1
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Mendez-Gonzalez D, Torres Vera V, Zabala Gutierrez I, Gerke C, Cascales C, Rubio-Retama J, G Calderón O, Melle S, Laurenti M. Upconverting Nanoparticles in Aqueous Media: Not a Dead-End Road. Avoiding Degradation by Using Hydrophobic Polymer Shells. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2105652. [PMID: 34897995 DOI: 10.1002/smll.202105652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 11/04/2021] [Indexed: 06/14/2023]
Abstract
The stunning optical properties of upconverting nanoparticles (UCNPs) have inspired promising biomedical technologies. Nevertheless, their transfer to aqueous media is often accompanied by intense luminescence quenching, partial dissolution by water, and even complete degradation by molecules such as phosphates. Currently, these are major issues hampering the translation of UCNPs to the clinic. In this work, a strategy is developed to coat and protect β-NaYF4 UCNPs against these effects, by growing a hydrophobic polymer shell (HPS) through miniemulsion polymerization of styrene (St), or St and methyl methacrylate mixtures. This allows one to obtain single core@shell UCNPs@HPS with a final diameter of ≈60-70 nm. Stability studies reveal that these HPSs serve as a very effective barrier, impeding polar molecules to affect UCNPs optical properties. Even more, it allows UCNPs to withstand aggressive conditions such as high dilutions (5 µg mL-1 ), high phosphate concentrations (100 mm), and high temperatures (70 °C). The physicochemical characterizations prove the potential of HPSs to overcome the current limitations of UCNPs. This strategy, which can be applied to other nanomaterials with similar limitations, paves the way toward more stable and reliable UCNPs with applications in life sciences.
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Affiliation(s)
- Diego Mendez-Gonzalez
- Department of Chemistry in Pharmaceutical Sciences, Faculty of Pharmacy Complutense University of Madrid, Plaza Ramon y Cajal 2, Madrid, 28040, Spain
- Nanomaterials for Bioimaging Group (nanoBIG), Departamento de Física de Materiales, Facultad de Ciencias, Universidad Autónoma de Madrid, C/Francisco Tomás y Valiente 7, Madrid, 28049, Spain
- Nanobiology Group, Instituto Ramón y Cajal de Investigación, Sanitaria Hospital Ramón y Cajal, Ctra. De Colmenar Viejo, Km. 9100, Madrid, 28034, Spain
| | - Vivian Torres Vera
- Department of Chemistry in Pharmaceutical Sciences, Faculty of Pharmacy Complutense University of Madrid, Plaza Ramon y Cajal 2, Madrid, 28040, Spain
| | - Irene Zabala Gutierrez
- Department of Chemistry in Pharmaceutical Sciences, Faculty of Pharmacy Complutense University of Madrid, Plaza Ramon y Cajal 2, Madrid, 28040, Spain
| | - Christoph Gerke
- Department of Chemistry in Pharmaceutical Sciences, Faculty of Pharmacy Complutense University of Madrid, Plaza Ramon y Cajal 2, Madrid, 28040, Spain
- Nanobiology Group, Instituto Ramón y Cajal de Investigación, Sanitaria Hospital Ramón y Cajal, Ctra. De Colmenar Viejo, Km. 9100, Madrid, 28034, Spain
| | - Concepción Cascales
- Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas CSIC, c/Sor Juana Inés de la Cruz 3, Madrid, 28049, Spain
| | - Jorge Rubio-Retama
- Department of Chemistry in Pharmaceutical Sciences, Faculty of Pharmacy Complutense University of Madrid, Plaza Ramon y Cajal 2, Madrid, 28040, Spain
- Nanobiology Group, Instituto Ramón y Cajal de Investigación, Sanitaria Hospital Ramón y Cajal, Ctra. De Colmenar Viejo, Km. 9100, Madrid, 28034, Spain
| | - Oscar G Calderón
- Department of Optics, Faculty of Optics and Optometry Complutense University of Madrid, Avda. Arcos de Jalón 118, Madrid, E-28037, Spain
| | - Sonia Melle
- Department of Optics, Faculty of Optics and Optometry Complutense University of Madrid, Avda. Arcos de Jalón 118, Madrid, E-28037, Spain
| | - Marco Laurenti
- Department of Chemistry in Pharmaceutical Sciences, Faculty of Pharmacy Complutense University of Madrid, Plaza Ramon y Cajal 2, Madrid, 28040, Spain
- Nanobiology Group, Instituto Ramón y Cajal de Investigación, Sanitaria Hospital Ramón y Cajal, Ctra. De Colmenar Viejo, Km. 9100, Madrid, 28034, Spain
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2
