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Brosz M, Michelarakis N, Bunz UHF, Aponte-Santamaría C, Gräter F. Martini 3 coarse-grained force field for poly( para-phenylene ethynylene)s. Phys Chem Chem Phys 2022; 24:9998-10010. [PMID: 35412534 DOI: 10.1039/d1cp04237h] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Poly(para-phenylene ethynylene)s, or short PPEs, are a class of conjugated and semi-flexible polymers with a strongly delocalized π electron system and increased chain stiffness. Due to this, PPEs have a wide range of technological applications. Although the material properties of single-chains or mixtures of few PPE chains have been studied in detail, the properties of large assemblies remain to be fully explored. Here, we developed a coarse-grained model for PPEs with the Martini 3 force field to enable computational studies of PPEs in large-scale assembly. We used an optimization geometrical approach to take the shape of the π conjugated backbone into account and also applied an additional angular potential to tune the mechanical bending stiffness of the polymer. Our Martini 3 model reproduces key structural and thermodynamic observables of single PPE chains and mixtures, such as persistence length, density, packing and stacking. We show that chain entanglement increases with the expense of nematic ordering with growing PPE chain length. With the Martini 3 PPE model at hand, we are now able to cover large spatio-temporal scales and thereby to uncover key aspects for the structural organization of PPE bulk systems. The model is also predicted to be of high applicability to investigate out-of-equilibrium behavior of PPEs under mechanical force.
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Affiliation(s)
- Matthias Brosz
- Heidelberg Institute for Theoretical Studies, Am Schlosswolfsbrunnenweg 35, 69118 Heidelberg, Germany. .,Interdisciplinary Center for Scientific Computing, Heidelberg University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Nicholas Michelarakis
- Heidelberg Institute for Theoretical Studies, Am Schlosswolfsbrunnenweg 35, 69118 Heidelberg, Germany.
| | - Uwe H F Bunz
- Institute of Organic Chemistry, Heidelberg University, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany
| | - Camilo Aponte-Santamaría
- Heidelberg Institute for Theoretical Studies, Am Schlosswolfsbrunnenweg 35, 69118 Heidelberg, Germany.
| | - Frauke Gräter
- Heidelberg Institute for Theoretical Studies, Am Schlosswolfsbrunnenweg 35, 69118 Heidelberg, Germany. .,Interdisciplinary Center for Scientific Computing, Heidelberg University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
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2
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Prada A, González RI, Camarada MB, Allende S, Torres A, Sepúlveda J, Rojas-Nunez J, Baltazar SE. Nanoparticle Shape Influence over Poly(lactic acid) Barrier Properties by Molecular Dynamics Simulations. ACS OMEGA 2022; 7:2583-2590. [PMID: 35252636 PMCID: PMC8890032 DOI: 10.1021/acsomega.1c04589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 12/29/2021] [Indexed: 06/14/2023]
Abstract
Climate change is leading us to search for new materials that allow a more sustainable environmental situation in the long term. Poly(lactic acid) (PLA) has been proposed as a substitute for traditional plastics due to its high biodegradability. Various components have been added to improve their mechanical, thermal, and barrier properties. The modification of the PLA barrier properties by introducing nanoparticles with different shapes is an important aspect to control the molecular diffusion of oxygen and other gas compounds. In this work, we have described changes in oxygen diffusion by introducing nanoparticles of different shapes through molecular dynamics simulations. Our model illustrates that the existence of curved surfaces and the deposition of PLA around them by short chains generate small holes where oxygen accumulates, forming clusters and reducing their mobility. From the several considered shapes, the sphere is the most suitable structure to improve the barrier properties of the PLA.
