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Search for "contact angle" in Full Text gives 141 result(s) in Beilstein Journal of Nanotechnology.
Oxygen-plasma-modified biomimetic nanofibrous scaffolds for enhanced compatibility of cardiovascular implants
Beilstein J. Nanotechnol. 2015, 6, 254–262, doi:10.3762/bjnano.6.24
- . Goniometry (contact angle measurements), scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS) measurements were used to evaluate the morphological and chemical changes induced by the plasma treatment. Moreover, depth-sensing nanoindentation was
- observed from the contact angle measurements presented in Table 1, the untreated PCL scaffold demonstrated a water contact angle of 91.3°. A significant decrease of the contact angle was found for both modified systems with insignificant differences in the measured values (21.4° and 19.8° for P = 20 W and
- not appear to have any additional effect as far as the goniometry analysis is concerned. It is worth noting that the presented data from the contact angle measurements are particularly valid only for comparative purposes as the nanofibrous scaffolds are not smooth and homogeneous solid surfaces but
Mechanical properties of MDCK II cells exposed to gold nanorods
Beilstein J. Nanotechnol. 2015, 6, 223–231, doi:10.3762/bjnano.6.21
- , of approximately 1 micrometer. While for untreated cells we found a pre stress of T0 = 0.7 ± 0.1 mN/m and an area compressibility modulus of KA = 0.8 ± 0.02 N/m assuming a radius of the cap of R1 = 12 μm and a contact angle of 0 = 20° (Figure 4) , cells exposed to CTAB coated gold nanorods even at
Synthesis of boron nitride nanotubes and their applications
Beilstein J. Nanotechnol. 2015, 6, 84–102, doi:10.3762/bjnano.6.9
- substrate where the contact angle was found to be more than 170° [8]. The origin of this super hydrophobicity was attributed to the surface morphology and adsorption capacity of BNNTs for airborne molecules [9]. BNNTs were also used to prepare composite materials to enhance their physical properties. Bansal
Formation of stable Si–O–C submonolayers on hydrogen-terminated silicon(111) under low-temperature conditions
Beilstein J. Nanotechnol. 2015, 6, 19–26, doi:10.3762/bjnano.6.3
- model we compare the results from reactions with bifunctional alkynes carried out under thermal treatment (<130 °C) and under UV irradiation, respectively. X-ray photoelectron spectroscopy and contact angle measurements showed that under thermal conditions, the Si–H surface predominately reacts to form
- UV-irradiated surfaces. Considering that the exposed end groups on the surface of the UV-irradiated samples were C–OH, the reason for the absorbance of water is considered to be a more hydrophilic surface. To further examine the nature of the grafting, contact angle (CA) measurements were performed
- susceptible to oxidation. The O 1s spectra from the ethynylbenzyl alcohol had been already discussed in the previous section with C–O contributing to the high percentage of oxygen observed. Conclusion From the XPS analysis and the contact angle measurements, several conclusions can be drawn from this study
The capillary adhesion technique: a versatile method for determining the liquid adhesion force and sample stiffness
Beilstein J. Nanotechnol. 2015, 6, 11–18, doi:10.3762/bjnano.6.2
- its elastic properties. Capillary bridges were thoroughly studied with respect to kinetics and geometry dependence, in addition to the investigation and discussion of the contact angle and the related capillary length. The nucleation radius and growth of the liquid meniscus pulled from a flat surface
- were studied by Debregeas et al. [16]. The contact angle and contact angle hysteresis measurements on a curved surface (lens) pulling away from a meniscus were used to determine the advancing and receding contact angle of different solid materials [17] and the dynamics of this formation process [18
- . The effect of the surface coating of human head hair on its adhesive properties is highly relevant, for example, in the field of hair cosmetics. We investigated natural hair, hair with silicone-coated ends (poly(dimethylsiloxane) (PDMS), Sylgard 184, Dow Corning, water contact angle approx. 110°) and
Si/Ge intermixing during Ge Stranski–Krastanov growth
