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Search for "entropy" in Full Text gives 66 result(s) in Beilstein Journal of Nanotechnology.

Coexisting spin and Rabi oscillations at intermediate time regimes in electron transport through a photon cavity

  • Vidar Gudmundsson,
  • Hallmann Gestsson,
  • Nzar Rauf Abdullah,
  • Chi-Shung Tang,
  • Andrei Manolescu and
  • Valeriu Moldoveanu

Beilstein J. Nanotechnol. 2019, 10, 606–616, doi:10.3762/bjnano.10.61

Graphical Abstract
  • solution is effectively evaluated at all needed points in time using parallel methods for linear algebra operations in FORTRAN or CUDA [29]. The reduced density operator is used to calculate mean values of relevant physical quantities and the Réniy-2 entropy of the central system [31][32][33] The trace
  • initially empty central system. In addition, this figure shows the mean value of the z-component of the total spin of the electrons, the trace of the reduced density matrix and the Réniy-2 entropy of the central system S (Equation 9). Initially, the central system gains electric charge through the states in
  • the bias window. The plunger gate voltage is placed at Vg = 1.6 mV moving the one-electron ground state below the bias window. The steady state is reached when the ground state is fully occupied and the system is Coulomb blocked with no mean current flowing through it. The entropy of the central
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Published 01 Mar 2019

Mo-doped boron nitride monolayer as a promising single-atom electrocatalyst for CO2 conversion

  • Qianyi Cui,
  • Gangqiang Qin,
  • Weihua Wang,
  • Lixiang Sun,
  • Aijun Du and
  • Qiao Sun

Beilstein J. Nanotechnol. 2019, 10, 540–548, doi:10.3762/bjnano.10.55

Graphical Abstract
  • -point energy (ZPE) difference between the products and reactants in the reaction whose expression is similar to ΔE, where T represents the temperature (T = 298.15 K), and ΔS represents the change of entropy. The entropies of free gas molecules and vibrational frequencies were all obtained from the NIST
  • database [64], and the data of ZPE and entropy for the gas molecules at 298.15 K are shown in Table S1 in the Supporting Information File 1. ΔGU is the free energy of the electrode potential, which is ΔGU = −neU (n is the number of electrons transferred corresponding to the elementary steps and U is the
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Published 22 Feb 2019

Polymorphic self-assembly of pyrazine-based tectons at the solution–solid interface

  • Achintya Jana,
  • Puneet Mishra and
  • Neeladri Das

Beilstein J. Nanotechnol. 2019, 10, 494–499, doi:10.3762/bjnano.10.50

Graphical Abstract
  • proportional to the surface density of the molecules. This loss in entropy is compensated by enthalpic contributions from the intermolecular interactions and the molecule–substrate interaction. In the present system, slightly larger surface density for polymorph I and lesser hydrogen bonding sites make it less
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Published 18 Feb 2019

Interaction of Te and Se interlayers with Ag or Au nanofilms in sandwich structures

  • Arkadiusz Ciesielski,
  • Lukasz Skowronski,
  • Marek Trzcinski,
  • Ewa Górecka,
  • Wojciech Pacuski and
  • Tomasz Szoplik

Beilstein J. Nanotechnol. 2019, 10, 238–246, doi:10.3762/bjnano.10.22

Graphical Abstract
  • interstitial lattice sites accessible to the minority atom as well as higher coordination number. Therefore, a system in which minority atoms reside in such voids has a higher entropy S (and thus lower free enthalpy G) than a system in which they reside in a simple grain boundary. Therefore, the distribution
  • sites available for semiconductor atoms to occupy [20][21] – precisely at the metal/semiconductor interface. Since such a system already has a high configurational entropy, and migration of semiconductor atoms towards the surface of the metal is unlikely to increase it. Therefore, the decrease in the
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Published 21 Jan 2019

pH-mediated control over the mesostructure of ordered mesoporous materials templated by polyion complex micelles

  • Emilie Molina,
  • Mélody Mathonnat,
  • Jason Richard,
  • Patrick Lacroix-Desmazes,
  • Martin In,
  • Philippe Dieudonné,
  • Thomas Cacciaguerra,
  • Corine Gérardin and
  • Nathalie Marcotte

Beilstein J. Nanotechnol. 2019, 10, 144–156, doi:10.3762/bjnano.10.14

Graphical Abstract
  • of Pluronic-templated mesostructured silica [5][41][42][43], in which the primary step for a good mesostructure to be obtained is entropy driven by hydrogen bonding between the silica oligomers and PEO chains [5]. Variations in the respective sizes of the two nanodomains of the system, (1) the
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Published 11 Jan 2019

