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Search for "free energy" in Full Text gives 134 result(s) in Beilstein Journal of Nanotechnology.

Three-gradient regular solution model for simple liquids wetting complex surface topologies

  • Sabine Akerboom,
  • Marleen Kamperman and
  • Frans A. M. Leermakers

Beilstein J. Nanotechnol. 2016, 7, 1377–1396, doi:10.3762/bjnano.7.129

Graphical Abstract
  • to arrange the fluid and the vacancies is given by and the mixing entropy is found by Smix = −kB·lnΩ = −kB(N·ln φ + NV·ln φV) with φ = N/M and kB the Boltzmann constant. The free energy of mixing is given by Fmix = Umix – T·Smix. Introducing the dimensionless free energy density f = Fmix/(Mb3kBT
  • ) wherein the thermal energy kBT and the volume V are used to reduce the free energy, we obtain the well-known regular solution free energy density: with φ + φV = 1. The first two terms are negative and promote the mixing of the solvent and vapour. The last term drives the demixing. The critical conditions
  • are found by setting the second and third derivatives of the free energy density (Equation 5) with respect to the volume fraction of liquid to zero. From such analysis it is found that there is a solubility gap as soon as χ > χcr = 2. By symmetry the critical density φcr = 1/2. Liquid/vapour interface
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Published 04 Oct 2016

Influence of ambient humidity on the attachment ability of ladybird beetles (Coccinella septempunctata)

  • Lars Heepe,
  • Jonas O. Wolff and
  • Stanislav N. Gorb

Beilstein J. Nanotechnol. 2016, 7, 1322–1329, doi:10.3762/bjnano.7.123

Graphical Abstract
  • surface free energy should be performed in the future. Attachment devices of Coccinella septempuctata (A) attachment devices. Tarsi of forelegs (B), midlegs (C), and hindlegs (D) in females are ventrally covered by different types of tenent setae (E–G). Tarsi of forelegs (H), midlegs (I), and hindlegs (J
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Published 22 Sep 2016

Microscopic characterization of Fe nanoparticles formed on SrTiO3(001) and SrTiO3(110) surfaces

  • Miyoko Tanaka

Beilstein J. Nanotechnol. 2016, 7, 817–824, doi:10.3762/bjnano.7.73

Graphical Abstract
  • be illustrated as shown in Figure 2. Figure 2a,b present the same schematic model being cut along different planes. They are drawn using only the least-energy surface and the second-least-energy surface, namely {110} and {100}, respectively. The surface free energy values are taken from the
  • in some cases. The shape of nanoparticles at surfaces is determined by the Wulff–Kaishev construction [59] such as where hi is the distance from the Wulff point to each facet, Δh is the distance from the Wulff point to the interface, γi is the surface free energy of the nanoparticle facet i, γSTO is
  • that of the STO substrate, and γint is the interfacial free energy, respectively. Since hi can be expressed in terms of geometrical factors such as height-to-length (h/l) ratios, the value of Δγ ≡ γSTO − γint for each nanoparticle shape can be obtained as for truncated pyramids, distorted hexagons seen
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Published 07 Jun 2016

Correlative infrared nanospectroscopic and nanomechanical imaging of block copolymer microdomains

  • Benjamin Pollard and
  • Markus B. Raschke

Beilstein J. Nanotechnol. 2016, 7, 605–612, doi:10.3762/bjnano.7.53

Graphical Abstract
  • elasticity and the hardness of the sample [32]. Polymers, including syndiotactic PMMA, tend to pack in a semi-ordered way to minimize the total free energy, though this is highly dependent on tacticity and molecular weight distribution [35]. Crystallinity also creates varying mechanical properties, as
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Published 22 Apr 2016
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  • increase in the sample surface area, which has an associated energy cost either due to elasticity or surface free energy, or both [19][20]. The overall effect is that as the tip travels into the surface, the surface profile evolves in a way that minimizes the associated energy cost. Third, these surface
  • free energy and elastic energy effects are often neither isotropic nor uniform, as there is generally a variation in the structure and morphology of most viscoelastic surfaces (e.g., polymers) in the horizontal direction (examples are provided below). Furthermore, at the scale of an AFM indentation it
  • mechanism to the total driving force counteracting increases in surface area can vary [19]. Some of the most striking examples of surface free energy effects are observed in covalent crystals, for which the creation of new surface area by splitting the crystal requires breaking covalent bonds and leaving
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Published 15 Apr 2016