Beilstein J. Nanotechnol. 2014, 5, 2374–2382, doi:10.3762/bjnano.5.246
- the sample, thus assessment of atomic ordering would be difficult to evidence in the APT volumes. In addition, {15 3 23} facets (contact angle ≈36°) and {105} facets (contact angle ≈11°, i.e., the facets on top of the island in Figure 5a) were not clearly identified in our measurements. However, one
Modification of a single-molecule AFM probe with highly defined surface functionality
Beilstein J. Nanotechnol. 2014, 5, 2122–2128, doi:10.3762/bjnano.5.221
- Information File 1). The slides were washed with DMF, CHCl3, MeOH, and dried in a stream of argon. After each modification process, the probe and substrate surfaces were characterized with FTIR and contact angle measurements. As shown in Figure S4 and Table S1 in Supporting Information File 1. AFM force
Properties of plasmonic arrays produced by pulsed-laser nanostructuring of thin Au films
Beilstein J. Nanotechnol. 2014, 5, 2102–2112, doi:10.3762/bjnano.5.219
- contact angle values around 90º and higher (e.g., 105º, 120º, 131º for Ni, Au and Cu, respectively) [28]. Recently, increasing interest in dewetting of thin metal films has occurred due to the fabrication potential for self-organized nanostructures [1][2][3][4][5][6][7][8][9], which can be applied for
- postulated how the NP shapes depend on the equilibrium of the surface tension forces [34]. The partially spherical/spheroidal shapes correspond to the case of partial wetting of the substrate by the molten metal and are characterized by a contact angle value of less than 90°. This angle approaches 180° in
Controlling the dispersion of supported polyoxometalate heterogeneous catalysts: impact of hybridization and the role of hydrophilicity–hydrophobicity balance and supramolecularity
Beilstein J. Nanotechnol. 2014, 5, 1749–1759, doi:10.3762/bjnano.5.185
- individual Keggin-POM units (Figure 8b). Contact angle measurements were performed in order to verify the effect of UV–ozone treatment on the hydrophobic property of HOPG. Table S1 (Supporting Information File 1) shows that water contact angle decreased from 62.5 to 25° when the UV–ozone treatment duration
Hydrophobic interaction governs unspecific adhesion of staphylococci: a single cell force spectroscopy study
Beilstein J. Nanotechnol. 2014, 5, 1501–1512, doi:10.3762/bjnano.5.163
- contact angle measurements, this protocol enables the preparation of a self-assembled monolayer (SAM) with a thickness of about 2.6 nm and an rms roughness below 0.2 nm. In [21] it was shown that the SAM is hydrophobic, homogeneous, dense, upright and in all-trans configuration. The contact angles
Surface topography and contact mechanics of dry and wet human skin
Beilstein J. Nanotechnol. 2014, 5, 1341–1348, doi:10.3762/bjnano.5.147
- were measured 5 times at different locations for each state of the skin by using a contact angle measurement device OCA20 (Dataphysics Instruments, Filderstadt, Germany). According to our measurements the advancing water contact angle on human wrist skin is (112.9 ± 1)° (mean ± s.e.m., n = 10) on dry
- skin and (121.4 ± 1.6)° (n = 9) on wet skin. The larger contact angle on wet skin could reflect either a change in the skin surface chemistry, or more likely may be due to the increase in the surface roughness of wet skin. The receding contact angle was not measured but it would be smaller than the
- advancing contact angle. In the literature, the values of the water contact angle on human skin range from 80 to 110° [7]. Results and Discussion Surface roughness power spectrum of skin Similar to [6] the measured height profiles z = h(x) were used to calculate the surface roughness power spectrum defined
Topology assisted self-organization of colloidal nanoparticles: application to 2D large-scale nanomastering
Beilstein J. Nanotechnol. 2014, 5, 1203–1209, doi:10.3762/bjnano.5.132
- containing PS beads and the contact angle between the droplet and the substrate, thus influencing the auto-organization process. Comparison of structures without template (simple self-organization) and structures with template (topology assisted self-organization) Although self-organization presents a simple
Physical principles of fluid-mediated insect attachment - Shouldn’t insects slip?
