1
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Shi J, Zhou J, Liu L, Miao C. Molecular dynamics simulations of single polyethylene chain folding during fast quenching using all-atom and united-atom models. Phys Chem Chem Phys 2024; 26:24995-25004. [PMID: 39300936 DOI: 10.1039/d4cp02746a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/22/2024]
Abstract
Molecular dynamics simulations have been employed to investigate the folding behavior of a single linear polyethylene (PE) chain containing 1000 backbone carbon atoms under fast quenching based on all-atom and united-atom models. The single-chain folding characteristics were studied in detail for six different force fields by analyzing the evolution of chain conformations, folded structure characterisation, free energy and crystallisation. The results show that the all-trans chain undergoes a similar two-stage chain collapse mechanism during isothermal relaxation at T = 500 K, transitioning from local collapse to global collapse into a molten globule state under different force fields. During fast quenching at 100 K ns-1, the molten globule of all-atom model transitions into a folded, significantly anisotropic ordered structure under AMBER-AA or OPLS-AA force fields, while that of the united-atom model remains unchanged in its globular structure. The chain crystallization evolution indicates that the single chain folds into ordered lamellar structures with higher crystallinity under AMBER-AA and OPLS-AA force fields. In contrast, under the other four force fields, the single chain remains in a stable amorphous state.
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Affiliation(s)
- Jingfu Shi
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin 150001, P. R. China.
| | - Jianqiu Zhou
- Institute of Basic Medical Sciences, Harbin Medical University, Harbin, 150086, P. R. China.
| | - Lei Liu
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin 150001, P. R. China.
| | - Changqing Miao
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin 150001, P. R. China.
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2
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Rouhollahi A, Rismanian M, Ebrahimi A, Ilegbusi OJ, Nezami FR. Prediction of directional solidification in freeze casting of biomaterial scaffolds using physics-informed neural networks. Biomed Phys Eng Express 2024; 10:065023. [PMID: 39260383 DOI: 10.1088/2057-1976/ad7960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Accepted: 09/11/2024] [Indexed: 09/13/2024]
Abstract
Freeze casting, a manufacturing technique widely applied in biomedical fields for fabricating biomaterial scaffolds, poses challenges for predicting directional solidification due to its highly nonlinear behavior and complex interplay of process parameters. Conventional numerical methods, such as computational fluid dynamics (CFD), require adequate and accurate boundary condition knowledge, limiting their utility in real-world transient solidification applications due to technical limitations. In this study, we address this challenge by developing a physics-informed neural networks (PINNs) model to predict directional solidification in freeze-casting processes. The PINNs model integrates physical constraints with neural network predictions, requiring significantly fewer predetermined boundary conditions compared to CFD. Through a comparison with CFD simulations, the PINNs model demonstrates comparable accuracy in predicting temperature distribution and solidification patterns. This promising model achieves such a performance with only 5000 data points in space and time, equivalent to 250,000 timesteps, showcasing its ability to predict solidification dynamics with high accuracy. The study's major contributions lie in providing insights into solidification patterns during freeze-casting scaffold fabrication, facilitating the design of biomaterial scaffolds with finely tuned microstructures essential for various tissue engineering applications. Furthermore, the reduced computational demands of the PINNs model offer potential cost and time savings in scaffold fabrication, promising advancements in biomedical engineering research and development.
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Affiliation(s)
- Amir Rouhollahi
- Department of Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, United States of America
| | | | - Amin Ebrahimi
- Department of Materials Science and Engineering, Faculty of Mechanical Engineering, Delft University of Technology, Mekelweg 2, 2628 CD, Delft, The Netherlands
| | - Olusegun J Ilegbusi
- Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, FL, United States of America
| | - Farhad R Nezami
- Department of Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, United States of America
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3
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Yang J, Chen Y, Yang Z, Dai L, Choi H, Meng Z. Unveiling the Nanoconfinement Effect on Crystallization of Semicrystalline Polymers Using Coarse-Grained Molecular Dynamics Simulations. Polymers (Basel) 2024; 16:1155. [PMID: 38675074 PMCID: PMC11053607 DOI: 10.3390/polym16081155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 04/13/2024] [Accepted: 04/16/2024] [Indexed: 04/28/2024] Open
Abstract
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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Affiliation(s)
| | | | | | | | | | - Zhaoxu Meng
- Department of Mechanical Engineering, Clemson University, Clemson, SC 29631, USA; (J.Y.); (Y.C.); (Z.Y.); (L.D.); (H.C.)
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4
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Vao-soongnern V, Sukhonthamethirat N, Rueangsri K, Sirirak K, Matsuba G. Molecular simulation of the structural formation of mono- and bidisperse polyethylene upon cooling from the melts. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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5
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Hagita K, Murashima T, Sakata N, Shimokawa K, Deguchi T, Uehara E, Fujiwara S. Molecular Dynamics of Topological Barriers on the Crystallization Behavior of Ring Polyethylene Melts with Trefoil Knots. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c01843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Katsumi Hagita
- Department of Applied Physics, National Defense Academy, 1-10-20, Hashirimizu, Yokosuka239-8686, Japan
| | - Takahiro Murashima
- Department of Physics, Tohoku University, 6-3, Aramaki-aza-Aoba, Aoba-ku, Sendai980-8578, Japan
| | - Naoki Sakata
- Department of Mathematics, Saitama University, 255, Shimo-Okubo, Sakura-ku, Saitama338-8570, Japan
- Department of Physics, Ochanomizu University, 2-1-1, Otsuka, Bunkyo-ku, Tokyo112-8610, Japan
| | - Koya Shimokawa
- Department of Mathematics, Saitama University, 255, Shimo-Okubo, Sakura-ku, Saitama338-8570, Japan
- Department of Mathematics, Ochanomizu University, 2-1-1, Otsuka, Bunkyo-ku, Tokyo112-8610, Japan
| | - Tetsuo Deguchi
- Department of Physics, Ochanomizu University, 2-1-1, Otsuka, Bunkyo-ku, Tokyo112-8610, Japan
| | - Erica Uehara
- Department of Physics, Ochanomizu University, 2-1-1, Otsuka, Bunkyo-ku, Tokyo112-8610, Japan
| | - Susumu Fujiwara
- Faculty of Materials Science and Engineering, Kyoto Institute of Technology, Matsugasaki,
Sakyo-ku, Kyoto606-8585, Japan
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6
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Ma R, Xu D, Luo CF. Effect of Crystallization and Entropy Contribution Upon the Mechanical Response of Polymer Nano-fibers: A Steered Molecular Dynamics Study. CHINESE JOURNAL OF POLYMER SCIENCE 2022. [DOI: 10.1007/s10118-022-2817-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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7
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Nie C, Peng F, Cao R, Cui K, Sheng J, Chen W, Li L. Recent progress in flow‐induced polymer crystallization. JOURNAL OF POLYMER SCIENCE 2022. [DOI: 10.1002/pol.20220330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Cui Nie
- National Synchrotron Radiation Laboratory, Anhui Provincial Engineering Laboratory of Advanced Functional Polymer Film, CAS Key Laboratory of Soft Matter Chemistry University of Science and Technology of China Hefei China
| | - Fan Peng
- National Synchrotron Radiation Laboratory, Anhui Provincial Engineering Laboratory of Advanced Functional Polymer Film, CAS Key Laboratory of Soft Matter Chemistry University of Science and Technology of China Hefei China
| | - Renkuan Cao
- National Synchrotron Radiation Laboratory, Anhui Provincial Engineering Laboratory of Advanced Functional Polymer Film, CAS Key Laboratory of Soft Matter Chemistry University of Science and Technology of China Hefei China
| | - Kunpeng Cui
- Department of Polymer Science and Engineering, Anhui Provincial Engineering Laboratory of Advanced Functional Polymer Film University of Science and Technology of China Hefei China
| | - Junfang Sheng
- National Synchrotron Radiation Laboratory, Anhui Provincial Engineering Laboratory of Advanced Functional Polymer Film, CAS Key Laboratory of Soft Matter Chemistry University of Science and Technology of China Hefei China
| | - Wei Chen
