Influence of the Graft Length on Nanocomposite Structure and Interfacial Dynamics
Both the dispersion state of nanoparticles (NPs) within polymer nanocomposites (PNCs) and the dynamical state of the polymer altered by the presence of the NP/polymer interfaces have a strong impact on the macroscopic properties of PNCs. In particular, mechanical properties are strongly affected by...
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| Format: | Article |
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MDPI AG
2023-02-01
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| Series: | Nanomaterials |
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| Online Access: | https://www.mdpi.com/2079-4991/13/4/748 |
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| author | Anne-Caroline Genix Vera Bocharova Bobby Carroll Philippe Dieudonné-George Edouard Chauveau Alexei P. Sokolov Julian Oberdisse |
| author_facet | Anne-Caroline Genix Vera Bocharova Bobby Carroll Philippe Dieudonné-George Edouard Chauveau Alexei P. Sokolov Julian Oberdisse |
| author_sort | Anne-Caroline Genix |
| collection | DOAJ |
| description | Both the dispersion state of nanoparticles (NPs) within polymer nanocomposites (PNCs) and the dynamical state of the polymer altered by the presence of the NP/polymer interfaces have a strong impact on the macroscopic properties of PNCs. In particular, mechanical properties are strongly affected by percolation of hard phases, which may be NP networks, dynamically modified polymer regions, or combinations of both. In this article, the impact on dispersion and dynamics of surface modification of the NPs by short monomethoxysilanes with eight carbons in the alkyl part (C<sub>8</sub>) is studied. As a function of grafting density and particle content, polymer dynamics is followed by broadband dielectric spectroscopy and analyzed by an interfacial layer model, whereas the particle dispersion is investigated by small-angle X-ray scattering and analyzed by reverse Monte Carlo simulations. NP dispersions are found to be destabilized only at the highest grafting. The interfacial layer formalism allows the clear identification of the volume fraction of interfacial polymer, with its characteristic time. The strongest dynamical slow-down in the polymer is found for unmodified NPs, while grafting weakens this effect progressively. The combination of all three techniques enables a unique measurement of the true thickness of the interfacial layer, which is ca. 5 nm. Finally, the comparison between longer (C<sub>18</sub>) and shorter (C<sub>8</sub>) grafts provides unprecedented insight into the efficacy and tunability of surface modification. It is shown that C<sub>8</sub>-grafting allows for a more progressive tuning, which goes beyond a pure mass effect. |
| first_indexed | 2024-03-11T08:20:12Z |
| format | Article |
| id | doaj.art-be3548ff4a0343a6ab6e138cdb4d1388 |
| institution | Directory Open Access Journal |
| issn | 2079-4991 |
| language | English |
| last_indexed | 2024-03-11T08:20:12Z |
| publishDate | 2023-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Nanomaterials |
| spelling | doaj.art-be3548ff4a0343a6ab6e138cdb4d13882023-11-16T22:28:23ZengMDPI AGNanomaterials2079-49912023-02-0113474810.3390/nano13040748Influence of the Graft Length on Nanocomposite Structure and Interfacial DynamicsAnne-Caroline Genix0Vera Bocharova1Bobby Carroll2Philippe Dieudonné-George3Edouard Chauveau4Alexei P. Sokolov5Julian Oberdisse6Laboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, F-34095 Montpellier, FranceChemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USADepartment of Physics, University of Tennessee, Knoxville, TN 37996, USALaboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, F-34095 Montpellier, FranceLaboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, F-34095 Montpellier, FranceChemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USALaboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, F-34095 Montpellier, FranceBoth the dispersion state of nanoparticles (NPs) within polymer nanocomposites (PNCs) and the dynamical state of the polymer altered by the presence of the NP/polymer interfaces have a strong impact on the macroscopic properties of PNCs. In particular, mechanical properties are strongly affected by percolation of hard phases, which may be NP networks, dynamically modified polymer regions, or combinations of both. In this article, the impact on dispersion and dynamics of surface modification of the NPs by short monomethoxysilanes with eight carbons in the alkyl part (C<sub>8</sub>) is studied. As a function of grafting density and particle content, polymer dynamics is followed by broadband dielectric spectroscopy and analyzed by an interfacial layer model, whereas the particle dispersion is investigated by small-angle X-ray scattering and analyzed by reverse Monte Carlo simulations. NP dispersions are found to be destabilized only at the highest grafting. The interfacial layer formalism allows the clear identification of the volume fraction of interfacial polymer, with its characteristic time. The strongest dynamical slow-down in the polymer is found for unmodified NPs, while grafting weakens this effect progressively. The combination of all three techniques enables a unique measurement of the true thickness of the interfacial layer, which is ca. 5 nm. Finally, the comparison between longer (C<sub>18</sub>) and shorter (C<sub>8</sub>) grafts provides unprecedented insight into the efficacy and tunability of surface modification. It is shown that C<sub>8</sub>-grafting allows for a more progressive tuning, which goes beyond a pure mass effect.https://www.mdpi.com/2079-4991/13/4/748nanoparticlessurface modificationsegmental dynamicsslow-downinterfacial polymer layerinterlayer thickness |
| spellingShingle | Anne-Caroline Genix Vera Bocharova Bobby Carroll Philippe Dieudonné-George Edouard Chauveau Alexei P. Sokolov Julian Oberdisse Influence of the Graft Length on Nanocomposite Structure and Interfacial Dynamics Nanomaterials nanoparticles surface modification segmental dynamics slow-down interfacial polymer layer interlayer thickness |
| title | Influence of the Graft Length on Nanocomposite Structure and Interfacial Dynamics |
| title_full | Influence of the Graft Length on Nanocomposite Structure and Interfacial Dynamics |
| title_fullStr | Influence of the Graft Length on Nanocomposite Structure and Interfacial Dynamics |
| title_full_unstemmed | Influence of the Graft Length on Nanocomposite Structure and Interfacial Dynamics |
| title_short | Influence of the Graft Length on Nanocomposite Structure and Interfacial Dynamics |
| title_sort | influence of the graft length on nanocomposite structure and interfacial dynamics |
| topic | nanoparticles surface modification segmental dynamics slow-down interfacial polymer layer interlayer thickness |
| url | https://www.mdpi.com/2079-4991/13/4/748 |
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