1
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Novel in-situ synthesis of copper oxide nanoparticle in smart polymer microgel for catalytic reduction of methylene blue. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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2
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Friesen S, Kakorin S, Hellweg T. Modified Flory–Rehner Theory Describes Thermotropic Swelling Transition of Smart Copolymer Microgels. Polymers (Basel) 2022; 14:polym14101999. [PMID: 35631881 PMCID: PMC9143634 DOI: 10.3390/polym14101999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 05/09/2022] [Accepted: 05/10/2022] [Indexed: 12/10/2022] Open
Abstract
In the present article, we use an improved Flory–Rehner theory to describe the swelling behavior of copolymer microgels, where the interaction parameter is modeled by a Hill-like equation for a cooperative thermotropic transition. This description leads to very good fits of the swelling curves of the copolymer microgels at different comonomer contents (30 mol%, 50 mol% and 70 mol%) obtained by photon correlation spectroscopy. Fixed parameters, which are universally applicable for the respective monomers given in our previous work, are used to fit the swelling curves. The analysis of the swelling curves yields physically reasonable and meaningful results for the remaining adjustable parameters. The comonomer content of the statistical copolymer microgels poly(NNPAM-co-NIPAM), poly(NIPAM-co-NIPMAM) and poly(NIPMAM-co-NNPAM) is determined by nuclear magnetic resonance spectroscopy and is in agreement with the nominal comonomer feed used in the synthesis. To investigate the volume phase transition at a molecular level, swelling curves are also measured by Fourier transformation infrared spectroscopy. The obtained swelling curves are also fitted using the Hill-like model. The fits provide physically reasonable parameters too, consistent with the results from photon correlation spectroscopy.
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3
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Sabadasch V, Fandrich P, Annegarn M, Hellweg T. Effect of Methacrylic Acid in PNNPAM Microgels on the Catalytic Activity of Embedded Palladium Nanoparticles. MACROMOL CHEM PHYS 2022. [DOI: 10.1002/macp.202200045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Viktor Sabadasch
- Physical and Biophysical Chemistry Bielefeld University Bielefeld 33615 Germany
| | - Pascal Fandrich
- Physical and Biophysical Chemistry Bielefeld University Bielefeld 33615 Germany
| | - Marco Annegarn
- Physical and Biophysical Chemistry Bielefeld University Bielefeld 33615 Germany
| | - Thomas Hellweg
- Physical and Biophysical Chemistry Bielefeld University Bielefeld 33615 Germany
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4
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Comparison of different approaches to describe the thermotropic volume phase transition of smart microgels. Colloid Polym Sci 2022. [DOI: 10.1007/s00396-022-04950-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AbstractThe description of gel swelling by Flory and Rehner using the original Flory–Huggins interaction parameter for the polymer–solvent interaction cannot be applied to most smart microgels. Here, we compare descriptions of the swelling curves of such microgels using series expansions of the Flory–Huggins parameter $$\chi$$
χ
with the results of Hill-like equation for $$\chi$$
χ
. We study N-isopropyl-acrylamide particles at different concentrations of the cross-linker N,N-methylenebisacrylamide. The hydrodynamic radius $$R_{\mathrm {H}}$$
R
H
of the microgel particles is determined using photon correlation spectroscopy. The fits with the series expansion of $$\chi$$
χ
nicely follow the experimental data. However, already with the first-order series expansion, the computed $$\Theta$$
Θ
temperatures are not physically reasonable. Moreover, the physical meaning of the parameters of the series expansion is not clear. The Hill-like equation, which we recently introduced, yields a good description of all measured microgel swelling curves and provides physically meaningful parameters. For instance, the Hill parameter $$\nu$$
ν
corresponds to the number of water molecules per network chain cooperatively leaving the chain at the volume phase transition.
Graphical abstract
Different approaches to model the Flory-Huggins interaction parameter are explored and compared with respect to the quality of the fit of microgel swelling curves.
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5
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Marsili L, Dal Bo M, Berti F, Toffoli G. Thermoresponsive Chitosan-Grafted-Poly( N-vinylcaprolactam) Microgels via Ionotropic Gelation for Oncological Applications. Pharmaceutics 2021; 13:1654. [PMID: 34683947 PMCID: PMC8539247 DOI: 10.3390/pharmaceutics13101654] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/23/2021] [Accepted: 09/25/2021] [Indexed: 12/19/2022] Open
Abstract
Microgels can be considered soft, porous and deformable particles with an internal gel structure swollen by a solvent and an average size between 100 and 1000 nm. Due to their biocompatibility, colloidal stability, their unique dynamicity and the permeability of their architecture, they are emerging as important candidates for drug delivery systems, sensing and biocatalysis. In clinical applications, the research on responsive microgels is aimed at the development of "smart" delivery systems that undergo a critical change in conformation and size in reaction to a change in environmental conditions (temperature, magnetic fields, pH, concentration gradient). Recent achievements in biodegradable polymer fabrication have resulted in new appealing strategies, including the combination of synthetic and natural-origin polymers with inorganic nanoparticles, as well as the possibility of controlling drug release remotely. In this review, we provide a literature review on the use of dual and multi-responsive chitosan-grafted-poly-(N-vinylcaprolactam) (CP) microgels in drug delivery and oncological applications.
