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Search for "enthalpy" in Full Text gives 80 result(s) in Beilstein Journal of Nanotechnology.

TiO2 immobilized on 2D mordenite: effect of hydrolysis conditions on structural, textural, and optical characteristics of the nanocomposites

  • Marina G. Shelyapina,
  • Rosario Isidro Yocupicio-Gaxiola,
  • Gleb A. Valkovsky and
  • Vitalii Petranovskii

Beilstein J. Nanotechnol. 2025, 16, 128–140, doi:10.3762/bjnano.16.12

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  • calorimetric hydrolysis study of Ti(OR)4 at different concentrations, the values of reaction enthalpy of the first hydrolysis stage were measured for R = Et, iPr, and n-Bu [29]. It turned out that further hydrolysis proceeds much slower and with very little heat release (for R = Et its value is zero within the
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Published 10 Feb 2025

Heterogeneous reactions in a HFCVD reactor: simulation using a 2D model

  • Xochitl Aleyda Morán Martínez,
  • José Alberto Luna López,
  • Zaira Jocelyn Hernández Simón,
  • Gabriel Omar Mendoza Conde,
  • José Álvaro David Hernández de Luz and
  • Godofredo García Salgado

Beilstein J. Nanotechnol. 2024, 15, 1627–1638, doi:10.3762/bjnano.15.128

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  • ) + H° (g) was developed to obtain the extensive properties of this reaction using FactSage in the temperature range from 500 to 1500 °C. Enthalpy (H), Gibbs energy (G), entropy (S), heat capacity (Cp), and Helmholtz energy (A) were obtained to calculate Keq through Equation 5 [27]. The thermodynamic
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Published 17 Dec 2024

Effect of radiation-induced vacancy saturation on the first-order phase transformation in nanoparticles: insights from a model

  • Aram Shirinyan and
  • Yuriy Bilogorodskyy

Beilstein J. Nanotechnol. 2024, 15, 1453–1472, doi:10.3762/bjnano.15.117

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  • enthalpy and entropy of vacancy formation in Fe. First-order phase transformations are accompanied by nucleation and the overcoming of energy barriers. To our knowledge, the consideration of nucleation energy barriers and the alteration of surface energies during transformation under irradiation has been
  • , respectively) and can be expressed as follows [17]: where, ΔHf is the enthalpy change for forming of a vacancy, ΔSf is the entropy change for vacancy formation, and ΔHmix is the ideal entropy of vacancy mixing, which may be given as: Here, T is the absolute temperature, and kB is the Boltzmann constant
  • transformations from bcc to fcc and from fcc to bcc that occur in an iron-like nanomaterial. We detail the findings for pure iron at the end of the paper. The enthalpy change for vacancy formation can be estimated from the equilibrium melting temperature, Tm, and is ΔHfα = 3.76·10−19 J for the α phase and ΔHfβ
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Published 21 Nov 2024

Facile synthesis of Fe-based metal–organic frameworks from Fe2O3 nanoparticles and their application for CO2/N2 separation

  • Van Nhieu Le,
  • Hoai Duc Tran,
  • Minh Tien Nguyen,
  • Hai Bang Truong,
  • Toan Minh Pham and
  • Jinsoo Kim

Beilstein J. Nanotechnol. 2024, 15, 897–908, doi:10.3762/bjnano.15.74

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  • . These findings have been compared with the CO2 uptake capacities of MIL-100(Fe)-based adsorbents created through different methods, as well as other MOFs and conventional materials, all of which are detailed in Table S2 (Supporting Information File 1). Isosteric enthalpy of CO2 adsorption over M-100Fe
  • determine the isosteric enthalpy of CO2 adsorption (Supporting Information File 1). As anticipated, the capture of CO2 molecules using M-100Fe@Fe2O3#1.80 releases approximately 20 to 17 kJ·mol−1 when the CO2 uptake is increased up to 1.0 mmol·g−1 (Figure 10). The obtained results fall within the value range
  • selectivities over M-100Fe@Fe2O3 samples for a mixture with 10% N2 and 90% CO2 at 298 K. Enthalpy of CO2 adsorption over M-100Fe@Fe2O3#1.80 sample. CO2 adsorption/desorption isotherms over M-100Fe@Fe2O3#1.80 sample for five cycles at 298 K. Textural properties of Fe2O3 and the as-prepared samples. Supporting
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Published 19 Jul 2024

