Journal articles: 'Polymer simulations'

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Zhang, Anni, and Eric S. G. Shaqfeh. "Rheology of non-Brownian particle suspensions in viscoelastic solutions. Part 1: Effect of the polymer concentration." Journal of Rheology 67, no. 2 (March 2023): 499–516. http://dx.doi.org/10.1122/8.0000540.

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We study the effect of varying polymer concentration, measured by the dimensionless polymer viscosity partition function [Formula: see text], on the steady shear rheology of rigid particle suspensions using direct numerical simulation of the Oldroyd-B model. We compare the bulk rheology using immersed boundary simulations at [Formula: see text] and [Formula: see text] to body-fitted single-particle simulations and find that the per-particle viscosity and first normal stress difference coefficient are always shear-thickening at all values of [Formula: see text] considered. However, as [Formula: see text] decreases, the polymer stress transforms the flow field near each particle from closed concentric streamlines to helical streamlines that advect stretched polymers away from the particle surface. At low [Formula: see text], the polymer stress is diffuse, where the distribution of the particle induced fluid stress (PIFS) caused by the stretched polymers is spread out in the simulation domain rather than concentrated near the particle surface. Therefore in multiparticle simulations, the polymer stress can be significantly affected by particle-particle interactions. The stress generated by a given particle is disrupted by the presence of particles in its vicinity, leading to a significantly lower PIFS than that of the single-particle simulation. In addition, at increased volume fractions and low values of [Formula: see text], the polymer stress distribution on the particle surface shifts so as to increase the magnitude of the polymer stress moments, resulting in a shear-thickening stresslet contribution to the viscosity that is not seen in single particle or high [Formula: see text] simulations. This result indicates that for suspensions in highly viscoelastic suspending fluids that are characterized by a low [Formula: see text] parameter, hydrodynamic interactions are significant even at modest particle concentrations and fully resolved multiparticle simulations are necessary to understand the rheological behavior.

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Zhang, Fan, Rui Yang, and Diannan Lu. "Investigation of Polymer Aging Mechanisms Using Molecular Simulations: A Review." Polymers 15, no. 8 (April 18, 2023): 1928. http://dx.doi.org/10.3390/polym15081928.

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Aging has a serious impact on the properties of functional polymers. Therefore, it is necessary to study the aging mechanism to prolong the service and storage life of polymer-based devices and materials. Due to the limitations of traditional experimental methods, more and more studies have adopted molecular simulations to analyze the intrinsic mechanisms of aging. In this paper, recent advances in molecular simulations of the aging of polymers and their composites are reviewed. The characteristics and applications of commonly used simulation methods in the study of the aging mechanisms (traditional molecular dynamics simulation, quantum mechanics, and reactive molecular dynamics simulation) are outlined. The current simulation research progress of physical aging, aging under mechanical stress, thermal aging, hydrothermal aging, thermo-oxidative aging, electric aging, aging under high-energy particle impact, and radiation aging is introduced in detail. Finally, the current research status of the aging simulations of polymers and their composites is summarized, and the future development trend has been prospected.

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Ostrovsky, B., M. A. Smith, and Y. Bar-Yam. "Simulations of Polymer Interpenetration in 2D Melts." International Journal of Modern Physics C 08, no. 04 (August 1997): 931–39. http://dx.doi.org/10.1142/s0129183197000801.

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Polymers in high density 2D melts are believed to segregate into compact disks. This is in contrast to the entanglement and interpenetration characteristic of 3D melts. We investigate this problem using the two-space algorithm, which is both a Cellular Automaton and a Monte Carlo algorithm for polymer structure and dynamics. Our simulations of high density melts in 2D show that contrary to expectations polymers do not completely segregate at high density — there is significant interpenetration. We show that the characteristic size of a polymer in the high density limit is intermediate between the size of a compact disk and a random walk. We then introduce a "shape factor" that measures the ratio of the polymer circumference squared to the area. The shape factor increases with increasing melt density, clearly indicating the observed interpenetration.

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Chremos, Alexandros, Cheol Jeong, and Jack F. Douglas. "Influence of polymer architectures on diffusion in unentangled polymer melts." Soft Matter 13, no. 34 (2017): 5778–84. http://dx.doi.org/10.1039/c7sm01018d.

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Molecular dynamics simulations of polymer melts composed of polymers of different branching complexity suggests that the average polymer shape and hydrodynamic radius are important for the understanding of the polymer diffusion, as in polymer solutions.

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Zechner, Markus, Torsten Clemens, Ajay Suri, and Mukul M. Sharma. "Simulation of Polymer Injection Under Fracturing Conditions—An Injectivity Pilot in the Matzen Field, Austria." SPE Reservoir Evaluation & Engineering 18, no. 02 (March 23, 2015): 236–49. http://dx.doi.org/10.2118/169043-pa.

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Summary Polymer flooding leads to enhanced oil recovery by accelerating oil production and improving sweep efficiency. However, because of the higher viscosity, the injectivity of polymer solutions is of some concern and is important to understand to predict incremental oil recoveries. Achieving high polymer-injection rates is required to increase oil-production rates. In the field test performed in the Matzen field (Austria), polyacrylamide polymers were injected for the past 2 years. Coreflood experiments with these polymers showed a significant increase in apparent viscosity because of the viscoelastic properties of the polymer solutions. Also, severe degradation of the polymer solution at high flow velocities was detected. In addition to coreflood experiments, flow experiments through fractures were performed. In these experiments, shear thinning and limited degradation of the polymer solution were observed and quantified. Detailed polymer-injection simulations were conducted that included complex polymer rheology in the fractures and the matrix. The reservoir stress changes and their effects on the fractures were also taken into account as a result of cold-polymer injection. The results of the simulations matched the field data both for waterfloods and polymer-test floods. The simulations revealed two distinct phases during the injection of the polyacrylamide-polymer solution: Injection under matrix conditions in an early phase resulting in severe degradation of the polymers Injection under fracturing conditions after the formation parting pressure is reached, leading to limited degradation of the polymers The calibrated model was used to investigate the impact of polymer rheology and particle plugging on injectivity and fracture growth. The results of the field test and the simulations indicate that screening of fields for polyacrylamide-polymer projects needs to include geomechanical properties of the reservoir sand and cap/base rock in addition to the conventional parameters used in screening such as oil viscosity, water salinity, reservoir temperature, and reservoir permeability.

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Watanabe, Takeshi, and Toshiyuki Gotoh. "Hybrid Eulerian–Lagrangian simulations for polymer–turbulence interactions." Journal of Fluid Mechanics 717 (February 1, 2013): 535–75. http://dx.doi.org/10.1017/jfm.2012.595.

