23]. Similarly, for the normal angle deposited flat Teflon thin film, the average contact angle was about 108 • (see figure 4(b)), which indicates a hydrophobic surface, and it is in close agreement with the previously reported values of the contact angle of Teflon films [1,10]. [14,15] is likely due to the competition between the hydrophilic Pt nanorod base and the hydrophobic Teflon patches at the nanorod tips. ...
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Introducing a hydrophobic property to vertically aligned hydrophilic metallic nanorods was investigated experimentally and theoretically. First, platinum nanorod arrays were deposited on flat silicon substrates using a sputter Glancing Angle Deposition Technique (GLAD). Then a thin layer of Teflon (nanopatches) was partially deposited on the tips o...
Nanoparticles of TiO2 were successfully prepared from pre-sputtered Ti films using the controlled thermal oxidation. The effect of oxidation temperature on structural, morphological and optical properties in addition to photocatalysis activity of the sputtered films was tested and explained. Analysis of XRD and EDAX elucidated the enhancement in cr...
In the present work, HfO2 thin film (100nm) has been deposited by sputtering technique and annealed at various temperatures ranging from 400 to 1000 ºC (in step of 200 ºC) in O2 ambient for 10 min. The samples have been characterized using XRD, FTIR, EDAX, AFM and Laser Ellipsometer. The impact of annealing temperatures in O2 ambient on structural...
Citations
... So we have measuredcontact angle and surface energy of water and aniline for zirconium oxide films deposited at various oxygen partial pressures as shown in Fig. 2a and Fig. 2b. The surfaceenergy is inversely proportional to the contact angle values (Khudhayer et al., 2009). The deposited zirconium oxide films are hydrophobic having contact angle values of morethan 90º at various oxygen partial pressures. ...
Thin films of zirconium oxide were synthesized by magnetron sputtering process using Zr target. The effect of oxygen partial pressure variation at 22%, 50%, 71% and 82% values on deposited zirconium oxide thin films was studied. The crystallinity of nano-structured zirconium oxide thin films was determined by X-ray Diffraction (XRD) technique. The increase in oxygen partial pressure leads to increase in crystallinity of (111) m-phase giving maximum intensity at 71% oxygen partial pressure. Contact angle measuring system was used to determine the wettability properties of zirconium oxide thin films namely: contact angle and surface energy. The zirconium oxide thin films changes its behavior from hydrophilic to hydrophobic with increase in oxygen partial pressure. The transmission and band gap were investigated to examine the optical properties of deposited nano-structured zirconium oxide thin films
... The reason behind such behavior is surface roughness and the formation of TiO 2 . TiO 2 is more hydrophilic in nature than TiN, 38,39 so it is obvious to observe a reduction in contact angle at 973 K. ...
Structural and wettability properties of titanium nitride (TiN) thin films for different annealing temperatures have been characterized, and critical parameters have been identified. TiN thin films were deposited onto the silicon substrates by using the magneto-sputtering technique for two different powers, 150 W and 350 W. Subsequently, the films were annealed in the air at 573-973 K for the duration of 1 h. The X-ray diffraction spectra showed the appearance of titanium dioxide (TiO 2) above 773 K temperature (termed as transformation temperature). The relative intensity of the TiO 2 peaks rapidly increase with the temperature. The thin and dense oxide overlayer appeared at 773 K, and the thicker oxide layer was observed at 973 K. Surface roughness is observed to increase with the increase in annealing temperature but with the limiting value at 773 K; after that, the roughness decreases because of the stable formation of TiO 2. Similarly, with an increase in temperature, the hydrophobic nature of thin films becomes more significant; however at 973 K, the formation of TiO 2 declines the hydro-phobic nature, and thus the surface energy increases. Transformation temperature is also found to be responsible for the reduction in grain size and compressive strain of the thin film. Nomenclature α = Coefficient of thermal expansion γ = Surface energy θ = Diffraction angle θ e = Equilibrium contact angle λ = X-ray wavelength ε = Strain
... The spaces between nanorods was increased; and concomitantly, 2. the amount of surface available to contact liquid water was decreased. These changes results in an increase in the area fraction of the trapped air beneath the water droplet leading to increased contact angle [40]. ...
Surface enhanced Raman scattering (SERS) is a surface sensitive technique that is attractive for molecular detection. SERS performance has nanometallic structure dependence however fabrication of a substrate with high sensitivity, uniformity, reproducibility and stability is still one of the most active topics in SERS research. In this study, we report the fabrication of Au-Ag dealloyed nanorod SERS substrates via a co-sputtering technique by oblique angle deposition (OAD) followed by selective chemical etching. Substrates were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, water contact angle, ultraviolet-visible spectrometry, x-ray diffraction, acid-base titration, and Raman spectroscopy. Results showed that the surface roughness increases on the dealloyed substrate compared to the alloy substrate and more gold atoms are available on the surface of the dealloyed substrates for 4-MBA absorption which played a vital role in enhancing the SERS effect. The optimal SERS substrate was achieved by etching in methanol, hydrogen peroxide, and ammonium hydroxide solution for 40 s. The Au-Ag dealloyed substrates exhibited increased SERS enhancement factor in the range of 1.5x10⁶. Long-term stability of the optimal dealloyed substrates was observed over a month of storage time under ambient conditions, superior to the Au-Ag alloyed and Ag only nanorod substrates. In addition, the Au-Ag dealloyed substrates demonstrated uniformity and reproducibility with an acceptable relative standard deviation.