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Affiliation(s)
- Lorenzo Marsili
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via Licio Giorgieri 1, 34127 Trieste, Italy;
- Experimental and Clinical Pharmacology Unit, CRO National Cancer Institute IRCCS, Via Franco Gallini 2, 33081 Aviano, Italy; (M.D.B.); (G.T.)
| | - Michele Dal Bo
- Experimental and Clinical Pharmacology Unit, CRO National Cancer Institute IRCCS, Via Franco Gallini 2, 33081 Aviano, Italy; (M.D.B.); (G.T.)
| | - Federico Berti
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via Licio Giorgieri 1, 34127 Trieste, Italy;
| | - Giuseppe Toffoli
- Experimental and Clinical Pharmacology Unit, CRO National Cancer Institute IRCCS, Via Franco Gallini 2, 33081 Aviano, Italy; (M.D.B.); (G.T.)
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6
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Hannappel Y, Wiehemeier L, Dirksen M, Kottke T, Hellweg T. Smart Microgels from Unconventional Acrylamides. MACROMOL CHEM PHYS 2021. [DOI: 10.1002/macp.202100067] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Yvonne Hannappel
- Physical and Biophysical Chemistry Bielefeld University Universitätsstr. 25 33615 Bielefeld Germany
| | - Lars Wiehemeier
- Physical and Biophysical Chemistry Bielefeld University Universitätsstr. 25 33615 Bielefeld Germany
| | - Maxim Dirksen
- Physical and Biophysical Chemistry Bielefeld University Universitätsstr. 25 33615 Bielefeld Germany
| | - Tilman Kottke
- Physical and Biophysical Chemistry Bielefeld University Universitätsstr. 25 33615 Bielefeld Germany
| | - Thomas Hellweg
- Physical and Biophysical Chemistry Bielefeld University Universitätsstr. 25 33615 Bielefeld Germany
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7
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Dirksen M, Kinder TA, Brändel T, Hellweg T. Temperature Controlled Loading and Release of the Anti-Inflammatory Drug Cannabidiol by Smart Microgels. Molecules 2021; 26:3181. [PMID: 34073361 PMCID: PMC8199058 DOI: 10.3390/molecules26113181] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/14/2021] [Accepted: 05/21/2021] [Indexed: 11/27/2022] Open
Abstract
CBD is a promising candidate for treatment of many diseases and plays a major role in the growing trend to produce high-end drugs from natural, renewable resources. In the present work, we demonstrate a way to incorporate the anti-inflammatory drug CBD into smart microgel particles. The copolymer microgels that we chose as carrier systems exhibit a volume phase transition temperature of 39 ∘C, which is just above normal body temperature and makes them ideal candidates for hyperthermia treatment. While a simple loading route of CBD was not successful due to the enormous hydrophobicity of CBD, an alternative route was developed by immersing the microgels in ethanol. Despite the expected loss of thermoresponsive behaviour of the microgel matrix due to the solvent exchange, a temperature-dependent release of CBD was detected by the material, creating an interesting question of interactions between CBD and the microgel particles in ethanol. Furthermore, the method developed for loading of the microgel particles with CBD in ethanol was further improved by a subsequent transfer of the loaded particles into water, which proves to be an even more promising approach due to the successful temperature-dependent release of the drug above the collapse temperature of the microgels.
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Affiliation(s)
- Maxim Dirksen
- Physical and Biophysical Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany; (M.D.); (T.B.)
| | | | - Timo Brändel
- Physical and Biophysical Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany; (M.D.); (T.B.)
- Daikin Chemical Europe GmbH, Am Wehrhahn 50, 40211 Düsseldorf, Germany
| | - Thomas Hellweg
- Physical and Biophysical Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany; (M.D.); (T.B.)
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8
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Flexible Sample Environments for the Investigation of Soft Matter at the European Spallation Source: Part I—The In Situ SANS/DLS Setup. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11094089] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
As part of the development of the new European Spallation Source (ESS) in Lund (Sweden), which will provide the most brilliant neutron beams worldwide, it is necessary to provide different sample environments with which the potential of the new source can be exploited as soon as possible from the start of operation. The overarching goal of the project is to reduce the downtimes of the instruments related to changing the sample environment by developing plug and play sample environments for different soft matter samples using the same general carrier platform and also providing full software integration and control by just using unified connectors. In the present article, as a part of this endeavor, the sample environment for in situ SANS and dynamic light scattering measurements is introduced.