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AbstractThe effects of polymer additives on decaying isotropic turbulence are numerically investigated using a hybrid approach consisting of Brownian dynamics simulations for an enormous number of dumbbells (of the order of 10 billion,$O(1{0}^{10} )$) and direct numerical simulations of turbulence making full use of large-scale parallel computations. Reduction of the energy dissipation rate and modification of the kinetic energy spectrum in the dissipation range scale were observed when the reaction term due to the polymer additives was incorporated into the equation of motion for the solvent fluid. An increase in the polymer concentration or Weissenberg number${W}_{i} $yielded significant modifications of the turbulence statistics at small scales, such as a suppression of the local energy dissipation fluctuations. A power-law decay of the kinetic energy spectrum$E(k, t)\sim {k}^{- 4. 7} $was observed in the wavenumber range below the Kolmogorov length scale when${W}_{i} = 25$. The generation of intense vortices was suppressed by the polymer additives, consistent with previous studies using the constitutive equations. The field structures of the trace of the polymer stress depended on the intensity of its fluctuation: sheet-like structures were observed for the intermediate intensity region and filamentary structures were observed for the intense region. The results obtained with few polymers and large replicas could approximate those with many polymers and smaller replicas as far as the large-scale statistics were concerned.

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Halun, Joanna, Pawel Karbowniczek, Piotr Kuterba, and Zoriana Danel. "Investigation of Ring and Star Polymers in Confined Geometries: Theory and Simulations." Entropy 23, no. 2 (February 19, 2021): 242. http://dx.doi.org/10.3390/e23020242.

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The calculations of the dimensionless layer monomer density profiles for a dilute solution of phantom ideal ring polymer chains and star polymers with f=4 arms in a Θ-solvent confined in a slit geometry of two parallel walls with repulsive surfaces and for the mixed case of one repulsive and the other inert surface were performed. Furthermore, taking into account the Derjaguin approximation, the dimensionless layer monomer density profiles for phantom ideal ring polymer chains and star polymers immersed in a solution of big colloidal particles with different adsorbing or repelling properties with respect to polymers were calculated. The density-force relation for the above-mentioned cases was analyzed, and the universal amplitude ratio B was obtained. Taking into account the small sphere expansion allowed obtaining the monomer density profiles for a dilute solution of phantom ideal ring polymers immersed in a solution of small spherical particles, or nano-particles of finite size, which are much smaller than the polymer size and the other characteristic mesoscopic length of the system. We performed molecular dynamics simulations of a dilute solution of linear, ring, and star-shaped polymers with N=300, 300 (360), and 1201 (4 × 300 + 1-star polymer with four arms) beads accordingly. The obtained analytical and numerical results for phantom ring and star polymers are compared with the results for linear polymer chains in confined geometries.

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Kim, Taehyung, Kyoungsei Choi, and Won Ho Jo. "A Stochastic Dynamics Simulation of Viscoelastic Properties of Polymer Blends: Intermolecular Interaction Effects." Journal of Polymer Engineering 18, no. 1-2 (March 1, 1998): 1–16. http://dx.doi.org/10.1515/polyeng-1998-1-203.

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Abstract Stochastic dynamics simulations were performed to investigate the viscoelastic properties of polymer blends. In this simulation, three model systems with different intermolecular interactions are used to examine the effect of intermolecular interaction on the viscoelastic properties of polymer blends. Structural information such as the radius of gyration, orientation factor and radial distribution function of polymers is calculated from computer simulations as a function of shear rate and then is related to simulated viscoelastic properties of polymer blends. The effect of intermolecular interaction on the viscosity becomes different depending upon the magnitude of shear rate. At lower shear rate regions, more attractive intermolecular interaction results in lower viscosity due to chain stretching. But, at higher shear rate regions, more attractive interaction results in higher viscosity due to more dense packing of chains induced by the intermolecular attraction.

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9

Grest, Gary S., Martin-D. Lacasse, and Michael Murat. "Molecular-Dynamics Simulations of Polymer Surfaces and Interfaces." MRS Bulletin 22, no. 1 (January 1997): 27–31. http://dx.doi.org/10.1557/s0883769400032309.

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From a single chain in a dilute solution to an entangled polymer melt, from bulk systems to more complex interfacial problems, computer simulations have played a critical role not only in testing the basic assumptions of various theoretical models but also in interpreting experimental results. Early computer simulations of polymers were mostly carried out on a lattice using Monte Carlo methods. This approach has led to significant progress in recent years and will continue to do so in many areas. In some cases however, for example in the study of shear, lattice models have serious limitations. For this reason and also due to the availability of more powerful computers, continuum, off-lattice polymer models have recently become popular. In this article, we review some of the recent progress in studying polymers at surfaces and interfaces using continuum models.

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Chremos, Alexandros, and Jack F. Douglas. "Influence of Branching on the Configurational and Dynamical Properties of Entangled Polymer Melts." Polymers 11, no. 6 (June 14, 2019): 1045. http://dx.doi.org/10.3390/polym11061045.

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We probe the influence of branching on the configurational, packing, and density correlation function properties of polymer melts of linear and star polymers, with emphasis on molecular masses larger than the entanglement molecular mass of linear chains. In particular, we calculate the conformational properties of these polymers, such as the hydrodynamic radius R h , packing length p, pair correlation function g ( r ) , and polymer center of mass self-diffusion coefficient, D, with the use of coarse-grained molecular dynamics simulations. Our simulation results reproduce the phenomenology of simulated linear and branched polymers, and we attempt to understand our observations based on a combination of hydrodynamic and thermodynamic modeling. We introduce a model of “entanglement” phenomenon in high molecular mass polymers that assumes polymers can viewed in a coarse-grained sense as “soft” particles and, correspondingly, we model the emergence of heterogeneous dynamics in polymeric glass-forming liquids to occur in a fashion similar to glass-forming liquids in which the molecules have soft repulsive interactions. Based on this novel perspective of polymer melt dynamics, we propose a functional form for D that can describe our simulation results for both star and linear polymers, covering both the unentangled to entangled polymer melt regimes.

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11

Melissinos, G., and M. Danikas. "On Polymers Nanocomposites: Electrical Treeing, Breakdown models and Related Simulations." Engineering, Technology & Applied Science Research 8, no. 2 (April 19, 2018): 2627–32. http://dx.doi.org/10.48084/etasr.1726.

