Article
Chemistry, Physical
Leo Lue, Marvin Bishop, Paula A. Whitlock
Summary: This study investigated the behavior of six-dimensional hard hypersphere systems in the A(6), D-6, and E-6 crystalline phases using molecular dynamics simulations. The pair correlation functions in different states did not exhibit typical freezing signatures of the fluid phase.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Pritam Kumar Jana, Julien Lam, Rahul Mangal, Mikko J. Alava, Nagma Parveen, Lasse Laurson
Summary: This study investigated the phase transition behavior of liquid crystals in the presence of different types of impurities, finding that associative liquids like water do not affect the phase transition, while non-associative liquids like hexane induce sharp transitions in liquid crystals. The mixing/demixing phenomenon in the liquid crystal + impurity system was found to influence the entropy of the system, leading to entropy-driven phase transitions.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Xinlan Tan, Ya Chen, Huaguang Wang, Zexin Zhang, Xinsheng Sean Ling
Summary: By using an external magnetic field to assist a colloidal system of super-paramagnetic anisotropic particles, researchers have successfully overcome the local free energy barriers in metastable states and approached the equilibrium phase, demonstrating a 2D isotropic-nematic phase transition with increasing packing density. The study explored the effects of anisotropy of colloidal particles on the 2D isotropic-nematic transition, comparing experimental results with previous computational work and reaching quantitative agreements.
Article
Chemistry, Physical
Grant E. Bauman, Timothy J. White
Summary: The alignment and thermal history play important roles in the rheological properties of liquid crystalline oligomers. The transition to an aligned nematic state occurs gradually when oligomers start in a polydomain nematic state, while they behave as a Newtonian fluid until a critical shear rate is reached if they start in an isotropic state. The viscosity of the oligomer decreases and the critical shear rate increases with the decrease of liquid crystalline content or the increase of temperature. The normal stress of oligomers decreases significantly with increasing temperature.
Article
Multidisciplinary Sciences
Gregor Skacej, Claudio Zannoni
Summary: Through large-scale MC simulations, a notable free-energy barrier between the isotropic and nematic phases was observed, leading to long-lived metastable states and hysteresis. Improved estimates of the nematic-isotropic transition temperature and related parameters were provided, along with an analysis of the size distribution of ordered domains above T-NI.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2021)
Article
Chemistry, Physical
Joanna Los, Aleksandra Drozd-Rzoska, Sylwester J. Rzoska, Szymon Starzonek, Krzysztof Czuprnski, Prabir Mukherjee
Summary: The Landau-de Gennes mean-field model predicts a discontinuous transition in the isotropic-nematic phase transition, characterized by uniaxial ordering and a quadrupolar order parameter in three dimensions. This study investigates the pressure-related dielectric properties of rod-like nematogenic pentylcyanobiphenyl (5CB) and its nano-colloids with BaTiO3 nanoparticles. The dielectric constant scan reveals a near-continuous I-N phase transition in the compressed nanocolloid with a small amount of nanoparticles (x = 0.1%). The nematic phase in 5CB and its x = 1% nanocolloid exhibit high dielectric constants and bending-type, long-range pretransitional behavior.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Polymer Science
Takuya Ohzono, Kaoru Katoh, Eugene M. Terentjev
Summary: The study found that the ordering transition of polydomain main-chain nematic liquid crystal elastomers differs from the classical first-order transition, showing a continuous nature. Unexpectedly, the characteristic correlation length of the fading polydomain structure remains unchanged across the transition.
Article
Chemistry, Multidisciplinary
Shweta Mishra, V. Manjuladevi, R. K. Gupta, Sandeep Kumar
Summary: By incorporating CdS nanowires into nematic liquid crystal, the weakly first-order discontinuous isotropic-nematic phase transition evolves into a continuous phase transition, affecting the dielectric permittivity and bulk conductivity. In addition, the nanocomposites show increased ionic conductivity with higher concentrations of CdS nanowires.