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Wang Z, Kim H, Secchi M, Montagna M, Furst EM, Djafari-Rouhani B, Fytas G. Quantization of Acoustic Modes in Dumbbell Nanoparticles. PHYSICAL REVIEW LETTERS 2022; 128:048003. [PMID: 35148122 DOI: 10.1103/physrevlett.128.048003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 01/05/2022] [Indexed: 06/14/2023]
Abstract
The vibrational eigenmodes of dumbbell-shaped polystyrene nanoparticles are recorded by Brillouin light spectroscopy (BLS), and the full experimental spectra are calculated theoretically. Different from spheres with a degeneracy of (2l+1), with l being the angular momentum quantum number, the eigenmodes of dumbbells are either singly or doubly degenerate owing to their axial symmetry. The BLS spectrum reveals a new, low-frequency peak, which is attributed to the out-of-phase vibration of the two lobes of the dumbbell. The quantization of acoustic modes in these molecule-shaped dumbbell particles evolves from the primary colloidal spheres as the separation between the two lobes increases.
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Affiliation(s)
- Zuyuan Wang
- Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz 55128, Germany
- Institute for Measurement and Automation, Division of Sensor Technology and Measurement Systems, Bundeswehr University Munich, Werner Heisenberg Weg 39, 85579 Neubiberg, Germany
| | - Hojin Kim
- Department of Chemical & Biomolecular Engineering, Allan P. Colburn Laboratory, University of Delaware, Newark, Delaware 19716, USA
| | - Maria Secchi
- Department of Industrial Engineering, University of Trento, via Sommarive 9, I-38123 Trento, Italy
| | - Maurizio Montagna
- Dipartimento di Fisica, Universitá di Trento, via Sommarive 14, I-38123 Trento, Italy
| | - Eric M Furst
- Department of Chemical & Biomolecular Engineering, Allan P. Colburn Laboratory, University of Delaware, Newark, Delaware 19716, USA
| | - Bahram Djafari-Rouhani
- Institut d'Électronique, de Microélectronique et de Nanotechnologie (IEMN), UMRCNRS 8520, Department of Physics, University of Lille, Villeneuve d'Ascq 59655, France
| | - George Fytas
- Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz 55128, Germany
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3
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Liu S, Lv M, Li H, Wang S, Feng C, Wang X, Hu W, Wang W. Optical Imaging of the Molecular Mobility of Single Polystyrene Nanospheres. J Am Chem Soc 2022; 144:1267-1273. [PMID: 35014804 DOI: 10.1021/jacs.1c10575] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An ultrathin surface layer with extraordinary molecular mobility has been discovered and intensively investigated on thin-film polymer materials for decades. However, because of the lack of suitable characterization techniques, it remains largely unexplored whether such a surface mobile layer also exists on individual polymeric nanospheres. Here, we propose a thermal-optical imaging technique to determine the glass transition (Tg) and rubber-fluid transition (Tf) temperatures of single isolated polystyrene nanospheres (PSNS) in a high-throughput and nonintrusive manner for the first time. Two distinct steps, corresponding to the glass transition and rubber-fluid transition, respectively, were clearly observed in the optical trace of single PSNS during temperature ramping. Because the transition temperature and size of the same individuals were both determined, single nanoparticle measurements revealed the reduced apparent Tf and increased Tg of single PSNS on the gold substrate with a decreasing radius from 130 to 70 nm. Further experiments revealed that the substrate effect played an important role in the increased Tg. More importantly, a gradual decrease in the optical signal was detected prior to the glass transition, which was consistent with a surface layer with enhanced molecular mobility. Quantitative analysis further revealed the thickness of this layer to be ∼8 nm. This work not only uncovered the existence and thickness of a surface mobile layer in single isolated nanospheres but also demonstrated a general bottom-up strategy to investigate the structure-property relationship of polymeric nanomaterials by correlating the thermal property (Tg and Tf) and structural features (size) at single nanoparticle level.