- National Synchrotron Radiation Laboratory, Anhui Provincial Engineering Laboratory of Advanced Functional Polymer Film, CAS Key Laboratory of Soft Matter Chemistry University of Science and Technology of China Hefei China
| | - Liangbin Li
- National Synchrotron Radiation Laboratory, Anhui Provincial Engineering Laboratory of Advanced Functional Polymer Film, CAS Key Laboratory of Soft Matter Chemistry University of Science and Technology of China Hefei China
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8
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Yamamoto T, Hussain MA, Yao S. Material Property Recovery by Controlling the Melt Memory Effects on Recrystallization and on Crystal Deformation: An Approach by the Molecular Dynamics Simulation for Polyethylene. Polymers (Basel) 2022; 14:polym14153082. [PMID: 35956605 PMCID: PMC9370743 DOI: 10.3390/polym14153082] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 07/21/2022] [Accepted: 07/24/2022] [Indexed: 02/04/2023] Open
Abstract
Degradation in the mechanical properties of recycled polymer materials has been recently appearing as a big issue in polymer science. The molecular mechanism of the degradation is considered in part due to residual memories of flow experienced during molding processes, and therefore the mechanical recycling through remolding involving melting and recrystallization has been attempted in recent years. In the present paper, the molecular processes of melting and recrystallization are investigated by the molecular dynamics simulation for polyethylene with special interest in the melt memory effects. We also studied the mechanical properties of the recrystalized materials that have undergone different recrystallization processes aiming to discover better recycling strategies. A successive step-by-step approach is adopted to study the loss of the crystal memory during retention in the melt, the effects of the melt memory on the mode of recrystallization, the relation between the recrystallization mode and the resulting higher-order structure, and the mechanical properties controlled by the higher-order structures. It is shown that the melt memory clearly remains in various order parameters that persist over time scales corresponding to the Rouse time, the remaining melt memory markedly affects the crystallization mode leading to distinct crystalline morphologies, and the distinct morphologies obtained give different mechanical responses during large deformations.
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Affiliation(s)
- Takashi Yamamoto
- Graduate School of Science and Engineering, Yamaguchi University, Yamaguchi 753-8512, Japan
- Correspondence:
| | | | - Shigeru Yao
- Faculty of Technology, Fukuoka University, Fukuoka 814-0180, Japan; (M.A.H.); (S.Y.)
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9
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Yamamoto T. Chiral selecting crystallization of helical polymers: A molecular dynamics simulation for the POM-like bare helix. J Chem Phys 2022; 157:014901. [DOI: 10.1063/5.0097112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Polymer crystallization has long been a fascinating problem and is still attracting many researchers. Most of the previous simulations are concentrated on clarifying the universal aspects of polymer crystallization using model linear polymers such as polyethylene. We are recently focusing on a nearly untouched but very interesting problem of chiral selecting crystallization in helical polymers. We previously proposed a stepwise approach using two kinds of helical polymers, simple "bare" helical polymers made of backbone atoms only such as polyoxymethylene (POM) and "general" helical polymers containing complicated side groups such as isotactic polypropylene (iPP). We have already reported on the crystallization in oligomeric POM-like helix but have observed only weak chiral selectivity during crystallization. In the present paper, we investigate the crystallization of sufficiently long POM-like polymer both from the isotropic melt and from the highly stretched melt. We find in both cases that the polymer shows a clear chiral selecting crystallization. Especially the observation of a single crystal growing from the isotropic melt is very illuminating. It shows that the crystal thickness and the crystal chirality is closely correlated; thicker crystals show definite chirality while thinner ones are mostly mixtures of the R- and the L- handed stems. The single crystal is found to have a marked lenticular shape, where the thinner growth front, since being made of the mixture, shows no chiral selectivity. Final chiral crystal is found to be completed through helix reversal processes within thicker regions.
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Affiliation(s)
- Takashi Yamamoto
- Department of Physics and Informatics, Yamaguchi University, Japan
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10
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Salahshoori I, Babapoor A, Seyfaee A. Elevated performance of the neat, hybrid and composite membranes by the addition of nanoparticles (ZIF-67): A molecular dynamics study. Polym Bull (Berl) 2022. [DOI: 10.1007/s00289-021-03673-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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11
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AlPO
4
film with rose surface structure: One‐step coating process, superhydrophilic and rapid super‐spreading. NANO SELECT 2022. [DOI: 10.1002/nano.202100308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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12
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Majerczak K, Wadkin‐Snaith D, Magueijo V, Mulheran P, Liggat J, Johnston K. Polyhydroxybutyrate: a review of experimental and simulation studies on the effect of fillers on crystallinity and mechanical properties. POLYM INT 2022. [DOI: 10.1002/pi.6402] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Katarzyna Majerczak
- Department of Pure and Applied Chemistry Thomas Graham Building, 295 Cathedral Street, University of Strathclyde Glasgow G1 1XL United Kingdom
| | - Dominic Wadkin‐Snaith
- Department of Chemical and Processing Engineering James Weir Building, 75 Montrose Street, University of Strathclyde Glasgow G1 1XJ United Kingdom
| | - Vitor Magueijo
- Department of Chemical and Processing Engineering James Weir Building, 75 Montrose Street, University of Strathclyde Glasgow G1 1XJ United Kingdom
| | - Paul Mulheran
- Department of Chemical and Processing Engineering James Weir Building, 75 Montrose Street, University of Strathclyde Glasgow G1 1XJ United Kingdom
| | - John Liggat
- Department of Pure and Applied Chemistry Thomas Graham Building, 295 Cathedral Street, University of Strathclyde Glasgow G1 1XL United Kingdom
| | - Karen Johnston
- Department of Chemical and Processing Engineering James Weir Building, 75 Montrose Street, University of Strathclyde Glasgow G1 1XJ United Kingdom
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13
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Sheng J, Chen W, Cui K, Li L. Polymer crystallization under external flow. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2022; 85:036601. [PMID: 35060493 DOI: 10.1088/1361-6633/ac4d92] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 01/20/2022] [Indexed: 06/14/2023]
Abstract
The general aspects of polymer crystallization under external flow, i.e., flow-induced crystallization (FIC) from fundamental theoretical background to multi-scale characterization and modeling results are presented. FIC is crucial for modern polymer processing, such as blowing, casting, and injection modeling, as two-third of daily-used polymers is crystalline, and nearly all of them need to be processed before final applications. For academics, the FIC is intrinsically far from equilibrium, where the polymer crystallization behavior is different from that in quiescent conditions. The continuous investigation of crystallization contributes to a better understanding on the general non-equilibrium ordering in condensed physics. In the current review, the general theories related to polymer nucleation under flow (FIN) were summarized first as a preliminary knowledge. Various theories and models, i.e., coil-stretch transition and entropy reduction model, are briefly presented together with the modified versions. Subsequently, the multi-step ordering process of FIC is discussed in detail, including chain extension, conformational ordering, density fluctuation, and final perfection of the polymer crystalline. These achievements for a thorough understanding of the fundamental basis of FIC benefit from the development of various hyphenated rheometer, i.e., rheo-optical spectroscopy, rheo-IR, and rheo-x-ray scattering. The selected experimental results are introduced to present efforts on elucidating the multi-step and hierarchical structure transition during FIC. Then, the multi-scale modeling methods are summarized, including micro/meso scale simulation and macroscopic continuum modeling. At last, we briefly describe our personal opinions related to the future directions of this field, aiming to ultimately establish the unified theory of FIC and promote building of the more applicable models in the polymer processing.