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This paper deals with polymer nanocomposites and their related breakdown mechanisms. Polymer nanocomposites seem to be a very promising alternative to conventional polymers regarding high voltage applications. Some developed breakdown models are discussed as well as the mechanism of treeing in such materials. Treeing simulation results are presented.

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Ganesan, V., and G. H. Fredrickson. "Field-theoretic polymer simulations." Europhysics Letters (EPL) 55, no. 6 (September 2001): 814–20. http://dx.doi.org/10.1209/epl/i2001-00353-8.

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13

Wessels, Michiel G., and Arthi Jayaraman. "Self-assembly of amphiphilic polymers of varying architectures near attractive surfaces." Soft Matter 16, no. 3 (2020): 623–33. http://dx.doi.org/10.1039/c9sm02104c.

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We use coarse-grained molecular dynamics simulations to investigate the assembly of A–B amphiphilic polymers near/on surfaces as a function of polymer architecture and surface attraction to the solvophobic B-block in the polymer.

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Ahuja, Vishal Raju, Jasper van der Gucht, and Wim Briels. "Large Scale Hydrodynamically Coupled Brownian Dynamics Simulations of Polymer Solutions Flowing through Porous Media." Polymers 14, no. 7 (March 31, 2022): 1422. http://dx.doi.org/10.3390/polym14071422.

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Large scale simulations of polymer flow through porous media provide an important tool for solving problems in enhanced oil recovery, polymer processing and biological applications. In order to include the effects of a wide range of velocity and density fluctuations, we base our work on a coarse-grain particle-based model consisting of polymers following Brownian dynamics coupled to a background fluid flow through momentum conserving interactions. The polymers are represented as Finitely Extensible Non-Linear Elastic (FENE) dumbbells with interactions including slowly decaying transient forces to properly describe dynamic effects of the eliminated degrees of freedom. Model porous media are constructed from arrays of parallel solid beams with circular or square cross-sections, arranged periodically in the plane perpendicular to their axis. No-slip boundary conditions at the solid–fluid interfaces are imposed through interactions with artificial particles embedded within the solid part of the system. We compare the results of our simulations with those of standard Smoothed Particle Hydrodynamics simulations for Newtonian flow through the same porous media. We observe that in all cases the concentration of polymers at steady state is not uniform even though we start the simulations with a uniform polymer concentration, which is indicative of shear-induced cross-flow migration. Furthermore, we see the characteristic flattening of the velocity profile experimentally observed for shear-thinning polymer solutions flowing through channels as opposed to the parabolic Poiseuille flow profile for Newtonian fluids.

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Cromer, Michael, and Paula A. Vasquez. "Macro–Micro-Coupled Simulations of Dilute Viscoelastic Fluids." Applied Sciences 13, no. 22 (November 13, 2023): 12265. http://dx.doi.org/10.3390/app132212265.

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Modeling the flow of polymer solutions requires knowledge at various length and time scales. The macroscopic behavior is described by the overall velocity, pressure, and stress. The polymeric contribution to the stress requires knowledge of the evolution of polymer chains. In this work, we use a microscopic model, the finitely extensible nonlinear elastic (FENE) model, to capture the polymer’s behavior. The benefit of using microscopic models is that they remain faithful to the polymer dynamics without information loss via averaging. Their downside is the computational cost incurred in solving the thousands to millions of differential equations describing the microstructure. Here, we describe a multiscale flow solver that utilizes GPUs for massively parallel, efficient simulations. We compare and contrast the microscopic model with its macroscopic counterpart under various flow conditions. In particular, significant differences are observed under nonlinear flow conditions, where the polymers become highly stretched and oriented.

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Kraska, Thomas. "Particle simulations for inquiry-based teaching of polymer shape and entropic elasticity using computational thinking." Physics Education 58, no. 6 (September 15, 2023): 065010. http://dx.doi.org/10.1088/1361-6552/acf086.

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Abstract An inquiry-based approach is proposed that allows students to develop and understand computer codes for simulations at the particle level. Computational thinking is employed as a low-threshold approach for students without programming experience. The resulting computer code cores are concise and traceable. Here, the topic of the simulations concerns polymer molecules. A special property of polymers, coiling, and the related entropic elasticity is suitable for the setup of a simulation in class. Students at the upper secondary level were introduced into the topic by an activity. This was a stochastic game serving as a basis to for the development of the corresponding algorithm. Once students are involved in the development of the code, they can meaningfully investigate the model by running the program, changing its parameters, or altering the code. With these simulations, students can prove wrong the early belief that polymer molecules exhibit a stretched chain structure. Furthermore, the confinement of the system leads to a decrease in entropy, which in turn results in a force acting on the walls that can be elaborated comprehensively by students through such simulations.

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Horn, Tobias Daniel, Dario Heidrich, Hans Wulf, Michael Gehde, and Jörn Ihlemann. "Multiscale Simulation of Semi-Crystalline Polymers to Predict Mechanical Properties." Polymers 13, no. 19 (September 23, 2021): 3233. http://dx.doi.org/10.3390/polym13193233.

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A multiscale simulation method for the determination of mechanical properties of semi-crystalline polymers is presented. First, a four-phase model of crystallization of semi-crystalline polymers is introduced, which is based on the crystallization model of Strobl. From this, a simulation on the nanoscale is derived, which models the formation of lamellae and spherulites during the cooling of the polymer by using a cellular automaton. In the solidified state, mechanical properties are assigned to the formed phases and thus the mechanical behavior of the nanoscale is determined by a finite element (FE) simulation. At this scale, simulations can only be performed up to a simulation range of a few square micrometers. Therefore, the dependence of the mechanical properties on the degree of crystallization is determined by means of homogenization. At the microscale, the cooling of the polymer is simulated by a cellular automaton according to evolution equations. In combination with the mechanical properties determined by homogenization, the mechanical behavior of a macroscopic component can be predicted.

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Li, Lujuan, Qianqian Cao, Hao Liu, Zhiqing Gu, Ying Yu, Fengli Huang, and Chuncheng Zuo. "Transport of polymer-modified nanoparticles in nanochannels coated with polymers." RSC Advances 9, no. 67 (2019): 38944–51. http://dx.doi.org/10.1039/c9ra08365k.

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Gosecki, Mateusz, Malgorzata Urbaniak, Nuno Martinho, Monika Gosecka, and Mire Zloh. "Evaluation of Encapsulation Potential of Selected Star-Hyperbranched Polyglycidol Architectures: Predictive Molecular Dynamics Simulations and Experimental Validation." Molecules 28, no. 21 (October 28, 2023): 7308. http://dx.doi.org/10.3390/molecules28217308.