Article
Chemistry, Physical
Giorgio Cinacchi
Summary: This work describes the derivation of a random contact equation to predict the packing fraction of a dense disordered state of elongate particles. The derivation is based on the compressibility equation and the pair-correlation function, and the predicted results are compared to experimental data.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Kelum Perera, Rony Saha, Pawan Nepal, Rohan Dharmarathna, Md Sakhawat Hossain, Md Mostafa, Alex Adaka, Ronan Waroquet, Robert J. Twieg, Antal Jakli
Summary: The experimental results and theoretical considerations of novel electromechanical effects of ferroelectric nematic liquid crystal droplets coexisting with the isotropic melt are presented in this study. It is found that the droplets have flat pancake-like shapes thinner than the sample thickness. A wing-shaped defect with low birefringence is present in the center of the droplets, moving perpendicular to a weak electric field, and dividing into two at higher fields. The entire droplet drifts along the electric field with a speed independent of droplet size and proportional to the electric field amplitude.
Article
Physics, Fluids & Plasmas
Pierre-Michel Dejardin
Summary: The theory presents a formulation of the linear static dielectric constant and linear complex permittivity for polar fluids. It introduces reduced densities and derives equations governing their dynamics. The theory provides integral expressions for the Kirkwood correlation factor g(K), revealing the limitations of comparing it with 1 to deduce pair dipolar ordering. In the dynamical situation, the theory shows the complex permittivity spectrum of a simple liquid exhibits an infinite set of relaxation times, some of which may have thermally activated behavior. The theory encompasses previous results while ignoring molecular inertial effects, making it valid at frequencies below the far-infrared region. Additionally, it can be applied to the relaxation of interacting magnetic nanoparticles with neglected macroscopic magnetic anisotropy arising from nanoparticle assembly.
Article
Physics, Multidisciplinary
Carlindo Vitoriano
Summary: Experimental observations reveal that the time constants for spectral diffusion in the isotropic phase of 5CB diverge as (T - T*)(-1/2), indicating that the correlation length of the density-density correlation function xi(rho) also displays the same temperature dependence near the nematic-isotropic phase transition. By extending the Landau-de Gennes theory, which includes mass density fluctuations, we successfully calculate xi(rho) in the isotropic phase and find agreement with experimental results. This implies that the isothermal compressibility diverges as K-T ~ xi(2)(rho) near the transition, supporting the suggestion that the isotropic phase of nematic liquid crystals exhibits features of supercritical fluids. Furthermore, we explore the energetic coupling between mass density gradients and the liquid crystal director in the biaxial nematic phase.
BRAZILIAN JOURNAL OF PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Francesco Grandi, Armando Consiglio, Michael A. Sentef, Ronny Thomale, Dante M. Kennes
Summary: Kagome metals AV3Sb5 (A = K, Rb, Cs) exhibit an exotic charge order with broken symmetries and orbital currents. It is still debated whether the origin of the charge order is due to electron-electron or electron-phonon interactions. We systematically characterize different charge order configurations and propose using resonant ultrasound spectroscopy to experimentally characterize the order parameters.
Article
Optics
Fengfeng Yao, Rongqu Hong, Lu Yang, Yanbo Pei, Chunfeng Hou, Xiudong Sun
Summary: Random lasing emission from the lateral end face of dye doped nematic liquid crystal (DDLC) cells was investigated during the nematic-isotropic phase transition process. An enhancement of light scattering in DDLCs during the phase transition was observed, which was greatly dependent on temperature. The random lasing induced by resonant feedback near peak-scattering temperature could be controlled by temperature or pump energy.