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Affiliation(s)
- Junfang Sheng
- National Synchrotron Radiation Laboratory, Anhui Provincial Engineering Laboratory of Advanced Functional Polymer Film, CAS Key Laboratory of Soft Matter Chemistry, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Wei Chen
- National Synchrotron Radiation Laboratory, Anhui Provincial Engineering Laboratory of Advanced Functional Polymer Film, CAS Key Laboratory of Soft Matter Chemistry, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Kunpeng Cui
- National Synchrotron Radiation Laboratory, Anhui Provincial Engineering Laboratory of Advanced Functional Polymer Film, CAS Key Laboratory of Soft Matter Chemistry, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Liangbin Li
- National Synchrotron Radiation Laboratory, Anhui Provincial Engineering Laboratory of Advanced Functional Polymer Film, CAS Key Laboratory of Soft Matter Chemistry, University of Science and Technology of China, Hefei 230026, People's Republic of China
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14
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Jiang S, Lu Y, Luo C. State Transitions and Crystalline Structures of a Single Polyethylene Chain: MD Simulations. J Phys Chem B 2022; 126:964-975. [DOI: 10.1021/acs.jpcb.1c09471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Shengming Jiang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
- University of Science and Technology of China, Hefei 230 026, P. R. China
| | - Yuyuan Lu
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
- University of Science and Technology of China, Hefei 230 026, P. R. China
| | - Chuanfu Luo
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
- University of Science and Technology of China, Hefei 230 026, P. R. China
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15
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Romanos N, Megariotis G, Theodorou DN. Molecular dynamics simulations of stretch‐induced crystallization in layered polyethylene. POLYMER CRYSTALLIZATION 2021. [DOI: 10.1002/pcr2.10172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Nikolaos Romanos
- School of Chemical Engineering National Technical University of Athens (NTUA) Athens Greece
| | - Grigorios Megariotis
- School of Chemical Engineering National Technical University of Athens (NTUA) Athens Greece
| | - Doros N. Theodorou
- School of Chemical Engineering National Technical University of Athens (NTUA) Athens Greece
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16
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Tubiana L, Kobayashi H, Potestio R, Dünweg B, Kremer K, Virnau P, Daoulas K. Comparing equilibration schemes of high-molecular-weight polymer melts with topological indicators. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:204003. [PMID: 33765663 DOI: 10.1088/1361-648x/abf20c] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 03/25/2021] [Indexed: 06/12/2023]
Abstract
Recent theoretical studies have demonstrated that the behaviour of molecular knots is a sensitive indicator of polymer structure. Here, we use knots to verify the ability of two state-of-the-art algorithms-configuration assembly and hierarchical backmapping-to equilibrate high-molecular-weight (MW) polymer melts. Specifically, we consider melts with MWs equivalent to several tens of entanglement lengths and various chain flexibilities, generated with both strategies. We compare their unknotting probability, unknotting length, knot spectra, and knot length distributions. The excellent agreement between the two independent methods with respect to knotting properties provides an additional strong validation of their ability to equilibrate dense high-MW polymeric liquids. By demonstrating this consistency of knotting behaviour, our study opens the way for studying topological properties of polymer melts beyond time and length scales accessible to brute-force molecular dynamics simulations.
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Affiliation(s)
- Luca Tubiana
- Physics Department, University of Trento, via Sommarive, 14 I-38123 Trento, Italy
- INFN-TIFPA, Trento Institute for Fundamental Physics and Applications, I-38123 Trento, Italy
- Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria
| | - Hideki Kobayashi
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Raffaello Potestio
- Physics Department, University of Trento, via Sommarive, 14 I-38123 Trento, Italy
- INFN-TIFPA, Trento Institute for Fundamental Physics and Applications, I-38123 Trento, Italy
| | - Burkhard Dünweg
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
- Department of Chemical Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Kurt Kremer
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Peter Virnau
- Institute of Physics, Johannes Gutenberg University, Staudingerweg 9, 55128 Mainz, Germany
| | - Kostas Daoulas
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
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17
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Higuchi Y. Coarse-grained molecular dynamics simulations of void generation and growth processes in the fracture of the lamellar structure of polyethylene. Phys Rev E 2021; 103:042502. [PMID: 34005872 DOI: 10.1103/physreve.103.042502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 03/25/2021] [Indexed: 06/12/2023]
Abstract
We investigate the void generation and growth process in semicrystalline polymers by large-scale coarse-grained molecular dynamics simulations. Voids are generated in the amorphous layers and grow spherically and then cylindrically, consistent with the results of previous experiments. Interestingly, the fusion of voids is indicated to enlarge the voids in the direction perpendicular to the stretching direction, but not beyond the crystalline layers. The orientational order along the stretching direction increased sharply before void generation, but the increase leveled off afterward. The simulations also clearly reveal that the crystalline layers break but do not bend in the fragmentation process. The dependence of the void growth process on stretching velocity and the stability levels of voids at constant strain are also discussed.
