Nanoparticle shapes by using Wulff constructions and first-principles calculations

• Georgios D. Barmparis,
• Zbigniew Lodziana,
• Nuria Lopez and
• Ioannis N. Remediakis

Beilstein J. Nanotechnol. 2015, 6, 361–368, doi:10.3762/bjnano.6.35

• shape of these nanoparticles. Wulff construction offers a simple method of predicting the equilibrium shape of nanoparticles given the surface energies of the material. Results: We review the mathematical formulation and the main applications of Wulff construction during the last two decades. We then

• -principles calculations, is a powerful tool for the analysis and prediction of the shapes of nanoparticles and tailor the properties of shape-inducing species. Keywords: density functional theory (DFT); hydrogen storage; multi-scale simulations; nanoparticles; surface energies; surfactants; Wulff

• calculations of surface energies are routinely employed to explain experimental findings and lead to the design of better materials with tailored properties. In the following, we review the concept of Wulff construction, present its mathematical formulation and limitations, and review modern uses in the

Aquatic versus terrestrial attachment: Water makes a difference

• Petra Ditsche and
• Adam P. Summers

Beilstein J. Nanotechnol. 2014, 5, 2424–2439, doi:10.3762/bjnano.5.252

• that account for the compliance of the substrate and the attachment organ, the surface energies and the shapes of real world examples of attachment. Submerged organisms must cope with water and also with ubiquitous biofilms. The complexities of a pure liquid pale in comparison to the presumably non

Synthesis of Pt nanoparticles and their burrowing into Si due to synergistic effects of ion beam energy losses

• Pravin Kumar,
• Udai Bhan Singh,
• Kedar Mal,
• Sunil Ojha,
• Indra Sulania,
• Dinakar Kanjilal,
• Dinesh Singh and
• Vidya Nand Singh

Beilstein J. Nanotechnol. 2014, 5, 1864–1872, doi:10.3762/bjnano.5.197

• melting of islands (melting point of Pt is ≈1768 K). The molten Pt islands take a spherical shape to minimize their surface energy (dewetting). The surface energies of Pt and silicon are 2.49 and 1.51 J/m2, respectively. There could be electronic sputtering of these molten Pt islands giving rise to a

Hydrophobic interaction governs unspecific adhesion of staphylococci: a single cell force spectroscopy study

• Nicolas Thewes,
• Peter Loskill,
• Philipp Jung,
• Henrik Peisker,
• Markus Bischoff,
• Mathias Herrmann and
• Karin Jacobs

Beilstein J. Nanotechnol. 2014, 5, 1501–1512, doi:10.3762/bjnano.5.163

• , surface roughnesses and surface energies for hydrophilic and hydrophobic wafers are given in Table 1 and streaming potential measurements reveal that both surfaces are negatively charged at the used pH of 7.3 (Table 1). For this study, OTS surfaces of the same batch as in [21] have been used. Prior to the

Template-directed synthesis and characterization of microstructured ceramic Ce/ZrO₂@SiO₂ composite tubes

• Jörg J. Schneider and
• Meike Naumann

Beilstein J. Nanotechnol. 2014, 5, 1152–1159, doi:10.3762/bjnano.5.126

• surface energies γ (11.3 × 10−5 Jcm2 vs 7.5–7.7 × 10−5 Jcm2) [17][18]. Consequently, the tetragonal phase is the more stable one for the solid solution Ce0.13/Zr0.87O2 due to its lower surface energy. Moreover, the incorporation of Ce4+ into its crystal lattice increases that effect. In addition to the

Plasma-assisted synthesis and high-resolution characterization of anisotropic elemental and bimetallic core–shell magnetic nanoparticles

• M. Hennes,
• A. Lotnyk and
• S. G. Mayr

Beilstein J. Nanotechnol. 2014, 5, 466–475, doi:10.3762/bjnano.5.54

• approaches are practicable. On the one hand, self organizational properties of matter at the nanoscale can be exploited. Immiscibility of the involved components combined with pronounced differences in surface energies can result in CS structures through a single step process relying on the creation of a