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Polymers, including non-linear copolymers, have great potential in the development of drug delivery systems with many advantages, but the design requires optimizing polymer–drug interactions. Molecular dynamics (MD) simulations can provide insights into polymer–drug interactions for designing delivery systems, but mimicking formulation processes such as drying is often not included in in silico studies. This study demonstrates an MD approach to model drying of systems comprising either hydrophilic tinidazole or hydrophobic clotrimazole drugs with amphiphilic hyperbranched copolyethers. The simulated drying protocol was critical for elucidating drug encapsulation and binding mechanisms. Experimentally, two polymers were synthesized and shown to encapsulate clotrimazole with up to 83% efficiency, guided by interactions with the hydrophobic core observed in simulations. In contrast, tinidazole is associated with surface regions, indicating capacity differences between drug types. Overall, this work highlights MD simulation of the drying process as an important tool for predicting drug–polymer complex behaviour. The modelled formulation protocol enabled high encapsulation efficiency and opened possibilities for the design of delivery systems based on computationally derived binding mechanisms. This demonstrates a computational–experimental approach where simulated drying was integral to elucidating interactions and developing optimized complexes, emphasizing the value of molecular modelling for the development of drug delivery formulations.

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Sindu, B. S., and Saptarshi Sasmal. "Atomistic to continuum scale investigations on mechanical properties of epoxy bonded fiber reinforced polymer composite systems under hygro-thermal exposures." Modelling and Simulation in Materials Science and Engineering 30, no. 3 (March 3, 2022): 035012. http://dx.doi.org/10.1088/1361-651x/ac5565.

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Abstract Epoxy polymers are widely used as adhesives in bonded composite systems. In this study, multi-scale computational investigations from molecular dynamics (MD) to finite element (FE) simulations are carried out to understand the material behaviour at atomistic level and to evaluate the performance at macro level. MD investigations are carried out to understand the extent of degradation of mechanical (such as strength, modulus) and transport properties (such as moisture diffusion coefficient) due to different environmental conditions like moisture ingress and high temperature. The influence of degree of curing of epoxy (diglycidyl ether of bisphenol-A) and type of hardener (diethyltoluene diamine, diethylene triamine, trimethylene hexadiamine) on the mechanical performance of the cross-linked epoxy polymer systems is also investigated. In-depth investigations are also carried out to identify the factors contributing to the total potential energy of cross-linked epoxy polymers and their role during the process of curing. Diffusion coefficient (key transport property) of epoxy polymer under moisture exposure is also determined using MD simulations. It has been demonstrated that high temperature causes the increase in diffusion in epoxy polymer systems. The observations on the performance of the epoxy system under moisture exposure obtained from MD simulations are translated to the higher length scale. The moisture ingress (in turn, significant reduction in mechanical properties) in epoxy polymer used for bonded composite system is also investigated using FE simulations. It is found that the extent of moisture ingress in the epoxy adhesive increases rapidly when epoxy polymer is environmentally exposed (under high temperature), and thus, the whole system gradually loses its effectiveness due to mechanical degradation. The findings of this study will help in understanding crucial parameters and aid to better use/engineering of epoxy polymers.

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DE SOUZA FERREIRA, LUCAS, and ÁLVARO DE ALMEIDA CAPARICA. "COMPUTER SIMULATIONS OF A POLYMER WITH EXACT SOLUTION." International Journal of Modern Physics C 23, no. 08 (August 2012): 1240012. http://dx.doi.org/10.1142/s0129183112400128.

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In this work we apply a refined Wang–Landau simulation to a simple polymer model which has an exact solution both in the microcanonical and the canonical formalisms. We investigate the behavior of the microcanonical and canonical averages during the Wang–Landau simulation. The simulations were carried out using conventional Wang–Landau sampling (WLS) and the 1/t scheme. Our results show that updating the density of states only after every N monomer moves leads to a much better precision. During the simulations the canonical averages such as the location of the maximum of the specific heat calculated from independent runs tend asymptotically to values around the correct value obtained from the exact calculations of the density of states and remain unchanged for some final modification factor. Since this f final is found for the model analyzed, one has a criterion to stop the simulations. We compare our results with the exact value and with those of the 1/t scheme.

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Raj, Anshu, Sk Md Ahnaf Akif Alvi, Khayrul Islam, Mohammad Motalab, and Shuozhi Xu. "An Atomistic Study of the Tensile Deformation of Carbon Nanotube–Polymethylmethacrylate Composites." Polymers 15, no. 13 (July 5, 2023): 2956. http://dx.doi.org/10.3390/polym15132956.

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There has been growing interest in polymer/carbon nanotube (CNT) composites due to an exceptional enhancement in mechanical, structural, thermal, and electronic properties resulting from a small percentage of CNTs. However, the performance of these composites is influenced by the type of polymer used. PMMA is a polymer of particular interest among many other polymers because of its biomaterial applications due to its biocompatibility, non-toxicity, and non-biodegradability. In this research, we utilized a reactive force field to conduct molecular dynamics simulations to investigate changes in the mechanical properties of single-walled carbon nanotube (SWCNT)-reinforced Poly (methyl methacrylate) (PMMA) matrix composites. To explore the potential of SWCNT-reinforced PMMA composites in these applications, we conducted simulations with varying CNT diameters (0.542–1.08 nm), CNT volume fractions (8.1–16.5%), and temperatures (100 K–700 K). We also analyzed the dependence of Young’s modulus and interaction energy with different CNT diameters, along with changes in fracture toughness with varying temperatures. Our findings suggest that incorporating a small amount of SWCNT into the PMMA polymer matrix could significantly enhance the mechanical properties of the resulting composite. It is also found that the double-walled carbon nanotube has roughly twice the tensile strength of SWCNT, while maintaining the same simulation cell dimensions.

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Yana, Janchai, Piyarat Nimmanpipug, and Vannajan Sanghiran Lee. "J-9 DRY AND WET MOLECULAR DYNAMICS SIMULATIONS OF NAFION(R) POLYMER ELECTROLYTE FUEL CELL MEMBRANE(Session: Simulation)." Proceedings of the Asian Symposium on Materials and Processing 2006 (2006): 165. http://dx.doi.org/10.1299/jsmeasmp.2006.165.

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Cha, JinHyeok, Wooju Lee, and Jihye Baek. "Penetration of Hydrogen into Polymer Electrolyte Membrane for Fuel Cells by Quantum and Molecular Dynamics Simulations." Polymers 13, no. 6 (March 19, 2021): 947. http://dx.doi.org/10.3390/polym13060947.

