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Nigro V, Angelini R, Buratti E, Colantonio C, D’Amato R, Dinelli F, Franco S, Limosani F, Montereali RM, Nichelatti E, Piccinini M, Vincenti MA, Ruzicka B. Influence of a Solid Surface on PNIPAM Microgel Films. Gels 2024; 10:473. [PMID: 39057496 PMCID: PMC11276228 DOI: 10.3390/gels10070473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2024] [Revised: 07/09/2024] [Accepted: 07/14/2024] [Indexed: 07/28/2024] Open
Abstract
Stimuli-responsive microgels have attracted great interest in recent years as building blocks for fabricating smart surfaces with many technological applications. In particular, PNIPAM microgels are promising candidates for creating thermo-responsive scaffolds to control cell growth and detachment via temperature stimuli. In this framework, understanding the influence of the solid substrate is critical for tailoring microgel coatings to specific applications. The surface modification of the substrate is a winning strategy used to manage microgel-substrate interactions. To control the spreading of microgel particles on a solid surface, glass substrates are coated with a PEI or an APTES layer to improve surface hydrophobicity and add positive charges on the interface. A systematic investigation of PNIPAM microgels spin-coated through a double-step deposition protocol on pristine glass and on functionalised glasses was performed by combining wettability measurements and Atomic Force Microscopy. The greater flattening of microgel particles on less hydrophilic substrates can be explained as a consequence of the reduced shielding of the water-substrate interactions that favors electrostatic interactions between microgels and the substrate. This approach allows the yielding of effective control on microgel coatings that will help to unlock new possibilities for their application in biomedical devices, sensors, or responsive surfaces.
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Affiliation(s)
- Valentina Nigro
- ENEA C.R. Frascati, Nuclear Department, Via Enrico Fermi 45, 00044 Frascati, Italy
- Institute for Complex Systems, National Research Council (ISC-CNR), Sapienza University of Rome, P.le A. Moro 2, 00185 Rome, Italy
| | - Roberta Angelini
- Institute for Complex Systems, National Research Council (ISC-CNR), Sapienza University of Rome, P.le A. Moro 2, 00185 Rome, Italy
- Physics Department, Sapienza University, P.le Aldo Moro 2, 00185 Rome, Italy
| | - Elena Buratti
- Institute for Complex Systems, National Research Council (ISC-CNR), Sapienza University of Rome, P.le A. Moro 2, 00185 Rome, Italy
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, Via Luigi Borsari 46, 14412 Ferrara, Italy
| | - Claudia Colantonio
- Institute for Complex Systems, National Research Council (ISC-CNR), Sapienza University of Rome, P.le A. Moro 2, 00185 Rome, Italy
| | - Rosaria D’Amato
- ENEA C.R. Frascati, Nuclear Department, Via Enrico Fermi 45, 00044 Frascati, Italy
| | - Franco Dinelli
- National Institute of Optics (INO-CNR), Via Moruzzi 1, 56124 Pisa, Italy
| | - Silvia Franco
- Institute for Complex Systems, National Research Council (ISC-CNR), Sapienza University of Rome, P.le A. Moro 2, 00185 Rome, Italy
- Physics Department, Sapienza University, P.le Aldo Moro 2, 00185 Rome, Italy
| | - Francesca Limosani
- ENEA C.R. Casaccia, Nuclear Department, Via Anguillarese, 301, 00123 Rome, Italy
| | | | - Enrico Nichelatti
- ENEA C.R. Casaccia, Nuclear Department, Via Anguillarese, 301, 00123 Rome, Italy
| | - Massimo Piccinini
- ENEA C.R. Frascati, Nuclear Department, Via Enrico Fermi 45, 00044 Frascati, Italy
| | | | - Barbara Ruzicka
- Institute for Complex Systems, National Research Council (ISC-CNR), Sapienza University of Rome, P.le A. Moro 2, 00185 Rome, Italy
- Physics Department, Sapienza University, P.le Aldo Moro 2, 00185 Rome, Italy
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Komarova GA, Kozhunova EY, Potemkin II. Behavior of PNIPAM Microgels in Different Organic Solvents. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27238549. [PMID: 36500646 PMCID: PMC9737493 DOI: 10.3390/molecules27238549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/29/2022] [Accepted: 11/30/2022] [Indexed: 12/07/2022]
Abstract
In this research, we studied, in detail, the behavior of common PNIPAM microgels, obtained through surfactant-free precipitation polymerization, in a number of organic solvents. We showed that many of the selected solvents serve as good solvents for the PNIPAM microgels and that the size and architecture of the microgels depend on the solvent chosen. Expanding the range of solvents used for PNIPAM microgel incubation greatly enhances the possible routes for microparticle functionalization and modification, as well as the encapsulation of water-insoluble species. In this demonstration, we successfully encapsulated water-insoluble Sudan III dye in PNIPAM microgels and prepared the aqueous dispersions of such composite-colored microparticles.
