Contact angle studies on anodic porous alumina

Redón, Rocı́o; Vázquez-Olmos, A.; Mata-Zamora, M.E.; Ordóñez-Medrano, A.; Rivera-Torres, Filiberto; Sániger, José M.

doi:10.1016/j.jcis.2005.02.036

Cited by 76 publications

(66 citation statements)

References 27 publications

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“…The overshoot in the Fig. 1 may be due to oligomers and dimmers formed at the first instance (Gade et al, 2006) or due to time taken for wetting between a liquid and a solid surface (Redon et al, 2005). The very small size of the overshoot compared to the steady state value reveals that the significance of them is small and it had become steady within a few seconds.…”

Section: Sensor Fabricationmentioning

confidence: 95%

“…As the feasibility of high enzyme loading and enhanced characteristics have been proved by using commercially available nano-porous alumina Anodisc TM s, the same nano-porous alumina membrane can be produced by using fabrication procedures reported by several researches (Redon et al, 2005;Yang et al, 2003;Yu et al, 2006) to optimize the pore size and electrode thickness to gain much improved performances of biosensors.…”

Section: Measurements and Calculationsmentioning

confidence: 99%

See 1 more Smart Citation

Polypyrrole nanotube array sensor for enhanced adsorption of glucose oxidase in glucose biosensors

Ekanayake¹,

Preethichandra²,

Kaneto³

2007

Biosensors and Bioelectronics

185

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Section: Sensor Fabricationmentioning

confidence: 95%

Section: Measurements and Calculationsmentioning

confidence: 99%

Polypyrrole nanotube array sensor for enhanced adsorption of glucose oxidase in glucose biosensors

Ekanayake¹,

Preethichandra²,

Kaneto³

2007

Biosensors and Bioelectronics

185

View full text Add to dashboard Cite

“…As Redón et al 21 showed, the PAA surfaces interact with liquid phases via surface groups, thus, the polar component partially defines the strength of the interaction between the liquid and the PAA surface. 34 Water exhibits high values of the dielectric constant (ε r ) and dipole moment (μ), but it also has the highest value of the surface tension (γ) which prevents water from spreading and filling the pores to afford high equilibrium contact angle (θ eq ) values and so results in a worse hydrogen bond interaction with the hydroxide groups from the PAA surface with respect to DMSO which has higher values of ε r and μ, but lower γ and therefore a higher wetting force.…”

Section: Resultsmentioning

confidence: 99%

“…It has been shown that in case of low energy liquids such as dimethyl sulfoxide (DMSO), the equilibrium is achieved between polar and surface tension properties for a complete filling of the porous surface. 21 Although many efforts have been made for ZnO synthesis by template electrodepositon, it has not yet been fully exploited from an industrialization standpoint. It is still a challenge to design highly transparent electrodes based on single-crystalline ZnO nanorod arrays in order to be integrated in hybrid devices since controlling the nanowires/nanorods orientation and position during the deposition is highly important as it facilitates the subsequent fabrication processes in the design of new devices.…”

mentioning

confidence: 99%

High-Efficiency Electrodeposition of Large Scale ZnO Nanorod Arrays for Thin Transparent Electrodes

