Article
Physics, Applied
Philippe Nicollier, Christian Schwemmer, Francesca Ruggeri, Daniel Widmer, Xiaoyu Ma, Armin W. Knoll
Summary: The nanoparticle size-separation device is based on a nanofluidic rocking Brownian motor, utilizing a ratchet-shaped electrostatic particle potential to separate particle suspensions into multiple subpopulations by exploiting the sharp drop of particle current with increasing barrier heights. The separation mechanism is governed by the energy landscape under forward tilt of the ratchet, where the applied force is the only tunable parameter to increase the separation resolution. Experimental conditions of 3.5 V applied voltage and 20 s sorting predict a separation resolution of approximately 2 nm, supported by experimental data for separating spherical gold particles of nominal diameters of 80 and 100 nm.
PHYSICAL REVIEW APPLIED
(2021)
Article
Chemistry, Multidisciplinary
Ignacio Madrid, Zhiyong Zheng, Cedric Gerbelot, Akira Fujiwara, Shuo Li, Simon Grall, Katsuhiko Nishiguchi, Soo Hyeon Kim, Arnaud Chovin, Christophe Demaille, Nicolas Clement
Summary: The study investigated Brownian motion of tethered DNA under nanoconfinement, and found a transition into the ballistic Brownian motion regime for short DNA in sub-5 nm gaps.
Article
Chemistry, Physical
Amael Obliger
Summary: By starting from orthogonal dynamics, a set of coupled Volterra equations can be obtained to describe the projected time correlation functions between variables of interest. These equations can be solved using standard numerical inversion methods, providing a convenient and efficient approach to obtain projected time correlation functions or contributions to the memory kernel in a generalized Langevin equation.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Physics, Fluids & Plasmas
Kristian Stolevik Olsen
Summary: This study investigates the nonequilibrium steady state arising from stochastic resetting to a distribution. It is shown that for a range of processes, the steady-state moments can be expressed as a linear combination of the moments of the resetting position distribution. The coefficients of this series are universal and only dependent on the underlying dynamics, regardless of the resetting distribution. The study focuses on Brownian particles and run-and-tumble particles confined in a harmonic potential, providing explicit closed-form expressions for all moments for any resetting distribution, which are verified through numerical simulations.
Article
Astronomy & Astrophysics
Nathan G. Caldeira, Eduardo Folco Capossoli, Carlos A. D. Zarro, Henrique Boschi-Filho
Summary: This study investigates the fluctuations and dissipation of a string in a deformed AdS-Schwarzschild spacetime, calculating various quantities such as admittance, diffusion coefficient, two-point functions, and mean square displacement. The researchers also confirmed the fluctuation-dissipation theorem within this holographic model.
Article
Chemistry, Physical
Sina G. Lewis, Kori E. Smyser, Joel D. Eaves
Summary: The article discusses how clock transitions can reduce intrinsic and extrinsic quantum noise in molecules.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Andreas M. Menzel
Summary: This study focuses on the spontaneous symmetry breaking of the direction of active drive in propulsion of passive objects. By investigating examples such as self-propelled droplets, gliding bacteria, and nonpolar vibrated hoppers, the study reveals that under constant active forcing, there are velocity distributions with multiple peaks and spatial statistics showing outward propagating maxima.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Mechanics
Giuseppe Mussardo, Andre LeClair
Summary: The validity of the Riemann hypothesis is closely related to the growth of the Mertens function, which can be established through a new probabilistic approach based on global properties. Statistical analysis on the Mobius coefficients for square-free numbers confirms the random nature, while a violation of the RH is deemed extremely improbable based on theoretical probabilistic arguments and statistical tests.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2021)
Article
Astronomy & Astrophysics
Xin Guo, Kimball A. Milton, Gerard Kennedy, William P. McNulty, Nima Pourtolami, Yang Li
Summary: This study investigates the impact of quantum fluctuations-induced friction on the energy of particles, focusing on the energetics of a particle moving uniformly in vacuum. The quantum frictional power and force on the particle are calculated in the rest frame of blackbody radiation and the particle, demonstrating the equivalence of two approaches. The quantum vacuum frictional force is shown to be a true drag in the nonequilibrium steady state, independent of the particle's polarizability model and polarization state.
Article
Physics, Fluids & Plasmas
Sanku Paul, J. Bharathi Kannan, M. S. Santhanam
Summary: Quantum directed transport can be achieved in chaotic systems by breaking symmetries and introducing interactions, allowing for control of the currents.