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Affiliation(s)
- Galina A. Komarova
- Physics Department, Lomonosov Moscow State University, Leninskie Gory 1-2, Moscow 119991, Russia
| | - Elena Yu. Kozhunova
- Physics Department, Lomonosov Moscow State University, Leninskie Gory 1-2, Moscow 119991, Russia
- A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova St. 28, Moscow 119991, Russia
- Correspondence: (E.Yu.K.); (I.I.P.)
| | - Igor I. Potemkin
- Physics Department, Lomonosov Moscow State University, Leninskie Gory 1-2, Moscow 119991, Russia
- A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova St. 28, Moscow 119991, Russia
- Correspondence: (E.Yu.K.); (I.I.P.)
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3
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Buratti E, Tavagnacco L, Zanatta M, Chiessi E, Buoso S, Franco S, Ruzicka B, Angelini R, Orecchini A, Bertoldo M, Zaccarelli E. The role of polymer structure on water confinement in poly(N-isopropylacrylamide) dispersions. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118924] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Thermal Behaviour of Microgels Composed of Interpenetrating Polymer Networks of Poly( N-isopropylacrylamide) and Poly(acrylic acid): A Calorimetric Study. Polymers (Basel) 2021; 14:polym14010115. [PMID: 35012137 PMCID: PMC8747536 DOI: 10.3390/polym14010115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 12/23/2021] [Accepted: 12/26/2021] [Indexed: 12/17/2022] Open
Abstract
Stimuli-responsive microgels have recently attracted great attention in fundamental research as their soft particles can be deformed and compressed at high packing fractions resulting in singular phase behaviours. Moreover, they are also well suited for a wide variety of applications such as drug delivery, tissue engineering, organ-on-chip devices, microlenses fabrication and cultural heritage. Here, thermoresponsive and pH-sensitive cross-linked microgels, composed of interpenetrating polymer networks of poly(N-isopropylacrylamide) (PNIPAM) and poly(acrylic acid) (PAAc), are synthesized by a precipitation polymerization method in water and investigated through differential scanning calorimetry in a temperature range across the volume phase transition temperature of PNIPAM microgels. The phase behaviour is studied as a function of heating/cooling rate, concentration, pH and PAAc content. At low concentrations and PAAc contents, the network interpenetration does not affect the transition temperature typical of PNIPAM microgel in agreement with previous studies; on the contrary, we show that it induces a marked decrease at higher concentrations. DSC analysis also reveals an increase of the overall calorimetric enthalpy with increasing concentration and a decrease with increasing PAAc content. These findings are discussed and explained as related to emerging aggregation processes that can be finely controlled by properly changing concentration, PAAc content an pH. A deep analysis of the thermodynamic parameters allows to draw a temperature–concentration state diagram in the investigated concentration range.
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Li Q, Peng X, Chen D, McKenna GB. Softness mapping of the concentration dependence of the dynamics in model soft colloidal systems. J Colloid Interface Sci 2021; 605:398-409. [PMID: 34332413 DOI: 10.1016/j.jcis.2021.07.089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 07/06/2021] [Accepted: 07/16/2021] [Indexed: 11/28/2022]
Abstract
The dynamics of a series of soft colloids comprised of polystyrene cores with poly(N-isopropylacrylamide) (PNIPAM) coronas was investigated by diffusing wave spectroscopy (DWS). The modulus of the coronas was varied by changing the cross-link density and we were able to interpret the results within a hard-soft mapping framework. The soft, swellable particle properties were modeled using an extended Flory-Rehner theory and a Hertzian pair potential. Following volume fraction jumps, softness effects on the concentration dependence of dynamics were determined, with a 'soft colloids make strong glass-forming liquid'-type of behavior observed close to the nominal glass transition volume fraction, φg. Such behavior from the current systems cannot be fully explained by the osmotic deswelling model alone. However, inspired by the soft-hard mapping from Schmiedeberg et al, [Europhys. Lett. 2011, 96(3), 36010] we estimated effective hard-sphere diameters and achieved a successful mapping of the α-relaxation times to a master curve below φg. Above φg, the curves no longer collapse but show strong deviations from a Vogel-Fulcher type of divergence onto soft jamming plateaux. Our results provide evidence that osmotic deswelling itself cannot fully explain the observed dynamics. Softness also plays an important role in the dynamics of soft, concentrated colloids.