Beilstein J. Nanotechnol. 2014, 5, 1160–1166, doi:10.3762/bjnano.5.127
- 1 can be estimated by using By using a few experimentally accessible parameters such as mediating fluid height, viscosity, and contact angle (for a more detailed review on the challenges on measuring these parameters see [14]), this model can then be used to discuss and qualitatively predict a few
- model. The contact of a circular rigid disk (radius R) and a plane rigid surface is mediated by a thin fluid layer (height h). The contact angle of the fluid to the surface and the disk θ is assumed to be identical in this case. Regions of hydrodynamic and boundary lubrication of two fluid mediated
The study of surface wetting, nanobubbles and boundary slip with an applied voltage: A review
Beilstein J. Nanotechnol. 2014, 5, 1042–1065, doi:10.3762/bjnano.5.117
- this review, the influence of an applied voltage on the surface wettability, nanobubbles, surface charge density and slip length are discussed. The contact angle (CA) and contact angle hysteresis (CAH) of a droplet of deionized (DI) water on a hydrophobic polystyrene (PS) surface were measured with
- of liquid flow in micro/nano scale. In this review, recent studies on the effect of an applied voltage on surface wetting, nanobubbles at the interface, and boundary slip are summarized. Firstly, the influence of an applied voltage on the contact angle (CA) and contact angle hysteresis (CAH) on a
- section, a summary and an outlook are provided. Review 1 Contact angle and contact angle hysteresis with applied voltage When a voltage is applied to a droplet deposited on a solid surface, the surface tension between solid and liquid changes, which leads to a change of the wettability of the surface, the
Insect attachment on crystalline bioinspired wax surfaces formed by alkanes of varying chain lengths
Beilstein J. Nanotechnol. 2014, 5, 1031–1041, doi:10.3762/bjnano.5.116
- apparent contact angle of water, which were very close to those measured on plant surfaces bearing three-dimensional waxes (e.g., [49][50][51]). The tarsal attachment system of the C. septempunctata beetle used in this study has been previously described in detail by Gorb et al. [52]. The tarsus bears two
- -distilled water on wax surfaces were performed by using a high-speed optical contact angle measuring device OCAH 200 (DataPhysics Instruments GmbH, Filderstadt, Germany) according to the needle-in sessile drop method. For a detailed description of the method, see [50]. We applied 1 μL drops and ellipse
Measuring air layer volumes retained by submerged floating-ferns Salvinia and biomimetic superhydrophobic surfaces
Beilstein J. Nanotechnol. 2014, 5, 812–821, doi:10.3762/bjnano.5.93
- structured, superhydrophobic, self-cleaning plant surfaces (Lotus-effect) [1][2] there has been an increasing interest in superhydrophobic surfaces [3][4][5]. Superhydrophobicity describes the extreme repellence of water by a surface. The level of water repellence is usually described by the contact angle
- which is the angle between the solid and the liquid at the three-phase contact line. Contact angles above 90° are considered hydrophobic while surfaces with contact angles above 150° are called superhydrophobic [6][7][8][9]. Smooth surfaces can reach a maximum contact angle of 120° [10]. Accordingly
- of the surface structures (Cassie–Baxter wetting state) [13]. The contact angle of water droplets can be equally high in both wetting states [14][15]. However, in the Wenzel wetting state the water is in full contact with the surface and individual droplets adhere firmly [16]. In contrast to this in
The surface microstructure of cusps and leaflets in rabbit and mouse heart valves
Beilstein J. Nanotechnol. 2014, 5, 622–629, doi:10.3762/bjnano.5.73
- fabrication of valve substitutes or partial substitutes. Namely, the model may help ameliorate heart valve replacement surgery. Keywords: contact angle; geometric parameter; heart valve; hemocompatibility; microstructure; Introduction Bionics, or biomimetics, have made tremendous developments in the past
- be used to calculate the fractal roughness factor. By changing the roughness factor, the relationship between the contact angle of the rough surface θf and that of the smooth surface θY can be described by Equation 1: Where f1 and f2 are the surface area fractions of solid-liquid and gas-liquid on
- the contact depth h′ is determined by the contact angle between the droplet and the solid (namely Young’s contact angle θY), which is shown in Figure 9. Since the size of the droplet is much larger than that of the microstructure, the bottom of the droplet can be approximated as a straight line and
Manipulation of nanoparticles of different shapes inside a scanning electron microscope
Beilstein J. Nanotechnol. 2014, 5, 133–140, doi:10.3762/bjnano.5.13
- model can be applied to determine the geometry of the resulted Ag NP given that the contact angle of NP–substrate interface is known. In this case the real shape of the Ag NP is a truncated sphere. NP–substrate contact area. Depending on the NP morphology two basic approaches for the determination of
- of the contact: where Θ is the contact angle for Ag/SiO2 interface. As described previously [20], for sphere-like NPs contact mechanics (adhesive contact approach) must be applied. The contact area is typically calculated on the basis of continuum elasticity models for deformable spheres such as the
Cyclic photochemical re-growth of gold nanoparticles: Overcoming the mask-erosion limit during reactive ion etching on the nanoscale
Beilstein J. Nanotechnol. 2013, 4, 886–894, doi:10.3762/bjnano.4.100
