Article
Chemistry, Physical
Hasan Zerze
Summary: Polymer crystallization is an important topic in both fundamental physics and manufacturing. Molecular dynamics simulations were used to study polyethylene crystal nucleation and growth, revealing that the nucleation rate decreases with increasing droplet size and nuclei primarily emerge from the surface.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
W. Zhu, Y. Xia, B. G. Aitken, S. Sen
Summary: In deeply supercooled regime, the onset of shear thinning and transition from Newtonian to non-Newtonian behavior in select chalcogenide and oxide network glass-forming liquids were studied, showing a temperature-dependent relationship. The shear thinning mechanism in network liquids appears to be fundamentally different from other types of glass-forming liquids, with reduced shear rate decreasing with increasing temperature, particularly with higher fragility.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
B. Q. Wu, L. T. Kong, J. F. Li
Summary: This study thoroughly investigated the glass-forming ability of Cu-Ag alloys at different compositions using molecular dynamics simulations. The results showed that the eutectic alloy exhibited the best glass-forming ability, with a critical cooling rate significantly lower than that of pure metals. The number of densely packed icosahedral-like clusters increased with increasing solute content in the alloy. While the dynamical properties of Cu-Ag melts were composition-independent at high temperatures, they clearly changed with composition at low temperatures.
Article
Physics, Condensed Matter
Jalim Singh, Prasanth P. Jose
Summary: Molecular dynamics simulations on model linear polymers reveal violations of Stokes-Einstein relation in monomer density relaxation across different densities, with a weak violation of Stokes-Einstein-Debye relation near the transition temperature in lower density systems. Additionally, jumplike motions are observed in typical monomer trajectories, contributing to the violations, along with a decoupling of translational and rotational dynamics in the polymer system.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Polymer Science
Yexin Zheng, Mesfin Tsige, Shi-Qing Wang
Summary: In this study, molecular dynamics simulations were used to investigate the entanglement lockup phenomena in the uniaxial melt stretching of entangled polymer melts. The results revealed that under high strains, the entanglement network became increasingly tighter, leading to chain tension and the formation of network junctions. It was hypothesized that the interchain entanglement at junctions can lockup as long as certain conditions are met. This study provides insights into the mechanical properties of polymer materials.
MACROMOLECULAR RAPID COMMUNICATIONS
(2023)
Article
Biochemistry & Molecular Biology
Yi Pan, Xinyue Zhang, Qianru Zhan, Shuangchun Yang, Yanchao Wang, Jian Guan, Gang Yang, Peng Yang, Zain Ullah Abdul Qayum
Summary: In this study, a temperature-sensitive modified bentonite based on NIPAM was developed through intercalation modification. The results showed that the synthesized bentonite exhibited good temperature sensitivity and rheological properties in the range of 40-70 degrees Celsius.
Article
Medicine, Research & Experimental
Lara Roewekamp, Kevin Moch, Catalin Gainaru, Roland Boehmer
Summary: Acetaminophen, nicotine, and lidocaine hydro-chloride were studied in their deeply supercooled liquid states using oscillatory shear rheology. A modified version of the GDB model successfully predicted the dielectric spectra for all liquids except lidocaine hydrochloride. The reverse transformation, calculating rheological spectra based on dielectrics, was also demonstrated.
MOLECULAR PHARMACEUTICS
(2022)
Article
Chemistry, Multidisciplinary
Frederico Duarte, Cristian Cuerva, Carlos Fernandez-Lodeiro, Javier Fernandez-Lodeiro, Raquel Jimenez, Mercedes Cano, Carlos Lodeiro
Summary: Polymer nanoparticles encapsulating B(III) compounds with an average size of about 200 nm were successfully prepared via the reprecipitation method, forming stable colloidal dispersions in water and maintaining the photophysical behavior of dyes. The study found that the B(III) particles continued to emit greenish light at high temperatures, with emission being restored upon cooling back to room temperature, showing reversibility.
Article
Materials Science, Ceramics
Yuantao Zhang, Jianguo Huang, Xiangchun Ning
Summary: By substituting MgO with MgF2, the network structure of the glass is disrupted, but the addition of fluoride ions can improve the mechanical properties of the glass.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2023)
Article
Chemistry, Physical
Zijing Li, Ji Wang, Shaopeng Pan, Frederic Affouard, Suhong Zhang, Shidong Feng, Yingdan Liu, Li-min Wang
Summary: A new criterion Z for glass forming ability is proposed based on the time-temperature-transformation interpretation, considering the stability of the liquid and the devitrification of glassy phases. A non-linear relationship between Z and the critical glassy size is found, showing stronger correlation than previously reported parameters. The advantage of using Z as a GFA parameter lies in its reflection of the relative influences of the thermodynamics and kinetics of systems on glass formation.
Article
Automation & Control Systems
Zhengcheng Long, Hongsheng Liu, Ziqin Yan, Xiaohui Cui
Summary: In this study, a flat spiral coil is used for the micro-forming of thin sheet metal, and the effects of discharge voltage, cushion block thickness, and number of discharge times on sheet forming quality are analyzed. The results show that increasing discharge voltage and using successive discharges can improve moldability.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Pharmacology & Pharmacy
S. E. Lapuk, T. A. Mukhametzyanov, C. Schick, A. Gerasimov
Summary: The use of amorphous forms of drugs is a modern approach to enhance bioavailability. Fast Scanning Calorimetry was applied to create amorphous states of dopamine hydrochloride and atenolol for the first time, determining critical cooling rates and glass transition temperatures. The Nakamura crystallization model provided the best description of the crystallization process, useful for predicting the long term stability of the drugs' amorphous forms.