OPTICS AND LASER TECHNOLOGY
(2021)
Article
Chemistry, Physical
Semen S. Tenishchev, Ivan M. Tambovtcev, Alexei D. Kiselev, Valery M. Uzdin
Summary: The study discovered that the critical voltage of the Freedericksz transition is proportional to the free twisting wave number for branches with non-vanishing half-turn number. The energy barrier exhibits hysteresis with respect to the electric field dependence, and a first-order electrically driven transition involving out-of-plane director deformations was observed when passing through a first-order saddle point in minimum-energy pathways.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Chemistry, Physical
Martin B. Sweatman
Article
Chemistry, Physical
Javier Cardona, Rui Fartaria, Martin B. Sweatman, Leo Lue
MOLECULAR SIMULATION
(2016)
Article
Energy & Fuels
C. F. Martin, M. B. Sweatman, S. Brandani, X. Fan
Article
Chemistry, Physical
Martin B. Sweatman, Leo Lue
JOURNAL OF CHEMICAL PHYSICS
(2016)
Article
Chemistry, Physical
M. B. Sweatman
Article
Chemistry, Physical
N. D. Afify, M. B. Sweatman
JOURNAL OF CHEMICAL PHYSICS
(2019)
Article
Chemistry, Physical
Jiazheng Tan, Nasser D. Afify, Carlos A. Ferreiro-Rangel, Xianfeng Fan, Martin B. Sweatman
Summary: The equilibrium cluster fluid state of a symmetric binary mixture of particles with short-ranged attractive and long-ranged repulsive interactions was studied through Monte Carlo simulations. The clustering behavior of the system was found to be controlled by the cross-interaction between the two types of particles. Different levels of cross-attraction led to different clustering behaviors, from independent giant clusters to composite clusters.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Review
Geosciences, Multidisciplinary
Martin B. Sweatman
Summary: Research suggests that a major cosmic impact around 10,835 BC may have caused the Younger Dryas climate shift, changes in human cultures, and megafaunal extinctions. While some claims are still unconfirmed, the majority of studies support the idea of a significant cosmic impact at this time, warranting further research.
EARTH-SCIENCE REVIEWS
(2021)
Review
Geosciences, Multidisciplinary
Martin B. Sweatman
Summary: Jorgeson, Breslawski, and Fisher challenge comments made in Sweatman's review paper, raising concerns about the confidence in their modeling of radiocarbon data from the Younger Dryas boundary.
EARTH-SCIENCE REVIEWS
(2022)
Article
Chemistry, Physical
Martin B. Sweatman, Nasser D. Afify, Carlos A. Ferreiro-Rangel, Miguel Jorge, Jan Sefcik
Summary: Recent experiments have found the presence of giant liquid-like clusters or nanodroplets in undersaturated aqueous glycine solutions. Molecular dynamics simulations suggest that these clusters may not be composed purely of glycine and water. Instead, they may result from the aggregation of reaction products of glycine solution, which is difficult to separate from glycine using conventional methods.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Article
Chemistry, Physical
Nasser D. Afify, Carlos A. Ferreiro-Rangel, Martin B. Sweatman
Summary: This work presents a general methodology based on molecular dynamics to investigate the formation of apparently stable clusters of pentaethylenehexamine (PEHA) in water. The study shows that large stable clusters are formed by singly charged PEHA with chloride or acetate as the counterion, and large clusters also appear to be stable for doubly charged PEHA with acetate counterion. This behavior is attributed to a form of complex coacervation, observed for relatively small and highly soluble molecules rather than the large polyions usually found in such coacervates.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Review
Multidisciplinary Sciences
Martin B. Sweatman, Leo Lue
ADVANCED THEORY AND SIMULATIONS
(2019)
Article
Multidisciplinary Sciences
Martin B. Sweatman, Robert Insall
ADVANCED THEORY AND SIMULATIONS
(2019)
Article
Chemistry, Multidisciplinary
Jack D. Evans, Simon Krause, Stefan Kaskel, Martin B. Sweatman, Lev Sarkisov
Article
Energy & Fuels
Stephen J. McGurk, Claudia F. Martin, Stefano Brandani, Martin B. Sweatman, Xianfeng Fan
Correction
Chemistry, Physical
Chen Luo, Yan Shao, Hua Yu, Hong-zhi Ma, Yu-hao Zhang, Long Gu, Bo Yin, Ming-bo Yang
CHEMICAL PHYSICS LETTERS
(2024)
Article
Chemistry, Physical
Stefano Borocci, Armando Camerlingo, Felice Grandinetti, Maria Rutigliano, Nico Sanna
Summary: The complexes of He, Ne, Ar, Kr, and Xe with B3N3H6 were investigated using MP2, CCSD(T), and SAPT ab initio methods. The complexes can be described as mono-, di-, and tri-coordinated to the N atoms, with stability following the order N-mono < N-di < N-tri. The interactions are dominated by dispersion and the binding energies are within the range of 1 or 2 kcal mol(-1). The results were compared with a recent DFT study on larger BN sheets complexes [Phys. Chem. Chem. Phys. 24 (2022) 2554-2566.].