... As a result, the highest contact angle of 101°was achieved at 4.5 sccm oxygen flow rate. Surface energy and contact angle are inversely proportional to each other [8]. The tantalum oxide-nitride thin films are hydrophobic and have higher contact angle and lower surface energy values. ...
Tantalum oxynitride thin films were prepared by reactive sputtering. The argon and nitrogen flow rate were kept stable whereas oxygen flow rate was incremented periodically. The effect of oxygen flow rate on various properties of tantalum oxynitride thin films is reported in this research paper. XRD patterns of tantalum oxynitride thin films displayed peaks commonly as for nano-crystalline materials. Surface topography observed to be smooth and exhibited smaller grain structure. Wettability test showed promising results for hydrophobicity. Wear test was done on uncoated and coated tantalum oxynitride thin films on 10 mm diameter cylindrical pins of brass and mild steel.
... So we have measuredcontact angle and surface energy of water and aniline for zirconium oxide films deposited at various oxygen partial pressures as shown in Fig. 2a and Fig. 2b. The surfaceenergy is inversely proportional to the contact angle values (Khudhayer et al., 2009). The deposited zirconium oxide films are hydrophobic having contact angle values of morethan 90º at various oxygen partial pressures. ...
Thin films of zirconium oxide were synthesized by magnetron sputtering process using Zr target. The effect of oxygen partial pressure variation at 22%, 50%, 71% and 82% values on deposited zirconium oxide thin films was studied. The crystallinity of nano-structured zirconium oxide thin films was determined by X-ray Diffraction (XRD) technique. The increase in oxygen partial pressure leads to increase in crystallinity of (111) m-ZrO2 phase giving maximum intensity at 71% oxygen partial pressure. Contact angle measuring system was used to determine the wettability properties of zirconium oxide thin films namely: contact angle and surface energy. The zirconium oxide thin films changes its behavior from hydrophilic to hydrophobic with increase in oxygen partial pressure. The transmission and band gap were investigated to examine the optical properties of deposited nano-structured zirconium oxide thin films.
... They found 14.38nm surface roughness at 250W of RF power and concluded that with a rise in ZnO coating thickness its surface roughness also increases. W.J. Khudhayer et al. 28 noted that with rise in ZnO coating thickness, the surface roughness is also increased and with that contact angle also increases. So the roughness of surface and contact angle exhibit a direct relationship. ...
This paper is aimed to synthesize reactive sputtered ZnO coatings at altered RF powers of 50W, 75W, 100W and 125W and study it's, optical structural and wettability properties. For characterization of ZnO coatings, X technique was used. XRD graphs indicate power from 50W to 125W. ZnO thin films become well crystalline with along (002) texture is observed. Surface energy and goniometer. UV-Vis-NIR spectrophotometer was utilized to differentiate optical properties of zinc oxide films
... for different argon:oxygen gas flow ratio as given in Table 1. ZnO films are getting thicker with larger average crystallize size as the proportion of argon increases and oxygen decreases in argon:oxygen gas flow ratio resulting in higher band gap values which are consistent with literatures [12][18][23] [25]. The transmission of ZnO films also decreases with increase in argon:oxygen gas flow ratio as evident from Fig. 2 resulting in more absorption and greater band gap values. ...
... Surfaces with high thickness of film commonly show fewer mechanical properties than flat surfaces, and this is a crucial problem for the application of highly hydrophobic surfaces [26]. Surface energy and contact angle are inversely proportional to each other [25]. Wettability of solid surface is determined through contact angle. ...
Nano-structured zinc oxide thin films were deposited on corning glass substrate by magnetron sputtering process. Zinc oxide films were deposited at different gas ratio values of argon:oxygen kept at 2sccm:18sccm, 6sccm:14sccm, 10sccm:10sccm and 14sccm:6sccm. X-ray Diffraction (XRD) technique was used to characterize ZnO thin films. The XRD graphs indicate presence of (100) and (002) peaks for ZnO thin films. Contact angle and surface energy of nano-structured ZnO thin films were determined by contact angle goniometer. Zinc oxide films are hydrophobic by nature and their contact angle value varies from 98.3° to 102.1° with decrease in flow rate of oxygen gas and increase in argon gas flow rate. UV-Vis-NIR spectrophotometer was used to characterize optical properties of ZnO thin films.