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Affiliation(s)
- Qi Li
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409, United States
| | - Xiaoguang Peng
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409, United States
| | - Dongjie Chen
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409, United States
| | - Gregory B McKenna
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409, United States.
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From Femtoseconds to Hours—Measuring Dynamics over 18 Orders of Magnitude with Coherent X-rays. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11136179] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
X-ray photon correlation spectroscopy (XPCS) enables the study of sample dynamics between micrometer and atomic length scales. As a coherent scattering technique, it benefits from the increased brilliance of the next-generation synchrotron radiation and Free-Electron Laser (FEL) sources. In this article, we will introduce the XPCS concepts and review the latest developments of XPCS with special attention on the extension of accessible time scales to sub-μs and the application of XPCS at FELs. Furthermore, we will discuss future opportunities of XPCS and the related technique X-ray speckle visibility spectroscopy (XSVS) at new X-ray sources. Due to its particular signal-to-noise ratio, the time scales accessible by XPCS scale with the square of the coherent flux, allowing to dramatically extend its applications. This will soon enable studies over more than 18 orders of magnitude in time by XPCS and XSVS.
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Drozdov AD, deClaville Christiansen J. Equilibrium swelling of thermo‐responsive core‐shell microgels. J Appl Polym Sci 2021. [DOI: 10.1002/app.50354] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Aleksey D. Drozdov
- Department of Materials and Production Aalborg University Aalborg Denmark
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Abstract
Abstract
The review presents current research results for Carbopol-based microgels as yield-stress materials, covering three aspects: chemical, physical and rheological. Such a joint three-aspect study has no analog in the literature. The chemical aspects of Carbopol polymers are presented in terms of a cross-linking polymerization of acrylic acid, their molecular structure, microgel formulation, polyacid dissociation and neutralization, osmotic pressure and associated immense microgel swelling. The physical characterization is focused on models of the shear-induced solid-to-liquid transition of microgels, which are formed of mesoscopic particles typical for soft matter materials. Models that describe interparticle effects are presented to explain the energy states of microgel particles at the mesoscale of scrutiny. Typical representatives of the models utilize attributes of jamming dispersions, micromechanical and polyelectrolyte reactions. Selected relationships that result from the models, such as scaling rules and nondimensional flow characteristics are also presented. The rheological part presents the discussion of problems of yield stress in 2D and 3D deformations, appearance and magnitude of the wall slip. The theory and characteristics of Carbopol microgel deformation in rotational rheometers are presented with graphs for the steady-state measurements, stress-controlled oscillation and two types of transient shear deformation. The review is concluded with suggestions for future research.
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Affiliation(s)
- Zdzisław Jaworski
- Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology , Aleja Piastow 42 , 71-065 , Szczecin , Poland
| | - Tadeusz Spychaj
- Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology , Aleja Piastow 42 , 71-065 , Szczecin , Poland
| | - Anna Story
- Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology , Aleja Piastow 42 , 71-065 , Szczecin , Poland
| | - Grzegorz Story
- Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology , Aleja Piastow 42 , 71-065 , Szczecin , Poland
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Franco S, Buratti E, Ruzicka B, Nigro V, Zoratto N, Matricardi P, Zaccarelli E, Angelini R. Volume fraction determination of microgel composed of interpenetrating polymer networks of PNIPAM and polyacrylic acid. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:174004. [PMID: 33524963 DOI: 10.1088/1361-648x/abe1ec] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 02/01/2021] [Indexed: 06/12/2023]
Abstract
Interpenetrated polymer network microgels, composed of crosslinked networks of poly(N-isopropylacrylamide) and polyacrylic acid (PAAc), have been investigated through rheological measurements at four different amounts of PAAc. Both PAAc content and crosslinking degree modify particle dimensions, mass and softness, thereby strongly affecting the volume fraction and the system viscosity. Here the volume fraction is derived from the flow curves at low concentrations by fitting the zero-shear viscosity with the Einstein-Batchelor equation which provides a parameterkto shift weight concentration to volume fraction. We find that particles with higher PAAc content and crosslinker are characterized by a greater value ofkand therefore by larger volume fractions when compared to softer particles. The packing fractions obtained from rheological measurements are compared with those from static light scattering for two PAAc contents revealing a good agreement. Moreover, the behaviour of the viscosity as a function of packing fraction, at room temperature, has highlighted an Arrhenius dependence for microgels synthesized with low PAAc content and a Vogel-Fulcher-Tammann dependence for the highest investigated PAAc concentration. A comparison with the hard spheres behaviour indicates a steepest increase of the viscosity with decreasing particles softness. Finally, the volume fraction dependence of the viscosity at a fixed PAAc and at two different temperatures, below and above the volume phase transition, shows a quantitative agreement with the structural relaxation time measured through dynamic light scattering indicating that interpenetrated polymer network microgels softness can be tuned with PAAc and temperature and that, depending on particle softness, two different routes are followed.