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Affiliation(s)
- Yuji Higuchi
- Institute for Solid State Physics, The University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8581, Japan and Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
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18
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Ono Y, Kumaki J. In Situ AFM Observation of Folded‐Chain Crystallization of a Low‐Molecular‐Weight Isotactic Poly(methyl methacrylate) in a Langmuir Monolayer at the Molecular Level. MACROMOL CHEM PHYS 2021. [DOI: 10.1002/macp.202000372] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Yuki Ono
- Department of Organic Materials Science Graduate School of Organic Materials Science Yamagata University Yonezawa Yamagata 992–8510 Japan
| | - Jiro Kumaki
- Department of Organic Materials Science Graduate School of Organic Materials Science Yamagata University Yonezawa Yamagata 992–8510 Japan
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19
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Lotfi-Sousefi Z, Mehrnejad F, Khanmohammadi S, Kaboli SF. Insight into the Microcosm of the Human Growth Hormone and Its Interactions with Polymers and Copolymers: A Molecular Dynamics Perspective. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:90-104. [PMID: 33356301 DOI: 10.1021/acs.langmuir.0c02441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Therapeutic proteins nowadays have increasingly been applied for their considerable potential in treating a wide variety of diseases. The effectiveness and potency of native therapeutic proteins are limited by various factors (e.g., stability, blood circulation time, specificity). Over the past years, a great deal of effort has been devoted to developing safe and efficient protein delivery systems. Entrapment of protein into polymeric and copolymeric matrices is common among the different types of protein-based drug formulation. However, despite the massive efforts toward developing therapeutic protein delivery in experimental studies and industrial applications, there is relatively little data on the influence of polymers and copolymers on therapeutic proteins at the atomic and molecular levels. Herein, molecular dynamics (MD) simulations are used to study the effects of biocompatible synthetic polymers including methoxy poly(ethylene glycol) (MPEG), poly(lactic acid) (PLA), and poly(lactic acid) copolymers (poly(lactic-co-glycolic acid)) PLGA and MPEG-PLA(PELA)) on the structure and dynamics of the human growth hormone (hGH), and the results are compared with previous experimental findings. Our results indicate that the hGH conformation remains stable both in pure water and in the presence of polymers, and these results are in good agreement with previous experimental data. It is shown that the MPEG chains are self-assembled and folded into a semicrystalline structure; therefore, only a small portion of the protein interacts with the polymer. The other three polymers, however, interact well with the protein and partially cover its surface. Our findings suggest that the use of these polymers for protein encapsulation has the advantage of reducing protein aggregation and thus increasing drug serum half-life. Eventually, we anticipate that the research results will expand the current knowledge about encapsulation mechanisms and the molecular interactions between hGH and the polymers.
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Affiliation(s)
- Zahra Lotfi-Sousefi
- Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, 14395-1561 Tehran, Iran
| | - Faramarz Mehrnejad
- Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, 14395-1561 Tehran, Iran
| | - Somayeh Khanmohammadi
- Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, 14395-1561 Tehran, Iran
| | - S Fatemeh Kaboli
- Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, 14395-1561 Tehran, Iran
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20
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Venkatram S, Batra R, Chen L, Kim C, Shelton M, Ramprasad R. Predicting Crystallization Tendency of Polymers Using Multifidelity Information Fusion and Machine Learning. J Phys Chem B 2020; 124:6046-6054. [PMID: 32539396 DOI: 10.1021/acs.jpcb.0c01865] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The degree of crystallinity of a polymer is a critical parameter that controls a variety of polymer properties. A high degree of crystallinity is associated with excellent mechanical properties crucial for high-performing applications like composites. Low crystallinity promotes ion and gas mobility critical for battery and membrane applications. Experimental determination of the crystallinity for new polymers is time and cost intensive. A data-driven machine learning-based method capable of rapidly predicting the crystallinity could counter these disadvantages and be used to screen polymers for a myriad of applications in a fast, inexpensive fashion. In this work, we developed the first-of-its-kind, data-driven machine learning model to predict the most-likely polymer crystallinity trained on experimental data and theoretical group contribution methods. Since polymer data under consistent processing conditions are unavailable, we tackled process variability by using the "most-likely" polymer values which we refer to as the polymer's tendency to crystallize. Experimental data for polymers' tendency to crystallize is limited by number and diversity, and to tackle this, we augmented experimentation-based data with data using group contribution methods. Therefore, this work utilized two data sets, viz., a high-fidelity, experimental data set for 107 polymers and a more diverse, less accurate low-fidelity data set for 429 polymers which used group contribution methods. We used a multifidelity information fusion strategy to utilize all the information captured in the low-fidelity data set while still predicting at the high-fidelity accuracy. Although this model inherently assumed "typical" processing conditions and estimated the "most-likely" percent crystallinity value, it can help in the estimation of a polymer's tendency to crystallize in a far more cost-effective and efficient manner.
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Affiliation(s)
- Shruti Venkatram
- School of Materials Science and Engineering, Georgia Institute of Technology 771 Ferst Drive NW, Atlanta, Georgia 30332, United States
| | - Rohit Batra
- School of Materials Science and Engineering, Georgia Institute of Technology 771 Ferst Drive NW, Atlanta, Georgia 30332, United States
| | - Lihua Chen
- School of Materials Science and Engineering, Georgia Institute of Technology 771 Ferst Drive NW, Atlanta, Georgia 30332, United States
| | - Chiho Kim
- School of Materials Science and Engineering, Georgia Institute of Technology 771 Ferst Drive NW, Atlanta, Georgia 30332, United States
| | - Madeline Shelton
- School of Materials Science and Engineering, Georgia Institute of Technology 771 Ferst Drive NW, Atlanta, Georgia 30332, United States
| | - Rampi Ramprasad
- School of Materials Science and Engineering, Georgia Institute of Technology 771 Ferst Drive NW, Atlanta, Georgia 30332, United States
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21
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Song W, Fan YZ, Hua Y, Sun WF. Magnetic and Dielectric Properties of Nano- and Micron-BiFeO 3/LDPE Composites with Magnetization Treatments. MATERIALS 2019; 13:ma13010120. [PMID: 31888019 PMCID: PMC6982264 DOI: 10.3390/ma13010120] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 12/20/2019] [Accepted: 12/24/2019] [Indexed: 11/16/2022]
Abstract
By means of magnetization treatments at ambient temperature and elevated temperatures, the nano- and micron-bismuth ferrate/low density polyethylene (BiFeO3/LDPE) dielectric composites are developed to explore the material processing method to modify the crystalline morphology, magnetic and dielectric properties. The magnetic field treatment can induce the dipole in the LDPE macromolecular chain which leads to preferred orientation of polyethylene crystal grains to the direction of the magnetization field. The surface morphology of the materials measured by atomic force microscope (AFM) implies that the LDPE macromolecular chains in BiFeO3/LDPE composites have been orderly arranged and form thicker lamellae accumulated with a larger spacing after high temperature magnetization, resulting in the increased dimension and orientation of spherulites. The residual magnetization intensities of BiFeO3/LDPE composites have been significantly improved by magnetization treatments at ambient temperature. After this magnetization at ambient temperature, the MR of nano- and micron-BiFeO3/LDPE composites approach to 4.415 × 10−3 and 0.690 × 10−3 emu/g, respectively. The magnetic moments of BiFeO3 fillers are arranged parallel to the magnetic field direction, leading to appreciable enhancement of the magnetic interactions between BiFeO3 fillers, which will inhibit the polarization of the electric dipole moments at the interface between BiFeO3 fillers and the LDPE matrix. Therefore, magnetization treatment results in the lower dielectric constant and higher dielectric loss of BiFeO3/LDPE composites. It is proven that the magnetic and dielectric properties of polymer dielectric composites can be effectively modified by the magnetization treatment in the melt blending process of preparing composites, which is expected to provide a technical strategy for developing magnetic polymer dielectrics.