A review on the structural characterization of nanomaterials for nano-QSAR models

  • Salvador Moncho,
  • Eva Serrano-Candelas,
  • Jesús Vicente de Julián-Ortiz and
  • Rafael Gozalbes

Beilstein J. Nanotechnol. 2024, 15, 854–866, doi:10.3762/bjnano.15.71

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  • reference parameters by empirical formulas [31]. Additionally, QM calculations can be performed in very simplified models that only describe a part of the material, such as single metal atom, to calculate the enthalpy of formation of the cation [26]. However, there is an alternative, simplified way of
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Published 11 Jul 2024

Synthesis of silver–palladium Janus nanoparticles using co-sputtering of independent sources: experimental and theorical study

  • Maria J. Martínez-Carreón,
  • Francisco Solís-Pomar,
  • Abel Fundora,
  • Claudio D. Gutiérrez-Lazos,
  • Sergio Mejía-Rosales,
  • Hector N. Fernández-Escamilla,
  • Jonathan Guerrero-Sánchez,
  • Manuel F. Meléndrez and
  • Eduardo Pérez-Tijerina

Beilstein J. Nanotechnol. 2024, 15, 808–816, doi:10.3762/bjnano.15.67

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  • offered by the same two metals in the bulk, such as Au and Ni [4]. Alloying immiscible elements is feasible in the nanoscale regime because the enthalpy of the mixture decreases as the size of the nanoparticles decreases, and it generally becomes negative below a certain particle size [5]. Silver
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Published 04 Jul 2024

Laser synthesis of nanoparticles in organic solvents – products, reactions, and perspectives

  • Theo Fromme,
  • Sven Reichenberger,
  • Katharine M. Tibbetts and
  • Stephan Barcikowski

Beilstein J. Nanotechnol. 2024, 15, 638–663, doi:10.3762/bjnano.15.54

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  • -heptane (Figure 5). While the overall gas formation was ruled by the solvent’s molar enthalpy of vaporization, the correlation of hydrogen formation with the physical properties of the solvents was not possible. Instead, the hydrogen formation depends on the liquid’s pyrolysis behavior. As such, 1-hexene
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Published 05 Jun 2024

Experimental investigation of usage of POE lubricants with Al2O3, graphene or CNT nanoparticles in a refrigeration compressor

  • Kayhan Dağıdır and
  • Kemal Bilen

Beilstein J. Nanotechnol. 2023, 14, 1041–1058, doi:10.3762/bjnano.14.86

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  • and condensation temperatures. To validate the study, the actual refrigeration cycle with R1234yf is presented as in previous studies [36]. The pressure (P) – specific enthalpy (h) diagram obtained from the validation tests was given in Figure 11. Accordingly, it was seen that the actual P–h diagram
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Published 02 Nov 2023

Fragmentation of metal(II) bis(acetylacetonate) complexes induced by slow electrons

  • Janina Kopyra and
  • Hassan Abdoul-Carime

Beilstein J. Nanotechnol. 2023, 14, 980–987, doi:10.3762/bjnano.14.81

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  • constant. Taking into account the sublimation enthalpy, ΔHsub, for MnL2 and CoL2 (i.e., 139.3 and 130.1 kJ/mol, respectively [24]), and the working temperature (i.e., 390 and 420 K, respectively), we estimate the value of PCoL2/PMnL2 to be about 38, assuming C to be constant. This ratio of pressures, also
  • of the precursor anion leads to a substantial increase in the M···O bond length. Thus, stabilization of the [ML2]− anion prevents the dissociation of the TNI and, hence, the production of [L]− near 0 eV. Furthermore, the formation enthalpy of this fragment has been calculated to be 2.01, 1.72, 0.95
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Published 26 Sep 2023

Antibody-conjugated nanoparticles for target-specific drug delivery of chemotherapeutics