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Affiliation(s)
- S Franco
- Dipartimento di Scienze di Base e Applicate per l'Ingegneria (SBAI), Sapienza Università di Roma, 00185 Roma, Italy
- Instituto dei Sistemi Complessi del Consiglio Nazionale delle Ricerche (ISC-CNR), Sede Sapienza, 00185 Roma, Italy
| | - E Buratti
- Instituto dei Sistemi Complessi del Consiglio Nazionale delle Ricerche (ISC-CNR), Sede Sapienza, 00185 Roma, Italy
| | - B Ruzicka
- Instituto dei Sistemi Complessi del Consiglio Nazionale delle Ricerche (ISC-CNR), Sede Sapienza, 00185 Roma, Italy
- Dipartimento di Fisica, Sapienza Università di Roma, 00185 Roma, Italy
| | - V Nigro
- ENEA Centro Ricerche Frascati, Via Enrico Fermi, 45, 00044 Frascati, Italy
| | - N Zoratto
- Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, 00185 Roma, Italy
| | - P Matricardi
- Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, 00185 Roma, Italy
| | - E Zaccarelli
- Instituto dei Sistemi Complessi del Consiglio Nazionale delle Ricerche (ISC-CNR), Sede Sapienza, 00185 Roma, Italy
- Dipartimento di Fisica, Sapienza Università di Roma, 00185 Roma, Italy
| | - R Angelini
- Instituto dei Sistemi Complessi del Consiglio Nazionale delle Ricerche (ISC-CNR), Sede Sapienza, 00185 Roma, Italy
- Dipartimento di Fisica, Sapienza Università di Roma, 00185 Roma, Italy
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Nigro V, Angelini R, Bertoldo M, Buratti E, Franco S, Ruzicka B. Chemical-Physical Behaviour of Microgels Made of Interpenetrating Polymer Networks of PNIPAM and Poly(acrylic Acid). Polymers (Basel) 2021; 13:polym13091353. [PMID: 33919087 PMCID: PMC8122350 DOI: 10.3390/polym13091353] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 04/01/2021] [Accepted: 04/13/2021] [Indexed: 01/06/2023] Open
Abstract
Microgels composed of stimuli responsive polymers have attracted worthwhile interest as model colloids for theorethical and experimental studies and for nanotechnological applications. A deep knowledge of their behaviour is fundamental for the design of new materials. Here we report the current understanding of a dual responsive microgel composed of poly(N-isopropylacrylamide) (PNIPAM), a temperature sensitive polymer, and poly(acrylic acid) (PAAc), a pH sensitive polymer, at different temperatures, PAAc contents, concentrations, solvents and pH. The combination of multiple techniques as Dynamic Light Scattering (DLS), Raman spectroscopy, Small Angle Neutron Scattering (SANS), rheology and electrophoretic measurements allow to investigate the hydrodynamic radius behaviour across the typical Volume Phase Transition (VPT), the involved molecular mechanism and the internal particle structure together with the viscoelastic properties and the role of ionic charge in the aggregation phenomena.
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Affiliation(s)
- Valentina Nigro
- Istituto dei Sistemi Complessi del Consiglio Nazionale delle Ricerche (ISC-CNR), Sede Sapienza, 00185 Roma, Italy; (V.N.); (E.B.)
| | - Roberta Angelini
- Istituto dei Sistemi Complessi del Consiglio Nazionale delle Ricerche (ISC-CNR), Sede Sapienza, 00185 Roma, Italy; (V.N.); (E.B.)