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Affiliation(s)
- Shasha Liu
- State Key Laboratory of Analytical Chemistry for Life Science, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Mengqi Lv
- State Key Laboratory of Analytical Chemistry for Life Science, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Haoran Li
- State Key Laboratory of Analytical Chemistry for Life Science, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Sa Wang
- State Key Laboratory of Analytical Chemistry for Life Science, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Chengdong Feng
- State Key Lab of Coordination Chemistry, Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Xiaoliang Wang
- State Key Lab of Coordination Chemistry, Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Wenbing Hu
- State Key Lab of Coordination Chemistry, Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Wei Wang
- State Key Laboratory of Analytical Chemistry for Life Science, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
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4
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Wang J, Kang E, Sultan U, Merle B, Inayat A, Graczykowski B, Fytas G, Vogel N. Influence of Surfactant-Mediated Interparticle Contacts on the Mechanical Stability of Supraparticles. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2021; 125:23445-23456. [PMID: 34737841 PMCID: PMC8558861 DOI: 10.1021/acs.jpcc.1c06839] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 09/15/2021] [Indexed: 05/14/2023]
Abstract
Colloidal supraparticles are micron-scale spherical assemblies of uniform primary particles, which exhibit emergent properties of a colloidal crystal, yet exist as a dispersible powder. A prerequisite to utilize these emergent functionalities is that the supraparticles maintain their mechanical integrity upon the mechanical impacts that are likely to occur during processing. Understanding how the internal structure relates to the resultant mechanical properties of a supraparticle is therefore of general interest. Here, we take the example of supraparticles templated from water/fluorinated oil emulsions in droplet-based microfluidics and explore the effect of surfactants on their mechanical properties. Stable emulsions can be generated by nonionic block copolymers consisting of a hydrophilic and fluorophilic block and anionic fluorosurfactants widely available under the brand name Krytox. The supraparticles formed in the presence of both types of surfactants appear structurally similar, but differ greatly in their mechanical properties. While the nonionic surfactant induces superior mechanical stability and ductile fracture behavior, the anionic Krytox surfactant leads to weak supraparticles with brittle fracture. We complement this macroscopic picture with Brillouin light spectroscopy that is very sensitive to the interparticle contacts for subnanometer-thick adsorbed layers atop of the nanoparticle. While the anionic Krytox does not significantly affect the interparticle bonds, the amphiphilic nonionic surfactant drastically strengthens these bonds to the point that individual particle vibrations are not resolved in the experimental spectrum. Our results demonstrate that seemingly subtle changes in the physicochemical properties of supraparticles can drastically impact the resultant mechanical properties.
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Affiliation(s)
- Junwei Wang
- Institute
of Particle Technology, Friedrich-Alexander
University Erlangen-Nürnberg, Cauerstrasse 4, 91058 Erlangen, Germany
| | - Eunsoo Kang
- Max
Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Umair Sultan
- Institute
of Particle Technology, Friedrich-Alexander
University Erlangen-Nürnberg, Cauerstrasse 4, 91058 Erlangen, Germany
- Institute
of Chemical Reaction Engineering, Friedrich-Alexander
University Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen, Germany
| | - Benoit Merle
- Materials
Science and Engineering I and Interdisciplinary Center for Nanostructured
Films (IZNF), Friedrich-Alexander University
Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Alexandra Inayat
- Institute
of Chemical Reaction Engineering, Friedrich-Alexander
University Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen, Germany
| | - Bartlomiej Graczykowski
- Max
Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
- Faculty
of Physics, Adam Mickiewicz University, Uniwersytetu Poznanskiego 2, Poznan 61-614, Poland
| | - George Fytas
- Max
Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
- E-mail:
| | - Nicolas Vogel
- Institute
of Particle Technology, Friedrich-Alexander
University Erlangen-Nürnberg, Cauerstrasse 4, 91058 Erlangen, Germany
- E-mail:
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5
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Randazzo K, Bartkiewicz M, Graczykowski B, Cangialosi D, Fytas G, Zuo B, Priestley RD. Direct Visualization and Characterization of Interfacially Adsorbed Polymer atop Nanoparticles and within Nanocomposites. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c01557] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Katelyn Randazzo
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | | | - Bartlomiej Graczykowski
- Faculty of Physics, Adam Mickiewicz University, Uniwersytetu Poznanskiego 2, Poznan 61-614, Poland
| | - Daniele Cangialosi