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The advent of the Hydrogen Society created great interest around hydrogen-based energy a decade ago, with several types of vehicles based on hydrogen fuel cells already being produced in the automotive sector. For highly efficient fuel cell systems, the control of hydrogen inside a polymer-based electrolyte membrane is crucial. In this study, we investigated the molecular behavior of hydrogen inside a polymer-based proton-exchange membrane, using quantum and molecular dynamics simulations. In particular, this study focused on the structural difference of the pendent-like side chain polymer, resulting in the penetration ratio of hydrogen into the membrane deriving from the penetration depth of the membrane’s thickness while keeping the simulation time constant. The results reveal that the penetration ratio of the polymer with a shorter side chain was higher than that with the longer side chain. This was justified via two perspectives; electrostatic and van der Waals molecular interactions, and the structural difference of the polymers resulting in the free volume and different behavior of the side chain. In conclusion, we found that a longer side chain is more trembling and acts as an obstruction, dominating the penetration of hydrogen inside the polymer membrane.

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Zhang, Min, Guo Fang Zhang, and Yu Xi Jia. "Molecular Dynamic and Mesoscopic Dynamic Simulations for Polymer Blends." Advanced Materials Research 1033-1034 (October 2014): 496–500. http://dx.doi.org/10.4028/www.scientific.net/amr.1033-1034.496.

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The compatibilities of polymer blends, Polypropylene (PP) and Polyamide12(PA12) with the quantity ratio 10/90, was simulated by Molecular Dynamics (MD) and Mesoscopic Dynamic simulation (MesoDyn) simulations. Cohesive energy density (CED) and solubility parameters (δ) of pure substances and PP/PA12 blends were got by MD simulations. Flory-Huggins parameter was calculated based on CED values. The mesoscale simulation was related to the molecular simulation through Flory-Huggins parameter. Free energy density and the density profiles were got through MesoDyn simulation. Results showed that solubility parameter difference (Δδ) of PP/PA12 is 4.092 and free energy density value is 0.17 in the equivalent system. And phase separation behavior was observed in the density profiles. All these indicates that PP and PA12 is not miscible which is the same as the experiment results.

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Zhang, Danhui, Houbo Yang, Zhongkui Liu, and Anmin Liu. "Molecular dynamics simulations of single-walled carbon nanotubes and polynylon66." International Journal of Modern Physics B 33, no. 23 (September 20, 2019): 1950258. http://dx.doi.org/10.1142/s0217979219502588.

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Polynylon66, as a kind of important engineering plastics, is widely used in various fields. In this work, we studied the interfacial interactions between polynylon66 and single-walled carbon nanotubes (SWCNTs) using molecular dynamics (MD) simulations. The results showed that the polynylon66 could interact with the SWCNTs and the mechanism of interfacial interaction between polynylon66 and SWCNTs was also discussed. Furthermore, the morphology of polynylon66 adsorbed to the surface of SWCNTs was investigated by the radius of gyration. Influence factors such as the initial angle between polynylon66 chain and nanotube axis, SWCNT radius and length of polynylon66 on interfacial adhesion of single-walled carbon nanotube-polymer and the radius of gyration of the polymers were studied. These results will help to better understand the interfacial interaction between polymer and carbon nanotube (CNT) and also guide the fabrication of high performance polymer/carbon nanotube nanocomposites.

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Cajiao, Adriana, Ezra Kwok, Bhushan Gopaluni, and Jayachandran N. Kizhakkedathu. "Use of Molecular Dynamics for the Refinement of an Electrostatic Model for the In Silico Design of a Polymer Antidote for the Anticoagulant Fondaparinux." Journal of Medical Engineering 2013 (July 24, 2013): 1–11. http://dx.doi.org/10.1155/2013/487387.

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Molecular dynamics (MD) simulations results are herein incorporated into an electrostatic model used to determine the structure of an effective polymer-based antidote to the anticoagulant fondaparinux. In silico data for the polymer or its cationic binding groups has not, up to now, been available, and experimental data on the structure of the polymer-fondaparinux complex is extremely limited. Consequently, the task of optimizing the polymer structure is a daunting challenge. MD simulations provided a means to gain microscopic information on the interactions of the binding groups and fondaparinux that would have otherwise been inaccessible. This was used to refine the electrostatic model and improve the quantitative model predictions of binding affinity. Once refined, the model provided guidelines to improve electrostatic forces between candidate polymers and fondaparinux in order to increase association rate constants.

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Yu, Shi, Ruizhi Chu, Guoguang Wu, and Xianliang Meng. "A Novel Fractional Brownian Dynamics Method for Simulating the Dynamics of Confined Bottle-Brush Polymers in Viscoelastic Solution." Polymers 16, no. 4 (February 15, 2024): 524. http://dx.doi.org/10.3390/polym16040524.

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In crowded fluids, polymer segments can exhibit anomalous subdiffusion due to the viscoelasticity of the surrounding environment. Previous single-particle tracking experiments revealed that such anomalous diffusion in complex fluids (e.g., in bacterial cytoplasm) can be described by fractional Brownian motion (fBm). To investigate how the viscoelastic media affects the diffusive behaviors of polymer segments without resolving single crowders, we developed a novel fractional Brownian dynamics method to simulate the dynamics of polymers under confinement. In this work, instead of using Gaussian random numbers (“white Gaussian noise”) to model the Brownian force as in the standard Brownian dynamics simulations, we introduce fractional Gaussian noise (fGn) in our homemade fractional Brownian dynamics simulation code to investigate the anomalous diffusion of polymer segments by using a simple “bottle-brush”-type polymer model. The experimental results of the velocity autocorrelation function and the exponent that characterizes the subdiffusion of the confined polymer segments can be reproduced by this simple polymer model in combination with fractional Gaussian noise (fGn), which mimics the viscoelastic media.

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Zhang, Min, Guo Fang Zhang, and Yu Xi Jia. "Molecular Dynamic Simulations on the Compatibility of PP/PA12 Blends." Applied Mechanics and Materials 633-634 (September 2014): 270–73. http://dx.doi.org/10.4028/www.scientific.net/amm.633-634.270.

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The compatibilities of polymer blends, Polypropylene (PP) and Polyamide12(PA12), was simulated by molecular dynamics (MD) simulations. Density, cohesive energy density (CED) ,and solubility parameters (δ) of pure substances and PP/PA12 blends were calculated by MD simulations with the COMPASS force field for the prediction of polymer blends compatibility . Results showed that PP/PA12 is not miscrible by comparing the difference in the solubility parameter value ( Δδ), radial distribution function value. The predictions agreed well with the experimental results. So it can be showed that MD simulation is a valid method to provide information on miscibility of polymer blends.