INTERNATIONAL JOURNAL OF PHARMACEUTICS
(2021)
Article
Mechanics
Mary A. A. Joens, Patrick S. S. Doyle, Gareth H. H. McKinley, James W. W. Swan
Summary: This study investigates the motion of a small rotating spherical particle in a two-dimensional trajectory through a viscoelastic fluid using the Giesekus model. The study analyzes both steady-state and time-dependent flows, quantifying the relative unsteadiness and nonlinearity of the flows. The impact of changing dimensionless parameters on the flow characteristics is discussed.
Article
Polymer Science
M. A. Logunov, N. D. Orekhov
Summary: The relationship between the local topology of molecular entanglements and the mechanical properties in polymer science is still an open question. This study used molecular dynamics to model pore formation in amorphous polyethylene during uniaxial stretching, and investigated how changes in intermolecular entanglement concentration affect the dynamics of nanosized pore formation. Statistical analysis of pore sizes showed that intermolecular entanglements slow down the growth and aggregation processes of pores within the polymer.
POLYMER SCIENCE SERIES A
(2021)
Article
Materials Science, Multidisciplinary
Mariona Tarrago, Charles Le Losq, Thibaut Robine, Solenn Reguer, Dominique Thiaudiere, Daniel R. Neuville
Summary: In this study, experiments were conducted to investigate the valence state of titanium in silicate glasses under high temperatures and reduced conditions. It was found that titanium remained tetravalent and showed crystallization behavior instead of becoming trivalent. Furthermore, the use of reduced gas mixtures was explored as a novel method to induce surface crystallization and produce ceramic-coated glass materials.
Article
Physics, Fluids & Plasmas
A. Kuhnhold, W. Paul
Article
Chemistry, Physical
A. Kuhnhold, T. Schilling
JOURNAL OF CHEMICAL PHYSICS
(2016)
Article
Chemistry, Multidisciplinary
Johanna R. Bruckner, Anja Kuhnhold, Camila Honorato-Rios, Tanja Schilling, Jan P. F. Lagerwall
Article
Materials Science, Multidisciplinary
Camila Honorato-Rios, Anja Kuhnhold, Johanna R. Bruckner, Rick Dannert, Tanja Schilling, Jan P. F. Lagerwall
FRONTIERS IN MATERIALS
(2016)
Article
Biophysics
Anja Kuhnhold, Aicko Y. Schumann, Ronny P. Bartsch, Romy Ubrich, Petra Barthel, Georg Schmidt, Jan W. Kantelhardt
PHYSIOLOGICAL MEASUREMENT
(2017)
Article
Chemistry, Physical
A. Kuhnhold, S. M. Giesen, T. Schilling
Article
Physics, Fluids & Plasmas
A. Kuhnhold, W. Paul
Article
Chemistry, Physical
Anja Kuhnhold, Nils Goeth, Nadja Helmer
Summary: Monte Carlo simulations were used to study colloidal membranes consisting of chiral rod-like particles, revealing the sensitivity of membrane shape and structure to various parameters. Two approximations were made to compare simulation results to elastic theory, both of which provided reasonable descriptions of the colloidal membrane system's behavior. Additionally, different twisting properties of colloidal membranes under various conditions were identified.
Article
Chemistry, Physical
Anja Kuhnhold, Paul van der Schoot
Summary: The internal structure of nematic droplets or tactoids formed by rod-like particles in a gas of spherical ghost particles is studied using Monte Carlo simulations. The size of the droplets strongly affects their shape and internal structure. An external quadrupolar alignment field makes the director field more uniform, but does not significantly increase the aspect ratio of the droplets.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Physics, Fluids & Plasmas
P. Elsaesser, A. Kuhnhold
Summary: In this study, we combined two extensions of the Lebwohl-Lasher model and investigated the phase behavior and phase transitions of the resulting generalized chiral Lebwohl-Lasher model in liquid crystalline systems using Monte Carlo simulations. We found that the type and existence of the transition depend on the combination of the interaction potential width, the strength of the chiral part of the interaction, and the system geometry. Additionally, the pitch of the cholesteric bulk phase changes if the interaction width differs from the original Lebwohl-Lasher model, and we identified parameter combinations that can tune the properties of the ordered phase and the nature of the order-disorder transition.
Article
Chemistry, Physical
Joeri Opdam, Poshika Gandhi, Anja Kuhnhold, Tanja Schilling, Remco Tuinier
Summary: In this paper, we study excluded volume interactions, free volume fraction available, and phase behavior in mixtures of hard spheres and hard rods. Comparing the results of free volume theory and Monte Carlo simulations, we find that the novel approach predicts free volume and phase stability accurately.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Physics, Fluids & Plasmas
A. Kuhnhold, V Taenzel
Summary: This study investigates the properties of thin smectic fibrils composed of chiral rodlike particles using Monte Carlo simulations, finding that the layers of the fibrils relax into a twisted state naturally and showing a slight preference for an alternating sequence. The fibrils contract with increasing chiral interaction strength, indicating potential for further research on self-assembled functional materials.
Article
Physics, Fluids & Plasmas
Anja Kuhnhold, Hugues Meyer, Graziano Amati, Philipp Pelagejcev, Tanja Schilling
Meeting Abstract
Chemistry, Multidisciplinary
Anja Kuhnhold, Wolfgang Paul
ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY
(2015)