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9
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Friesen S, Hannappel Y, Kakorin S, Hellweg T. Accounting for Cooperativity in the Thermotropic Volume Phase Transition of Smart Microgels. Gels 2021; 7:gels7020042. [PMID: 33918048 PMCID: PMC8167792 DOI: 10.3390/gels7020042] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/26/2021] [Accepted: 04/02/2021] [Indexed: 01/12/2023] Open
Abstract
A full quantitative description of the swelling of smart microgels is still problematic in many cases. The original approach of Flory and Huggins for the monomer–solvent interaction parameter χ cannot be applied to some microgels. The reason for this obviously is that the cross-linking enhances the cooperativity of the volume phase transitions, since all meshes of the network are mechanically coupled. This was ignored in previous approaches, arguing with distinct transition temperatures for different meshes to describe the continuous character of the transition of microgels. Here, we adjust the swelling curves of a series of smart microgels using the Flory–Rehner description, where the polymer–solvent interaction parameter χ is modeled by a Hill-like equation for a cooperative thermotropic transition. This leads to a very good description of all measured microgel swelling curves and yields the physically meaningful Hill parameter ν. A linear decrease of ν is found with increasing concentration of the cross-linker N,N′-methylenebisacrylamide in the microgel particles p(NIPAM), p(NNPAM), and p(NIPMAM). The linearity suggests that the Hill parameter ν corresponds to the number of water molecules per network chain that cooperatively leave the chain at the volume phase transition. Driven by entropy, ν water molecules of the solvate become cooperatively “free” and leave the polymer network.
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10
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Bookhold J, Dirksen M, Wiehemeier L, Knust S, Anselmetti D, Paneff F, Zhang X, Gölzhäuser A, Kottke T, Hellweg T. Smart membranes by electron beam cross-linking of copolymer microgels. SOFT MATTER 2021; 17:2205-2214. [PMID: 33459755 DOI: 10.1039/d0sm02041a] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Poly(N-isopropylacrylamide) (pNIPAM) based copolymer microgels were used to create free-standing, transferable, thermoresponsive membranes. The microgels were synthesized by copolymerization of NIPAM with N-benzylhydrylacrylamide (NBHAM). Monolayers of these colloidal gels were subsequently cross-linked using an electron gun leading to the formation of a connected monolayer. Furthermore, the cross-linked microgel layer is detached from the supporting material by dissolving the substrate. These unique systems can be used as transferable, thermoresponsive coatings and as thermoresponsive membranes. As a proof of principle for the use of such membranes we studied the ion transport through them at different temperatures revealing drastic changes when the lower critical solution temperature of the copolymer microgels is reached.
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Affiliation(s)
- Johannes Bookhold
- University Bielefeld, Department of Chemistry, Physical and Biophysical Chemistry, Universitätsstr. 25, 33615 Bielefeld, Germany.
| | - Maxim Dirksen
- University Bielefeld, Department of Chemistry, Physical and Biophysical Chemistry, Universitätsstr. 25, 33615 Bielefeld, Germany.
| | - Lars Wiehemeier
- University Bielefeld, Department of Chemistry, Physical and Biophysical Chemistry, Universitätsstr. 25, 33615 Bielefeld, Germany.
| | - Sebastian Knust
- University Bielefeld, Department of Physics, Experimental Biophysics, Universitätsstr. 25, 33615 Bielefeld, Germany
| | - Dario Anselmetti
- University Bielefeld, Department of Physics, Experimental Biophysics, Universitätsstr. 25, 33615 Bielefeld, Germany
| | - Florian Paneff
- University Bielefeld, Department of Physics, Physics of Supermolecular Systems and Surfaces, Universitätsstr. 25, 33615 Bielefeld, Germany
| | - Xianghui Zhang
- University Bielefeld, Department of Physics, Physics of Supermolecular Systems and Surfaces, Universitätsstr. 25, 33615 Bielefeld, Germany
| | - Armin Gölzhäuser
- University Bielefeld, Department of Physics, Physics of Supermolecular Systems and Surfaces, Universitätsstr. 25, 33615 Bielefeld, Germany
| | - Tilman Kottke
- University Bielefeld, Department of Chemistry, Physical and Biophysical Chemistry, Universitätsstr. 25, 33615 Bielefeld, Germany.
| | - Thomas Hellweg
- University Bielefeld, Department of Chemistry, Physical and Biophysical Chemistry, Universitätsstr. 25, 33615 Bielefeld, Germany.
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11
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Wrede O, Bergmann S, Hannappel Y, Hellweg T, Huser T. Smart microgels investigated by super-resolution fluorescence microscopy: influence of the monomer structure on the particle morphology. SOFT MATTER 2020; 16:8078-8084. [PMID: 32789349 DOI: 10.1039/d0sm00597e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In a recent publication [Bergmann et al. Phys. Chem. Chem. Phys., 2018, 20, 5074-5083] we presented a method which enables to investigate the morphology of microgels by superresolution fluorescence microscopy. Here, this method is applied to three microgel species, based on N-isopropylmethacrylamide (NIPMAM), N-n-propylacrylamide (NNPAM) and N-n-propylmethacrylamide (NNPMAM)) with 5, 7.5 and 10 mol% cross-linker, respectively. Super-resolution microscopy reveals differences of the network morphology of the synthesized particles showing the importance of the monomer structure.
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Affiliation(s)
- Oliver Wrede
- Biomolecular Photonics, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany.