• alternative. For systematic experimental studies of these scenarios, Cu/Ni constitutes an interesting model system with a moderate miscibility gap in the bulk solid phase (Tc = 630 K) [26] and a moderate difference in the surface energies between Cu and Ni (γCu = 1.78 J/m2 and γNi = 2.37 J/m2) [27]. Recent

Single-asperity contact mechanics with positive and negative work of adhesion: Influence of finite-range interactions and a continuum description for the squeeze-out of wetting fluids

• Martin H. Müser

Beilstein J. Nanotechnol. 2014, 5, 419–437, doi:10.3762/bjnano.5.50

3D-nanoarchitectured Pd/Ni catalysts prepared by atomic layer deposition for the electrooxidation of formic acid

• Loïc Assaud,
• Evans Monyoncho,
• Kristina Pitzschel,
• Anis Allagui,
• Matthieu Petit,
• Margrit Hanbücken,
• Elena A. Baranova and
• Lionel Santinacci

Beilstein J. Nanotechnol. 2014, 5, 162–172, doi:10.3762/bjnano.5.16

• . Such a spherical morphology suggests a Volmer–Weber growth mechanism of Pd. Such a formation of 3D islands is due to the high difference of surface energies between the metallic Pd and the oxidized support [39][40]. The formation of 3D islands can also be supported by the H-hfac ligands that are

Synthesis of embedded Au nanostructures by ion irradiation: influence of ion induced viscous flow and sputtering

• Udai B. Singh,
• D. C. Agarwal,
• S. A. Khan,
• S. Mohapatra,
• H. Amekura,
• D. P. Datta,
• Ajay Kumar,
• R. K. Choudhury,
• T. K. Chan,
• Thomas Osipowicz and
• D. K. Avasthi

Beilstein J. Nanotechnol. 2014, 5, 105–110, doi:10.3762/bjnano.5.10

• implantation of Au atoms and of thermodynamic driving forces for embedding of Au NPs, which can result from different surface energies of NPs and the substrate. Experimental The glass substrates used for deposition were thoroughly cleaned with boiling trichloroethylene (TCE), then in boiling acetone, followed

• embedding of NPs result from the different surface energies, i.e., the surface energy of the particle and its substrate, and the particle–substrate interface energy. It is reported that surface energy of embedded NPs is less than the surface energy of both glass and NPs [23]. The ion bombardment provides

Dynamic nanoindentation by instrumented nanoindentation and force microscopy: a comparative review

• Sidney R. Cohen and
• Estelle Kalfon-Cohen

Beilstein J. Nanotechnol. 2013, 4, 815–833, doi:10.3762/bjnano.4.93

• [7] is still used today even at the nanoscale under certain limiting constraints. This theory was extended to a range of indenter geometries by Sneddon [8]. However, the pure Hertzian model does not consider surface energies and related adhesion forces, which become significant and may even dominate

• vicinity of the contact are significant. The Johnson–Kendall–Roberts (JKR) theory is appropriate for characterizing contacts of compliant samples with high surface energies, i.e., when there is strong adhesive contact between the tip and the sample [12]. This model balances the elastic energy with the

Distribution of functional groups in periodic mesoporous organosilica materials studied by small-angle neutron scattering with in situ adsorption of nitrogen

• Monir Sharifi,
• Dirk Wallacher and
• Michael Wark

Beilstein J. Nanotechnol. 2012, 3, 428–437, doi:10.3762/bjnano.3.49

• order to determine the structure, surface area and functionalities of the inorganic–organic materials. In addition inverse gas chromatography is quite often used to measure retention volumes in mesoporous silica gels or dispersive surface energies in glasses, for example [16][17]. However, these

Reduced electron recombination of dye-sensitized solar cells based on TiO₂ spheres consisting of ultrathin nanosheets with [001] facet exposed

