The hierarchical bulk molecular structure of poly(acrylamide) hydrogels: beyond the fishing net
| Autor: | Fabrice Roncoroni, Nicholas D. Spencer, Antoni Sánchez-Ferrer, Yvonne Gombert |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
chemistry.chemical_classification
Materials science Scanning electron microscope Context (language use) 02 engineering and technology General Chemistry Polymer 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences ddc 0104 chemical sciences chemistry.chemical_compound Monomer chemistry Chemical engineering Polymerization Agglomerate Self-healing hydrogels Molecule 0210 nano-technology |
| Zdroj: | Soft Matter, 16 (42) Soft Matter |
| ISSN: | 1744-683X 1744-6848 |
| Popis: | The polymeric structure of hydrogels is commonly presented in the literature as resembling a fishing net. However, this simple view cannot fully capture all the unique properties of these materials. Crucial for a detailed description of the bulk structure in free-radical polymerized vinylic hydrogels is a thorough understanding of the cross-linker distribution. This work focuses on the precise role of the tetra-functional cross-linker in the hydrogel system: acrylamide-N,N′-methylenebis(acrylamide). Clusters of crosslinker smaller than 4 nm and their agglomerates, as well as polymer domains with sizes from the 100 nm to the μm-range, have been identified by means of both X-ray and visible-light scattering. Placed in the context of the extensive literature on this system, these observations demonstrate the heterogeneous organisation of the polymer within the hydrogel network structure, and can be accounted for by the different polymerization behavior of the monomer and crosslinker. Together with polymer-network chain-length approximations based on swelling experiments and structural observations with scanning electron microscopy, these results indicate a hierarchical structure of the polymer network surrounding pockets of water. Soft Matter, 16 (42) ISSN:1744-683X ISSN:1744-6848 |
| Databáze: | OpenAIRE |
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