- Dipartimento di Fisica, Sapienza Università, 00185 Rome, Italy
- Correspondence: (R.A.); (B.R.)
| | - Monica Bertoldo
- Dipartimento di Scienze Chimiche, Farmaceutiche ed Agrarie, Università degli Studi di Ferrara, 45121 Ferrara, Italy;
| | - Elena Buratti
- Istituto dei Sistemi Complessi del Consiglio Nazionale delle Ricerche (ISC-CNR), Sede Sapienza, 00185 Roma, Italy; (V.N.); (E.B.)
| | - Silvia Franco
- Dipartimento di Scienze di Base e Applicate per l’Ingegneria (SBAI), Sapienza Università, 00185 Rome, Italy;
| | - Barbara Ruzicka
- Istituto dei Sistemi Complessi del Consiglio Nazionale delle Ricerche (ISC-CNR), Sede Sapienza, 00185 Roma, Italy; (V.N.); (E.B.)
- Dipartimento di Fisica, Sapienza Università, 00185 Rome, Italy
- Correspondence: (R.A.); (B.R.)
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11
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Nigro V, Angelini R, King S, Franco S, Buratti E, Bomboi F, Mahmoudi N, Corvasce F, Scaccia R, Church A, Charleston T, Ruzicka B. Apparatus for simultaneous dynamic light scattering-small angle neutron scattering investigations of dynamics and structure in soft matter. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:023907. [PMID: 33648116 DOI: 10.1063/5.0035529] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 01/14/2021] [Indexed: 06/12/2023]
Abstract
Dynamic Light Scattering (DLS) and Small-Angle Neutron Scattering (SANS) are two key tools to probe the dynamic and static structure factors, respectively, in soft matter. Usually, DLS and SANS measurements are performed separately, in different laboratories, on different samples, and at different times. However, this methodology has particular disadvantages for a large variety of soft materials, which exhibit a high sensitivity to small changes in fundamental parameters, such as waiting times, concentration, pH, and ionic strength. Here, we report on a new portable DLS-SANS apparatus that allows one to simultaneously measure both the microscopic dynamics (through DLS) and the static structure (through SANS) on the same sample. The apparatus has been constructed as a collaboration between two laboratories, each an expert in one of the scattering methods, and was commissioned on the LOQ and ZOOM SANS instruments at the ISIS Pulsed Neutron and Muon Source, U.K.
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Affiliation(s)
- V Nigro
- Institute for Complex Systems, National Research Council (CNR-ISC), Sapienza University of Rome, Pz.le A. Moro 2, 00185 Rome, Italy
| | - R Angelini
- Institute for Complex Systems, National Research Council (CNR-ISC), Sapienza University of Rome, Pz.le A. Moro 2, 00185 Rome, Italy
| | - S King
- ISIS Pulsed Neutron and Muon Source, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxon OX11 0QX, United Kingdom
| | - S Franco
- Dipartimento di Scienze di Base e Applicate per l'Ingegneria (SBAI), Sapienza University of Rome, 00185 Rome, Italy
| | - E Buratti
- Institute for Complex Systems, National Research Council (CNR-ISC), Sapienza University of Rome, Pz.le A. Moro 2, 00185 Rome, Italy
| | - F Bomboi
- Institute for Complex Systems, National Research Council (CNR-ISC), Sapienza University of Rome, Pz.le A. Moro 2, 00185 Rome, Italy
| | - N Mahmoudi
- ISIS Pulsed Neutron and Muon Source, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxon OX11 0QX, United Kingdom
| | - F Corvasce
- Institute for Complex Systems, National Research Council (CNR-ISC), Sapienza University of Rome, Pz.le A. Moro 2, 00185 Rome, Italy
| | - R Scaccia
- Institute for Complex Systems, National Research Council (CNR-ISC), Sapienza University of Rome, Pz.le A. Moro 2, 00185 Rome, Italy
| | - A Church
- ISIS Pulsed Neutron and Muon Source, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxon OX11 0QX, United Kingdom
| | - T Charleston
- ISIS Pulsed Neutron and Muon Source, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxon OX11 0QX, United Kingdom
| | - B Ruzicka
- Institute for Complex Systems, National Research Council (CNR-ISC), Sapienza University of Rome, Pz.le A. Moro 2, 00185 Rome, Italy
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Drozdov AD, Christiansen JD. Modulation of the volume phase transition temperature of thermo-responsive gels. J Mech Behav Biomed Mater 2020; 114:104215. [PMID: 33234497 DOI: 10.1016/j.jmbbm.2020.104215] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 10/26/2020] [Accepted: 11/15/2020] [Indexed: 12/13/2022]
Abstract
Thermo-responsive (TR) gels swell substantially below their volume phase transition temperature Tc and shrink above this temperature. Applications of TR gels in controlled drug delivery and their use as biosensors and temperature-triggered soft actuators require fine tuning of Tc. As the critical temperature is independent of the preparation conditions and molar fractions of monomers and cross-linkers, it is modulated by incorporation of (neutral or ionic) monomers and polymer chains into pre-gel solutions for TR gels. A model is developed for the mechanical response and equilibrium swelling of TR gels. Analytical formulas are derived for the effect of molar fraction of comonomers on the volume phase transition temperature Tc in copolymer gels and gels with semi-interpenetrating networks. Adjustable parameters are found by fitting equilibrium swelling diagrams on poly(N,N-diethylacrylamide) gels. Good agreement is demonstrated between predictions of the model and experimental data.