  • Mamta Kumari,
  • Amitabha Acharya and
  • Praveen Thaggikuppe Krishnamurthy

Beilstein J. Nanotechnol. 2023, 14, 912–926, doi:10.3762/bjnano.14.75

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  • binding is a highly selective interaction because both enthalpy and entropy are involved in the binding thermodynamics [73]. In case of multivalent particles, the entropy loss on binding is less than that of the two molecules in free solution. The multivalent NPs are very specific for the corresponding
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Published 04 Sep 2023

Two-dimensional molecular networks at the solid/liquid interface and the role of alkyl chains in their building blocks

  • Suyi Liu,
  • Yasuo Norikane and
  • Yoshihiro Kikkawa

Beilstein J. Nanotechnol. 2023, 14, 872–892, doi:10.3762/bjnano.14.72

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  • were partially desorbed from the surface of HOPG. Desorption from the surface is unfavorable regarding enthalpy. However, the detached alkyl chain is mobile in the solution phase; thus, desorption from the surface is favorable concerning entropy. Therefore, the peculiar 2D structural change can be
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Published 23 Aug 2023

Nanostructured lipid carriers containing benznidazole: physicochemical, biopharmaceutical and cellular in vitro studies

  • Giuliana Muraca,
  • María Esperanza Ruiz,
  • Rocío C. Gambaro,
  • Sebastián Scioli-Montoto,
  • María Laura Sbaraglini,
  • Gisel Padula,
  • José Sebastián Cisneros,
  • Cecilia Yamil Chain,
  • Vera A. Álvarez,
  • Cristián Huck-Iriart,
  • Guillermo R. Castro,
  • María Belén Piñero,
  • Matias Ildebrando Marchetto,
  • Catalina Alba Soto,
  • Germán A. Islan and
  • Alan Talevi

Beilstein J. Nanotechnol. 2023, 14, 804–818, doi:10.3762/bjnano.14.66

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  • thermograms are shown in Figure 2, whereas the melting temperature (Tm), the enthalpy of fusion (ΔHf), and crystallinity index (CI) are presented in Table 1. Whereas BNZ showed an endothermic peak at its melting point (191.2 °C) [23], the formulation showed two endothermic peaks in the range of 40–50 °C
  • the nanoparticle thermogram, indicating that BNZ was dispersed within the lipid matrix [24]. Correlating with the lower enthalpy of fusion, the CI (%) value of the nanoparticles was lower than that of the bulk myristyl myristate. Lipid molecules could be less ordered in the nanoparticles than in the
  • to identify significant differences against the control group. *p < 0.05, **p < 0.01. Thermal properties of benznidazole (BNZ), myristyl myristate, poloxamer 188, and nanoparticles (NLC-VEHICLE and NLC-BNZ). Abbreviations: Tm, melting temperature; ΔHf, fusion enthalpy; CI (%), crystallinity index
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Published 28 Jul 2023

Conjugated photothermal materials and structure design for solar steam generation

  • Chia-Yang Lin and
  • Tsuyoshi Michinobu

Beilstein J. Nanotechnol. 2023, 14, 454–466, doi:10.3762/bjnano.14.36

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  • the initial temperature of water, c is the specific heat of water (4.2 J·g−1·K−1), Q is the sensible heat of water, HLV is the enthalpy of water vaporization, and Ein is the energy of the incident light. Conjugated organic photothermal materials Conjugated organic small molecules Organic molecular
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Published 04 Apr 2023

Plasmonic nanotechnology for photothermal applications – an evaluation

  • A. R. Indhu,
  • L. Keerthana and
  • Gnanaprakash Dharmalingam

Beilstein J. Nanotechnol. 2023, 14, 380–419, doi:10.3762/bjnano.14.33

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  • water vaporisation can be calculated from Δm is the water mass loss during irradiation, is the phase change enthalpy of water to vapour, M is the molar mass of water, I is the solar power intensity at the surface of the sample, S is the irradiated area of the water surface, and τ is the irradiation
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Published 27 Mar 2023