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22
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Tang Q, Müller M, Li CY, Hu W. Anomalous Ostwald Ripening Enables 2D Polymer Crystals via Fast Evaporation. PHYSICAL REVIEW LETTERS 2019; 123:207801. [PMID: 31809069 DOI: 10.1103/physrevlett.123.207801] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Indexed: 06/10/2023]
Abstract
We demonstrate by molecular simulations that the Ostwald ripening of crystalline polymer nuclei within the fast-evaporation-induced 2D skin layer is retarded at suitable temperatures and evaporation rates. Such an anomalous ripening can be attributed to the interplay between the thermodynamically driven diffusion of noncrystalline fragments toward the growing nuclei and the diffusive current away from the free surface caused by the densification in the nonequilibrium skin layer. The growth orientation of the nuclei inside the skin plane can be adjusted during this anomalous ripening process, which is beneficial for fabricating 2D polymer crystals.
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Affiliation(s)
- Qiyun Tang
- Department of Polymer Science and Engineering, State Key Lab of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, 210023 Nanjing, China
- Institut für Theoretische Physik, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Marcus Müller
- Institut für Theoretische Physik, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Christopher Y Li
- Department of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104, USA
| | - Wenbing Hu
- Department of Polymer Science and Engineering, State Key Lab of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, 210023 Nanjing, China
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23
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Hu Y, Shao Y, Liu Z, He X, Liu B. Dominant Effects of Short-Chain Branching on the Initial Stage of Nucleation and Formation of Tie Chains for Bimodal Polyethylene as Revealed by Molecular Dynamics Simulation. Polymers (Basel) 2019; 11:E1840. [PMID: 31717356 PMCID: PMC6918436 DOI: 10.3390/polym11111840] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 11/01/2019] [Accepted: 11/05/2019] [Indexed: 11/21/2022] Open
Abstract
The molecular mechanism of short-chain branching (SCB), especially the effects of methylene sequence length (MSL) and short-chain branching distribution (SCBD) on the initial stage of nucleation, the crystallization process, and particularly the tie chain formation process of bimodal polyethylene (BPE), were explored using molecular dynamics simulation. This work constructed two kinds of BPE models in accordance with commercial BPE pipe resins: SCB incorporated in the long chain or in the short chains. The initial stage of nucleation was determined by the MSL of the system, as the critical MSL for a branched chain to nucleate is about 60 CH2. SCB incorporated in the long chain led to a delay of the initial stage of nucleation relative to the case of SCB incorporated in the short chains. The increase of branch length could accelerate the delay to nucleation. The location of short chain relative to the long chain depended on the MSL of the short chain. As the MSL of the system decreased, the crystallinity decreased, while the tie chains concentration increased. The tie chains concentration of the BPE model with branches incorporated in the long chain was higher than that with branches incorporated in the short chain.
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Affiliation(s)
- Yanling Hu
- Shanghai Key Laboratory of Multiphase Material Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China; (Y.H.); (Y.S.); (Z.L.)
| | - Yunqi Shao
- Shanghai Key Laboratory of Multiphase Material Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China; (Y.H.); (Y.S.); (Z.L.)
| | - Zhen Liu
- Shanghai Key Laboratory of Multiphase Material Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China; (Y.H.); (Y.S.); (Z.L.)
| | - Xuelian He
- Shanghai Key Laboratory of Multiphase Material Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China; (Y.H.); (Y.S.); (Z.L.)
| | - Boping Liu
- College of Materials and Energy, South China Agricultural University, Guangzhou 510642, China
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24
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Single-chain folding of a quenched isotactic polypropylene chain through united atom molecular dynamics simulations. POLYMER 2019. [DOI: 10.1016/j.polymer.2019.121861] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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25
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Effect of Mold Geometry on Pore Size in Freeze-Cast Chitosan-Alginate Scaffolds for Tissue Engineering. Ann Biomed Eng 2019; 48:1090-1102. [PMID: 31654152 DOI: 10.1007/s10439-019-02381-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 10/09/2019] [Indexed: 02/06/2023]
Abstract
Freeze-casting is a popular method to produce biomaterial scaffolds with highly porous structures. The pore structure of freeze-cast biomaterial scaffolds is influenced by processing parameters but has mostly been controlled experimentally. A mathematical model integrating Computational Fluid Dynamics with Population Balance Model was developed to predict average pore size (APS) of 3D porous chitosan-alginate scaffolds and to assess the influence of the geometrical parameters of mold on scaffold pore structure. The model predicted the crystallization pattern and APS for scaffolds cast in different diameter molds and filled to different heights. The predictions demonstrated that the temperature gradient and solidification pattern affect ice crystal nucleation and growth, subsequently influencing APS homogeneity. The predicted APS compared favorably with APS measurements from a corresponding experimental dataset, validating the model. Sensitivity analysis was performed to assess the response of the APS to the three geometrical parameters of the mold: well radius; solution fill height; and spacing between wells. The pore size was most sensitive to the distance between the wells and least sensitive to solution height. This validated model demonstrates a method for optimizing the APS of freeze-cast biomaterial scaffolds that could be applied to other compositions or applications.
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26
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The Origins of Enhanced and Retarded Crystallization in Nanocomposite Polymers. NANOMATERIALS 2019; 9:nano9101472. [PMID: 31623232 PMCID: PMC6835676 DOI: 10.3390/nano9101472] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 10/11/2019] [Accepted: 10/13/2019] [Indexed: 02/03/2023]
Abstract
Controlling the crystallinity of hybrid polymeric systems has an important impact on their properties and is essential for developing novel functional materials. The crystallization of nanocomposite polymers with gold nanoparticles is shown to be determined by free space between nanoparticles. Results of large-scale molecular dynamics simulations reveal while crystallinity is affected by the nanoparticle size and its volume fraction, their combined effects can only be measured by interparticle free space and characteristic size of the crystals. When interparticle free space becomes smaller than the characteristic extended length of the polymer molecule, nanoparticles impede the crystallization because of the confinement effects. Based on the findings from this work, equations for critical particle size or volume fraction that lead to this confinement-induced retardation of crystallization are proposed. The findings based on these equations are demonstrated to agree with the results reported in experiments for nanocomposite systems. The results of simulations also explain the origin of a two-tier crystallization regime observed in some of the hybrid polymeric systems with planar surfaces where the crystallization is initially enhanced and then retarded by the presence of nanoparticles.