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Affiliation(s)
- A D Drozdov
- Department of Materials and Production, Aalborg University, Fibigerstraede 16, Aalborg 9220, Denmark.
| | - J deClaville Christiansen
- Department of Materials and Production, Aalborg University, Fibigerstraede 16, Aalborg 9220, Denmark
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13
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Franco MKKD, Sepulveda AF, Vigato AA, Oshiro A, Machado IP, Kent B, Clemens D, Yokaichiya F, Araujo DR. Supramolecular Structure of Temperature‐Dependent Polymeric Hydrogels Modulated by Drug Incorporation. ChemistrySelect 2020. [DOI: 10.1002/slct.202001116] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
| | - Anderson F. Sepulveda
- Human and Natural Sciences Center Federal University of ABC Santo André, SP Brazil
- Drugs and Bioactives Delivery Systems Research Group – SISLIBIO Federal University of ABC. Av. dos Estados 5001. Bl. A, T3, Lab. 503-3. Bangú. Santo André-SP Brazil
| | - Aryane A. Vigato
- Human and Natural Sciences Center Federal University of ABC Santo André, SP Brazil
- Drugs and Bioactives Delivery Systems Research Group – SISLIBIO Federal University of ABC. Av. dos Estados 5001. Bl. A, T3, Lab. 503-3. Bangú. Santo André-SP Brazil
| | - Alisson Oshiro
- Human and Natural Sciences Center Federal University of ABC Santo André, SP Brazil
| | - Ian Pompermayer Machado
- Department of Fundamental Chemistry Institute of Chemistry University of São Paulo São Paulo SP Brazil
| | - Ben Kent
- Institute for Soft Matter and Functional Materials Helmholtz-Zentrum Berlin für Materialien Berlin Germany
- School of Chemistry University of New South Wales. Kensington Australia
| | - Daniel Clemens
- Institute for Soft Matter and Functional Materials Helmholtz-Zentrum Berlin für Materialien Berlin Germany
| | - Fabiano Yokaichiya
- Institute for Soft Matter and Functional Materials Helmholtz-Zentrum Berlin für Materialien Berlin Germany
| | - Daniele Ribeiro Araujo
- Human and Natural Sciences Center Federal University of ABC Santo André, SP Brazil
- Drugs and Bioactives Delivery Systems Research Group – SISLIBIO Federal University of ABC. Av. dos Estados 5001. Bl. A, T3, Lab. 503-3. Bangú. Santo André-SP Brazil
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14
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Drozdov AD, deClaville Christiansen J. Mechanical response and equilibrium swelling of thermoresponsive copolymer hydrogels. POLYM INT 2020. [DOI: 10.1002/pi.6051] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Aleksey D Drozdov
- Department of Materials and Production Aalborg University Aalborg Denmark
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Nigro V, Ruzicka B, Ruta B, Zontone F, Bertoldo M, Buratti E, Angelini R. Relaxation Dynamics, Softness, and Fragility of Microgels with Interpenetrated Polymer Networks. Macromolecules 2020. [DOI: 10.1021/acs.macromol.9b01560] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Valentina Nigro
- Istituto dei Sistemi Complessi del Consiglio Nazionale delle Ricerche (ISC-CNR), sede Sapienza, Pz.le Aldo Moro 5, I-00185 Roma, Italy
- Dipartimento di Fisica, Sapienza Università di Roma, I-00185 Roma, Italy
| | - Barbara Ruzicka
- Istituto dei Sistemi Complessi del Consiglio Nazionale delle Ricerche (ISC-CNR), sede Sapienza, Pz.le Aldo Moro 5, I-00185 Roma, Italy
- Dipartimento di Fisica, Sapienza Università di Roma, I-00185 Roma, Italy
| | - Beatrice Ruta
- France Univ Lyon, Universitè Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, 69100 Villeurbanne, France
- ESRF The European Synchrotron, CS40220, 38043 Grenoble Cedex 9, France
| | - Federico Zontone
- ESRF The European Synchrotron, CS40220, 38043 Grenoble Cedex 9, France