Sputtering onto liquids: a critical review

  • Anastasiya Sergievskaya,
  • Adrien Chauvin and
  • Stephanos Konstantinidis

Beilstein J. Nanotechnol. 2022, 13, 10–53, doi:10.3762/bjnano.13.2

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  • while the distance between the target and the substrate is of the order of several centimeters. Ultimately, these atoms may be thermalized if the number of collisions is high and the atoms land on the surface with a kinetic energy of the order of the gas temperature (ca. 1/40 eV). Condensation enthalpy
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Published 04 Jan 2022

Criteria ruling particle agglomeration

  • Dieter Vollath

Beilstein J. Nanotechnol. 2021, 12, 1093–1100, doi:10.3762/bjnano.12.81

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  • direction of a minimum of the free enthalpy. In this context, one may observe mechanisms leading to a reduction of the surface energy or controlled by the van der Waals interaction. Additionally, the ensemble may arrange in the direction of a maximum of the entropy. Simulations based on Monte Carlo methods
  • of an agglomerated ensemble, that is, an exponential function characterized by two parameters. In this context, it is important to realize that one has to take care of fluctuations of the entropy. Keywords: agglomeration; enthalpy; entropy; simulation; surface energy; van der Waals interaction
  • . Synthesis of larger particles may be carried out in the gas phase, where the probability of collision is controlled by the geometry of the particles or forces among the particles [1]. Alternatively, in case of existing particles, the agglomeration is controlled by the minimum of free enthalpy. In this case
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Published 29 Sep 2021

Prediction of Co and Ru nanocluster morphology on 2D MoS2 from interaction energies

  • Cara-Lena Nies and
  • Michael Nolan

Beilstein J. Nanotechnol. 2021, 12, 704–724, doi:10.3762/bjnano.12.56

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  • , this indicates a strong interaction with the MoS2 ML, while tetrahedral geometries have an energy gain originating from Co–Co interactions instead. If we compare with Cu, the Co–S bond enthalpy is much higher than the Cu–S bond enthalpy, at 331 kJ/mol and 274.5 kJ/mol respectively (we did not find data
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Published 14 Jul 2021

Surface-enhanced Raman scattering of water in aqueous dispersions of silver nanoparticles

  • Paulina Filipczak,
  • Krzysztof Hałagan,
  • Jacek Ulański and
  • Marcin Kozanecki

Beilstein J. Nanotechnol. 2021, 12, 497–506, doi:10.3762/bjnano.12.40

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  • -exponential factor and R is the universal gas constant. This data treatment is analogous to the procedures proposed by Walrafen et al. [46] for the calculation of the enthalpy ΔH° referring to the formation of O–H∙∙∙O units. The results presented here are consistent with the results proposed by Walrafen et al
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Published 25 May 2021

ZnO and MXenes as electrode materials for supercapacitor devices

  • Ameen Uddin Ammar,
  • Ipek Deniz Yildirim,
  • Feray Bakan and
  • Emre Erdem

Beilstein J. Nanotechnol. 2021, 12, 49–57, doi:10.3762/bjnano.12.4

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  • abundant raw materials. Also, it is less harmful to the environment [19]. Miao et al. fabricated 3D porous MXene-rGO films by using a self-propagating approach, which involves great enthalpy change, chain reactions, and drastically propagates onto the entire film in seconds. As a result, a specific
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Published 13 Jan 2021

Magnetohydrodynamic stagnation point on a Casson nanofluid flow over a radially stretching sheet

  • Ganji Narender,
  • Kamatam Govardhan and
  • Gobburu Sreedhar Sarma

Beilstein J. Nanotechnol. 2020, 11, 1303–1315, doi:10.3762/bjnano.11.114

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  • enthalpy. The kinetic energy of the fluid particles increases for higher values of Ec. Hence, the temperature of the fluid rises marginally and therefore, the associated momentum and thermal boundary layer thickness are enhanced. Figure 14 and Figure 15 elucidate the effect of the radiation parameter, R
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Published 02 Sep 2020

Growth of a self-assembled monolayer decoupled from the substrate: nucleation on-command using buffer layers