- Centro de Física de Materiales (CSIC-UPV/EHU), Paseo Manuel de Lardizábal 5, San Sebastián 20018, Spain
- Donostia International Physics Center (DIPC), Paseo Manuel de Lardizábal 4, 20018, San Sebastián 20018, Spain
| | - George Fytas
- Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz 55128, Germany
| | - Biao Zuo
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
- Department of Chemistry, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Rodney D. Priestley
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
- Princeton Institute for the Science and Technology of Materials, Princeton University, Princeton, New Jersey 08544, United States
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6
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Monnier X, Colmenero J, Wolf M, Cangialosi D. Reaching the Ideal Glass in Polymer Spheres: Thermodynamics and Vibrational Density of States. PHYSICAL REVIEW LETTERS 2021; 126:118004. [PMID: 33798388 DOI: 10.1103/physrevlett.126.118004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 12/04/2020] [Accepted: 02/17/2021] [Indexed: 06/12/2023]
Abstract
The existence of an ideal glass and the resolution to the Kauzmann paradox is a long-standing open question in materials science. To address this problem, we exploit the ability of glasses with large interfacial area to access low energy states. We submit aggregates of spheres of a polymeric glass former to aging well below their glass transition temperature, T_{g}; and characterize their thermodynamic state by calorimetry, and the vibrational density of state (VDOS) by inelastic neutron scattering (INS). We show that, when aged at appropriate temperatures, glassy spheres attain a thermodynamic state corresponding to an ideal glass in time scales of about one day. In this state, the boson peak, underlying the deviation from the Debye level of the VDOS, is essentially suppressed. Our results are discussed in the framework of the link between the macroscopic thermodynamic state of glasses and their vibrational properties.
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Affiliation(s)
- Xavier Monnier
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
| | - Juan Colmenero
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
- Departamento de Fisica de Materiales (UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain
- Centro de Fisica de Materiales (CSIC-UPV/EHU) Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
| | - Marcel Wolf
- Heinz Maier-Leibnitz Zentrum (MLZ), Lichtenbergstrasse 1 85747, Garching, Germany
| | - Daniele Cangialosi
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
- Centro de Fisica de Materiales (CSIC-UPV/EHU) Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
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7
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Cang Y, Liu B, Das S, Xu X, Xie J, Deng X, Fytas G. Surface contacts strongly influence the elasticity and thermal conductivity of silica nanoparticle fibers. Phys Chem Chem Phys 2021; 23:3707-3715. [PMID: 33398320 DOI: 10.1039/d0cp05377e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Granular materials are often encountered in science and engineering disciplines, in which controlling the particle contacts is one of the critical issues for the design, engineering, and utilization of their desired properties. The achievable rapid fabrication of nanoparticles with tunable physical and chemical properties facilitates tailoring the macroscopic properties of particle assemblies through contacts at the nanoscale. Models have been developed to predict the mechanical properties of macroscopic granular materials; however, their predicted power in the case of nanoparticle assemblies is still uncertain. Here, we investigate the influence of nanocontacts on the elasticity and thermal conductivity of a granular fiber comprised of close-packed silica nanoparticles. A complete elastic moduli characterization was realized by non-contact and non-destructive Brillouin light spectroscopy, which also allowed resolving the stiffness of the constituent particles in situ. In the framework of effective medium models, the strong enhancement of the elastic moduli is attributed to the formation of adhesive nanocontacts with physical and/or chemical bondings. The nanoparticle contacts are also responsible for the increase in the fiber thermal conductivity that emphasizes the role of interface thermal resistance, which tends to be ignored in most porosity models. This insight into the fundamental understanding of structure-property relationships advances knowledge on the manipulation of granular systems at the nanoscale.
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Affiliation(s)
- Yu Cang
- School of Aerospace Engineering and Applied Mechanics, Tongji University, 100 Zhangwu Road, 200092, Shanghai, China and Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany.
| | - Bohai Liu
- Center for Phononics and Thermal Energy Science, School of Physical Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Sudatta Das
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany.
| | - Xiangfan Xu
- Center for Phononics and Thermal Energy Science, School of Physical Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Jingli Xie
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Xu Deng
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - George Fytas
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany.
