Structural evolutions of the n-heneicosane and n-tricosane molecular alloys at 293 K

Jouti, B.; Petitjean, D.; Provost, Élise; Bouroukba, M.; Dirand, M.

doi:10.1016/0022-2860(95)08956-v

Cited by 15 publications

(9 citation statements)

References 34 publications

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“…Mixing of n-alkanes generally has a dramatic influence on the polymorphic relationships, in particular, when even (n in Cn is even) alkanes are mixed with odd alkanes. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] In previous papers we have reported on the phase behavior of a number of individual binary systems. [16][17][18][19][20] For these systems all mixed phases were characterized as to their crystallographic properties.…”

Section: Introductionmentioning

confidence: 99%

n-Alkane Binary Molecular Alloys

et al. 2004

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The experimental systems considered in this paper are normal alkanes, in the range from octane to octacosane; and their binary mixtures {(1-x) mol of CnH2n+2 + x mol of Cn′H2n′+2}, with n′ > n, and ∆n ) n′ -n taking the values 1 and 2. The alkanes and their mixtures have a rich, complex polymorphic nature, for the description of which a distinction is made between a high-temperature and a low-temperature domain. The high-temperature domain is occupied by rotator phases, and the low-temperature domain by a variety of mixed crystalline phases, referred to as the "ordered" phases. Experimental phase diagram data for 19 binariessincluding 11 binaries for which original data are presentedsare used to give a uniform and coherent description of the phase relationships for the ensemble of alkane alloys.

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Section: Introductionmentioning

confidence: 99%

n-Alkane Binary Molecular Alloys

et al. 2004

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“…Ideal crystal systems are constructed by positioning heneicosane molecules in an orthorhombic crystal with lattice parameters given by Jouti et al from X-ray diffraction. 48 As a first step, the systems are simulated in the NPT ensemble for 2 ns with the Nose−Hoover barostat (1 atm) and thermostat (259 K) with coupling times of 5.0 and 1.0 ps, respectively. After that, systems are equilibrated in the NVE ensemble for 2 ns.…”

Section: Molecular Model and Simulation Detailsmentioning

confidence: 99%

“…Simulation systems are made up of a pristine or defective graphene sheet sandwiched between heneicosane nanofilms in the required phase as illustrated in Figure . Ideal crystal systems are constructed by positioning heneicosane molecules in an orthorhombic crystal with lattice parameters given by Jouti et al from X-ray diffraction . As a first step, the systems are simulated in the NPT ensemble for 2 ns with the Nosé–Hoover barostat (1 atm) and thermostat (259 K) with coupling times of 5.0 and 1.0 ps, respectively.…”

Section: Molecular Model and Simulation Detailsmentioning

confidence: 99%

Effect of Defects on the Interfacial Thermal Conductance between n-Heneicosane in Solid and Liquid Phases and a Graphene Monolayer

Zhou

Chilukoti

et al. 2021

J. Phys. Chem. C

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The molecular level mechanism of heat transport across the interface between solid and liquid n-heneicosane and monolayer graphene with three types of defects (single-vacancy, multivacancy (MV), and Stone–Wales (SW) (SW1 and SW2 cases are considered based on the orientation of the defects) has been studied using nonequilibrium molecular dynamics simulations. The influence of the alignment of an ideal crystal structure (heneicosane molecules positioned perpendicular and parallel to the graphene basal plane) and two heating modes (in the “heat-matrix” mode, heat enters the defective graphene sheet from one side of its basal plane and leaves from the other side, and in the “heat-graphene” mode, the heat is entering from the heated graphene layer to the cooled heneicosane from both sides of the basal plane) on the thermal conductance has been examined. With an increase in the defect percentage (up to 9.0%), the thermal conductance is found to be increasing for all types of defects under both heating modes. It is observed that both MV and SW2 defects in graphene result in the largest enhancement in the conductance under the heat-matrix mode, whereas the SW1 defect yields maximum improvement under the heat-graphene mode. Spectral analysis indicates that the vibrational modes of all frequencies are important for the interfacial heat transfer.

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“…25 It is experimentally known that the heneicosane molecules pack themselves in an orthorhombic crystal system. Perfect heneicosane crystals in the perpendicular-aligned and parallel-aligned systems are created with the lattice parameters reported for heneicosane crystals from X-ray diffraction by Jouti et al 33 Each graphene layer in the parallel-aligned systems has a cross section of L x × L y = 5.27 × 5.62 nm 2 and contains 1092 carbon atoms. For perpendicular-aligned systems, a cross section of L x × L y = 5.22 × 5.87 nm 2 is used for each graphene layer and contains 1176 carbon atoms.…”

Section: Molecular Model and Molecularmentioning

confidence: 99%

“…To investigate the thermal energy transfer across the graphene−heneicosane interfaces, computational systems that consist of desired numbers of graphene layers sandwiched between two heneicosane films in the desired state have been created as shown in Figure 1. Initial configurations of the crystal systems were constructed by positioning the heneicosane molecules in an orthorhombic crystal with lattice parameters given in Jouti et al 33 After that, the systems were first simulated in the NPT ensemble for 2 ns with the Nose− Hoover thermostat and barostat with coupling times of 1.0 and 5.0 ps, respectively. It has been verified that the pressure components along normal (z) and lateral directions (x and y) are close to same value in the bulk region of the system (see Supporting Information).…”

Section: Molecular Model and Molecularmentioning

confidence: 99%

Thermal Energy Transport across the Interface between Phase Change Material n-Heneicosane in Solid and Liquid Phases and Few-Layer Graphene

et al. 2019

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Molecular dynamics simulations have been performed to investigate the mechanism of thermal energy transport at the interface between n-heneicosane in solid and liquid phases and few-layer graphene at different temperatures under two heating modes (in the "heat-matrix" mode, heat is flowing from the heated heneicosane molecules to the cooled ones through the graphene layers and in the "heat-graphene" mode, the energy is flowing from the heated graphene to the cooled heneicosane). The effect of orientation of the perfect crystal structure (heneicosane molecules are positioned perpendicular and parallel to the graphene basal plane) on the interfacial thermal conductance has been examined. It is observed that the interfacial thermal conductance is 2 orders of magnitude higher under the heat-matrix mode than under the heat-graphene mode, for liquid or solid heneicosane and monolayer graphene. With an increase in the number of graphene layers, the interfacial thermal conductance under the heat-matrix mode decreases and reaches a plateau when the number of the graphene layer is more than eight. This is caused by the decreasing contribution of direct heat transfer from the matrix to matrix across the graphene layers via nonbonded intermolecular interactions. The interfacial thermal conductance becomes similar for both heating modes, once the number of graphene layers in the system is over 15. The influence of temperature on the interfacial thermal conductance is found to be insignificant in the range (175−250 K; 350−400 K). Both the phase and structure of heneicosane significantly influence the interfacial conductance. Spectral analysis suggests that graphene vibrational modes of all frequencies contribute to the interfacial heat transfer.

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Structural evolutions of the n-heneicosane and n-tricosane molecular alloys at 293 K

Cited by 15 publications

References 34 publications

n-Alkane Binary Molecular Alloys

n-Alkane Binary Molecular Alloys

Effect of Defects on the Interfacial Thermal Conductance between n-Heneicosane in Solid and Liquid Phases and a Graphene Monolayer

Thermal Energy Transport across the Interface between Phase Change Material n-Heneicosane in Solid and Liquid Phases and Few-Layer Graphene

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