  • Robby Reynaerts,
  • Kunal S. Mali and
  • Steven De Feyter

Beilstein J. Nanotechnol. 2020, 11, 1291–1302, doi:10.3762/bjnano.11.113

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  • following major avenues: (1) The buffer layers, in principle, offer a new substrate with a different, often lower, symmetry. (2) The buffer layer has a different lattice constant compared to the solid substrate. (3) The adsorption enthalpy of the assembling moiety on the buffer layer is often different
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Published 01 Sep 2020

Agglomerates of nanoparticles

  • Dieter Vollath

Beilstein J. Nanotechnol. 2020, 11, 854–857, doi:10.3762/bjnano.11.70

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  • Dieter Vollath NanoConsulting, Primelweg 3, Stutensee 76297, Germany 10.3762/bjnano.11.70 Abstract Nanoparticles tend to agglomerate. The process of agglomeration is ruled by thermodynamics. Depending on the sign of the enthalpy of interaction, ensembles consist of (repelling) poorly agglomerated
  • . The exact determination of the size distribution of the agglomerates also gives the maximum size of the agglomerates. These considerations lead to an improved understanding of ensembles of agglomerated nanoparticles. Keywords: agglomeration; enthalpy; entropy; Gibbs entropy; nanoparticles; size
  • experimental results, assuming that not all the particles of an ensemble are equal in size. The free enthalpy G of an ensemble with N particles showing interaction is given by The quantity U = N*u is the enthalpy of interaction. In an ensemble only N* particles having interaction partners are bound with the
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Published 02 Jun 2020

BergaCare SmartLipids: commercial lipophilic active concentrates for improved performance of dermal products

  • Florence Olechowski,
  • Rainer H. Müller and
  • Sung Min Pyo

Beilstein J. Nanotechnol. 2019, 10, 2152–2162, doi:10.3762/bjnano.10.208

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  • is very easy by measuring the melting enthalpy using differential scanning calorimetry (DSC). The melting enthalpy of a SmartLipids suspension can be determined before addition to the product, after addition to a gel or a cream and after storage. In case the particles dissolve, e.g., in an oil of a
  • cream, the melting enthalpy will decrease. Thus, the physical stability of SmartLipids is easy to analyze and to prove. Chemical stabilization of active agents Classical fluid carriers such as nanoemulsion and liposomes have a limited ability to protect labile lipophilic active agents. Due to the
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Published 04 Nov 2019

Energy distribution in an ensemble of nanoparticles and its consequences

  • Dieter Vollath

Beilstein J. Nanotechnol. 2019, 10, 1452–1457, doi:10.3762/bjnano.10.143

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  • . The energies ei and are given by The quantity u stands for the enthalpy, and cp for the heat capacity. As within one ensemble, only one average temperature is possible for the whole ensemble, only one characteristic temperature Tchar is assumed. The characteristic temperature Tchar may be interpreted
  • quantities gi−1 and gi−2 stand for the free enthalpy of the particle i in the phases 1 and 2, and |Δgi| stands for the difference of the free enthalpy of the two phases at the temperature Ti. Equation 5 gives the boundary condition for fluctuation, but does not give any information about the probability
  • . Therefore, the description of fluctuations has to be expanded. This necessary extension is demonstrated using as an example of melting gold particles at different particle sizes. Figure 1 displays the free enthalpy of the solid and the liquid phase of a 2 nm gold particle in the vicinity of the melting
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Published 19 Jul 2019

Gas sensing properties of individual SnO2 nanowires and SnO2 sol–gel nanocomposites

  • Alexey V. Shaposhnik,
  • Dmitry A. Shaposhnik,
  • Sergey Yu. Turishchev,
  • Olga A. Chuvenkova,
  • Stanislav V. Ryabtsev,
  • Alexey A. Vasiliev,
  • Xavier Vilanova,
  • Francisco Hernandez-Ramirez and
  • Joan R. Morante

Beilstein J. Nanotechnol. 2019, 10, 1380–1390, doi:10.3762/bjnano.10.136

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  • phenomenon can be explained by two factors. The first one is the single crystal character of the nanowires. Uniform adsorption enthalpy of all the centers is typical of Langmuir-type adsorption, which is characterized by low power factors in the power-law approximation. Vice versa, the small size of
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Published 08 Jul 2019
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