First-principles study of the structure of water layers on flat and stepped Pb electrodes

  • Xiaohang Lin,
  • Ferdinand Evers and
  • Axel Groß

Beilstein J. Nanotechnol. 2016, 7, 533–543, doi:10.3762/bjnano.7.47

Graphical Abstract
  • also be used to control structural properties. This is related, e.g., to the fact that the surface free energy, and therefore also the surface-induced strain, is sensitive to the structure of the Helmholtz layer. In this spirit, electrochemical structure control has recently be successfully employed to
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Published 11 Apr 2016

Molecular machines operating on the nanoscale: from classical to quantum

  • Igor Goychuk

Beilstein J. Nanotechnol. 2016, 7, 328–350, doi:10.3762/bjnano.7.31

Graphical Abstract
  • machines, are reviewed. Special attention is paid to the dual, constructive role of dissipation and thermal fluctuations, the fluctuation–dissipation theorem, heat losses and free energy transduction, thermodynamic efficiency, and thermodynamic efficiency at maximum power. Several basic models are
  • Figure 1. This models the periodic turnover of the motor within a continuum of intrinsic, conformational states [3], where is a chemical cyclic reaction coordinate. The motor cycles can be driven by an energy supplied by a constant driving force or torque, F, with free energy Δμ = 2πF spent per one
  • molecule bound to it and energy E2 of the whole complex. EP corresponds to an enzyme with product molecule(s) bound to it and energy E3. The forward cyclic transitions E→ES→EP→E are driven by the free energy per one molecule Δμ released in the S→P transformation facilitated by the enzyme, while the
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Published 03 Mar 2016

Plasticity-mediated collapse and recrystallization in hollow copper nanowires: a molecular dynamics simulation

  • Amlan Dutta,
  • Arup Kumar Raychaudhuri and
  • Tanusri Saha-Dasgupta

Beilstein J. Nanotechnol. 2016, 7, 228–235, doi:10.3762/bjnano.7.21

Graphical Abstract
  • site would create a [112]/6-type dislocation and, thus, would add to the free-energy of the system. That is why most of the remaining disordered atoms are found at the terminating sites of the stacking-faults (cf. Figure 2a). Stage 3 The third and final stage of the morphological evolution consists of
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Published 10 Feb 2016

Characterisation of thin films of graphene–surfactant composites produced through a novel semi-automated method

  • Nik J. Walch,
  • Alexei Nabok,
  • Frank Davis and
  • Séamus P. J. Higson

Beilstein J. Nanotechnol. 2016, 7, 209–219, doi:10.3762/bjnano.7.19

Graphical Abstract
  • production and also the surface free energy of graphene. The graphite suspension (10–50%) was then placed into the reactor, and sonicated continuously for 120 min at a power of 50 W. A total of 3.15 mL of surfactant solution was added in each case over the course of the synthesis. The sonication step was
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Published 08 Feb 2016

Nanostructured surfaces by supramolecular self-assembly of linear oligosilsesquioxanes with biocompatible side groups

  • Maria Nowacka,
  • Anna Kowalewska and
  • Tomasz Makowski

Beilstein J. Nanotechnol. 2015, 6, 2377–2387, doi:10.3762/bjnano.6.244

Graphical Abstract
  • composition and topography that define the free energy [6][7][8][9] also impact the pre-adsorbed protein layer and can mediate cell–substrate interactions [3][10][11][12][13][14][15][16][17][18][19][20][21]. Substrates bearing COOH groups can be used to control the cell behaviour via interactions with the
  • ≈1700 cm−1 and emergence of diffuse bands in the formed PSAMs was observed). Surface energy of LPSQ-COOH/X coated on native mica The surface free energy (γS) of each studied PSAM sample was determined by measuring the contact angle of water and glycerol as reference liquids (sessile drop technique and
  • -COOH/X coated on primed mica The surface free energy measurements (Figure 10) proved the proposed model of adsorption of NAC, CA and TG (Scheme 2) by ionic interactions of COOH substituents with K+ ions on the surface of mica. Such an arrangement of the multifunctional primers exposes reactive polar
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Published 11 Dec 2015