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Masubuchi, Yuichi, and Shin-ichiro Tanifuji. "Molecular Simulations for Polymer Processing." Seikei-Kakou 26, no. 9 (August 20, 2014): 422–25. http://dx.doi.org/10.4325/seikeikakou.26.422.

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Kremer, Kurt, and Gary S. Grest. "Computer simulations in polymer physics." Physics World 8, no. 3 (March 1995): 39–46. http://dx.doi.org/10.1088/2058-7058/8/3/26.

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Kremer, Kurt, Burkhard Dünweg, and Mark S. Stevens. "Computer simulations for polymer solutions." Physica A: Statistical Mechanics and its Applications 194, no. 1-4 (March 1993): 321–29. http://dx.doi.org/10.1016/0378-4371(93)90365-b.

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Milchev, Andrey, and Kurt Binder. "Cylindrical confinement of solutions containing semiflexible macromolecules: surface-induced nematic order versus phase separation." Soft Matter 17, no. 12 (2021): 3443–54. http://dx.doi.org/10.1039/d1sm00172h.

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Munasinghe, Aravinda, Stefanie L. Baker, Ping Lin, Alan J. Russell, and Coray M. Colina. "Structure–function–dynamics of α-chymotrypsin based conjugates as a function of polymer charge." Soft Matter 16, no. 2 (2020): 456–65. http://dx.doi.org/10.1039/c9sm01842e.

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Zhang, Z. Q., D. K. Ward, Y. Xue, H. W. Zhang, and M. F. Horstemeyer. "Interfacial Characteristics of Carbon Nanotube-Polyethylene Composites Using Molecular Dynamics Simulations." ISRN Materials Science 2011 (September 25, 2011): 1–10. http://dx.doi.org/10.5402/2011/145042.

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The rate-dependent interfacial behavior between a carbon nanotube (CNT) and a polyethylene (PE) matrix is investigated using molecular dynamics (MD) simulations. Various MD simulations were set up to determine the “size” effects on the interfacial properties, such as the molecular weight, or the length of the polymer, the diameter of the CNT, and the simulation model size. The interfacial rate-dependency was probed by applying various relative sliding velocities between the CNT and the polymer. Two quantities, directly obtained from the MD simulations, described the interfacial properties: the critical interfacial shear stress (CISS) and the steady interfacial shear stress (SISS). The simulations show that the SISS was not sensitive to the simulation size. In addition, the CISS was dependent upon the combined factors of the variation in PE stiffness, induced by simulation size changes and the effect of the fixed boundaries of the simulation models. The CISS increases almost linearly with the relative sliding velocity of CNTs. Also, a linear relationship between the SISS and the CNT-sliding velocity is observed when the SISS drops below a critical value. A clear size scaling is observed as the CISS and SISS decrease with increasing CNT radius and increase with the increasing polymer chain length.

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Yang, Ji, Yitong Chen, Zhangke Yang, Linjiale Dai, Hongseok Choi, and Zhaoxu Meng. "Unveiling the Nanoconfinement Effect on Crystallization of Semicrystalline Polymers Using Coarse-Grained Molecular Dynamics Simulations." Polymers 16, no. 8 (April 19, 2024): 1155. http://dx.doi.org/10.3390/polym16081155.

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Semicrystalline polymers under nanoconfinement show distinct structural and thermomechanical properties compared to their bulk counterparts. Despite extensive research on semicrystalline polymers under nanoconfinement, the nanoconfinement effect on the local crystallization process and the unique structural evolution of such polymers have not been fully understood. In this study, we unveil such effects by using coarse-grained molecular dynamics simulations to study the crystallization process of a model semicrystalline polymer—polyvinyl alcohol (PVA)—under different levels of nanoconfinement induced by nanoparticles that are represented implicitly. We quantify in detail the evolution of the degree of crystallinity (XC) of PVA and examine distinct crystalline regions from simulation results. The results show that nanoconfinement can promote the crystallization process, especially at the early stage, and the interfaces between nanoparticles and polymer can function as crystallite nucleation sites. In general, the final XC of PVA increases with the levels of nanoconfinement. Further, nanoconfined cases show region-dependent XC with higher and earlier increase of XC in regions closer to the interfaces. By tracking region-dependent XC evolution, our results indicate that nanoconfinement can lead to a heterogenous crystallization process with a second-stage crystallite nucleation in regions further away from the interfaces. In addition, our results show that even under very high cooling rates, the nanoconfinement still promotes the crystallization of PVA. This study provides important insights into the underlying mechanisms for the intricate interplay between nanoconfinement and the crystallization behaviors of semicrystalline polymer, with the potential to guide the design and characterization of semicrystalline polymer-based nanocomposites.

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Cukrowicz, Sylwia, Paweł Goj, Paweł Stoch, Artur Bobrowski, Bożena Tyliszczak, and Beata Grabowska. "Molecular Dynamic (MD) Simulations of Organic Modified Montmorillonite." Applied Sciences 12, no. 1 (December 29, 2021): 314. http://dx.doi.org/10.3390/app12010314.

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This study complements the knowledge about organobentonites, which are intended to be new binders in foundry technology. In the developed materials, acrylic polymers act as mineral modifying compounds. Modification of montmorillonite in bentonite was carried out in order to obtain a composite containing a polymer as a lustrous carbon precursor. The polymer undergoes thermal degradation during the casting process, which results in the formation of this specific carbon form, ensuring the appropriate quality of the casting surface without negative environmental impact. The present paper reports the results of computational simulation studies (LAMMPS software) aimed at broadening the knowledge of interactions of organic molecules in the form of acrylic acid and acrylate anions (from sodium acrylate) near the montmorillonite surface, which is a simplified model of bentonite/acrylic polymer systems. It has been proven that the –COOH group promotes the adsorption of acrylic acid (AA) to the mineral surface, while acrylate ions tend to be unpredictably scattered, which may be related to the electrostatic repulsion between anions and negatively charged clay surfaces. The simulation results are consistent with the results of structural tests carried out for actual organobentonites. It has been proven that the polymer mainly adsorbs on the mineral surface, although it also partially intercalates into the interlayer spaces of the montmorillonite. This comprehensive research approach is innovative in the engineering of foundry materials. Computer simulation methods have not been used in the production of new binding materials in molding sand technology so far.

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Panwar, Pawan, Paul Michael, Mark Devlin, and Ashlie Martini. "Critical Shear Rate of Polymer-Enhanced Hydraulic Fluids." Lubricants 8, no. 12 (November 25, 2020): 102. http://dx.doi.org/10.3390/lubricants8120102.