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27
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Lu X, Detrez F, Roland S. Numerical study of the relationship between the spherulitic microstructure and isothermal crystallization kinetics. Part I. 2-D analyses. POLYMER 2019. [DOI: 10.1016/j.polymer.2019.121642] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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28
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Gao R, Zhao L, Shao Y, Liu Z, He X, Liu B. Molecular dynamics study of polyethylene chain non-isothermal crystallisation: effects of chain length and branch structure. MOLECULAR SIMULATION 2019. [DOI: 10.1080/08927022.2019.1587759] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Rui Gao
- Shanghai Key Laboratory of Multiphase Material Chemical Engineering, East China University of Science and Technology, Shanghai, People’s Republic of China
| | - Li Zhao
- Shanghai Key Laboratory of Multiphase Material Chemical Engineering, East China University of Science and Technology, Shanghai, People’s Republic of China
| | - Yunqi Shao
- Shanghai Key Laboratory of Multiphase Material Chemical Engineering, East China University of Science and Technology, Shanghai, People’s Republic of China
| | - Zhen Liu
- Shanghai Key Laboratory of Multiphase Material Chemical Engineering, East China University of Science and Technology, Shanghai, People’s Republic of China
| | - Xuelian He
- Shanghai Key Laboratory of Multiphase Material Chemical Engineering, East China University of Science and Technology, Shanghai, People’s Republic of China
| | - Boping Liu
- College of Materials and Energy, South China Agricultural University, Guangzhou, People’s Republic of China
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29
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Higuchi Y. Stress Transmitters at the Molecular Level in the Deformation and Fracture Processes of the Lamellar Structure of Polyethylene via Coarse-Grained Molecular Dynamics Simulations. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b00636] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yuji Higuchi
- Institute for Solid State Physics, The University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8581, Japan
- Institute for Materials Research, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai, Miyagi 980-8577, Japan
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30
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Andrade FN, Fulchiron R, Collas F, McKenna TFL. Condensed Mode Cooling for Ethylene Polymerization: Part V—Reduction of the Crystallization Rate of HDPE in the Presence of Induced Condensing Agents. MACROMOL CHEM PHYS 2019. [DOI: 10.1002/macp.201800563] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Fabiana N. Andrade
- C2P2‐UMR 5265Université de Lyon, Bâtiment ESCPE 43 Blvd du 11 Novembre 1918 F‐69616 Villeurbanne France
| | - René Fulchiron
- CNRS UMR 5223Université de Lyon Ingénierie des Matériaux Polymères F‐69622 Villeurbanne France
| | - Franck Collas
- Mettler Toledo 18/20 avenue de la Pépinière F‐78222 Viroflay France
| | - Timothy F. L. McKenna
- C2P2‐UMR 5265Université de Lyon, Bâtiment ESCPE 43 Blvd du 11 Novembre 1918 F‐69616 Villeurbanne France
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31
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Hagita K, Fujiwara S, Iwaoka N. An accelerated united-atom molecular dynamics simulation on the fast crystallization of ring polyethylene melts. J Chem Phys 2019; 150:074901. [PMID: 30795675 DOI: 10.1063/1.5080332] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
To investigate crystallinities based on trans-structures, we determined the differences in the crystallization properties of ring and linear polymers by performing united-atom-model molecular dynamics (MD) simulations of homogeneous polyethylene melts of equal length, N, which refers to the number of monomers per chain. Modified parameters based on the DREIDING force field for the CH2 units were used in order to accelerate the crystallization process. To detect polymer crystallization, we introduced some local-order parameters that relate to trans-segments in addition to common crystallinities using neighboring bond orders. Through quenching MD simulations at 5 K/ns, we roughly determined temperature thresholds, Tth, at which crystallization is observed although it was hard to determine the precise Tth as observed in the laboratory time frame with the present computing resources. When N was relatively small (100 and 200), Tth was determined to be 320 and 350 K for the linear- and ring-polyethylene melts, respectively, while Tth was found to be 330 and 350 K, respectively, when N was 1000. Having confirmed that the crystallization of a ring-polyethylene melt occurs faster than that of the analogous linear melt, we conclude that the trans-segment-based crystallinities are effective for the analysis of local crystal behavior.
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Affiliation(s)
- Katsumi Hagita
- Department of Applied Physics, National Defense Academy, Yokosuka 239-8686, Japan
| | - Susumu Fujiwara
- Faculty of Materials Science and Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Nobuyuki Iwaoka
- Tsuruoka College, National Institute of Technology, Tsuruoka 997-8511, Japan
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32
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Yamamoto T. Molecular Dynamics Simulation of Stretch-Induced Crystallization in Polyethylene: Emergence of Fiber Structure and Molecular Network. Macromolecules 2019. [DOI: 10.1021/acs.macromol.8b02569] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Takashi Yamamoto
- Graduate School of Science and Engineering Yamaguchi University, Yamaguchi 753-8512, Japan
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33
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34
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Furushima Y, Schick C, Toda A. Crystallization, recrystallization, and melting of polymer crystals on heating and cooling examined with fast scanning calorimetry. POLYMER CRYSTALLIZATION 2018. [DOI: 10.1002/pcr2.10005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Yoshitomo Furushima
- Materials Characterization Laboratories, Toray Research Center Inc.Otsu Shiga 520‐8567 Japan
| | - Christoph Schick
- University of Rostock, Institute of Physics and Competence Centre CALOR18059 Rostock Germany
- Kazan Federal UniversityKazan 420008 Russian Federation
| | - Akihiko Toda
- Graduate school of Integrated Arts and SciencesHiroshima UniversityHigashi‐Hiroshima 739‐8521 Japan
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35
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Verho T, Paajanen A, Vaari J, Laukkanen A. Crystal Growth in Polyethylene by Molecular Dynamics: The Crystal Edge and Lamellar Thickness. Macromolecules 2018; 51:4865-4873. [PMID: 30258252 PMCID: PMC6150721 DOI: 10.1021/acs.macromol.8b00857] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 06/14/2018] [Indexed: 11/30/2022]
Abstract
We carried out large-scale atomistic molecular dynamics simulations to study the growth of twin lamellar crystals of polyethylene initiated by small crystal seeds. By examining the size distribution of the stems-straight crystalline polymer segments-we show that the crystal edge has a parabolic profile. At the growth front, there is a layer of stems too short to be stable, and new stable stems are formed within this layer, leading to crystal growth. Away from the edge, the lengthening of the stems is limited by a lack of available slack length in the chains. This frustration can be relieved by mobile crystal defects that allow topological relaxation by traversing through the crystal. The results shed light on the process of polymer crystal growth and help explain initial thickness selection and lamellar thickening.
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Affiliation(s)
- Tuukka Verho
- VTT Technical Research Centre of Finland
Ltd., Espoo, Finland
| | - Antti Paajanen
- VTT Technical Research Centre of Finland
Ltd., Espoo, Finland
| | - Jukka Vaari
- VTT Technical Research Centre of Finland
Ltd., Espoo, Finland
| | - Anssi Laukkanen
- VTT Technical Research Centre of Finland
Ltd., Espoo, Finland
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36
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Iyer K, Muthukumar M. Langevin dynamics simulation of crystallization of ring polymers. J Chem Phys 2018; 148:244904. [DOI: 10.1063/1.5023602] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Affiliation(s)
- Kiran Iyer
- Department of Chemical Engineering, University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - Murugappan Muthukumar
- Department of Polymer Science and Engineering, University of Massachusetts, Amherst, Massachusetts 01003, USA
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37
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Liu YF, Yang H, Zhang H. Molecular dynamics simulation of the folding of single alkane chains with different lengths on single-walled carbon nanotubes and graphene. J Mol Model 2018; 24:140. [PMID: 29855717 DOI: 10.1007/s00894-018-3675-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 05/14/2018] [Indexed: 10/14/2022]
Abstract
Chain folding is an important step during polymer crystallization. In order to study the effects of the surface on chain folding, molecular dynamics simulations of the folding of different alkane chains on three kinds of single-walled carbon nanotubes (SWCNTs) and graphene were performed. The folding behaviors of the single alkane chains on these surfaces were found to be different from their folding behaviors in vacuum. The end-to-end distances of the chains were calculated to explore the chain folding. An increasing tendency to fold into two or more stems with increasing alkane chain length was observed. This result indicates that the occurrence and the stability of chain folding are related to the surface curvature, the diameter of the SWCNT, and surface texture. In addition, the angle between the direction of the alkane chain segment and the direction of the surface texture was measured on different surfaces.