Silica-coated upconversion lanthanide nanoparticles: The effect of crystal design on morphology, structure and optical properties

  • Uliana Kostiv,
  • Miroslav Šlouf,
  • Hana Macková,
  • Alexander Zhigunov,
  • Hana Engstová,
  • Katarína Smolková,
  • Petr Ježek and
  • Daniel Horák

Beilstein J. Nanotechnol. 2015, 6, 2290–2299, doi:10.3762/bjnano.6.235

Graphical Abstract
  • successful approach to control crystal structures. Higher reaction temperature and longer reaction time are required to provide sufficient free energy to overcome the activation barrier of an α/ß phase transition [19][33]. In the XRD experiments, all crystal diffractions and amorphous halos of the OM–NaYF4
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Published 03 Dec 2015

Nanoscale rippling on polymer surfaces induced by AFM manipulation

  • Mario D’Acunto,
  • Franco Dinelli and
  • Pasqualantonio Pingue

Beilstein J. Nanotechnol. 2015, 6, 2278–2289, doi:10.3762/bjnano.6.234

Graphical Abstract
  • -b-PEO, the melting enthalpy of PEO, and the Helmholtz free energy for unfolding (and melting) of PEO. Composite films: Another class of samples showing a peculiar pattern formation are polymer blends. They can be miscible or immiscible, presenting clear phase separation or a similar morphology to
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Published 02 Dec 2015

An adapted Coffey model for studying susceptibility losses in interacting magnetic nanoparticles

  • Mihaela Osaci and
  • Matteo Cacciola

Beilstein J. Nanotechnol. 2015, 6, 2173–2182, doi:10.3762/bjnano.6.223

Graphical Abstract
  • orientations model of the magnetic moments [12][15]. In this model, we may assume that the magnetic moments μi are constrained to stable orientations along the local minimum of free energy, when the energy barriers are large in comparison with kBT. Due to thermal fluctuations, the time behaviour of μi is
  • determining energy barriers in the systems with interactions is quite complex. Generally, in 3D space, the normalized (over kBT) free energy of the i-th spherical nanoparticle, subject to a local magnetic field [13], is: where ξi = (μ0 Ms Vi Hi)/(kBT), σi = (Ki,effVi)/(kBT), and Ki,eff is the effective
  • nanoparticle. Without losing the generality of the problem, it is possible to consider a magnetic field acting onto the x–z plane. Considering Equation 14, the normalized free energy of an i-th nanoparticle subject to a local magnetic field Hi applied with an angle ψi to the easy axis is given by: The polar
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Published 19 Nov 2015

Light-powered, artificial molecular pumps: a minimalistic approach

  • Giulio Ragazzon,
  • Massimo Baroncini,
  • Serena Silvi,
  • Margherita Venturi and
  • Alberto Credi

Beilstein J. Nanotechnol. 2015, 6, 2096–2104, doi:10.3762/bjnano.6.214

Graphical Abstract
  • information about the relative position of the ring and axle components (i.e., whether they are associated or not) contributes to the gating. From the analysis of the free energy change of the system, it can be estimated that the maximum amount of work that could be performed by the pump in a cycle under the
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Published 02 Nov 2015

Distribution of Pd clusters on ultrathin, epitaxial TiOx films on Pt3Ti(111)

  • Christian Breinlich,
  • Maria Buchholz,
  • Marco Moors,
  • Tobias Pertram,
  • Conrad Becker and
  • Klaus Wandelt

Beilstein J. Nanotechnol. 2015, 6, 2007–2014, doi:10.3762/bjnano.6.204

Graphical Abstract
  • Pd metal on the oxide is smaller than twice the surface free energy of the vacuum–metal interface of the liquid metal [19]. In the case of late transition metals on oxides, this criterion is usually met, and thus 3D growth is observed in most cases [14]. From a kinetic point of view, the growth
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Published 09 Oct 2015