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12
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13
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Sabadasch V, Wiehemeier L, Kottke T, Hellweg T. Core-shell microgels as thermoresponsive carriers for catalytic palladium nanoparticles. SOFT MATTER 2020; 16:5422-5430. [PMID: 32490485 DOI: 10.1039/d0sm00433b] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Responsive core-shell microgels are promising systems for a stabilization of Pd nanoparticles and control of their catalytic activity. Here, poly-N-n-propylacrylamide (PNNPAM) was copolymerized with methacrylic acid to yield microgel core particles, which were subsequently coated with an additional, acid-free poly-N-isopropylmethacrylamide (PNIPMAM) shell. Both core and core-shell systems were used as pH- and temperature-responsive carrier systems for the incorporation of palladium nanoparticles. The embedded nanoparticles were found to have a uniform size distribution with diameters at around 20 nm. Their catalytic activity was investigated by following the kinetics of the reduction of p-nitrophenol to p-aminophenol using UV-vis spectroscopy. For the PNNPAM microgel core, the temperature dependence of the rate constant followed the Arrhenius equation, which is an unusual behaviour for thermoresponsive carrier systems but common for passive systems such as polyelectrolyte brushes. In contrast, the catalytic activity of nanoparticles embedded in microgel core-shell systems decreased drastically at the volume phase transition temperature (44 °C) of the PNIPMAM shell. Accordingly, a promising architecture of passive nanoparticle-carrying core and thermoresponsive shell was realized successfully.
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Affiliation(s)
- Viktor Sabadasch
- Physical and Biophysical Chemistry, Bielefeld University, Germany.
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14
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Zhu X, Tian Y, He B, Gan T, Hu X, Wang X. Synthesis of Dual-Responsive Materials with Reversible and Switchable Phase-Transition Properties for High-Performance Cellulose Enzymatic Hydrolysis. CHEMSUSCHEM 2020; 13:663-667. [PMID: 31802645 DOI: 10.1002/cssc.201903046] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/01/2019] [Indexed: 06/10/2023]
Abstract
The solid-solid (immobilized cellulase-insoluble cellulose) phase cellulose hydrolysis reaction is significant in cellulosic biomass conversion processes but hindered because of its low efficiency. Herein, a smart temperature-pH dual-responsive material (D-N-N material) was prepared to be used as a carrier for cellulase recovery. This D-N-N material could undergo reversible and switchable transitions between solution, hydrogel, and solid phases. The following results were demonstrated: 1) the hydrolytic degree of this strategy could be as high as that of free cellulase in buffer solution; 2) the cellulase could be encapsulated into the D-N-N hydrogel without significant leaching and most of the cellulase activity was retained after recycling for at least 10 batches; and 3) more than 95 % of the glucose inside the hydrogel could be extracted during the hydrogel-solid transition within 1 h, which can assist in the high-efficiency separation of cellulase from glucose. The results suggested that this strategy provides a feasible platform for efficient cellulose hydrolysis and could be applied to other bio-derived reactions.
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Affiliation(s)
- Xing Zhu
- College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, Shaanxi, P.R. China
- The Youth Innovation Team of Shaanxi Universities, Xi'an, 710021, Shaanxi, P.R. China
| | - Yi Tian
- College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, Shaanxi, P.R. China
| | - Bin He
- College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, Shaanxi, P.R. China
- Key Laboratory of Pulp and Paper Science&Technology of Ministry of Education/Shandong Province, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, Shandong, P.R. China
| | - Ting Gan
- College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, Shaanxi, P.R. China
| | - Xiao Hu
- Nanyang Environment & Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, Singapore, 637141, Singapore
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Xuechuan Wang
- College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, Shaanxi, P.R. China
- National Demonstration Center for Experimental Light Chemistry Engineering Education, Shaanxi University of Science & Technology, Xi'an, 710021, Shaanxi, P.R. China
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15
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Cors M, Wiehemeier L, Wrede O, Feoktystov A, Cousin F, Hellweg T, Oberdisse J. Contrast variation SANS measurement of shell monomer density profiles of smart core-shell microgels. SOFT MATTER 2020; 16:1922-1930. [PMID: 31995091 DOI: 10.1039/c9sm02036e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The radial density profile of deuterated poly(N,n-propyl acrylamide) shell monomers within core-shell microgels has been studied by small-angle neutron scattering in order to shed light on the origin of their linear thermally-induced swelling. The poly(N-isopropyl methacrylamide) core monomers have been contrast-matched by the H2O/D2O solvent mixture, and the intensity thus provides a direct measurement of the spatial distribution of the shell monomers. Straightforward modelling shows that their structure does not correspond to the expected picture of a well-defined external shell. A multi-shell model solved by a reverse Monte Carlo approach is then applied to extract the monomer density as a function of temperature and of the core crosslinking. It is found that most shell monomers fill the core at high temperatures approaching synthesis conditions of collapsed particles, forming only a dilute corona. As the core monomers tend to swell at lower temperatures, a skeleton of insoluble shell monomers hinders swelling, inducing the progressive linear thermoresponse.
