Influence of the Polymer Microstructure over the Phase Separation of Thermo-Responsive Nanoparticles
Thermo-responsive nanoparticles (NPs), i.e., colloids with a sharp and often reversible phase separation in response to thermal stimuli, are coming to the forefront due to their dynamic behavior, useful in applications ranging from biomedicine to advanced separations and smart optics. What is guidin...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-03-01
|
| Series: | Polymers |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4360/13/7/1032 |
| _version_ | 1797539954409078784 |
|---|---|
| author | Nicolò Manfredini Marco Tomasoni Mattia Sponchioni Davide Moscatelli |
| author_facet | Nicolò Manfredini Marco Tomasoni Mattia Sponchioni Davide Moscatelli |
| author_sort | Nicolò Manfredini |
| collection | DOAJ |
| description | Thermo-responsive nanoparticles (NPs), i.e., colloids with a sharp and often reversible phase separation in response to thermal stimuli, are coming to the forefront due to their dynamic behavior, useful in applications ranging from biomedicine to advanced separations and smart optics. What is guiding the macroscopic behavior of these systems above their critical temperature is mainly the microstructure of the polymer chains of which these NPs are comprised. Therefore, a comprehensive understanding of the influence of the polymer properties over the thermal response is highly required to reproducibly target a specific behavior. In this study, we synthesized thermo-responsive NPs with different size, polymeric microstructure and hydrophilic-lipophilic balance (HLB) and investigated the role of these properties over their phase separation. We first synthesized four different thermo-responsive oligomers via Reversible Addition-Fragmentation Chain Transfer (RAFT) Polymerization of poly(ethylene glycol)methyl ether methacrylate. Then, exploiting the RAFT living character, we chain-extended these oligomers with butyl methacrylate obtaining a library of NPs. Finally, we investigated the NP thermo-responsive behavior, their physical state above the cloud point (Tcp) as well as their reversibility once the stimulus is removed. We concluded that the solid content plays a minor role compared to the relative length of the two blocks forming the polymer chains. In particular, the longer the stabilizer, the more favored the formation of a gel. At the same time, the reversibility is mainly achieved at high HLB, independently from the absolute lengths of the block copolymers. |
| first_indexed | 2024-03-10T12:53:11Z |
| format | Article |
| id | doaj.art-5b553c9cc7de4393ac5b6e694366fa44 |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-10T12:53:11Z |
| publishDate | 2021-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-5b553c9cc7de4393ac5b6e694366fa442023-11-21T12:07:23ZengMDPI AGPolymers2073-43602021-03-01137103210.3390/polym13071032Influence of the Polymer Microstructure over the Phase Separation of Thermo-Responsive NanoparticlesNicolò Manfredini0Marco Tomasoni1Mattia Sponchioni2Davide Moscatelli3Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, via Mancinelli 7, 20131 Milan, ItalyDepartment of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, via Mancinelli 7, 20131 Milan, ItalyDepartment of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, via Mancinelli 7, 20131 Milan, ItalyDepartment of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, via Mancinelli 7, 20131 Milan, ItalyThermo-responsive nanoparticles (NPs), i.e., colloids with a sharp and often reversible phase separation in response to thermal stimuli, are coming to the forefront due to their dynamic behavior, useful in applications ranging from biomedicine to advanced separations and smart optics. What is guiding the macroscopic behavior of these systems above their critical temperature is mainly the microstructure of the polymer chains of which these NPs are comprised. Therefore, a comprehensive understanding of the influence of the polymer properties over the thermal response is highly required to reproducibly target a specific behavior. In this study, we synthesized thermo-responsive NPs with different size, polymeric microstructure and hydrophilic-lipophilic balance (HLB) and investigated the role of these properties over their phase separation. We first synthesized four different thermo-responsive oligomers via Reversible Addition-Fragmentation Chain Transfer (RAFT) Polymerization of poly(ethylene glycol)methyl ether methacrylate. Then, exploiting the RAFT living character, we chain-extended these oligomers with butyl methacrylate obtaining a library of NPs. Finally, we investigated the NP thermo-responsive behavior, their physical state above the cloud point (Tcp) as well as their reversibility once the stimulus is removed. We concluded that the solid content plays a minor role compared to the relative length of the two blocks forming the polymer chains. In particular, the longer the stabilizer, the more favored the formation of a gel. At the same time, the reversibility is mainly achieved at high HLB, independently from the absolute lengths of the block copolymers.https://www.mdpi.com/2073-4360/13/7/1032polymeric nanoparticlesemulsion polymerizationRAFTthermo-responsive polymerssmart materialsLCST |
| spellingShingle | Nicolò Manfredini Marco Tomasoni Mattia Sponchioni Davide Moscatelli Influence of the Polymer Microstructure over the Phase Separation of Thermo-Responsive Nanoparticles Polymers polymeric nanoparticles emulsion polymerization RAFT thermo-responsive polymers smart materials LCST |
| title | Influence of the Polymer Microstructure over the Phase Separation of Thermo-Responsive Nanoparticles |
| title_full | Influence of the Polymer Microstructure over the Phase Separation of Thermo-Responsive Nanoparticles |
| title_fullStr | Influence of the Polymer Microstructure over the Phase Separation of Thermo-Responsive Nanoparticles |
| title_full_unstemmed | Influence of the Polymer Microstructure over the Phase Separation of Thermo-Responsive Nanoparticles |
| title_short | Influence of the Polymer Microstructure over the Phase Separation of Thermo-Responsive Nanoparticles |
| title_sort | influence of the polymer microstructure over the phase separation of thermo responsive nanoparticles |
| topic | polymeric nanoparticles emulsion polymerization RAFT thermo-responsive polymers smart materials LCST |
| url | https://www.mdpi.com/2073-4360/13/7/1032 |
| work_keys_str_mv | AT nicolomanfredini influenceofthepolymermicrostructureoverthephaseseparationofthermoresponsivenanoparticles AT marcotomasoni influenceofthepolymermicrostructureoverthephaseseparationofthermoresponsivenanoparticles AT mattiasponchioni influenceofthepolymermicrostructureoverthephaseseparationofthermoresponsivenanoparticles AT davidemoscatelli influenceofthepolymermicrostructureoverthephaseseparationofthermoresponsivenanoparticles |