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Many application-relevant fluids exhibit shear thinning, where viscosity decreases with shear rate above some critical shear rate. For hydraulic fluids formulated with polymeric additives, the critical shear rate is a function of the molecular weight and concentration of the polymers. Here we present a model for predicting the critical shear rate and Newtonian viscosity of fluids, with the goal of identifying a fluid that shear thins in a specific range relevant to hydraulic pumps. The model is applied to predict the properties of fluids comprising polyisobutene polymer and polyalphaolefin base oil. The theoretical predictions are validated by comparison to viscosities obtained from experimental measurements and molecular dynamics simulations across many decades of shear rates. Results demonstrate that the molecular weight of the polymer plays a key role in determining the critical shear rate, whereas the concentration of polymer primarily affects the Newtonian viscosity. The simulations are further used to show the molecular origins of shear thinning and critical shear rate. The atomistic simulations and simple model developed in this work can ultimately be used to formulate polymer-enhanced fluids with ideal shear thinning profiles that maximize the efficiency of hydraulic systems.

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Tian, Shizhu, Hongxing Jia, and Yuanzheng Lin. "Hybrid simulation of a carbon fibre–reinforced polymer-strengthened continuous reinforced concrete girder bridge." Advances in Structural Engineering 20, no. 11 (February 1, 2017): 1658–70. http://dx.doi.org/10.1177/1369433217691772.

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The behaviour of bridge columns strengthened using carbon fibre–reinforced polymer composites has been studied extensively. However, few investigations have been conducted regarding the influence of carbon fibre–reinforced polymer-strengthened columns on the seismic behaviour of reinforced concrete continuous girder bridges. This article details the hybrid simulations of a continuous reinforced concrete girder bridge whose columns are strengthened by carbon fibre–reinforced polymer jackets. In the hybrid simulations, one ductile column is selected as the experimental element, which is represented by a 1/2.5-scale specimen, and the remaining bridge parts are simultaneously modelled in OpenSees (the Open System for Earthquake Engineering Simulation). After combining the experimental element and the numerical substructure, the hybrid analysis model is developed with the established hybrid simulation system. The displacements of the bridge and the lateral force–displacement response of the experimental element in hybrid simulation are obtained. Compared with the results of numerical simulation, the stability and accuracy of the established hybrid simulation system are demonstrated. Meanwhile, the comparative hybrid simulation results of the as-built bridge and the carbon fibre–reinforced polymer-strengthened bridge also prove the effectiveness of the carbon fibre–reinforced polymer jackets’ confinement in the continuous reinforced concrete girder bridge.

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Njoroge, Jean, Arnab Chakrabarty, and Tahir Çağın. "Shockwave Response of Polymer and Polymer Nanocomposites." Materials Science Forum 856 (May 2016): 64–69. http://dx.doi.org/10.4028/www.scientific.net/msf.856.64.

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We present non-equilibrium molecular dynamic simulations of the shock compression of polyurethane and its graphene-based nanocomposite systems. Using the projectile/wall approach, planar shock waves with piston velocity range from 0.1 to 2.5 km/s is applied for both systems. In this study, direct molecular-level simulations of shock-wave generation and propagation are utilized in order to construct the appropriate shock-Hugoniot relations. Through this study, we determined that inclusion of graphene into the polyurethane system has a significant effect on the shock propagation behavior when incorporated in the polymer matrix

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Mo, Yong-Fang, Chuan-Lu Yang, Yan-Fei Xing, Mei-Shan Wang, and Xiao-Guang Ma. "Nonbond interactions between graphene nanosheets and polymers: a computational study." e-Polymers 14, no. 3 (May 1, 2014): 169–76. http://dx.doi.org/10.1515/epoly-2013-0090.

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AbstractBased on the geometries from molecular dynamics simulations and a package compiled by us, the interactions between graphene nanosheet (GNS) and nine types of flexible polymers have been investigated with force field. Both the van der Waals (vdW) interaction and the electrostatic interaction (EI) for two same polymer chains and between a polymer and a GNS were calculated and compared. The effect of cut-off distance was explored. It was found that the cut-off distance plays a significant role in EI energy, but a less important role in vdW energy when the cut-off distance is over 9.5 Å. The reasonable cut-off distances for EI and vdW interactions for simulation are suggested.

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Narowski, Przemysław, and Krzysztof Wilczyński. "Polymer Injection Molding: Advanced Simulations or Tablet Computations." Challenges of Modern Technology 7, no. 4 (December 30, 2016): 3–5. http://dx.doi.org/10.5604/01.3001.0010.8782.

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Simulation of injection molding of polymeric materials is a common way of solving issues in plastic part and injection mold design. CAE software is getting more available and user-friendly, which sometimes leads to unreasonable use cases of these programs. The original, relatively simple tool has been introduced to validate runner systems in injection molds. It allows a fast identification of the most important design parameters of runner system. This tool does not require any support of FEM simulations, but results obtained from it have been successfully compared with injection molding simulations.

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Wessels, Michiel G., and Arthi Jayaraman. "Molecular dynamics simulation study of linear, bottlebrush, and star-like amphiphilic block polymer assembly in solution." Soft Matter 15, no. 19 (2019): 3987–98. http://dx.doi.org/10.1039/c9sm00375d.

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Shamsieva, Aigul, Alexander Evseev, Irina Piyanzina, Oleg Nedopekin, and Dmitrii Tayurskii. "Molecular Dynamics Modeling for the Determination of Elastic Moduli of Polymer–Single-Walled Carbon Nanotube Composites." International Journal of Molecular Sciences 24, no. 14 (July 22, 2023): 11807. http://dx.doi.org/10.3390/ijms241411807.

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The use of carbon nanotubes to improve the mechanical properties of polymers is one of the promising directions in materials science. The addition of single-walled carbon nanotubes (SWCNTs) to a polymer results in significant improvements in its mechanical, electrical, optical, and structural properties. However, the addition of SWCNTs does not always improve the polymer properties. Also, when a certain content of SWCNTs is exceeded, the mechanical properties of the nanocomposite become worse. This article reports the results of computer simulations for predicting the mechanical properties of polymer/single-walled carbon nanotube nanocomposites. The efficiency of reinforcing polymer composites is considered depending on the concentration of carbon nanotubes in the polymer matrix, their size, and structure. The elastic moduli of the nanocomposites are predicted using computer simulations for unit cell tension (0.1%). General trends in the mechanical properties of composites with polypropylene (PP), poly(ethyl methacrylate) (PEMA), polystyrene (PS) matrices, and SWCNTs are shown.