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Affiliation(s)
- Marian Cors
- Department of Physical and Biophysical Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany. and Laboratoire Charles Coulomb (L2C), University of Montpellier, CNRS, 34095 Montpellier, France.
| | - Lars Wiehemeier
- Department of Physical and Biophysical Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany.
| | - Oliver Wrede
- Department of Physical and Biophysical Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany.
| | - Artem Feoktystov
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science JCNS at Heinz Maier-Leibnitz Zentrum MLZ, 85748 Garching, Germany
| | - Fabrice Cousin
- Laboratoire Léon Brillouin, UMR 12 CEA/CNRS, CEA Saclay, 91191 Gif Sur Yvette, France
| | - Thomas Hellweg
- Department of Physical and Biophysical Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany.
| | - Julian Oberdisse
- Laboratoire Charles Coulomb (L2C), University of Montpellier, CNRS, 34095 Montpellier, France.
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16
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Chen Y, Wei W, Zhu Y, Luo J, Liu R, Liu X. Synthesis of Temperature/pH Dual-Stimuli-Response Multicompartmental Microcapsules via Pickering Emulsion for Preprogrammable Payload Release. ACS APPLIED MATERIALS & INTERFACES 2020; 12:4821-4832. [PMID: 31903756 DOI: 10.1021/acsami.9b20999] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Stimuli-responsive microcapsules, which can release the encapsulated payload under various environmental stimuli, have attracted great interests of the food, pharmaceutical, cosmetics, and agricultural fields in recent years. However, most reported responsive microcapsules normally have a single storage area and thus load/release only one type of payload under one stimulus. In this work, we fabricated a novel kind of multicompartmental intelligent microcapsule with two storage areas and independently controlled (preprogrammable) releasing behavior under different stimuli via rapid photopolymerization of Pickering emulsions. In our strategy, a temperature-sensitive polymeric (N-isopropyl acrylamide, pNIPAM) particle was prepared and loaded with Nile Red (NR), which was then employed as a Pickering emulsifier to stabilize oil-in-water droplets. The oil was composed of pH-responsive monomers and oil-soluble fluorescent green (OG). Upon exposure to photoirradiation, pH-responsive monomers were polymerized along the interior of the droplets and converted into microcapsules. With NR in the temperature-sensitive pNIPAM@NR particles and OG in the interior of the microcapsules, the as-prepared microcapsules possess dual-carrier capability with two payloads encapsulated dependently in two different compartments. In addition, the microcapsules could respond to two different external stimuli (temperature and pH) and realize the selective and independent release of encapsulated molecules (NR and OG) from the shell and core without any mutual interference. More importantly, the release of NR and OG can be programmed by preprogramming the order of the stimulus responses, which can be altered. Our work develops a simple and effective strategy to fabricate responsive multicompartment microcapsules with preprogrammable release of different molecules.
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Affiliation(s)
- Yaxin Chen
- The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering , Jiangnan University , Wuxi , Jiangsu 214122 , P. R. China
| | - Wei Wei
- The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering , Jiangnan University , Wuxi , Jiangsu 214122 , P. R. China
| | - Ye Zhu
- The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering , Jiangnan University , Wuxi , Jiangsu 214122 , P. R. China
| | - Jing Luo
- The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering , Jiangnan University , Wuxi , Jiangsu 214122 , P. R. China
| | - Ren Liu
- The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering , Jiangnan University , Wuxi , Jiangsu 214122 , P. R. China
| | - Xiaoya Liu
- The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering , Jiangnan University , Wuxi , Jiangsu 214122 , P. R. China
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17
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Otto P, Bergmann S, Sandmeyer A, Dirksen M, Wrede O, Hellweg T, Huser T. Resolving the internal morphology of core-shell microgels with super-resolution fluorescence microscopy. NANOSCALE ADVANCES 2020; 2:323-331. [PMID: 36134006 PMCID: PMC9416983 DOI: 10.1039/c9na00670b] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 11/28/2019] [Indexed: 06/10/2023]
Abstract
We investigate the internal morphology of smart core-shell microgels by super-resolution fluorescence microscopy exploiting a combination of 3D single molecule localization and structured illumination microscopy utilizing freely diffusing fluorescent dyes. This approach does not require any direct chemical labeling and does not perturb the network structure of these colloidal gels. Hence, it allows us to study the morphology of the particles with very high precision. We found that the structure of the core-forming seed particles is drastically changed by the second synthesis step necessary for making the shell, resulting in a core region with highly increased dye localization density. The present work shows that super-resolution microscopy has great potential with respect to the study of soft colloidal systems.