| | - Monica Bertoldo
- Istituto per la Sintesi Organica e la Fotoreattività del Consiglio Nazionale delle Ricerche (ISOF-CNR), via P. Gobetti
101, 40129 Bologna, Italy
| | - Elena Buratti
- Istituto dei Sistemi Complessi del Consiglio Nazionale delle Ricerche (ISC-CNR), sede Sapienza, Pz.le Aldo Moro 5, I-00185 Roma, Italy
| | - Roberta Angelini
- Istituto dei Sistemi Complessi del Consiglio Nazionale delle Ricerche (ISC-CNR), sede Sapienza, Pz.le Aldo Moro 5, I-00185 Roma, Italy
- Dipartimento di Fisica, Sapienza Università di Roma, I-00185 Roma, Italy
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Sbeih S, Mohanty PS, Morrow MR, Yethiraj A. Structural parameters of soft PNIPAM microgel particles as a function of crosslink density. J Colloid Interface Sci 2019; 552:781-793. [DOI: 10.1016/j.jcis.2019.05.047] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 05/14/2019] [Accepted: 05/15/2019] [Indexed: 10/26/2022]
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Nigro V, Ripanti F, Angelini R, Sarra A, Bertoldo M, Buratti E, Postorino P, Ruzicka B. Molecular mechanisms driving the microgels behaviour: A Raman spectroscopy and dynamic light scattering study. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.04.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Nigro V, Angelini R, Rosi B, Bertoldo M, Buratti E, Casciardi S, Sennato S, Ruzicka B. Study of network composition in interpenetrating polymer networks of poly(N isopropylacrylamide) microgels: The role of poly(acrylic acid). J Colloid Interface Sci 2019; 545:210-219. [PMID: 30889412 DOI: 10.1016/j.jcis.2019.03.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 03/01/2019] [Accepted: 03/02/2019] [Indexed: 12/20/2022]
Abstract
HYPOTHESIS The peculiar swelling behaviour of poly(N-isopropylacrylamide) (PNIPAM)4-based responsive microgels provides the possibility to tune both softness and volume fraction with temperature, making these systems of great interest for technological applications and theoretical implications. Their intriguing phase diagram can be even more complex if poly(acrylic acid) (PAAc)5 is interpenetrated within PNIPAM network to form Interpenetrating Polymer Network (IPN)6 microgels that exhibit an additional pH-sensitivity. The effect of the PAAc/PNIPAM polymeric ratio on both swelling capability and dynamics is still matter of investigation. EXPERIMENTS Here we investigate the role of PAAc in the behaviour of IPN microgels across the volume phase transition through dynamic light scattering (DLS),7 transmission electron microscopy (TEM)8 and electrophoretic measurements as a function of microgel concentration and pH. FINDINGS Our results highlight that aggregation is favored at increasing weight concentration, PAAc content and pH and that a crossover PAAc content CPAAc∗9 exists above which the ionic charges on the microgel become relevant. Moreover we show that the softness of IPN microgels can be tuned ad hoc by changing the PAAc/PNIPAM ratio. These findings provide new insights into the possibility to control experimentally aggregation properties, charge and softness of IPN microgels by varying PAAc content.
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Affiliation(s)
- Valentina Nigro
- Istituto dei Sistemi Complessi del Consiglio Nazionale delle Ricerche (ISC-CNR), sede Sapienza, Pz.le Aldo Moro 5, I-00185 Roma, Italy; Dipartimento di Fisica, Sapienza Università di Roma, P.le Aldo Moro 5, 00185 Roma, Italy.
| | - Roberta Angelini
- Istituto dei Sistemi Complessi del Consiglio Nazionale delle Ricerche (ISC-CNR), sede Sapienza, Pz.le Aldo Moro 5, I-00185 Roma, Italy; Dipartimento di Fisica, Sapienza Università di Roma, P.le Aldo Moro 5, 00185 Roma, Italy.