Block copolymers for designing nanostructured porous coatings

  • Roberto Nisticò

Beilstein J. Nanotechnol. 2018, 9, 2332–2344, doi:10.3762/bjnano.9.218

Graphical Abstract
  • /homopolymer formulations [81][82]. The microdomain arrangement is affected by heating, since BCs can exhibit phase mixing upon heating, due to the increase in the translational (or combinatorial) entropy and subsequent decrease of the phases interaction area. It can also exhibit phase separation as a result
  • of the thermal expansion coefficients and/or directional enthalpy (or entropy) changes, as shown in [83]. Furthermore, crystallinity is also an important parameter that can influence the domain orientation. As reported by Register and co-workers [84], there are three different levels of orientation
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Published 29 Aug 2018

The inhibition effect of water on the purification of natural gas with nanoporous graphene membranes

  • Krzysztof Nieszporek,
  • Tomasz Pańczyk and
  • Jolanta Nieszporek

Beilstein J. Nanotechnol. 2018, 9, 1906–1916, doi:10.3762/bjnano.9.182

Graphical Abstract
  • configuration causes an initial pressure difference between the feed side (below and above graphene sheets, see Figure 1) and the permeating area. Therefore, the increase of entropy is the driving force of the process. It is worth mentioning that the presence of 400 molecules (CH4 + N2) in the retentate area at
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Published 02 Jul 2018

Improving the catalytic activity for hydrogen evolution of monolayered SnSe2(1−x)S2x by mechanical strain

  • Sha Dong and
  • Zhiguo Wang

Beilstein J. Nanotechnol. 2018, 9, 1820–1827, doi:10.3762/bjnano.9.173

Graphical Abstract
  • phase of hydrogen; because this quantity has a small contribution to ΔGH, it was neglected in this work. T is the temperature. ΔSH is the entropy contribution to ΔGH, which can be approximated as: ΔSH = 1/2SH2, where SH2 is the entropy of H2 in the gas phase under standard conditions (300 K, 1 bar) [69
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Published 18 Jun 2018

Induced smectic phase in binary mixtures of twist-bend nematogens

  • Anamarija Knežević,
  • Irena Dokli,
  • Marin Sapunar,
  • Suzana Šegota,
  • Ute Baumeister and
  • Andreja Lesac

Beilstein J. Nanotechnol. 2018, 9, 1297–1307, doi:10.3762/bjnano.9.122

Graphical Abstract
  • % of BB. This corresponds to the ratio of two molecules of BB versus one molecule of CBI in the smectic phase. The entropy changes (ΔS/R) determined from the DSC thermograms (Table S1, Supporting Information File 1) for the NTB to SmCA transition exhibit the maximum around 70 mol % of BB which
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Published 26 Apr 2018

Formation and development of nanometer-sized cybotactic clusters in bent-core nematic liquid crystalline compounds

  • Yuri P. Panarin,
  • Sithara P. Sreenilayam,
  • Jagdish K. Vij,
  • Anne Lehmann and
  • Carsten Tschierske

Beilstein J. Nanotechnol. 2018, 9, 1288–1296, doi:10.3762/bjnano.9.121

Graphical Abstract
  • Equation 2 and Equation 3, respectively. In the molecular field approximation (MFA), the orientational entropy of a cluster in the nematic phase is the sum of two contributions: the reorientation of the individual molecules and the fluctuation of the cluster directors with respect to the macroscopic
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Published 25 Apr 2018

Magnetic field induced orientational transitions in liquid crystals doped with carbon nanotubes

  • Danil A. Petrov,
  • Pavel K. Skokov and
  • Alexander N. Zakhlevnykh

Beilstein J. Nanotechnol. 2017, 8, 2807–2817, doi:10.3762/bjnano.8.280

Graphical Abstract
  • CNTs in LCs [14][18][38]. The last term F5 is the contribution of the entropy of mixing of an ideal solution of CNTs in the LC matrix. As it is known, the state of thermodynamic equilibrium corresponds to the minimum of the free energy (Equation 1), which is a functional of the two vectors n and m, and
  • orientational elastic deformations (F1 = 0), in the entropy contribution to the energy (F5 = min), and in the magnetic energy of CNTs (F3 = min). When the diamagnetism of the LC matrix (F2) begins to predominate, at h ≈ hr+, the next transition from the homeotropic phase to the non-uniform state (the angular
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Published 29 Dec 2017

Beyond Moore’s technologies: operation principles of a superconductor alternative