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Affiliation(s)
- Alejandro Prada
- Departamento de Computación e
Ingenierías, Facultad de Ciencias de la Ingeniería, Universidad
Católica del Maule, Talca 3480112, Chile
- Center for the Development of Nanoscience
and Nanotechnology (CEDENNA), Santiago 9170124,
Chile
| | - Rafael I. González
- Center for the Development of Nanoscience
and Nanotechnology (CEDENNA), Santiago 9170124,
Chile
- Centro de Nanotecnología Aplicada,
Facultad de Ciencias, Universidad Mayor, Santiago 9170124,
Chile
| | - María B. Camarada
- Facultad de Química y Farmacia, Departamento de
Química Inorgánica, Pontificia Universidad Católica de
Chile, Santiago 9170124, Chile
- Centro Investigación en Nanotecnología y
Materiales Avanzados, CIEN-UC, Pontificia Universidad Católica de
Chile, Santiago 9170124, Chile
| | - Sebastián Allende
- Center for the Development of Nanoscience
and Nanotechnology (CEDENNA), Santiago 9170124,
Chile
- Departamento de Física, Universidad de
Santiago de Chile (USACH), Santiago 9170124,
Chile
| | - Alejandra Torres
- Center for the Development of Nanoscience
and Nanotechnology (CEDENNA), Santiago 9170124,
Chile
- Packaging Innovation Center (LABEN), Food Science and
Technology Department, Technology Faculty, University of Santiago de
Chile, Santiago 9170124, Chile
| | - Javiera Sepúlveda
- Center for the Development of Nanoscience
and Nanotechnology (CEDENNA), Santiago 9170124,
Chile
- Packaging Innovation Center (LABEN), Food Science and
Technology Department, Technology Faculty, University of Santiago de
Chile, Santiago 9170124, Chile
| | - Javier Rojas-Nunez
- Center for the Development of Nanoscience
and Nanotechnology (CEDENNA), Santiago 9170124,
Chile
- Departamento de Física, Universidad de
Santiago de Chile (USACH), Santiago 9170124,
Chile
| | - Samuel E. Baltazar
- Center for the Development of Nanoscience
and Nanotechnology (CEDENNA), Santiago 9170124,
Chile
- Departamento de Física, Universidad de
Santiago de Chile (USACH), Santiago 9170124,
Chile
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Guo P, Gao Y. Coalescence of Au Nanoparticles without Ligand Detachment. PHYSICAL REVIEW LETTERS 2020; 124:066101. [PMID: 32109082 DOI: 10.1103/physrevlett.124.066101] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 11/07/2019] [Accepted: 01/15/2020] [Indexed: 06/10/2023]
Abstract
Repulsion of ligands is known as the key factor for hindering nanoparticle (NP) coalescence. Thus, during the past decade, it has generally accepted that the full removal of capping ligands of the contact surface is the first step for NP coalescence. Herein, using molecular dynamics simulations, we have identified a new mechanism for the coalescence of S(CH_{2})_{n}COOH-coated Au NPs in water without ligand detachment. In contrast to the traditional mechanism, the aggregation of the NPs is induced by the twined hydrophobic chains of the ligands rather than the hydrophilic carboxyl tails as believed previously. Next, the exposed surface atoms attach to form the neck, and extend with the atomic rearrangement of the contact interface to merge the NPs, which do not need the removal of ligands as expected from traditional supposition. This finding refreshes the understanding of the atomic mechanism of the coalescence of NPs, which paves the way for the rational design and synthesis of NPs.
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Affiliation(s)
- Pan Guo
- Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Yi Gao
- Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
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Ethier JG, Hall LM. Modeling individual and pairs of adsorbed polymer-grafted nanoparticles: structure and entanglements. SOFT MATTER 2018; 14:643-652. [PMID: 29271451 DOI: 10.1039/c7sm02116j] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We analyze the canopy structure and entanglement network of isolated polymer-grafted nanoparticles (PGNs) adsorbed on a surface. As expected, increasing the monomer-surface adsorption strength causes the polymer chains to spread out to increase contact with the surface, leading to a canopy shape that is in qualitative agreement with recent experimental results. We compare height profiles and other structural features of four PGN systems to show the separate and combined effects of increasing chain length and graft density. At moderate graft density and low surface attraction strength, nearby PGN canopies interpenetrate substantially and their combined shape is similar to that of a single PGN canopy. At high graft density or surface interaction, the interparticle spacing increases significantly. We use a geometrical primitive path analysis to calculate average entanglement properties including canopy-canopy entanglements between pairs of PGNs. The longer chain systems are well entangled at both graft densities considered, and we find that as the monomer-surface interaction strength is increased (and the interparticle distance increases), entanglements between the two PGNs are reduced. We find that the number of inter-PGN entanglements per chain is slightly larger at the lower graft density, likely because steric constraints at high graft density tend to reduce interparticle entanglements.