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Raisal, Abu Yazid, Rosynanda Nur Fauziah, and Heru Kuswanto. "SIMULATION OF FREE ENERGY OF MIXING FOR A POLYMER SOLUTION USING A SPREADSHEET FOR LEARNING ACTIVITIES." Jurnal Pendidikan Fisika 12, no. 2 (December 21, 2023): 165. http://dx.doi.org/10.24114/jpf.v12i2.52810.

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Teaching physics is sometimes difficult to convey without using props or visualizations. Simulations can help teachers create and demonstrate real conditions in front of the class. In this article, we describe the usage of spreadsheets in simulating Gibbs free energy in mixing polymer solutions. We have created an model for the simulation consisting of a main spreadsheet and several secondary spreadsheets. A spreadsheet was chosen to simulate Gibbs free energy because spreadsheets can perform numerical representations in tables. This simple simulation can be used when discussing the topic of polymer thermodynamics. Teachers can start by deriving mathematical equations and then show simulations to visualize the equations. Another option is for students to be asked to create their simulations after deriving a mathematical equation. Using simulation in learning can make learning more interactive and help students understand material physics subjects more easily. Spreadsheets can be an alternative for teachers when explaining abstract material to students. Furthermore, simulations with spreadsheets can also support physics learning remotely.

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Majumdar, Bibhab Bandhu, Simon Ebbinghaus, and Matthias Heyden. "Macromolecular crowding effects in flexible polymer solutions." Journal of Theoretical and Computational Chemistry 17, no. 03 (May 2018): 1840006. http://dx.doi.org/10.1142/s0219633618400060.

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Biological environments are often “crowded” due to high concentrations (300–400[Formula: see text]g/L) of macromolecules. Computational modeling approaches like Molecular Dynamics (MD), rigid-body Brownian Dynamics and Monte Carlo simulations have recently emerged, which allow to study the effects macromolecular crowding at a microscopic level and to provide complementary information to experiments. Here, we use a recently introduced multiple-conformation Monte Carlo (mcMC) approach in order to study the influence of intermolecular interactions on the structural equilibrium of flexible polyethylene glycol (PEG) polymers under self-crowding conditions. The large conformational space accessible to PEG polymers allows us to evaluate the general applicability of the mcMC approach, which describes the intramolecular degrees of freedom by a finite-size ensemble of discrete conformations. Despite the simplicity of the approach, we show that influences of intermolecular interactions on the intramolecular free energy surface can be described qualitatively using mcMC. By varying the magnitude of distinct terms in the intermolecular potential, we can further study the compensating effects of repulsive and nonspecific attractive intermolecular interactions, which favor compact and extended polymer states, respectively. We use our simulation results to derive an analytical model that describes the effects of intermolecular interactions on the stability of PEG polymer conformations as a function of the radius of gyration and the corresponding solvent accessible surface. We use this model to confirm the role of molecular surfaces for attractive interactions that can counteract excluded volume effects. Extrapolation of the model further allows for the analysis of scenarios that are not easily accessible to direct simulations as described here.

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Megariotis, Grigorios, Georgios Vogiatzis, Aristotelis Sgouros, and Doros Theodorou. "Slip Spring-Based Mesoscopic Simulations of Polymer Networks: Methodology and the Corresponding Computational Code." Polymers 10, no. 10 (October 16, 2018): 1156. http://dx.doi.org/10.3390/polym10101156.

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In previous work by the authors, a new methodology was developed for Brownian dynamics/kinetic Monte Carlo (BD/kMC) simulations of polymer melts. In this study, this methodology is extended for dynamical simulations of crosslinked polymer networks in a coarse-grained representation, wherein chains are modeled as sequences of beads, each bead encompassing a few Kuhn segments. In addition, the C++ code embodying these simulations, entitled Engine for Mesoscopic Simulations for Polymer Networks (EMSIPON) is described in detail. A crosslinked network of cis-1,4-polyisoprene is chosen as a test system. From the thermodynamic point of view, the system is fully described by a Helmholtz energy consisting of three explicit contributions: entropic springs, slip springs and non-bonded interactions. Entanglements between subchains in the network are represented by slip springs. The ends of the slip springs undergo thermally activated hops between adjacent beads along the chain backbones, which are tracked by kinetic Monte Carlo simulation. In addition, creation/destruction processes are included for the slip springs at dangling subchain ends. The Helmholtz energy of non-bonded interactions is derived from the Sanchez–Lacombe equation of state. The isothermal compressibility of the polymer network is predicted from equilibrium density fluctuations in very good agreement with the underlying equation of state and with experiment. Moreover, the methodology and the corresponding C++ code are applied to simulate elongational deformations of polymer rubbers. The shear stress relaxation modulus is predicted from equilibrium simulations of several microseconds of physical time in the undeformed state, as well as from stress-strain curves of the crosslinked polymer networks under deformation.

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Rud, Oleg, Tobias Richter, Oleg Borisov, Christian Holm, and Peter Košovan. "A self-consistent mean-field model for polyelectrolyte gels." Soft Matter 13, no. 18 (2017): 3264–74. http://dx.doi.org/10.1039/c6sm02825j.

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We present a novel approach to modeling polyelectrolyte gels, exploiting the analogy between star-branched polymers and polymer networks, as a computationally inexpensive, yet reliable alternative to full-scale simulations.

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Prathab, B., V. Subramanian, and T. M. Aminabhavi. "Molecular dynamics simulations to investigate polymer–polymer and polymer–metal oxide interactions." Polymer 48, no. 1 (January 2007): 409–16. http://dx.doi.org/10.1016/j.polymer.2006.11.014.

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Hordijk, Wim, Mike Steel, and Stuart Kauffman. "Molecular Diversity Required for the Formation of Autocatalytic Sets." Life 9, no. 1 (March 1, 2019): 23. http://dx.doi.org/10.3390/life9010023.

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Systems chemistry deals with the design and study of complex chemical systems. However, such systems are often difficult to investigate experimentally. We provide an example of how theoretical and simulation-based studies can provide useful insights into the properties and dynamics of complex chemical systems, in particular of autocatalytic sets. We investigate the issue of the required molecular diversity for autocatalytic sets to exist in random polymer libraries. Given a fixed probability that an arbitrary polymer catalyzes the formation of other polymers, we calculate this required molecular diversity theoretically for two particular models of chemical reaction systems, and then verify these calculations by computer simulations. We also argue that these results could be relevant to an origin of life scenario proposed recently by Damer and Deamer.

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Journal articles on the topic 'Polymer simulations'

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