Pullini¹,

Prună²,

Zanin³

et al. 2011

J. Electrochem. Soc.

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In the present work an effective technique to synthesize large-scale c-axis oriented ZnO nanorod (NR) arrays is presented. The manuscript reports a single-step cathodic electrodeposition, either in aqueous and organic electrolytes, to fill up ultra-thin anodic nanoporous alumina templates. Prior to growing, self-ordered hexagonal array of cylindrical nanopores have been fabricated by anodizing Al thin films previously deposited onto ITO/glass substrates. The diameter and the aspect ratio of the vertically aligned nanopores are about 60 nm and 8:1, respectively. The results of this work demonstrate that using dimethyl sulfoxide (DMSO) as an electrolyte leads to a growth more homogeneous in shape and crystallinity, and with 60% deposition efficiency -the highest by now in literature. This fact is most probably due to a better infiltration of the alumina nanopores by this electrolyte. SEM and XRD analysis were employed for the study of morphology and crystalline structure of the obtained ZnO NR. These measurements showed furthermore that ZnO nanorod arrays are uniformly embedded into the hexagonally ordered nanopores of the anodic alumina membrane. DMSO proved to be an optimal electrolyte to obtain single-crystalline ZnO NR arrays, highly transparent in visible light range (80% transmittance). In recent years, self-assembled semiconductor nanostructures have attracted much interest, since they hold promise for various applications.1 Based on their remarkable physical properties and the motivation for device miniaturization, large effort has been focused on the synthesis, characterization and device applications of zinc oxide (ZnO) nanomaterials. ZnO has applications in optoelectronics in the ultraviolet (UV) and blue spectral region, piezoelectric devices, chemical sensors and spin electronics.2-5 Compared with other wide gap semiconductors, ZnO has a larger extinction binding energy (60 meV), which provides more efficient excitonic emission at room temperature.An assortment of ZnO nanostructures, such as nanowires, nanotubes or nano-tetrapods have been successfully grown via a variety of methods including chemical vapor deposition, thermal evaporation and electrodeposition.6-8 A popular strategy of ZnO nanowire synthesis is the vapor phase method, such as the (metal-catalyzed) thermal vapor transport and sedimentation method. 9 Besides the limitations of a high preparation temperature and energy-consuming experiment facilities, these vapor-phase methods usually need expensive and/or insulating substrates, such as sapphire 10 or gallium nitride (GaN) 11 for epitaxial growth. On the contrary, solution approaches are attractive due to their low cost and high yield. Electrodeposition is a cost-effective and very powerful method to grow and tailor a large range of materials. 12-14 For preparing one-dimensional nanostructure arrays, the most direct route and an elegant approach is the templateassisted method. 15 The ordered array of pores of high aspect ratio whose dimensions can be accurately tuned by the process param...

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“…8, contact angle changed mostly as the result of the decrease in droplet height due to the wetting behavior caused by water penetration into the nanofiber membrane rather than water spreading on the membrane surface. Since nanofiber membranes were materials with large porosity, water firstly spread on the pore walls in a constant rate and then filled in the space between fibers [25]. As a result, the membranes consist of thinner nanofibers presented higher water penetration rate due to their lager surface area and internal porosity [26].…”

Section: Water Contact Anglementioning

confidence: 99%

Effects of ethanol and isopropanol on the structures and properties of polyethersulfone/perfluorosulfonic acid nanofibers fabricated via electrospinning

Yang

et al. 2012

J Polym Res

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Blend solutions of polyethersulfone (PES) and perfluorosulfonic acid (PFSA) resin were fabricated into nanofibers via electrospinning. Ethanol (EtOH) and isopropanol (IPA) were employed to investigate the effects of nonsolvent (NS) on the structures and properties of the electrospun PES/PFSA nanofibers. Average diameters of the electrospun nanofibers increased with NS content while the water contact angles of the nanofiber membranes decreased. Although all the nanofiber membranes presented strong hydrophobicity initially, the water contact angle would drop to less than 90°within 30 min. Energy dispersive X-ray spectrums (EDS) showed that the nanofibers electrospun from solutions with more NS presented higher sodium content on the surface because more -SO 3 Na groups were on the external plane. N 2 adsorption-desorption measurement revealed that increase of NS content in the solvent mixtures resulted in nanofibers with surface area much bigger in experiment than that in calculation, which meant rough structures occurred on the surface of electrospun nanofibers. These rough structures were beneficial to improve the frictional resistance between nanofibers and therefore enhanced the break strength and Young's modulus of the nanofiber membranes.

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Contact angle studies on anodic porous alumina

Cited by 76 publications

References 27 publications

Polypyrrole nanotube array sensor for enhanced adsorption of glucose oxidase in glucose biosensors

Polypyrrole nanotube array sensor for enhanced adsorption of glucose oxidase in glucose biosensors

High-Efficiency Electrodeposition of Large Scale ZnO Nanorod Arrays for Thin Transparent Electrodes

Effects of ethanol and isopropanol on the structures and properties of polyethersulfone/perfluorosulfonic acid nanofibers fabricated via electrospinning

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