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Affiliation(s)
- Yan Fang Liu
- Tianjin Key Laboratory of Structure and Performance for Functional Molecules, Key Laboratory of Inorganic-Organic Hybrid Functional Material Chemistry, Ministry of Education, College of Chemistry, Tianjin Normal University, Tianjin, People's Republic of China
| | - Hua Yang
- Tianjin Key Laboratory of Structure and Performance for Functional Molecules, Key Laboratory of Inorganic-Organic Hybrid Functional Material Chemistry, Ministry of Education, College of Chemistry, Tianjin Normal University, Tianjin, People's Republic of China.
| | - Hui Zhang
- School of Chemical and Environmental Engineering, Harbin University of Science and Technology, Harbin, 150080, People's Republic of China
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38
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Higuchi Y. Fracture processes of crystalline polymers using coarse-grained molecular dynamics simulations. Polym J 2018. [DOI: 10.1038/s41428-018-0067-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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39
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Morthomas J, Fusco C, Zhai Z, Lame O, Perez M. Crystallization of finite-extensible nonlinear elastic Lennard-Jones coarse-grained polymers. Phys Rev E 2017; 96:052502. [PMID: 29347659 DOI: 10.1103/physreve.96.052502] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Indexed: 06/07/2023]
Abstract
The ability of a simple coarse-grained finite-extensible nonlinear elastic (FENE) Lennard-Jones (LJ) polymer model to be crystallized is investigated by molecular dynamics simulations. The optimal FENE Lennard-Jones parameter combinations (ratio between FENE and LJ equilibrium distances) and the optimal lattice parameters are calculated for five different perfect crystallite structures: simple tetragonal, body-centered tetragonal, body-centered orthorhombic, hexagonal primitive, and hexagonal close packed. It was found that the most energetically favorable structure is the body-centered orthorhombic. Starting with an equilibrated polymer liquid and with the optimal parameters found for the body-centered orthorhombic, an isothermal treatment led to the formation of large lamellar crystallites with a typical chain topology: folded, loop, and tie chains, and with a crystallinity of about 60%-70%, similar to real semicrystalline polymers. This simple coarse-grained Lennard-Jones model provides a qualitative tool to study semicrystalline microstructures for polymers.
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Affiliation(s)
- Julien Morthomas
- INSA de Lyon, Université de Lyon, MATEIS, UMR CNRS 5510, 69621 Villeurbanne, France
| | - Claudio Fusco
- INSA de Lyon, Université de Lyon, MATEIS, UMR CNRS 5510, 69621 Villeurbanne, France
| | - Zengqiang Zhai
- INSA de Lyon, Université de Lyon, MATEIS, UMR CNRS 5510, 69621 Villeurbanne, France
| | - Olivier Lame
- INSA de Lyon, Université de Lyon, MATEIS, UMR CNRS 5510, 69621 Villeurbanne, France
| | - Michel Perez
- INSA de Lyon, Université de Lyon, MATEIS, UMR CNRS 5510, 69621 Villeurbanne, France
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40
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Welch PM. Examining the role of fluctuations in the early stages of homogenous polymer crystallization with simulation and statistical learning. J Chem Phys 2017; 146:044901. [DOI: 10.1063/1.4973346] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
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41
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Furushima Y, Kumazawa S, Umetsu H, Toda A, Zhuravlev E, Wurm A, Schick C. Crystallization kinetics of poly(butylene terephthalate) and its talc composites. J Appl Polym Sci 2017. [DOI: 10.1002/app.44739] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yoshitomo Furushima
- Materials Characterization Laboratories; Toray Research Center Inc; 3-7, Sonoyama 3-chome Otsu Shiga 520-8567 Japan
- Institute of Physics; University of Rostock; Albert-Einstein-Str. 23-24 Rostock 18059 Germany
- Competence Center CALOR, Faculty of Interdisciplinary Research; University of Rostock; Albert-Einstein-Str. 25 Rostock 18059 Germany
| | - Sadanori Kumazawa
- R&D Planning Department; Toray Industries, Inc; 1-1, Sonoyama 1-chome Otsu Shiga 520-8558 Japan
| | - Hideyuki Umetsu
- Plastics Research Laboratory; Chemicals Research Laboratories, Toray Industries, Inc; 9-1, Oe-Cho Minatoku Nagoya 455-8502 Japan
| | - Akihiko Toda
- Graduate School of Integrated Arts and Sciences; Hiroshima University; Higashi-Hiroshima 739-8521 Japan
| | - Evgeny Zhuravlev
- Institute of Physics; University of Rostock; Albert-Einstein-Str. 23-24 Rostock 18059 Germany
- Competence Center CALOR, Faculty of Interdisciplinary Research; University of Rostock; Albert-Einstein-Str. 25 Rostock 18059 Germany
| | - Andreas Wurm
- Institute of Physics; University of Rostock; Albert-Einstein-Str. 23-24 Rostock 18059 Germany
- Competence Center CALOR, Faculty of Interdisciplinary Research; University of Rostock; Albert-Einstein-Str. 25 Rostock 18059 Germany
| | - Christoph Schick
- Institute of Physics; University of Rostock; Albert-Einstein-Str. 23-24 Rostock 18059 Germany
- Competence Center CALOR, Faculty of Interdisciplinary Research; University of Rostock; Albert-Einstein-Str. 25 Rostock 18059 Germany
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Sarathchandran C, Czajka M, Chan C, Shanks RA, Thomas S. Interfacial interactions of thermally reduced graphene in poly(trimethylene terephthalate)-epoxy resin based composites. POLYMER 2016. [DOI: 10.1016/j.polymer.2016.10.035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Gulde M, Rissanou AN, Harmandaris V, Müller M, Schäfer S, Ropers C. Dynamics and Structure of Monolayer Polymer Crystallites on Graphene. NANO LETTERS 2016; 16:6994-7000. [PMID: 27786488 DOI: 10.1021/acs.nanolett.6b03079] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Graphene-based nanostructured systems and van der Waals heterostructures comprise a material class of growing technological and scientific importance. Joining materials with vastly different properties, polymer/graphene heterosystems promise diverse applications in surface and nanotechnology, including photovoltaics or nanotribology. Fundamentally, molecular adsorbates are prototypical systems to study confinement-induced phase transitions exhibiting intricate dynamics, which require a comprehensive understanding of the dynamical and static properties on molecular time and length scales. Here, we investigate the dynamics and the structure of a single polyethylene chain on free-standing graphene by means of molecular dynamics simulations. In equilibrium, the adsorbed polymer is orientationally linked to the graphene as two-dimensional folded-chain crystallite or at elevated temperatures as a floating solid. The associated superstructure can be reversibly melted on a picosecond time scale upon quasi-instantaneous substrate heating, involving ultrafast heterogeneous melting via a transient floating phase. Our findings elucidate time-resolved molecular-scale ordering and disordering phenomena in individual polymers interacting with solids, yielding complementary information to collective friction and viscosity, and linking to recent experimental observables from ultrafast electron diffraction. We anticipate that the approach will help in resolving nonequilibrium phenomena of hybrid polymeric systems over a broad range of time and length scales.