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Affiliation(s)
- Jeffrey G Ethier
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, USA.
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Wijesinghe S, Maskey S, Perahia D, Grest GS. Luminescent tunable polydots: Charge effects in confined geometry. J Chem Phys 2017; 146:244907. [DOI: 10.1063/1.4990506] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Affiliation(s)
- Sidath Wijesinghe
- Chemistry Department, Clemson University, Clemson, South Carolina 29634, USA
| | - Sabina Maskey
- Chemistry Department, Clemson University, Clemson, South Carolina 29634, USA
| | - Dvora Perahia
- Chemistry Department, Clemson University, Clemson, South Carolina 29634, USA
| | - Gary S. Grest
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
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6
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Pietropaolo A, Tang S, Raymo FM. Free-energy predictions and absorption spectra calculations for supramolecular nanocarriers and their photoactive cargo. NANOSCALE 2017; 9:4989-4994. [PMID: 28383081 DOI: 10.1039/c7nr00839b] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We reconstructed the free-energy landscape for supramolecular nanoparticles of amphiphilic methacrylated-based co-polymers. Their self-assembly in aqueous solution and encapsulation of borondipyrromethene (BODIPY) derivatives were enforced through atomistic free-energy simulations. The BODIPY binding modes detected in each of the free-energy basins were validated through a comparison of theoretical absorption spectra, calculated at the TD-DFT level, to their experimental counterparts. The nanoparticle distribution is controlled within a thermodynamic regime, with free-energy barriers approaching 8 kcal mol-1, enabling the existence of different-sized nanoparticles in aqueous solution at room temperature. Two types of supramolecular morphologies were identified. One is compact and spherical in shape and the other is large and donut-like, with the former more stable than the latter by 4 kcal mol-1. The morphology of the supramolecular host affects the binding mode of the BODIPY guests. Stacked BODIPY aggregates are encapsulated in the spherical nanocarriers, whereas isolated chromophores associate with the donut-shaped assemblies.
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Affiliation(s)
- Adriana Pietropaolo
- Dipartimento di Scienze della Salute, Università di Catanzaro, Viale Europa 88100, Catanzaro, Italy.
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Xiang W, Zhu Z, Song X, Zhong C, Wang C, Ma Y. Concentration-induced structural transition of block polymer self-assemblies on a nanoparticle surface: computer simulation. RSC Adv 2016. [DOI: 10.1039/c6ra18739k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Film structure of asymmetric triblock copolymers assembled on different degrees of hydrophobic NP surfaces was controlled by concentration.
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Affiliation(s)
- Wenjun Xiang
- School of Chemistry and Chemical Engineering
- Sichuan University of Arts and Science
- Dazhou
- China
| | - Zhaoju Zhu
- School of Chemistry and Chemical Engineering
- Sichuan University of Arts and Science
- Dazhou
- China
| | - Xianyu Song
- Department of Mechanical and Electrical Engineering
- Dazhou Vocational and Technial College
- Dazhou
- China
| | - Cheng Zhong
- Department of Mechanical and Electrical Engineering
- Dazhou Vocational and Technial College
- Dazhou
- China
| | - Chengjie Wang
- School of Chemistry and Chemical Engineering
- Southwest Petroleum University
- Chengdu
- China
| | - Yongzhang Ma
- Sichuan Province Academy of Industrial Environmental Monitoring
- Chengdu 610500
- China
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