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Affiliation(s)
- Pia Otto
- Physical and Biophysical Chemistry, Bielefeld University Germany
| | | | | | - Maxim Dirksen
- Physical and Biophysical Chemistry, Bielefeld University Germany
| | - Oliver Wrede
- Physical and Biophysical Chemistry, Bielefeld University Germany
| | - Thomas Hellweg
- Physical and Biophysical Chemistry, Bielefeld University Germany
| | - Thomas Huser
- Biomolecular Photonics, Bielefeld University Germany
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Cors M, Wrede O, Wiehemeier L, Feoktystov A, Cousin F, Hellweg T, Oberdisse J. Spatial distribution of core monomers in acrylamide-based core-shell microgels with linear swelling behaviour. Sci Rep 2019; 9:13812. [PMID: 31554839 PMCID: PMC6761195 DOI: 10.1038/s41598-019-50164-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 09/06/2019] [Indexed: 01/31/2023] Open
Abstract
The peculiar linear temperature-dependent swelling of core-shell microgels has been conjectured to be linked to the core-shell architecture combining materials of different transition temperatures. Here the structure of pNIPMAM-core and pNNPAM-shell microgels in water is studied as a function of temperature using small-angle neutron scattering with selective deuteration. Photon correlation spectroscopy is used to scrutinize the swelling behaviour of the colloidal particles and reveals linear swelling. Moreover, these experiments are also employed to check the influence of deuteration on swelling. Using a form-free multi-shell reverse Monte Carlo approach, the small-angle scattering data are converted into radial monomer density profiles. The comparison of ‘core-only’ particles consisting of identical cores to fully hydrogenated core-shell microgels, and finally to H-core/D-shell architectures unambiguously shows that core and shell monomers display gradient profiles with strong interpenetration, leading to cores embedded in shells which are bigger than their isolated ‘core-only’ precursor particles. This surprising result is further generalized to different core cross-linker contents, for temperature ranges encompassing both transitions. Our analysis demonstrates that the internal structure of pNIPMAM-core and pNNPAM-shell microgels is heterogeneous and strongly interpenetrated, presumably allowing only progressive core swelling at temperatures intermediate to both transition temperatures, thus promoting linear swelling behaviour.
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Affiliation(s)
- Marian Cors
- Department of Physical and Biophysical Chemistry, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany.,Laboratoire Charles Coulomb (L2C), University of Montpellier, CNRS, 34095, Montpellier, France
| | - Oliver Wrede
- Department of Physical and Biophysical Chemistry, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany
| | - Lars Wiehemeier
- Department of Physical and Biophysical Chemistry, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany
| | - Artem Feoktystov
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science JCNS at Heinz Maier-Leibnitz Zentrum MLZ, 85748, Garching, Germany
| | - Fabrice Cousin
- Laboratoire Léon Brillouin, UMR 12 CEA/CNRS, CEA Saclay, 91191, Gif Sur Yvette, France
| | - Thomas Hellweg
- Department of Physical and Biophysical Chemistry, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany. .,Lund Institute of Advanced Neutron and X-ray Science (LINXS), IDEON Building: Delta 5, Scheelevägen 19, 22370, Lund, Sweden.
| | - Julian Oberdisse
- Laboratoire Charles Coulomb (L2C), University of Montpellier, CNRS, 34095, Montpellier, France.
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Tuning the Swelling Properties of Smart Multiresponsive Core-Shell Microgels by Copolymerization. Polymers (Basel) 2019; 11:polym11081269. [PMID: 31370213 PMCID: PMC6722827 DOI: 10.3390/polym11081269] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 07/29/2019] [Accepted: 07/30/2019] [Indexed: 01/17/2023] Open
Abstract
The present study focuses on the development of multiresponsive core-shell microgels and the manipulation of their swelling properties by copolymerization of different acrylamides—especially N-isopropylacrylamide (NIPAM), N-isopropylmethacrylamide (NIPMAM), and NNPAM—and acrylic acid. We use atomic force microscopy for the dry-state characterization of the microgel particles and photon correlation spectroscopy to investigate the swelling behavior at neutral (pH 7) and acidic (pH 4) conditions. A transition between an interpenetrating network structure for microgels with a pure poly-N,n-propylacrylamide (PNNPAM) shell and a distinct core-shell morphology for microgels with a pure poly-N-isopropylmethacrylamide (PNIPMAM) shell is observable. The PNIPMAM molfraction of the shell also has an important influence on the particle rigidity because of the decreasing degree of interpenetration. Furthermore, the swelling behavior of the microgels is tunable by adjustment of the pH-value between a single-step volume phase transition and a linear swelling region at temperatures corresponding to the copolymer ratios of the shell. This flexibility makes the multiresponsive copolymer microgels interesting candidates for many applications, e.g., as membrane material with tunable permeability.
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Deuteration-Induced Volume Phase Transition Temperature Shift of PNIPMAM Microgels. Polymers (Basel) 2019; 11:polym11040620. [PMID: 30960604 PMCID: PMC6523740 DOI: 10.3390/polym11040620] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 03/25/2019] [Accepted: 03/27/2019] [Indexed: 12/03/2022] Open
Abstract
The effect of deuteration on the volume phase transition (VPT) temperature of poly (N-isopropylmethacrylamide) (pNIPMAM) microgels in aqueous suspension is determined via IR spectroscopy and size measurements by photon correlation spectroscopy (PCS). We study the effect of a hydrogenated and a deuterated solvent (H2O/D2O), and of the hydrogenated and (partially) deuterated monomer. Deuteration of the monomer or copolymerization with deuterated monomers shifts the volume phase transition temperature (VPTT) by up to 8.4 K to higher temperatures, in good agreement with known results for pNIPAM microgels. Moreover, the shape of the swelling curve is found to depend on deuteration, with the highest deuteration leading to the sharpest VPT. Finally, the quantitative agreement between FTIR spectroscopy and PCS evidences the spatial homogeneity of the microgel particles. Our results are rationalized in terms of the effect of deuteration on hydrogen bonding. They shall be of primary importance for any experimental measurements close to the VPT involving isotopic substitution, and in particular contrast variation small angle neutron scattering.
