Characterizing the Core-Shell Architecture of Block Copolymer Nanoparticles with Electron Microscopy: A Multi-Technique Approach
Electron microscopy has proved to be a major tool to study the structure of self-assembled amphiphilic block copolymer particles. These specimens, like supramolecular biological structures, are problematic for electron microscopy because of their poor capacity to scatter electrons and their suscepti...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-07-01
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| Series: | Polymers |
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| Online Access: | https://www.mdpi.com/2073-4360/12/8/1656 |
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| author | Vitalii Tkachenko Loïc Vidal Ludovic Josien Marc Schmutz Julien Poly Abraham Chemtob |
| author_facet | Vitalii Tkachenko Loïc Vidal Ludovic Josien Marc Schmutz Julien Poly Abraham Chemtob |
| author_sort | Vitalii Tkachenko |
| collection | DOAJ |
| description | Electron microscopy has proved to be a major tool to study the structure of self-assembled amphiphilic block copolymer particles. These specimens, like supramolecular biological structures, are problematic for electron microscopy because of their poor capacity to scatter electrons and their susceptibility to radiation damage and dehydration. Sub-50 nm core-shell spherical particles made up of poly(hydroxyethyl acrylate)–<i>b</i>–poly(styrene) are prepared via polymerization-induced self-assembly (PISA). For their morphological characterization, we discuss the advantages, limitations, and artefacts of TEM with or without staining, cryo-TEM, and SEM. A number of technical points are addressed such as precisely shaping of particle boundaries, resolving the particle shell, differentiating particle core and shell, and the effect of sample drying and staining. TEM without staining and cryo-TEM largely evaluate the core diameter. Negative staining TEM is more efficient than positive staining TEM to preserve native structure and to visualize the entire particle volume. However, no technique allows for a satisfactory imaging of both core and shell regions. The presence of long protruding chains is manifested by patched structure in cryo-TEM and a significant edge effect in SEM. This manuscript provides a basis for polymer chemists to develop their own specimen preparations and to tackle the interpretation of challenging systems. |
| first_indexed | 2024-03-10T18:13:01Z |
| format | Article |
| id | doaj.art-6df06562b50a491b9d41fbab9217d039 |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-10T18:13:01Z |
| publishDate | 2020-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-6df06562b50a491b9d41fbab9217d0392023-11-20T07:57:23ZengMDPI AGPolymers2073-43602020-07-01128165610.3390/polym12081656Characterizing the Core-Shell Architecture of Block Copolymer Nanoparticles with Electron Microscopy: A Multi-Technique ApproachVitalii Tkachenko0Loïc Vidal1Ludovic Josien2Marc Schmutz3Julien Poly4Abraham Chemtob5Université de Haute-Alsace, CNRS, IS2M UMR7361, F-68100 Mulhouse, FranceUniversité de Haute-Alsace, CNRS, IS2M UMR7361, F-68100 Mulhouse, FranceUniversité de Haute-Alsace, CNRS, IS2M UMR7361, F-68100 Mulhouse, FranceUniversité de Strasbourg, CNRS, ICS UPR22, F-67034 Strasbourg, FranceUniversité de Haute-Alsace, CNRS, IS2M UMR7361, F-68100 Mulhouse, FranceUniversité de Haute-Alsace, CNRS, IS2M UMR7361, F-68100 Mulhouse, FranceElectron microscopy has proved to be a major tool to study the structure of self-assembled amphiphilic block copolymer particles. These specimens, like supramolecular biological structures, are problematic for electron microscopy because of their poor capacity to scatter electrons and their susceptibility to radiation damage and dehydration. Sub-50 nm core-shell spherical particles made up of poly(hydroxyethyl acrylate)–<i>b</i>–poly(styrene) are prepared via polymerization-induced self-assembly (PISA). For their morphological characterization, we discuss the advantages, limitations, and artefacts of TEM with or without staining, cryo-TEM, and SEM. A number of technical points are addressed such as precisely shaping of particle boundaries, resolving the particle shell, differentiating particle core and shell, and the effect of sample drying and staining. TEM without staining and cryo-TEM largely evaluate the core diameter. Negative staining TEM is more efficient than positive staining TEM to preserve native structure and to visualize the entire particle volume. However, no technique allows for a satisfactory imaging of both core and shell regions. The presence of long protruding chains is manifested by patched structure in cryo-TEM and a significant edge effect in SEM. This manuscript provides a basis for polymer chemists to develop their own specimen preparations and to tackle the interpretation of challenging systems.https://www.mdpi.com/2073-4360/12/8/1656core-shellTEMcryo-TEMSEMpositive stainingnegative staining |
| spellingShingle | Vitalii Tkachenko Loïc Vidal Ludovic Josien Marc Schmutz Julien Poly Abraham Chemtob Characterizing the Core-Shell Architecture of Block Copolymer Nanoparticles with Electron Microscopy: A Multi-Technique Approach Polymers core-shell TEM cryo-TEM SEM positive staining negative staining |
| title | Characterizing the Core-Shell Architecture of Block Copolymer Nanoparticles with Electron Microscopy: A Multi-Technique Approach |
| title_full | Characterizing the Core-Shell Architecture of Block Copolymer Nanoparticles with Electron Microscopy: A Multi-Technique Approach |
| title_fullStr | Characterizing the Core-Shell Architecture of Block Copolymer Nanoparticles with Electron Microscopy: A Multi-Technique Approach |
| title_full_unstemmed | Characterizing the Core-Shell Architecture of Block Copolymer Nanoparticles with Electron Microscopy: A Multi-Technique Approach |
| title_short | Characterizing the Core-Shell Architecture of Block Copolymer Nanoparticles with Electron Microscopy: A Multi-Technique Approach |
| title_sort | characterizing the core shell architecture of block copolymer nanoparticles with electron microscopy a multi technique approach |
| topic | core-shell TEM cryo-TEM SEM positive staining negative staining |
| url | https://www.mdpi.com/2073-4360/12/8/1656 |
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