- , the Au NP prepared by BCML on silica are stabilized by CVD-coating the substrate with OMTS. The success of this coating can be easily tested by contact angle measurements: The hydrophilic silica substrate changes its starting angle from almost zero to 104° due to the hydrophobic OTMS coating. The
- was analyzed by a self-made contact angle measurement system with a droplet volume of typically 10 µL. Schematics of nanopillar fabrication by applying Au NP as masks after fine tuning their size by an UV-light activated photochemical process. To stabilize the NP positions during the growth process
Micro- and nanoscale electrical characterization of large-area graphene transferred to functional substrates
Beilstein J. Nanotechnol. 2013, 4, 234–242, doi:10.3762/bjnano.4.24
- monoatomic thick membrane, due to an effect of constructive optical interference [21]. Since as-grown SiO2 typically exhibits a hydrophilic behaviour (as shown by contact-angle measurements, yielding values of 10 ± 2°), before graphene transfer proper surface treatments were performed to achieve a partially
- hydrophobic character (with contact-angle values of 52 ± 2°). The chemical status of the SiO2 surface before graphene transfer was also characterized by X-ray photoelectron spectroscopy (XPS) measurements. In Figure 2a the optical image of a large-area (cm2) graphene membrane transferred onto SiO2 is shown
- surface, contact-angle measurements on the as-received PEN substrate typically yield high values of the contact angle (≈80°), indicating the highly hydrophobic character of this surface. A representative morphological image of the PEN substrate is reported in Figure 3a, showing a high surface roughness
Functionalization of vertically aligned carbon nanotubes
Beilstein J. Nanotechnol. 2013, 4, 129–152, doi:10.3762/bjnano.4.14
Controlled deposition and combing of DNA across lithographically defined patterns on silicon
Beilstein J. Nanotechnol. 2013, 4, 72–76, doi:10.3762/bjnano.4.8
- temperature. On a sufficiently functionalized substrate, the droplet produces a contact angle of ≈90°, which makes it easy to gently move the droplet along the surface. In this experiment, we used a plastic pipette tip to drag the droplet out of the substrate. Preparation of DNA–peptide conjugates was
Friction and durability of virgin and damaged skin with and without skin cream treatment using atomic force microscopy
Beilstein J. Nanotechnol. 2012, 3, 731–746, doi:10.3762/bjnano.3.83
- . The nanoscale studies were performed by using atomic force microscope (AFM), and macroscale studies were performed by using a pin-on-disk (POD) reciprocating tribometer. It was found that damaged skin has different mechanical properties, surface roughness, contact angle, friction and durability
- common models for human skin. Surface roughness and mechanical properties are known to affect friction and these have been measured. A low contact angle is desirable for the adsorption of skin cream and has also been measured. Experimental Sample preparation There were four categories of skin samples
- reciprocating tribometer with a velocity 1 mm/s and at a normal load of 50 mN for 3000 cycles. Contact-angle measurements The apparent contact angles were measured for various samples. Measurements were made with a Rame-Hart automated goniometer model 290-F4, where 5 μL water droplets were deposited onto the
Conducting composite materials from the biopolymer kappa-carrageenan and carbon nanotubes
Beilstein J. Nanotechnol. 2012, 3, 415–427, doi:10.3762/bjnano.3.48
- angle increases linearly with CNT mass and volume fraction [8]. The contact angle of all buckypaper materials is higher than those of evaporation-cast films (Table 3). This could suggest that the CNT mass/volume fraction in the buckypapers is higher than those of the evaporation-cast samples. This is
- conductivity values of KC–SWNT buckypapers (25.4 ± 1.6 S/cm), were higher compared to those of the KC–MWNT buckypapers (16.4 ± 1.6 S/cm). Incorporation of the hydrophilic plasticizer glycerin in the composite films reduced their conductivity and contact angle values. For example, the conductivity of a KC–SWNT
- by mounting small pieces of films onto a brass stub (11 × 5 mm2) with double-sided, conductive carbon tape (Proscitech, Australia). Contact-angle measurements were carried out by using the sessile drop method on a goniometer (Data Physics SCA20), which was fitted with a digital camera. The contact
Variations in the structure and reactivity of thioester functionalized self-assembled monolayers and their use for controlled surface modification
Beilstein J. Nanotechnol. 2012, 3, 213–220, doi:10.3762/bjnano.3.24
- unless otherwise indicated. Contact angle goniometry, spectroscopic ellipsometry, XPS, ATR–FTIR, were all carried out as previously described [11][12]. Syntheses ω-Undecenylbromide was prepared as follows: In a round-bottom flask (500 mL) equipped with a magnetic stirring bar were placed CH2Cl2 (100 mL
- –4. The SAMs were characterized by contact angle, ATR–FTIR, UV–vis, ellipsometry, and XPS. These characterization tools were applied (as previously reported [12]) both on the directly deposited SAMs and on those that had been subjected to the oxidation reactions reported herein. General procedures
- . The SAM based on 1a (no methylene units) is relatively hydrophilic (contact angle 75°/67°) even when compared to the analogue containing only one methylene unit, 1b (82°/79°). This reflects both the shorter alkyl chain and the closer proximity of its carbonyl groups to the SAM surface. The contact
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