  • Igor I. Soloviev,
  • Nikolay V. Klenov,
  • Sergey V. Bakurskiy,
  • Mikhail Yu. Kupriyanov,
  • Alexander L. Gudkov and
  • Anatoli S. Sidorenko

Beilstein J. Nanotechnol. 2017, 8, 2689–2710, doi:10.3762/bjnano.8.269

Graphical Abstract
  • of switching a Josephson junction, EJ ≈ 2 × 10−19 J. While presuming logical irreversibility, this energy can be lowered down to Emin ≈ 4 × 10−23 J (at T = 4.2 K) by using adiabatic switching process. Note that the Landauer limit Emin in this context reflects the entropy change in the computing
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Published 14 Dec 2017

Ferrocholesteric–ferronematic transitions induced by shear flow and magnetic field

  • Dmitriy V. Makarov,
  • Alexander A. Novikov and
  • Alexander N. Zakhlevnykh

Beilstein J. Nanotechnol. 2017, 8, 2552–2561, doi:10.3762/bjnano.8.255

Graphical Abstract
  • ). F3 is the bulk density of the interaction energy of the magnetic field H with the magnetic moment μ = MSvpn of the particles (the dipole mechanism of the magnetic field effect on an FC). F4 is the contribution of the entropy of mixing of an ideal solution of magnetic particles to the free energy of a
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Published 30 Nov 2017

Spin-chemistry concepts for spintronics scientists

  • Konstantin L. Ivanov,
  • Alexander Wagenpfahl,
  • Carsten Deibel and
  • Jörg Matysik

Beilstein J. Nanotechnol. 2017, 8, 1427–1445, doi:10.3762/bjnano.8.143

Graphical Abstract
  • Introduction In general, chemical reactions are discussed in terms of thermodynamics: reaction enthalpy, reaction entropy and free energy. It is also recognized that steric and charge effects can lead to kinetic control of the reaction dynamics by introduction of activation energies. In some cases, chemical
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Published 11 Jul 2017

Calculating free energies of organic molecules on insulating substrates

  • Julian Gaberle,
  • David Z. Gao and
  • Alexander L. Shluger

Beilstein J. Nanotechnol. 2017, 8, 667–674, doi:10.3762/bjnano.8.71

Graphical Abstract
  • energy profiles and entropy changes were calculated for step adhesion and dimer formation of these molecules. However, converging these calculations is nontrivial and comes at large computational cost. We illustrate the difficulties as well as the possibilities of applying these methods towards
  • understanding dynamic processes of organic molecules on insulating substrates. Keywords: entropy; free energy; molecular dynamics; organic molecules; potential of mean force; thermodynamic integration surface step; Introduction In recent years molecular films and self-assembled monolayers have attracted a lot
  • entropy as degrees of freedom within the molecules become constrained. This means that free energies can vary significantly from calculated enthalpy values, which may have a direct impact on our understanding of the balance of interactions that govern self-assembly. Methods to compute the free energy from
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Published 21 Mar 2017

Fiber optic sensors based on hybrid phenyl-silica xerogel films to detect n-hexane: determination of the isosteric enthalpy of adsorption

  • Jesús C. Echeverría,
  • Ignacio Calleja,
  • Paula Moriones and
  • Julián J. Garrido

Beilstein J. Nanotechnol. 2017, 8, 475–484, doi:10.3762/bjnano.8.51

Graphical Abstract
  • , it loses translational entropy. The aim of this study was to assess the effect of temperature on the sensitivity of hybrid phenyl-silica films to n-hexane and to determine the variation of the isosteric enthalpy of adsorption. Materials and Methods Optical fibers and preparation of xerogel films
  • temperatures between 288 and 323 K. As we have explained in the Introduction section, when the analyte molecules are adsorbed on the silica xerogel the reflected intensity varies. Adsorption is an exothermic process, in which when a vapor molecules is adsorbed on a surface loses translational entropy because
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Published 21 Feb 2017

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
  • approximation) we can evaluate the mixing interaction energy in the system by Umix = NχφV, where we ignored boundary effects and φV = NV/M is the volume fraction of vacancies. The entropy of mixing can be evaluated when we assume once more that the sites are randomly filled by solvent. The total number of ways
  • 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
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Published 04 Oct 2016

Tunable longitudinal modes in extended silver nanoparticle assemblies

  • Serene S. Bayram,
  • Klas Lindfors and
  • Amy Szuchmacher Blum

Beilstein J. Nanotechnol. 2016, 7, 1219–1228, doi:10.3762/bjnano.7.113

Graphical Abstract
  • before reaching a steady-state in less than 60 min. The spontaneity is likely enthalpy-driven due to dipole–dipole binding events that are exothermic. Although the assembly process is entropically not favourable, some entropy is regained through branching (Figure 3). Figure 3 shows the development of
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Published 26 Aug 2016