CHEMICAL PHYSICS LETTERS
(2024)
Article
Chemistry, Physical
V. Nagarajan, R. Bhuvaneswari, R. Chandiramouli
Summary: In this study, stable phosphoborane was used as a sensor to detect isobutane and n-propane in Liquefied Petroleum Gas (LPG). Phosphoborane demonstrated structural stability and semiconducting nature, and exhibited promising adsorption properties for the LPG molecules.
CHEMICAL PHYSICS LETTERS
(2024)
Article
Chemistry, Physical
Xiaoxi Xu, Zijiang Yang, Bayaer Buren, Maodu Chen
Summary: In this study, the time-dependent wave packet method was used to investigate the reaction channels and mechanisms of Ca+ + HD. The results show that the CaH+ + D reaction channel plays a primary role, which is consistent with experimental results. Complex forming and direct-abstraction reaction mechanisms exist in this reaction process.
CHEMICAL PHYSICS LETTERS
(2024)
Article
Chemistry, Physical
Keshab Pandey, Hae Kyung Jeong
Summary: A free-standing silicon-carbon nanofiber composite film was synthesized and investigated for supercapacitor applications. It exhibited high specific capacitance, energy density, and power density. After 5000 cycles, the film showed excellent specific capacitance retention and Coulombic efficiency.
CHEMICAL PHYSICS LETTERS
(2024)
Article
Chemistry, Physical
Xinyu Zhang, Haosong Li, Xiaoyu Cao, Jing Gao, Yong Wei, Jianzhuo Zhu
Summary: The evaporation behavior of nanosized water aggregations on two-dimensional electroneutral solid surfaces with different surface polar unit densities was investigated. The results showed that the evaporation rate changes non-monotonically with the surface polar unit density, and the minimum evaporation rate is obtained when the surface has a modest surface polar unit ratio of 66.7%.
CHEMICAL PHYSICS LETTERS
(2024)
Article
Chemistry, Physical
Yanyan Xu, Rui Dai, Xiaojie Wang, Zhijun Qiao, Haowei Wen, Dianbo Ruan, Yuzuo Wang
Summary: This article presents an innovative solvothermal sodium insertion method for synthesizing Triphylite-NaFePO4, which demonstrates optimal electrochemical performance in sodium-ion batteries.
CHEMICAL PHYSICS LETTERS
(2024)
Article
Chemistry, Physical
Meiyi Jiang, Kun Yang, Yancheng Liu, Li Yao
Summary: The geometric structure and electronic properties of transition metal M (M = Cu, Fe, Mn)-TiO2 (101) surface adsorbed by NO2 and N2O were calculated by density functional theory (DFT) and DFT + U theory. The results showed that the adsorption of NO2 and N2O on Mn and Fe atoms is more stable, and a large number of active electrons are formed around these atoms, facilitating the catalytic reactions.
CHEMICAL PHYSICS LETTERS
(2024)
Article
Chemistry, Physical
Sergey A. Vyrko, Yulia G. Polynskaya, Nikita A. Matsokin, Andrey M. Popov, Andrey A. Knizhnik, Nikolai A. Poklonski, Yurii E. Lozovik
Summary: In this study, carbon nanobracelets, which are cyclic molecules composed of alternating polycyclic regions and double carbon chains, were investigated using spin-polarized density functional theory. The results show that carbon nanobracelets with odd number of monomers exhibit distinct electronic energy levels, band gaps, and carbon chain deformation compared to those with even number of monomers.