• Hongxia Wang,
• Meinan Liu,
• Cheng Yan and
• John Bell

Beilstein J. Nanotechnol. 2012, 3, 378–387, doi:10.3762/bjnano.3.44

• crystal facets [4]. It has been reported that the average surface energies of the different facets of anatase TiO2 lie in the order of [001] (0.90 J/m2) > [100] (0.53 J/m2) > [101] (0.44 J/m2) [5]. Apparently, the lowest surface energy of the [101] facet is the most stable surface of the TiO2 material

Size-dependent phase diagrams of metallic alloys: A Monte Carlo simulation study on order–disorder transitions in Pt–Rh nanoparticles

• Johan Pohl,
• Christian Stahl and
• Karsten Albe

Beilstein J. Nanotechnol. 2012, 3, 1–11, doi:10.3762/bjnano.3.1

• . These are the with n = 1, …, 4 and , and their values are given in Table 1. We obtain the site-energy constants from the cohesive energies Ecoh = ε12 and the surface energies for the fcc(111) and fcc(100) surface σ111 = ε12 − ε9 and σ100 = ε12 − ε8. The used values for the surface energies given in

• nanometer-sized particles with n = 9201, 2075 and 807 atoms, corresponding to a diameter of 7.8, 4.3 and 3.1 nm, respectively. The cluster shape was obtained from a face-centered cubic lattice by the Wulff construction by using the (100) and (111) surface energies for platinum and rhodium. The cluster shape

• was fixed during the simulations. The ratios between the (100) and the (111) surface energies are very similar for platinum and rhodium (Pt: 1.33, Rh: 1.36), thus resulting in the same Wulff-shape for the particle sizes we used. At low temperature it is therefore justified to constrain the particle

Sorting of droplets by migration on structured surfaces

• Wilfried Konrad and
• Anita Roth-Nebelsick

Beilstein J. Nanotechnol. 2011, 2, 215–221, doi:10.3762/bjnano.2.25

• droplet and solid, M is that part of the droplet surface which is in contact with fluid #2 and Stot – S is the area where plane and fluid #2 are in contact. σ ≡ σ12, σs1 and σ2s denote the surface tensions (or surface energies) with respect to fluid #1/fluid #2, solid/fluid #1 and fluid #2/solid

• lies between the curves Θ0(ε) = θ and Θ1(ε) = θ (Figure 2). 2. If the value of the contact angle is fixed and lies within the interval 0° < θ < 90°, the surface energies of droplets sitting on cones whose apex half-angle ε are close to the value εmax given in Equation 14 are higher than the surface

• energies of droplets attached to cones with greater or smaller apex half-angles. 3. If the value of the contact angle is fixed and lies within the interval 90° < θ < 180°, W (ε, θ) exhibits a minimum at ε = εmin (Equation 15). Thus, the surface energies of droplets sitting on cones which are very

Structural and magnetic properties of ternary Fe_1–xMn_xPt nanoalloys from first principles

• Markus E. Gruner and
• Peter Entel

Beilstein J. Nanotechnol. 2011, 2, 162–172, doi:10.3762/bjnano.2.20

• valence electron concentration e/a [58]. While the L11 phase is energetically lowest in CuPt, the L10 phase is clearly favored for CoPt and even more so for FePt and MnPt. On the other hand, recent surface energy calculations [55] have shown that L11 FePt and CoPt alloys possess extremely low surface

• energies for purely Pt covered (111) surfaces. The corresponding values are significantly lower than the contribution for all other low index surfaces that have been obtained for the L10 arrangement. Modeling the competition of the surface and bulk energy contributions by varying with cluster size, in

Biomimetics inspired surfaces for drag reduction and oleophobicity/philicity

• Bharat Bhushan

Beilstein J. Nanotechnol. 2011, 2, 66–84, doi:10.3762/bjnano.2.9

• can be determined from the values of surface energies of various interfaces and contact angles of water and oil in air. Many superoleophobic surfaces have been developed by modifying the surface chemistry with a coating of extreme low surface energy materials [20][48][49][50][51][52][53][54]. Tuteja

• interfaces is reviewed. For underwater applications, we have reviewed oleophobicity/philicity of an oil droplet in water on surfaces with different surface energies of various interfaces and contact angles of water and oil droplets in air. This article provides a useful guide for the development of