Metal hydrides: an innovative and challenging conversion reaction anode for lithium-ion batteries

  • Luc Aymard,
  • Yassine Oumellal and
  • Jean-Pierre Bonnet

Beilstein J. Nanotechnol. 2015, 6, 1821–1839, doi:10.3762/bjnano.6.186

Graphical Abstract
  • hydride and lithium is given in Equation 3, where MHx is the hydride, M the metal or the intermetallic phase, and x the number of hydrogen atoms. Under standard conditions (p = 1 atm and T = 298 K), the Gibbs free energy of the reaction in Equation 3, ΔrG in kJ·mol−1, can be calculated from the values of
  • Gibbs free energy of formation of MHx and LiH (ΔfG°298(LiH) and ΔfG°298(MHx). It corresponds to the sum of reactions (Equation 1 + Equation 2) given as: The Gibbs free energy of the reaction in Equation 3 is: According to the thermodynamics rules, the reaction is feasible for ΔrG°298 ≤ 0 and
  • spontaneous for ΔrG°298 < 0. Given the fact that the formation of LiH independent from the type of hydride MHx (common reaction product), another simple criterion to predict the possibility of the conversion process is the Gibbs free energy of formation of the hydride MHx divided by x. This value must be
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Published 31 Aug 2015

Two-phase equilibrium states in individual Cu–Ni nanoparticles: size, depletion and hysteresis effects

  • Aram S. Shirinyan

Beilstein J. Nanotechnol. 2015, 6, 1811–1820, doi:10.3762/bjnano.6.185

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  • .6.185 Abstract In isolated bimetallic nanoscale systems the limit amount of matter and surface-induced size effects can change the thermodynamics of first-order phase transformation. In this paper we present theoretical modification of Gibbs free energy concept describing first-order phase
  • one has to plot the Gibbs free energy densities as functions of composition and then find the conditions for minimal energy of a given system by using the rule of common tangent [22]. Corresponding modification and theoretical descriptions for nanosystems may be done taking into account the additional
  • energy condition. As result the stable phase in bulk material (say, phase 1) is one which has the lowest bulk Gibbs free energy density g (energy per number of atoms in a system): g1 < g2. Subindexes 1 and 2 are referred to the phase 1 or phase 2, respectively. In a multicomponent system it also depends
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Published 28 Aug 2015

Influence of surface chemical properties on the toxicity of engineered zinc oxide nanoparticles to embryonic zebrafish

  • Zitao Zhou,
  • Jino Son,
  • Bryan Harper,
  • Zheng Zhou and
  • Stacey Harper

Beilstein J. Nanotechnol. 2015, 6, 1568–1579, doi:10.3762/bjnano.6.160

Graphical Abstract
  • estimate the protein-ligand binding free energy [35], and molar refractivity (RF) represents the energy required to polarize one mole of the substance and is associated with receptor binding affinity [36]. Dreiding energy (DE) will be used to predict the binding affinity of organic molecules with Zn and
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Published 20 Jul 2015

Enhanced fullerene–Au(111) coupling in (2√3 × 2√3)R30° superstructures with intermolecular interactions

  • Michael Paßens,
  • Rainer Waser and
  • Silvia Karthäuser

Beilstein J. Nanotechnol. 2015, 6, 1421–1431, doi:10.3762/bjnano.6.147

Graphical Abstract
  • provided first. Furthermore, entropy (S) effects might play a role during the C60 monolayer preparation process at elevated temperatures (T), so that a pure hex-vac C60 domain on Au(111) might not correspond to the minimum free energy (F = U − TS) under these conditions. Nevertheless, 6:6-top C60, which
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Published 29 Jun 2015

Multiscale modeling of lithium ion batteries: thermal aspects

  • Arnulf Latz and
  • Jochen Zausch

Beilstein J. Nanotechnol. 2015, 6, 987–1007, doi:10.3762/bjnano.6.102

Graphical Abstract
  • mechanics in order to obtain the Gibbs free energy of bulk and interfaces at finite temperatures. Especially for the calculation of differences of Gibbs free energies, which are relevant for the determination of stable equilibrium configurations, the accuracy is higher than might be expected from the
  • ], which provide an approximate continuous description of the dynamics of interfaces [27]. They need as input the interface free energies between the phases. This interface free energy is accessible to DFT simulations [28][29]. On the basis of this information the intercalation properties of phase
  • change of the entropy density Here R is the yet unknown entropy production and μα is the chemical potential of species α. An expression for μα will be derived shortly. By eliminating the heat production from Equation 15 and some reformulations of we obtain Here φH is the specific free energy density
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Published 20 Apr 2015