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8
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Manoj Lalwani S, Eneh CI, Lutkenhaus JL. Emerging trends in the dynamics of polyelectrolyte complexes. Phys Chem Chem Phys 2020; 22:24157-24177. [PMID: 33094301 DOI: 10.1039/d0cp03696j] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Polyelectrolyte complexes (PECs) are highly tunable materials that result from the phase separation that occurs upon mixing oppositely charged polymers. Over the years, they have gained interest due to their broad range of applications such as drug delivery systems, protective coatings, food packaging, and surface adhesives. In this review, we summarize the structure, phase transitions, chain dynamics, and rheological and thermal properties of PECs. Although most literature focuses upon the thermodynamics and application of PECs, this review highlights the fundamental role of salt and water on mechanical and thermal properties impacting the PEC's dynamics. A special focus is placed upon experimental results and techniques. Specifically, the review examines phase behaviour and salt partitioning in PECs, as well as different techniques used to measure diffusion coefficients, relaxation times, various superpositioning principles, glass transitions, and water microenvironments in PECs. This review concludes with future areas of opportunity in fundamental studies and best practices in reporting.
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Affiliation(s)
- Suvesh Manoj Lalwani
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77840, USA.
| | - Chikaodinaka I Eneh
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77840, USA.
| | - Jodie L Lutkenhaus
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77840, USA. and Department of Materials Science and Engineering, Texas A&M University, College Station, Texas 77840, USA
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9
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Ooe M, Miyata K, Yoshioka J, Fukao K, Nemoto F, Yamada NL. Direct observation of mobility of thin polymer layers via asymmetric interdiffusion using neutron reflectivity measurements. J Chem Phys 2019; 151:244905. [PMID: 31893884 DOI: 10.1063/1.5132768] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this study, we investigated the diffusion dynamics at the interface between deuterated poly(methyl methacrylate) (d-PMMA) and protonated poly(methyl methacrylate) (h-PMMA) in two-layered thin films of d- and h-PMMA layers via neutron reflectivity (NR) measurements during isothermal annealing above the glass transition temperature Tg. When Tg of d-PMMA was higher than that of h-PMMA, the d-PMMA layer thickness increased with increasing annealing time ta and, simultaneously, the h-PMMA layer thickness decreased. However, the opposite ta dependence of the layer thicknesses was observed, if the Tg of d-PMMA was decreased by the increase in the fraction of the low-molecular weight d-PMMA: With increasing ta, the d-PMMA layer thickness decreased and the h-PMMA layer thickness increased when Tg of d-PMMA was lower than that of h-PMMA. This change in the ta dependence of the layer thickness was related to the change in the mobility of the d-PMMA layer accompanied by the change in the Tg value of d-PMMA. With the decrease in the d-PMMA layer thickness from 49 nm to 13 nm, when the h-PMMA layer thickness was maintained, the ta dependence of the layer thickness changed and the mobility of the d-PMMA layer dramatically increased. These results suggest that the mobility of thin polymer films can be determined by the observation of interfacial dynamics via NR measurements.