| | - Benedetta Rosi
- Dipartimento di Fisica, Sapienza Università di Roma, P.le Aldo Moro 5, 00185 Roma, Italy
| | - Monica Bertoldo
- Istituto per i Processi Chimico-Fisici del Consiglio Nazionale delle Ricerche (IPCF-CNR), Area della Ricerca, Via G.Moruzzi 1, I-56124 Pisa, Italy
| | - Elena Buratti
- Istituto per i Processi Chimico-Fisici del Consiglio Nazionale delle Ricerche (IPCF-CNR), Area della Ricerca, Via G.Moruzzi 1, I-56124 Pisa, Italy
| | - Stefano Casciardi
- Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, National Institution for Insurance Against Accidents at Work (INAIL Research), Via Fontana Candida 1, Monte Porzio Catone, 00040 Rome, Italy
| | - Simona Sennato
- Istituto dei Sistemi Complessi del Consiglio Nazionale delle Ricerche (ISC-CNR), sede Sapienza, Pz.le Aldo Moro 5, I-00185 Roma, Italy; Dipartimento di Fisica, Sapienza Università di Roma, P.le Aldo Moro 5, 00185 Roma, Italy
| | - Barbara Ruzicka
- Istituto dei Sistemi Complessi del Consiglio Nazionale delle Ricerche (ISC-CNR), sede Sapienza, Pz.le Aldo Moro 5, I-00185 Roma, Italy; Dipartimento di Fisica, Sapienza Università di Roma, P.le Aldo Moro 5, 00185 Roma, Italy.
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Emulsions stabilized by pH-responsive PNIPAM-based microgels: Effect of spatial distribution of functional carboxylic groups on the emulsion stability. J Taiwan Inst Chem Eng 2018. [DOI: 10.1016/j.jtice.2018.01.041] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Lopez CG, Richtering W. Does Flory-Rehner theory quantitatively describe the swelling of thermoresponsive microgels? SOFT MATTER 2017; 13:8271-8280. [PMID: 29071323 DOI: 10.1039/c7sm01274h] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The swelling of thermoresponsive microgels is widely modelled through Flory-Rehner theory, which combines Flory-Huggins solution thermodynamics with the affine network model of elasticity. While it has been shown that FR theory closely follows experimental results for a range of systems, the large number of free parameters required to fit size vs. temperature data make a proper evaluation of the theory difficult. In order to test the applicability of FR theory to microgel particles, we analyse viscosity and light scattering data for PNIPAM microgels as a function of temperature, cross-linking degree (f) and molar mass. In the collapsed state, the polymer volume fraction is estimated to be ϕC ≃ 0.44, independent of cross linking degree and molar mass. Fixing ϕC, f and the θ temperature to independent estimates, the FR model appears to describe microgel swelling well, particularly for high cross-linking densities. Estimates for the various fit parameters differ from earlier reports by an order of magnitude. A comparison of the χ parameter obtained from FR theory with values for the linear polymer reveals that the agreement between experiment and theory is somewhat fortuitous. Although the FR model can accurately describe experimental data, the accuracy of the obtained fit parameters is significantly poorer.
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Affiliation(s)
- Carlos G Lopez
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, D-52056 Aachen, Germany.
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Nigro V, Angelini R, Bertoldo M, Bruni F, Ricci MA, Ruzicka B. Dynamical behavior of microgels of interpenetrated polymer networks. SOFT MATTER 2017; 13:5185-5193. [PMID: 28664963 PMCID: PMC5898610 DOI: 10.1039/c7sm00739f] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Microgel suspensions of an interpenetrated Polymer Network (IPN) of PNIPAM and PAAc in D2O have been investigated through dynamic light scattering as a function of temperature, pH and concentration across the Volume Phase Transition (VPT). The dynamics of the system is slowed down under H/D isotopic substitution due to different balance states between polymer/polymer and polymer/solvent interactions suggesting the crucial role played by H-bonding. The swelling behavior, reduced with respect to PNIPAM and water, has been described by the Flory-Rehner theory, tested for PNIPAM microgel and successfully expanded to higher order for IPN microgels. Moreover the concentration dependence of the relaxation time at neutral pH has highlighted two different routes to approach the glass transition: Arrhenius and super-Arrhenius (Vogel Fulcher Tammann) respectively below and above the VPT and a fragility plot has been derived. Fragility can be tuned by changing temperature: across the VPT particles undergo a transition from soft-strong to stiff-fragile.
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Affiliation(s)
- Valentina Nigro
- Dipartimento di Fisica, Sapienza Università di Roma, P.le Aldo Moro 5, 00185 Roma, Italy.
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