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Wiehemeier L, Cors M, Wrede O, Oberdisse J, Hellweg T, Kottke T. Swelling behaviour of core–shell microgels in H2O, analysed by temperature-dependent FTIR spectroscopy. Phys Chem Chem Phys 2019; 21:572-580. [DOI: 10.1039/c8cp05911j] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The structural basis for linear thermoresponses of smart core–shell microgels is elucidated by FTIR spectroscopy, being sensitive to core processes.
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Affiliation(s)
- Lars Wiehemeier
- Physical and Biophysical Chemistry
- Department of Chemistry
- Bielefeld University
- 33615 Bielefeld
- Germany
| | - Marian Cors
- Physical and Biophysical Chemistry
- Department of Chemistry
- Bielefeld University
- 33615 Bielefeld
- Germany
| | - Oliver Wrede
- Physical and Biophysical Chemistry
- Department of Chemistry
- Bielefeld University
- 33615 Bielefeld
- Germany
| | - Julian Oberdisse
- Laboratoire Charles Coulomb (L2C)
- University of Montpellier
- CNRS
- 34095 Montpellier
- France
| | - Thomas Hellweg
- Physical and Biophysical Chemistry
- Department of Chemistry
- Bielefeld University
- 33615 Bielefeld
- Germany
| | - Tilman Kottke
- Physical and Biophysical Chemistry
- Department of Chemistry
- Bielefeld University
- 33615 Bielefeld
- Germany
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22
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Leite DC, Kakorin S, Hertle Y, Hellweg T, da Silveira NP. Smart Starch-Poly( N-isopropylacrylamide) Hybrid Microgels: Synthesis, Structure, and Swelling Behavior. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:10943-10954. [PMID: 30132672 DOI: 10.1021/acs.langmuir.8b00706] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In this study, we present hybrid microgels made of starch nanoparticles (SNPs) and poly( N-isopropylacrylamide) [p(NIPAM)]. SNPs were formed through nanoprecipitation. Hybrid microgels were prepared by surfactant-free precipitation polymerization (SFPP) or in the presence of surfactant precipitation polymerization (PP) at different NIPAM/SNP ratios. Dynamic light scattering results of hybrid microgels synthesized by SFPP revealed changes in volume phase transition temperature according to SNP amount, where the increase in the hydrophilic content caused small shifts in the lower critical solution temperature (LCST), reaching nearly 35 °C. Colloidal stability was improved with the SNP content, leading to increased stability because of the hydroxyl groups. Small-angle X-ray scattering indicates a core-shell structure above the LCST, where SNPs chains cover a p(NIPAM) core. Swelling curves experimentally obtained were analyzed using the Flory-Rehner model, where the interaction parameter (χ) has been modeled either by a series expansion of the swelling ratio or by a Hill-like equation for a cooperative thermotropic transition.
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Affiliation(s)
- Daiani C Leite
- Institute of Chemistry , Universidade Federal do Rio Grande do Sul , Av. Bento Gonçalves 9500 , 91501-970 Porto Alegre , Brazil
| | - Sergej Kakorin
- Faculty of Chemistry , Universität Bielefeld , Universitätstrasse 25 , 33615 Bielefeld , Germany
| | - Yvonne Hertle
- Faculty of Chemistry , Universität Bielefeld , Universitätstrasse 25 , 33615 Bielefeld , Germany
| | - Thomas Hellweg
- Faculty of Chemistry , Universität Bielefeld , Universitätstrasse 25 , 33615 Bielefeld , Germany
| | - Nádya P da Silveira
- Institute of Chemistry , Universidade Federal do Rio Grande do Sul , Av. Bento Gonçalves 9500 , 91501-970 Porto Alegre , Brazil
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Wrede O, Reimann Y, Lülsdorf S, Emmrich D, Schneider K, Schmid AJ, Zauser D, Hannappel Y, Beyer A, Schweins R, Gölzhäuser A, Hellweg T, Sottmann T. Volume phase transition kinetics of smart N-n-propylacrylamide microgels studied by time-resolved pressure jump small angle neutron scattering. Sci Rep 2018; 8:13781. [PMID: 30213960 PMCID: PMC6137196 DOI: 10.1038/s41598-018-31976-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 08/31/2018] [Indexed: 11/24/2022] Open
Abstract
The use of smart colloidal microgels for advanced applications critically depends on their response kinetics. We use pressure jump small angle neutron scattering with supreme time resolution to study the rapid volume phase transition kinetics of such microgels. Utilizing the pressure induced microphase separation inside the microgels we were able to resolve their collapse and swelling kinetics. While the collapse occurs on a time scale of 10 ms, the particle swelling turned out to be much faster. Photon correlation spectroscopy and static small angle neutron scattering unambiguously show, that the much slower collapse can be associated with the complex particle architecture exhibiting a loosely-crosslinked outer region and a denser inner core region. These insights into the kinetics of stimuli-responsive materials are of high relevance for their applications as nano-actuators, sensors or drug carriers. Moreover, the used refined pressure jump small angle neutron scattering technique is of broad interest for soft matter studies.