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Affiliation(s)
- Megumi Ooe
- Department of Physics, Ritsumeikan University, Noji-Higashi 1-1-1, Kusatsu 525-8577 Japan
| | - Kairi Miyata
- Department of Physics, Ritsumeikan University, Noji-Higashi 1-1-1, Kusatsu 525-8577 Japan
| | - Jun Yoshioka
- Department of Physics, Ritsumeikan University, Noji-Higashi 1-1-1, Kusatsu 525-8577 Japan
| | - Koji Fukao
- Department of Physics, Ritsumeikan University, Noji-Higashi 1-1-1, Kusatsu 525-8577 Japan
| | - Fumiya Nemoto
- Neutron Science Division, Institute for Materials Structure Science, High Energy Acceleration Research Organization, 203-1 Shirakata, Tokai, Naka 319-1106, Japan
| | - Norifumi L Yamada
- Neutron Science Division, Institute for Materials Structure Science, High Energy Acceleration Research Organization, 203-1 Shirakata, Tokai, Naka 319-1106, Japan
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10
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Kang E, Graczykowski B, Jonas U, Christie D, Gray LAG, Cangialosi D, Priestley RD, Fytas G. Shell Architecture Strongly Influences the Glass Transition, Surface Mobility, and Elasticity of Polymer Core-Shell Nanoparticles. Macromolecules 2019; 52:5399-5406. [PMID: 31367064 PMCID: PMC6659035 DOI: 10.1021/acs.macromol.9b00766] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 06/14/2019] [Indexed: 01/29/2023]
Abstract
Despite the growing application of nanostructured polymeric materials, there still remains a large gap in our understanding of polymer mechanics and thermal stability under confinement and near polymer-polymer interfaces. In particular, the knowledge of polymer nanoparticle thermal stability and mechanics is of great importance for their application in drug delivery, phononics, and photonics. Here, we quantified the effects of a polymer shell layer on the modulus and glass-transition temperature (T g) of polymer core-shell nanoparticles via Brillouin light spectroscopy and modulated differential scanning calorimetry, respectively. Nanoparticles consisting of a polystyrene (PS) core and shell layers of poly(n-butyl methacrylate) (PBMA) were characterized as model systems. We found that the high T g of the PS core was largely unaffected by the presence of an outer polymer shell, whereas the lower T g of the PBMA shell layer decreased with increasing PBMA thickness. The surface mobility was revealed at a temperature about 15 K lower than the T g of the PBMA shell layer. Overall, the modulus of the core-shell nanoparticles decreased with increasing PBMA shell layer thickness. These results suggest that the nanoparticle modulus and T g can be tuned independently through the control of nanoparticle composition and architecture.
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Affiliation(s)
- Eunsoo Kang
- Max
Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Bartlomiej Graczykowski
- Max
Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
- Faculty
of Physics, Adam Mickiewicz University, Umultowska 85, 61614 Poznan, Poland
| | - Ulrich Jonas
- Department
of Chemistry and Biology, University of
Siegen, Adolf-Reichwein-Strasse 2, 57076 Siegen, Germany
| | - Dane Christie
- Department
of Chemical and Biological Engineering and Princeton Institute for the Science
and Technology of Materials, Princeton University, Princeton, New Jersey 08544, United States
| | - Laura A. G. Gray
- Department
of Chemical and Biological Engineering and Princeton Institute for the Science
and Technology of Materials, Princeton University, Princeton, New Jersey 08544, United States
| | - Daniele Cangialosi
- Centro
de
Física de Materiales (CSIC-UPV/EHU), Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
- Donostia
International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
| | - Rodney D. Priestley
- Department
of Chemical and Biological Engineering and Princeton Institute for the Science
and Technology of Materials, Princeton University, Princeton, New Jersey 08544, United States
| | - George Fytas
- Max
Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
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11
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Li SJ, Qian HJ, Lu ZY. A simulation study on the glass transition behavior and relevant segmental dynamics in free-standing polymer nanocomposite films. SOFT MATTER 2019; 15:4476-4485. [PMID: 31111851 DOI: 10.1039/c9sm00267g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In polymer/nanoparticle composite (PNC) thin films, polymer chains experience strong confinement effects not only at the free surface area but also from nanoparticles (NPs). In this work, the influence of NP-polymer interaction and NP distribution on the polymer segmental dynamics and the glass transition behavior of PNC free-standing films are investigated through molecular dynamics simulations. We demonstrate that NPs will migrate to the film surface area and form an NP-concentrated layer when NP-polymer interactions are weak, while NPs are well dispersed in the bulk region when NP-polymer interactions are strong. In both cases, we find increases in the glass transition temperature Tg compared with the pure film without NPs, although with a different degree. The weakly interacting system has the same Tg as the pure bulk system without NPs. The NP layer formed at the surface area reduces both the mobility of the surface polymer beads and the mobility gradient in the film normal direction (MGFND), therefore resulting in an increase in the Tg which highlights the vital role of the mobile surface layer. In contrast, the NPs in the bulk region enlarge the MGFND. NPs have opposite influences on the polymer bead dynamic anisotropy when they interact weakly or strongly with polymers, weakened for the former and enhanced for the latter. These findings offer a clear picture of the segmental dynamics and glass transition behavior in free-standing PNC films with different NP-polymer interaction strengths. We hope these results will be helpful for the property design of related materials.
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Affiliation(s)
- Shu-Jia Li
- State Key Laboratory of Supramolecular Structure and Materials, International Joint Research Laboratory of Nano-Micro Architecture Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130021, China.
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