Article
Astronomy & Astrophysics
Xiangyi Meng
Summary: The Keldysh formalism is used to study driven-dissipative dynamics of open quantum systems as nonunitary effective field theories, potentially leading to new physics. The perturbative Lindblad term introduced enables the possibility of a new nonthermal conformal fixed point in the large N limit, with implications for UV/IR relevance in driven-dissipative dynamics beyond traditional thermodynamics. Examples such as a (0 + 1)-d harmonic oscillator and a (4 - epsilon)-d classic O(N) vector model with quartic interactions are studied in this context.
Article
Multidisciplinary Sciences
Luca Ornigotti, Radim Filip
Summary: Experimental investigation reveals that levitating nanoparticles in optical potentials at low pressure exhibit a range of nonlinear ballistic phenomena, including instantaneous speed and acceleration stimulated by initial position uncertainty. The study shows that observing these transient effects does not require cryogenic cooling, but necessitates low uncertainty in initial particle speed.
SCIENTIFIC REPORTS
(2021)
Article
Mechanics
Massimiliano Giona, Giuseppe Procopio, Roberto Mauri
Summary: The paper presents a simple representation of hydrodynamic Green functions based on the free propagation of a vector field without constraints, enabling the investigation of intrinsic singularities associated with the propagation of stresses in incompressible flows under unsteady conditions.
Article
Materials Science, Multidisciplinary
Lingyao Kong, Xianliang Chen, Weiwei Wang, Dongsheng Song, Haifeng Du
Summary: This study investigates the dynamics of interstitial skyrmions under a temperature gradient, showing that they move from the hot area to the cold area. The confinement of interstitial skyrmions in one-dimensional channels leads to their movement in the same direction as the magnon flow induced by the temperature gradient, with the beta-type thermomagnonic torque playing a crucial role.
Article
Chemistry, Multidisciplinary
Aniruddha Deb, Prerona Gogoi, Sunil K. Singh, Partho Sarathi Gooh Pattader
Summary: This study demonstrates that external noise can alleviate the effect of solid friction between the gel matrix and DNA molecules, enhancing the mobility of DNA in electrophoresis. In the presence of noise, DNA's mobility increases by more than 113% compared to traditional electrophoresis. Stochastic simulation successfully predicts the mobility of DNA molecules and reveals the salient features of the overall dynamics.
Article
Materials Science, Multidisciplinary
Ryan P. Collanton, Kevin D. Dorfman
Summary: Frank-Kasper phases are complex particle packings that are commonly found in various materials. Our simulations and analyses show that the formation of Frank-Kasper phases is driven by the sharpening of the interface between A and B monomers, which coincides with a reduction in the imprinting of Voronoi polyhedra on the micelle core, resulting in a decrease in enthalpy.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Polymer Science
Pengyu Chen, Mahesh K. Mahanthappa, Kevin D. Dorfman
Summary: In this study, the stability of three cubic single network structures in neat diblock copolymer melts was examined using self-consistent field theory (SCFT). The results revealed that the relative stability of single networks is related to their larger interfacial areas.
JOURNAL OF POLYMER SCIENCE
(2022)
Article
Biochemical Research Methods
Yiming Qiao, Zixue Ma, Clive Onyango, Xiang Cheng, Kevin D. Dorfman
Summary: By subjecting T4 DNA to shear in a cone-and-plate rheometer, researchers observed significant fragmentation and molecular weight changes, highlighting the importance of DNA manipulation in microfluidic devices.
Article
Polymer Science
Sarah C. Seeger, Timothy P. Lodge, Kevin D. Dorfman
Summary: By using dissipative particle dynamics simulations and umbrella sampling, we investigated the dependence of the free energy trajectory for chain expulsion from a diblock copolymer micelle in a selective solvent on the core chain length. It was found that the free energy barrier scales linearly with the core block length of the expelled tracer chain, and the simulations revealed the mechanism of chain expulsion.
Article
Materials Science, Multidisciplinary
Anshul Chawla, Frank S. Bates, Kevin D. Dorfman, David C. Morse
Summary: Molecular dynamics simulations were used to investigate the melts of asymmetric sphere-forming diblock copolymers. The simulations revealed the appearance of critical micelle temperature and lower order-disorder transition temperature during the cooling process. At the critical micelle temperature, large clusters with a strongly segregated core region were observed, while no clear signature of the critical micelle temperature was found in scattering experiments. Additionally, the study showed an increase in the product of Flory-Huggins parameter x and degree of polymerization N at the critical micelle temperature with decreasing N.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Polymer Science
So Jung Park, Frank S. Bates, Kevin D. Dorfman
Summary: Blending different block compositions of block polymers can create nanostructures that cannot be accessed from neat block copolymer melts. In this study, the equilibrium phase behavior in binary blends of an AB diblock copolymer and an ABC triblock terpolymer was investigated using self-consistent field theory (SCFT). Blending these simple linear block polymers resulted in complex phase behaviors, including unusual core-shell network phases and a new cylinder-in-O70 hybrid network phase. The phase diagrams revealed an unexpected morphological richness, illustrating the potential in blending these relatively simple components.