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Affiliation(s)
- Oliver Wrede
- Physical and Biophysical Chemistry, Bielefeld University, Bielefeld, Germany
| | - Yvonne Reimann
- Institute of Physical Chemistry, University of Cologne, Cologne, Germany
| | - Stefan Lülsdorf
- Institute of Physical Chemistry, University of Stuttgart, Stuttgart, Germany
| | - Daniel Emmrich
- Physics of Supermolecular Systems and Surfaces, Bielefeld University, Bielefeld, Germany
| | - Kristina Schneider
- Institute of Physical Chemistry, University of Stuttgart, Stuttgart, Germany
| | | | - Diana Zauser
- Institute of Physical Chemistry, University of Stuttgart, Stuttgart, Germany
| | - Yvonne Hannappel
- Physical and Biophysical Chemistry, Bielefeld University, Bielefeld, Germany
| | - André Beyer
- Physics of Supermolecular Systems and Surfaces, Bielefeld University, Bielefeld, Germany
| | | | - Armin Gölzhäuser
- Physics of Supermolecular Systems and Surfaces, Bielefeld University, Bielefeld, Germany
| | - Thomas Hellweg
- Physical and Biophysical Chemistry, Bielefeld University, Bielefeld, Germany.
| | - Thomas Sottmann
- Institute of Physical Chemistry, University of Stuttgart, Stuttgart, Germany.
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Wedel B, Brändel T, Bookhold J, Hellweg T. Role of Anionic Surfactants in the Synthesis of Smart Microgels Based on Different Acrylamides. ACS OMEGA 2017; 2:84-90. [PMID: 31457211 PMCID: PMC6641024 DOI: 10.1021/acsomega.6b00424] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 12/26/2016] [Indexed: 05/20/2023]
Abstract
We investigated the influence of two anionic surfactants, namely, sodium dodecyl sulfate and sodium decyl sulfate, on acrylamide-based microgels consisting of N-n-propylacrylamide. In this context, the main focus was on the influence of surfactant addition on the size of the microgels. The surfactant was added to the reaction mixture before or during the polymerization at different points in time. Microgels were characterized via photon correlation spectroscopy and atomic force microscopy. All results were compared to those for other more common acrylamide-based microgels consisting of N-isopropylacrylamide and N-isopropylmethacrylamide. A significant difference between the three microgels and a strong dependence on the surface activity of the surfactant was found.
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Affiliation(s)
| | | | - Johannes Bookhold
- Physical and Biophysical
Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Thomas Hellweg
- Physical and Biophysical
Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
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Wedel B, Hertle Y, Wrede O, Bookhold J, Hellweg T. Smart Homopolymer Microgels: Influence of the Monomer Structure on the Particle Properties. Polymers (Basel) 2016; 8:E162. [PMID: 30979256 PMCID: PMC6432239 DOI: 10.3390/polym8040162] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 04/12/2016] [Accepted: 04/15/2016] [Indexed: 11/16/2022] Open
Abstract
In this work, we compare the properties of smart homopolymer microgels based on N-n-propylacrylamide (NNPAM), N-isopropylacrylamide (NIPAM) and N-isopropylmethacrylamide (NIPMAM) synthesized under identical conditions. The particles are studied with respect to size, morphology, and swelling behavior using scanning electron and scanning force microscopy. In addition, light scattering techniques and fluorescent probes are employed to follow the swelling/de-swelling of the particles. Significant differences are found and discussed. Poly(N-n-propylacrylamide) (PNNPAM) microgels stand out due to their very sharp volume phase transition, whereas Poly(N-isopropylmethacrylamide) (PNIPMAM) particles are found to exhibit a more homogeneous network structure compared to the other two systems.
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Affiliation(s)
- Bastian Wedel
- Physical and Biophysical Chemistry, Bielefeld University, 33615 Bielefeld, Germany.
| | - Yvonne Hertle
- Physical and Biophysical Chemistry, Bielefeld University, 33615 Bielefeld, Germany.
| | - Oliver Wrede
- Physical and Biophysical Chemistry, Bielefeld University, 33615 Bielefeld, Germany.
| | - Johannes Bookhold
- Physical and Biophysical Chemistry, Bielefeld University, 33615 Bielefeld, Germany.
| | - Thomas Hellweg
- Physical and Biophysical Chemistry, Bielefeld University, 33615 Bielefeld, Germany.
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Scherzinger C, Balaceanu A, Hofmann C, Schwarz A, Leonhard K, Pich A, Richtering W. Cononsolvency of mono- and di-alkyl N-substituted poly(acrylamide)s and poly(vinyl caprolactam). POLYMER 2015. [DOI: 10.1016/j.polymer.2015.02.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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