Two-step deswelling in the Volume Phase Transition of thermoresponsive microgels
Del Monte, Giovanni ; Truzzolillo, Domenico ; Camerin, Fabrizio LU
; Ninarello, Andrea
; Chauveau, Edouard
; Tavagnacco, Letizia
; Gnan, Nicoletta
; Rovigatti, Lorenzo
; Sennato, Simona
and Zaccarelli, Emanuela
(2021)
In Proceedings of the National Academy of Sciences of the United States of America
118(37).
- Abstract
Thermoresponsive microgels are one of the most investigated types of soft colloids, thanks to their ability to undergo a Volume Phase Transition (VPT) close to ambient temperature. However, this fundamental phenomenon still lacks a detailed microscopic understanding, particularly regarding the presence and the role of charges in the deswelling process. This is particularly important for the widely used poly(N-isopropylacrylamide)-based microgels, where the constituent monomers are neutral but charged groups arise due to the initiator molecules used in the synthesis. Here, we address this point combining experiments with state-of-the-art simulations to show that the microgel collapse does not happen in a homogeneous fashion, but through... (More)
Thermoresponsive microgels are one of the most investigated types of soft colloids, thanks to their ability to undergo a Volume Phase Transition (VPT) close to ambient temperature. However, this fundamental phenomenon still lacks a detailed microscopic understanding, particularly regarding the presence and the role of charges in the deswelling process. This is particularly important for the widely used poly(N-isopropylacrylamide)-based microgels, where the constituent monomers are neutral but charged groups arise due to the initiator molecules used in the synthesis. Here, we address this point combining experiments with state-of-the-art simulations to show that the microgel collapse does not happen in a homogeneous fashion, but through a two-step mechanism, entirely attributable to electrostatic effects. The signature of this phenomenon is the emergence of a minimum in the ratio between gyration and hydrodynamic radii at the VPT. Thanks to simulations of microgels with different cross-linker concentrations, charge contents, and charge distributions, we provide evidence that peripheral charges arising from the synthesis are responsible for this behavior and we further build a universal master curve able to predict the twostep deswelling. Our results have direct relevance on fundamental soft condensed matter science and on applications where microgels are involved, ranging from materials to biomedical technologies.
(Less)
- author
- Del Monte, Giovanni
; Truzzolillo, Domenico
; Camerin, Fabrizio
LU
; Ninarello, Andrea
; Chauveau, Edouard
; Tavagnacco, Letizia
; Gnan, Nicoletta
; Rovigatti, Lorenzo
; Sennato, Simona
and Zaccarelli, Emanuela
- publishing date
- 2021-09-14
- type
- Contribution to journal
- publication status
- published
- keywords
- Coarse-grained modeling, Polymer networks, Soft colloids, Volume phase transition
- in
- Proceedings of the National Academy of Sciences of the United States of America
- volume
- 118
- issue
- 37
- article number
- e2109560118
- publisher
- National Academy of Sciences
- external identifiers
-
- pmid:34508008
- scopus:85114732807
- ISSN
- 0027-8424
- DOI
- 10.1073/pnas.2109560118
- language
- English
- LU publication?
- no
- additional info
- Publisher Copyright: © 2021 National Academy of Sciences. All rights reserved.
- id
- 3625fcee-99cf-47d9-a56c-34f660e0c6f6
- date added to LUP
- 2024-02-22 14:09:37
- date last changed
- 2024-04-22 00:08:24
@article{3625fcee-99cf-47d9-a56c-34f660e0c6f6,
abstract = {{<p>Thermoresponsive microgels are one of the most investigated types of soft colloids, thanks to their ability to undergo a Volume Phase Transition (VPT) close to ambient temperature. However, this fundamental phenomenon still lacks a detailed microscopic understanding, particularly regarding the presence and the role of charges in the deswelling process. This is particularly important for the widely used poly(N-isopropylacrylamide)-based microgels, where the constituent monomers are neutral but charged groups arise due to the initiator molecules used in the synthesis. Here, we address this point combining experiments with state-of-the-art simulations to show that the microgel collapse does not happen in a homogeneous fashion, but through a two-step mechanism, entirely attributable to electrostatic effects. The signature of this phenomenon is the emergence of a minimum in the ratio between gyration and hydrodynamic radii at the VPT. Thanks to simulations of microgels with different cross-linker concentrations, charge contents, and charge distributions, we provide evidence that peripheral charges arising from the synthesis are responsible for this behavior and we further build a universal master curve able to predict the twostep deswelling. Our results have direct relevance on fundamental soft condensed matter science and on applications where microgels are involved, ranging from materials to biomedical technologies.</p>}},
author = {{Del Monte, Giovanni and Truzzolillo, Domenico and Camerin, Fabrizio and Ninarello, Andrea and Chauveau, Edouard and Tavagnacco, Letizia and Gnan, Nicoletta and Rovigatti, Lorenzo and Sennato, Simona and Zaccarelli, Emanuela}},
issn = {{0027-8424}},
keywords = {{Coarse-grained modeling; Polymer networks; Soft colloids; Volume phase transition}},
language = {{eng}},
month = {{09}},
number = {{37}},
publisher = {{National Academy of Sciences}},
series = {{Proceedings of the National Academy of Sciences of the United States of America}},
title = {{Two-step deswelling in the Volume Phase Transition of thermoresponsive microgels}},
url = {{http://dx.doi.org/10.1073/pnas.2109560118}},
doi = {{10.1073/pnas.2109560118}},
volume = {{118}},
year = {{2021}},
}