Article
Chemistry, Physical
Logan J. Case, Frank S. Bates, Kevin D. Dorfman
Summary: Self-consistent field theory is used to investigate the phase behavior of binary blends of amphiphilic copolymers with different conformational asymmetries. The study shows that tuning the relative softness of the core blocks of different Laves phase particles can promote the formation of Laves phases. The results indicate that increasing the conformational asymmetry of the particles stabilizes the Laves phase, leading to a more stable phase field compared to symmetric systems. Furthermore, the presence of a hexagonal phase and a body-centered cubic phase is observed at lower temperatures.
Article
Chemistry, Physical
Runfang Mao, Kevin D. Dorfman
Summary: We used Langevin dynamics simulations to study the knot diffusion mechanisms and time scales governing the untying of trefoil knots in DNA molecules confined in nanochannels. Knot untying follows a process of expanding and fluctuating before annihilation. The average knot size increases with chain length, and knot diffusion in nanochannel-confined DNA molecules is subdiffusive. The identified scaling exponent and knot conformations suggest a combination of self-reptation and knot region breathing.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Polymer Science
Pengyu Chen, Frank S. Bates, Kevin D. Dorfman
Summary: In this study, the feasibility of adding ABC triblock copolymers into a polymer system was investigated using self-consistent field theory. The results showed that the addition of a small amount of ISO could stabilize the GA morphology, but the phase window was relatively narrow. Designing the system to have comparable domain sizes enhanced the stability of GA against competing lamellae.
Article
Polymer Science
Kevin. D. D. Dorfman, Zhen-Gang Wang
Summary: The Largecell self-consistent field theory (SCFT) solutions, initialized using the structure of a Lennard-Jones fluid, show the existence of numerous liquid-like states with higher free energies compared to the body-centered cubic (bcc) state near the order-disorder transition (ODT). The structure factor calculation indicates a slightly swollen intermicellar distance for these liquid-like states at temperatures below ODT. The presence of multiple liquid-like states and their near-degeneracy with the equilibrium bcc morphology explains the slow ordering kinetics observed in particle-forming diblock copolymer melts.
Article
Materials Science, Multidisciplinary
So Jung Park, Frank S. Bates, Kevin D. Dorfman
Summary: Single gyroid (SG) nanostructured materials with a complete photonic band gap structure are promising for next-generation optical applications. In this study, an equilibrium SG phase is predicted in H-shaped block polymers, and the relative stability of SG over the double gyroid (DG) phase is explained through the analysis of thermodynamic and geometric factors.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Chemistry, Physical
Ryan P. Collanton, Christopher J. Ellison, Kevin D. Dorfman
Summary: Block copolymers have been studied for their role in interface thermodynamics at homopolymer interfaces. The research finds that interface thermodynamics are more sensitive to block degree of polymerization than to the number of blocks. In addition, a strong correlation is identified between the spatial uniformity of block junctions on the interface and the reduction of interfacial tension.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Nima Sasanian, Rajhans Sharma, Quentin Lubart, K. K. Sriram, Marziyeh Ghaeidamini, Kevin D. Dorfman, Elin K. Esbjorner, Fredrik Westerlund
Summary: Amyloid fibrils play a central role in the pathology of many diseases and have significant structural polymorphism. A nanofluidic channel analysis technique was introduced to study single, fluorescently-labeled amyloid fibrils and determine their physical properties. The method allowed for accurate determination of fibril persistence length and revealed differences in physical properties between amyloid-beta(1-42) and alpha-synuclein fibrils.
Article
Polymer Science
Timothy P. Lodge, Claire L. Seitzinger, Sarah C. Seeger, Sanghee Yang, Supriya Gupta, Kevin D. Dorfman
Summary: The self-assembly of block copolymers into nanostructures is a vibrant research area, but the dynamic processes of equilibration are not fully understood. Equilibration is achievable only near critical temperatures or order-disorder transitions. The equilibration rate is often much slower than chain exchange, resulting in metastable particle phases.
Article
Chemistry, Multidisciplinary
Zhengyuan Shen, Ke Luo, So Jung Park, Daoyuan Li, Mahesh K. Mahanthappa, Frank S. Bates, Kevin D. Dorfman, Timothy P. Lodge, J. Ilja Siepmann
Summary: This study investigates binary blends of sugar-based (A) and hydrocarbon (B) blocks through molecular dynamics simulations. The results show that different ordered structures, such as a double gyroid network and perforated lamellae, can be formed under different compositions. The analysis reveals that the stability and internal configuration of these structures are determined by the nonuniform interfacial curvatures and local composition variations.