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Affiliation(s)
- Max Gulde
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen , 37077, Göttingen, Germany
| | - Anastassia N Rissanou
- Institute of Applied and Computational Mathematics, Foundation for Research and Technology Hellas , 71110 Heraklion, Crete, Greece
| | - Vagelis Harmandaris
- Institute of Applied and Computational Mathematics, Foundation for Research and Technology Hellas , 71110 Heraklion, Crete, Greece
- Department of Mathematics and Applied Mathematics, University of Crete , 71409, Heraklion, Crete, Greece
| | - Marcus Müller
- Institute for Theoretical Physics, University of Göttingen , 37077, Göttingen, Germany
| | - Sascha Schäfer
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen , 37077, Göttingen, Germany
| | - Claus Ropers
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen , 37077, Göttingen, Germany
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Shrivastav G, Agarwal M. Stress-Strain Relationships in Hydroxyl Substituted Polyethylene. J Phys Chem B 2016; 120:7598-605. [PMID: 27380115 DOI: 10.1021/acs.jpcb.6b05275] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Stress-strain relationships in semicrystalline hydroxylated polyethylene are studied using all-atom molecular dynamics simulations. Chain sizes ranging from 50 to 2000 carbons are gradually cooled from melt in order to obtain semicrystalline samples for pure, 4%, and 8% hydroxylated chains. Local orientational order of the polymer backbone and hydrogen bonding behavior is studied. The effects of -OH substitution and chain length on stress-strain relationships are examined at 300 K. The number of hydrogen bonds is found to be independent of the chain length. Stress-strain relationships are generally unaffected by 4% hydroxyl substitution in long chain polyethylene. The presence of 8% -OH tends to increase the elastic limit of the material. A method for comparing semicrystalline samples of substituted and unsubstituted polymeric chains is presented by eliminating differences in alignment, distribution, and extent of crystallization.
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Affiliation(s)
- Gourav Shrivastav
- Department of Chemistry, Indian Institute of Technology Delhi , Hauz Khas, New Delhi, India 110016
| | - Manish Agarwal
- Department of Chemistry, Indian Institute of Technology Delhi , Hauz Khas, New Delhi, India 110016.,Computer Services Center, Indian Institute of Technology Delhi , Hauz Khas, New Delhi, India 110016
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Romanos NA, Theodorou DN. Melting Point and Solid–Liquid Coexistence Properties of α1 Isotactic Polypropylene as Functions of Its Molar Mass: A Molecular Dynamics Study. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b00819] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nikolaos A. Romanos
- School of Chemical Engineering, Department of Materials Science & Engineering, National Technical University of Athens, 9 Heroon Polytechniou Street, Zografou Campus, 157 80 Athens, Greece
| | - Doros N. Theodorou
- School of Chemical Engineering, Department of Materials Science & Engineering, National Technical University of Athens, 9 Heroon Polytechniou Street, Zografou Campus, 157 80 Athens, Greece
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A Phase Field Technique for Modeling and Predicting Flow Induced Crystallization Morphology of Semi-Crystalline Polymers. Polymers (Basel) 2016; 8:polym8060230. [PMID: 30979323 PMCID: PMC6431983 DOI: 10.3390/polym8060230] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 05/27/2016] [Accepted: 06/02/2016] [Indexed: 11/17/2022] Open
Abstract
Flow induced crystallization of semi-crystalline polymers is an important issue in polymer science and engineering because the changes in morphology strongly affect the properties of polymer materials. In this study, a phase field technique considering polymer characteristics was established for modeling and predicting the resulting morphologies. The considered crystallization process can be divided into two stages, which are nucleation upon the flow induced structures and subsequent crystal growth after the cessation of flow. Accordingly, the proposed technique consists of two parts which are a flow induced nucleation model based on the calculated information of molecular orientation and stretch, and a phase field crystal growth model upon the oriented nuclei. Two-dimensional simulations are carried out to predict the crystallization morphology of isotactic polystyrene under an injection molding process. The results of these simulations demonstrate that flow affects crystallization morphology mainly by producing oriented nuclei. Specifically, the typical skin-core structures along the thickness direction can be successfully predicted. More importantly, the results reveal that flow plays a dominant part in generating oriented crystal morphologies compared to other parameters, such as anisotropy strength, crystallization temperature, and physical noise.
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Nitta KH. On the Orientation-Induced Crystallization of Polymers. Polymers (Basel) 2016; 8:E229. [PMID: 30979322 PMCID: PMC6431899 DOI: 10.3390/polym8060229] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 06/01/2016] [Accepted: 06/03/2016] [Indexed: 12/04/2022] Open
Abstract
In order to understand orientation-induced crystallization of polymers, we introduced an intermolecular interaction between polymer chains based on quantum mechanics. We therefore considered a pair of perfectly extended chains where the intermolecular interaction is assumed to be based on the hydrogen interaction with a single chain. When two protons of each extended chain become closer together under tension, the attractive force between the extended chains is caused by the interaction between hydrogen atoms surrounding the main chains based on the hydrogen molecule ion H 2 + . The energy is split into the ground and excited states, and the spontaneous process leading to the ground state is the origin for orientation-induced crystallization.
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Affiliation(s)
- Koh-Hei Nitta
- Division of Natural System, Institute of Science and Engineering, Kanazawa University, Kakuma Campus, Kanazawa 920-1192, Japan.
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Gao R, He X, Zhang H, Shao Y, Liu Z, Liu B. Molecular dynamics study of the isothermal crystallization mechanism of polyethylene chain: the combined effects of chain length and temperature. J Mol Model 2016; 22:67. [PMID: 26932477 DOI: 10.1007/s00894-016-2931-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 02/04/2016] [Indexed: 10/22/2022]
Abstract
A molecular level understanding of the polyethylene (PE) crystallization process was elucidated by molecular dynamics simulation of three states, with varying chain length and temperature. The process can be classified into the following three states: (1) nucleation controlled state, (2) competitive state of crystal growth process and new nuclei formation, and (3) crystal growth controlled state, which could be quantified by the evolution of nuclei number. With increasing chain length, two phenomena occur: the single crystallization mechanism changes from state (1) to (3), and the crystal size increases while the b/a axial ratio in the lateral surface decreases. These changes can be explained from a thermodynamic point of view, in that the van der Waals (vdW) interaction per CH2 unit is strengthened and more nucleation sites are generated for longer chain. Size effect (meaning different surface fractions when the chain collapses into a globule) was an important factor determining vdW energy per unit and the crystallization states of a single PE chain. On the other hand, the crystallization states were independent of chain length for short chains systems with the same size effect. In both conditions, a long chain generates multi-crystal domains, and a short chain prefers a single crystal domain. Our results not only provide molecular level evidence for crystallization states but also clarify the influence of chain length on the crystallization process.
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Affiliation(s)
- Rui Gao
- State Key Laboratory of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China.
| | - Xuelian He
- State Key Laboratory of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China.
| | - Haiyang Zhang
- State Key Laboratory of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China.
| | - Yunqi Shao
- State Key Laboratory of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China.
| | - Zhen Liu
- State Key Laboratory of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China.
| | - Boping Liu
- State Key Laboratory of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China.
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