CHEMICAL PHYSICS LETTERS
(2024)
Article
Chemistry, Physical
Chanchan Wang, Quan Yang, Yanzhi Ding, Xiaoyong Lu, Dong Tian
Summary: It has been found that the introduction of buffer layers improves the electrical performance of solid oxide fuel cells (SSOFCs). In this study, varying ratios of Gd-doped CeO2 were used as buffer layers in YSZ-based SSOFCs. The results demonstrate that the performance of SSOFCs is enhanced when a buffer layer is added, with the highest performance achieved using Ce0.8Gd0.2O2-delta (GDC20) as the buffer layer. This suggests that the use of GDC series buffer layers is an attractive strategy to optimize performance loss due to electrolyte-electrode interactions.
CHEMICAL PHYSICS LETTERS
(2024)
Article
Chemistry, Physical
Wang Li, Yi-Fan Zhang, Jia-Bin Huang, Chang-Yang Wang, Feng Zhang, Jiu-Zhong Yang, Long Zhao
Summary: The gas-phase reaction of propargyl with vinylacetylene was investigated using synchrotron photoionization and molecular-beam mass spectrometry methodologies. The formation mechanisms of the resulting cyclic structures were examined using quantum computations. Two previously unidentified isomers were detected and identified for the first time.
CHEMICAL PHYSICS LETTERS
(2024)
Article
Chemistry, Physical
Avijit Pramanik, Sanchita Kundu, Olorunsola Praise Kolawole, Kaelin Gates, Paresh Chandra Ray
Summary: This study investigates the influence of aspect ratio and quantum confinement on the single-photon and two-photon absorption cross-section of perovskite CsPbI3 nanorods. Experimental data shows that CsPbI3 nanorods have an extremely high two-photon absorption cross-section, significantly surpassing organic chromophores and other CsPbBr3 nanocrystals. Moreover, adjusting the aspect ratio can significantly enhance the absorption ability. Additionally, the study also reveals a moderate quantum confinement effect on the single-photon and two-photon absorption cross-section of the nanorods.
CHEMICAL PHYSICS LETTERS
(2024)
Article
Chemistry, Physical
Hyon-Tae Pak, Jin-A Choe, Kyong-Sik Ju, Yong -Son Rim
Summary: Drug-loaded cellulose diacetate (CDA) membranes were prepared using different compositions of mixed solvent. The microstructure and performance of the membranes were investigated, and a method to predict drug release properties was proposed. The results showed that the composition of the mixed solvent significantly affected the overall performance of CDA membranes, and the release rates of drugs were related to Δdelta and the intrinsic viscosity of CDA.
CHEMICAL PHYSICS LETTERS
(2024)
Article
Chemistry, Physical
Gabriella E. Ravin, E. Curotto
Summary: We have developed a systematic approach to optimize the training set sizes for neural networks in fitting ab initio potential energy surfaces. Using this approach, we have constructed several spectroscopic quality potential energy surfaces for [Li(H2)n]+, n = 1 - 9. The ground state properties have been computed for all the systems and selected states.
CHEMICAL PHYSICS LETTERS
(2024)
Article
Chemistry, Physical
Guohua Xu, Lei Xu, Feng Zhang, Chunling Yu, Yu Song
Summary: NiS1.03@Ni7S6/carbon composite was successfully prepared using corn stalk as a carbon source via a simple adsorption-sulphurization process. The composite exhibited a specific capacitance of 1554.6 F/g at 1 A/g as a supercapacitor electrode, with a capacitance retention rate of 80.4% after 5000 cycles. Furthermore, the NiS1.03@Ni7S6/carbon//AC asymmetric supercapacitor showed a high energy density of 41.2 Wh kg-1 at a power density of 750 W kg-1, and excellent cycling stability with 86.8% capacitance retention after 10,000 cycles.
CHEMICAL PHYSICS LETTERS
(2024)