Influence of synthesis conditions on microstructure and phase transformations of annealed Sr2FeMoO6−x nanopowders formed by the citrate–gel method

  • Marta Yarmolich,
  • Nikolai Kalanda,
  • Sergey Demyanov,
  • Herman Terryn,
  • Jon Ustarroz,
  • Maksim Silibin and
  • Gennadii Gorokh

Beilstein J. Nanotechnol. 2016, 7, 1202–1207, doi:10.3762/bjnano.7.111

Graphical Abstract
  • second-order phase transition has been revealed at 188 K for SFMO-6 and SFMO-9 powders and 330 K for all investigated powders (Figure 4). Such extremely small changes of entropy, as well as small temperature intervals of phase transformations (within 20 K), are caused by impurity phases distributed as
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Published 22 Aug 2016

Fast diffusion of silver in TiO2 nanotube arrays

  • Wanggang Zhang,
  • Yiming Liu,
  • Diaoyu Zhou,
  • Hui Wang,
  • Wei Liang and
  • Fuqian Yang

Beilstein J. Nanotechnol. 2016, 7, 1129–1140, doi:10.3762/bjnano.7.105

Graphical Abstract
  • ) is the melting temperature of the material in a spherical shape of radius r, Tm(∞) is the melting temperature of the material in bulk shape, R is the gas constant, Svib(∞) is the vibrational melting entropy of the material, h is the atomic radius of the material, and d = 0 for nanoparticles. As shown
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Published 03 Aug 2016

Hierarchical coassembly of DNA–triptycene hybrid molecular building blocks and zinc protoporphyrin IX

  • Rina Kumari,
  • Sumit Singh,
  • Mohan Monisha,
  • Sourav Bhowmick,
  • Anindya Roy,
  • Neeladri Das and
  • Prolay Das

Beilstein J. Nanotechnol. 2016, 7, 697–707, doi:10.3762/bjnano.7.62

Graphical Abstract
  • and Zn PpIX (Figure 6). The increase in Tm indicates the formation of a self-assembled ordered structure where DNA duplexes are closely packed and highly oriented. The increase in Tm is also ascribed to the combination of stacking of Zn PpIX along the DNA duplex, reduced configurational entropy and
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Published 12 May 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
  • , which in the differential form states that dS ≥ δQ/T (i.e., that the increase of entropy, or loss of information, dI ≡ −dS/kBln2 – a very fundamental equality, or rather tautology of the physical information theory), is equal to or exceeds the heat exchange with the environment in the units of T. For an
  • adiabatically isolated system, δQ = 0; hence, dI ≤ 0, i.e., entropy can increase and information can diminish spontaneously, without any heat being produced into the surroundings. This is just the second law of thermodynamics rephrased. As a matter of fact, δQ = |dI|kBTln2 is the maximal (not minimal!) amount
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Published 03 Mar 2016

Counterion effects on nano-confined metal–drug–DNA complexes

  • Nupur Biswas,
  • Sreeja Chakraborty,
  • Alokmay Datta,
  • Munna Sarkar,
  • Mrinmay K. Mukhopadhyay,
  • Mrinal K. Bera and
  • Hideki Seto

Beilstein J. Nanotechnol. 2016, 7, 62–67, doi:10.3762/bjnano.7.7

Graphical Abstract
  • laterally to the film surface, whereas in case of films prepared from buffered solution there is no such layering due to the increased orientational entropy of entangled shorter DNA molecules [8][9]. This indicates that both confinement and presence of charged and neutral species in the environment dictates
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Published 19 Jan 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
  • entropy–enthalpy compensation [51][52][53]. Thus, the mechanism of adsorption of LPSQ-COOH/X on mica should be discussed with respect to possible intermolecular interactions between polymer chains and their relations with the substrate. Macromolecules consisting of surface-reactive repeating units can
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Published 11 Dec 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
  • this position is obviously less stable than the hex-vac position. Here, advantageous entropy effects [26] or an adlayer buckling in order to minimize the lattice mismatch to the underlying substrate are given as possible explanations. However, solely entropy effects should result in completely random
  • 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
  • relevance. If fullerenes forming a dis-R30° superstructure can be described as an Ising-like system, as mentioned in the previous section, the ratio of bright C60 will be increased at elevated temperatures due to entropy effects. This process counteracts the forming of dim C60 based on the increased
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Published 29 Jun 2015
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