... This combination of properties is attractive for an extensive variety of applications which include laser mirrors, broadband interference filters and ionic conductors. In addition, thin ZrO 2 film is considered as a potential contender to supplant SiO 2 as high k gate dielectric in complementary metal-oxidesemiconductor technology, due to its high bulk dielectric constant (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30), wide energy band gap and offsets alonf with good thermal stability with silicon surface [3], [4]. However, in practice the suitability of ZrO 2 for these applications is questionable because it is known to experience several structure transformations (cubic phase, tetragonal phase, monoclinic phase, and amorphous structure) as a function of temperature [5]. ...
... The variation of surface energy and contact angle for zirconium oxide films as a function of argon partial pressure for water and aniline is shown in Fig. 4. (a) & (b) respectively. The surface energy is inversely proportional to the contact angle values [22]. The maximum contact angle values of 101º for water were observed at 45% argon partial pressure whereas contact angle of 49º for aniline was observed having surface roughness of 1.75nm at 45% argon partial pressure for deposited zirconium oxide films. ...
The aim of this paper is to deposit zirconium oxide films by magnetron sputtering process at different argon partial pressure values of 45%, 55%, 62% and 67%. The effect of argon partial pressure on structural, optical and wettability properties of zirconium oxide films is investigated in this research work. The increase in argon partial pressure leads to increase in intensity of (111) peak for zirconium oxide thin films as observed by X-ray Diffraction. The average crystallite size of zirconium oxide films increases from 19nm to 25nm with increase in argon partial pressure. Wettability properties of zirconium oxide films such as contact angle and surface energy were determined by contact angle measuring system. The minimum transmission values above 63% were observed for all zirconium oxide thin films deposited at different argon partial pressure. Band gap and refractive index of zirconium oxide thin films varies as a function of argon partial pressure.
... Furthermore, a new contact angle model utilizing Cassie and Baxter theory for heterogeneous surfaces was developed in order to explain the enhanced hydrophobicity of Pt/PTFE nanorods. According to the model, the solid-liquid interface is mainly at the PTFE tips, when the composite nanorods are in contact with water [7,8]. Similar results were obtained on hydrophobicity of the PTFE coated ZnO nanorods by using RF-MSp of PTFE [9]. ...
The paper summarizes in brief applications of perfluoropolymer thin films deposited from the gas phase by several different methods, for protection of various materials and devices both at the research stage and already in industry. Perfluoropolymer films protect from corrosion coated metals, attain superhydrophobic properties to various surfaces, enhance the lifetime of medical implants, passivating the surface of semiconductors, protect functional layers in organic light emitting diodes, field effect transistors etc. Organic molecules in the PTFE matrix revealed extreme stability and presents the new material for optical applications.
... The high versatility of this technique in obtaining different nanostructures (metals, organic compounds, oxides, hybrids and other complex heterostructures) is an additional feature that supports its use for wetting applications. Important achievements have been made in the last few years through the OAD fabrication of surfaces possessing singular adhesive properties [555], hydrophobicity [556][557][558][559], superhydrophobicity [186][187][188]557,[560][561][562][563], superhydrophilicity [366] or superolephobicity [564,565]. Initial approaches to the development of highly hydrophobic surfaces by OAD combined the surface nanostructuration capability of this technique with the chemical modification of the surface composition by different methods. ...
... Initial approaches to the development of highly hydrophobic surfaces by OAD combined the surface nanostructuration capability of this technique with the chemical modification of the surface composition by different methods. For example, the RF sputtering deposition at oblique and normal incidence of polytetrafluoroethylene (PTFE), a hydrophobic material commonly known as Teflon, has been reported to increase the water contact angle of OAD Pt [556] and W nanorods [558,559]. In this way, superhydrophobic WCAs as high as 138°and 160°, respectively, were achieved by controlling the deposition angle, substrate rotation and reactor pressure. ...
The oblique angle configuration has emerged as an invaluable tool for the deposition of nanostructured thin films. This review develops an up to date description of its principles, including the atomistic mechanisms governing film growth and nanostructuration possibilities, as well as a comprehensive description of the applications benefiting from its incorporation in actual devices. In contrast with other reviews on the subject, the electron beam assisted evaporation technique is analyzed along with other methods operating at oblique angles, including, among others, magnetron sputtering and pulsed laser or ion beam-assisted deposition techniques. To account for the existing differences between deposition in vacuum or in the presence of a plasma, mechanistic simulations are critically revised, discussing well-established paradigms such as the tangent or cosine rules, and proposing new models that explain the growth of tilted porous nanostructures. In the second part, we present an extensive description of applications wherein oblique-angle-deposited thin films are of relevance. From there, we proceed by considering the requirements of a large number of functional devices in which these films are currently being utilized (e.g., solar cells, Li batteries, electrochromic glasses, biomaterials, sensors, etc.), and subsequently describe how and why these nanostructured materials meet with these needs.