Observing the morphology of single-layered embedded silicon nanocrystals by using temperature-stable TEM membranes

  • Sebastian Gutsch,
  • Daniel Hiller,
  • Jan Laube,
  • Margit Zacharias and
  • Christian Kübel

Beilstein J. Nanotechnol. 2015, 6, 964–970, doi:10.3762/bjnano.6.99

Graphical Abstract
  • TEM (see insets of Figure 3b and Figure 3c) and electron diffraction, we found that both samples feature a high degree of crystallinity as is corrobated by detailed Raman studies [20][42]. However, the Si NC shape is not spherical at all. Due to the minimization of Gibbs free energy, a spherical shape
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Published 15 Apr 2015

Capillary and van der Waals interactions on CaF2 crystals from amplitude modulation AFM force reconstruction profiles under ambient conditions

  • Annalisa Calò,
  • Oriol Vidal Robles,
  • Sergio Santos and
  • Albert Verdaguer

Beilstein J. Nanotechnol. 2015, 6, 809–819, doi:10.3762/bjnano.6.84

Graphical Abstract
  • obtained experimentally by leaving the ambient humidity spontaneously increase from 10% to the ambient value of 40% after sample preparation (see Experimental section). This increase of RH should reduce the free energy barrier for water nucleation, thus increasing the water condensation rate [3]. It is
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Published 25 Mar 2015

Entropy effects in the collective dynamic behavior of alkyl monolayers tethered to Si(111)

  • Christian Godet

Beilstein J. Nanotechnol. 2015, 6, 583–594, doi:10.3762/bjnano.6.60

Graphical Abstract
  • , in the most stable all-trans conformation of the (CH2)n molecular backbone [17][22]. However, increasing temperature has a strong influence on the tethered polymethylene OML structure because new chain configurations can be reached from this free energy minimum by a trans–gauche isomerization
  • vibrations) are so strongly coupled as to be indistinguishable, the excitation must be treated by using the transition state theory and the Eyring equation, with a free energy for the transition, ΔG = ΔE − TΔS that includes the large entropy associated with this fluctuation. Hence, the resulting frequency
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Published 26 Feb 2015

Electrical properties of single CdTe nanowires

  • Elena Matei,
  • Camelia Florica,
  • Andreea Costas,
  • María Eugenia Toimil-Molares and
  • Ionut Enculescu

Beilstein J. Nanotechnol. 2015, 6, 444–450, doi:10.3762/bjnano.6.45

Graphical Abstract
  • electrodeposited semiconductor. The mechanism leading to the formation of the stoichiometric compound was thermodynamically explained based on the free energy corresponding to the compound formation reaction. In the case of this particular compound, this free energy opens up the possibility to obtain the
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Published 12 Feb 2015

Exploiting the hierarchical morphology of single-walled and multi-walled carbon nanotube films for highly hydrophobic coatings

  • Francesco De Nicola,
  • Paola Castrucci,
  • Manuela Scarselli,
  • Francesca Nanni,
  • Ilaria Cacciotti and
  • Maurizio De Crescenzi

Beilstein J. Nanotechnol. 2015, 6, 353–360, doi:10.3762/bjnano.6.34

Graphical Abstract
  • ][15][16], where the free energy surface presents one absolute minimum and one or more local minima separated from the former by large free energy barriers, as compared to the thermal energy. Metastability can also have a technological importance, as in practice, it represents a way of extending the
  • stable because lower in surface free energy. Moreover we fitted our data in Figure 4b with Wenzel’s equation [1] where r is the roughness factor (i.e, the ratio between the actual wet surface area and its projection on the plane). Interestingly, the fit returned r = 1.08 ± 0.01, which means that
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Published 02 Feb 2015
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