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Prause A, Hechenbichler M, Schmidt RF, Prévost S, Cavalcanti LP, Laschewsky A, Gradzielski M. Modifying the Properties of Microemulsion Droplets by Addition of Thermoresponsive BAB* Copolymers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:2022-2035. [PMID: 36715565 DOI: 10.1021/acs.langmuir.2c03103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Oil-in-water (O/W) microemulsions (ME) typically feature a low viscosity and exhibit ordinary viscosity reduction as a function of temperature. However, for certain applications, avoiding or even reverting the temperature trend might be required. This can be conceived by adding thermoresponsive (TR) block copolymers that induce network formation as the temperature increases. Accordingly, various ME-polymer mixtures were studied for which three different block copolymer architectures of BAB*-, B2AB*-, and B(AB*)2-types were employed. Here, "B" represents a permanently hydrophobic, "A" a permanently hydrophilic, and "B*" a TR block. For the TR-block, three different poly(acrylamide)s, namely poly(N-n-propylacrylamide) (pNPAm), poly(N,N-diethylacrylamide) (pDEAm), and poly(N-isopropylacrylamide) (pNiPAm), were used, which all exhibit a lower critical solution temperature. For a well-selected ME concentration, these block copolymers lead to a viscosity enhancement with increasing temperature. At a polymer concentration of about 22 g L-1, the most pronounced enhancement was observed for the pNPAm-based systems with factors up to 3, 5, and 8 for BAB*, B2AB*, and B(AB*)2, respectively. This phenomenon is caused by the formation of a transitory network mediated by TR-blocks, as evidenced by the direct correlation between the attraction strength and the viscosity enhancement. For applications requiring a high hydrophobic payload, which is attained via ME droplets, this kind of tailored temperature-dependent viscosity control of surfactant systems should therefore be advantageous.
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Affiliation(s)
- Albert Prause
- FG Physical Chemistry/Molecular Material Science, Technische Universität Berlin, Straße des 17. Juni 135, Berlin10623, Germany
| | - Michelle Hechenbichler
- Department of Chemistry, Universität Potsdam, Karl-Liebknecht-Straße 24-25, Potsdam14476, Germany
| | - Robert F Schmidt
- FG Physical Chemistry/Molecular Material Science, Technische Universität Berlin, Straße des 17. Juni 135, Berlin10623, Germany
| | - Sylvain Prévost
- Institut Laue-Langevin, DS/LSS, 71 Avenue des Martyrs, CS 20 156, Grenoble Cedex 9F-38042, France
| | - Leide P Cavalcanti
- ISIS Facility, STFC, Rutherford Appleton Laboratory, Harwell Campus, DidcotOX11 0QX, U.K
| | - André Laschewsky
- Department of Chemistry, Universität Potsdam, Karl-Liebknecht-Straße 24-25, Potsdam14476, Germany
- Fraunhofer Institute of Applied Polymer Research IAP, Geiselbergstraße 69, Potsdam14476, Germany
| | - Michael Gradzielski
- FG Physical Chemistry/Molecular Material Science, Technische Universität Berlin, Straße des 17. Juni 135, Berlin10623, Germany
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Malo de Molina P, Gradzielski M. Gels Obtained by Colloidal Self-Assembly of Amphiphilic Molecules. Gels 2017; 3:E30. [PMID: 30920526 PMCID: PMC6318676 DOI: 10.3390/gels3030030] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Revised: 07/29/2017] [Accepted: 07/31/2017] [Indexed: 11/17/2022] Open
Abstract
Gelation in water-based systems can be achieved in many different ways. This review focusses on ways that are based on self-assembly, i.e., a bottom-up approach. Self-assembly naturally requires amphiphilic molecules and accordingly the systems described here are based on surfactants and to some extent also on amphiphilic copolymers. In this review we are interested in cases of low and moderate concentrations of amphiphilic material employed to form hydrogels. Self-assembly allows for various approaches to achieve gelation. One of them is via increasing the effective volume fraction by encapsulating solvent, as in vesicles. Vesicles can be constructed in various morphologies and the different cases are discussed here. However, also the formation of very elongated worm-like micelles can lead to gelation, provided the structural relaxation times of these systems is long enough. Alternatively, one may employ amphiphilic copolymers of hydrophobically modified water soluble polymers that allow for network formation in solution by self-assembly due to having several hydrophobic modifications per polymer. Finally, one may combine such polymers with surfactant self-assemblies and thereby produce interconnected hybrid network systems with corresponding gel-like properties. As seen here there is a number of conceptually different approaches to achieve gelation by self-assembly and they may even become combined for further variation of the properties. These different approaches are described in this review to yield a comprehensive overview regarding the options for achieving gel formation by self-assembly.
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Affiliation(s)
- Paula Malo de Molina
- Centro de Física de Materiales (CSIC, UPV/EHU) and Materials Physics Center MPC, Paseo Manuel de Lardizabal 5, E-20018 San Sebastián, Spain.
| | - Michael Gradzielski
- Institut für Physikalische & Theoretische Chemie-Stranski Laboratorium, Technische Universität Berlin, Straße des 17. Juni 124, 10623 Berlin, Germany.
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Stubenrauch C, Gießelmann F. Gelled Complex Fluids: Combining Unique Structures with Mechanical Stability. Angew Chem Int Ed Engl 2016; 55:3268-75. [DOI: 10.1002/anie.201506603] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Cosima Stubenrauch
- Institut für Physikalische Chemie; Universität Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Frank Gießelmann
- Institut für Physikalische Chemie; Universität Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
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Stubenrauch C, Gießelmann F. Gelierte komplexe Fluide - die Verbindung einzigartiger Strukturen mit mechanischer Stabilität. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201506603] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Cosima Stubenrauch
- Institut für Physikalische Chemie; Universität Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Deutschland
| | - Frank Gießelmann
- Institut für Physikalische Chemie; Universität Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Deutschland
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de Molina PM, Herfurth C, Laschewsky A, Gradzielski M. Structure and dynamics of networks in mixtures of hydrophobically modified telechelic multiarm polymers and oil in water microemulsions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:15994-16006. [PMID: 23075139 DOI: 10.1021/la303673a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The structural and dynamical properties of oil-in-water (O/W) microemulsions (MEs) modified with telechelic polymers of different functionality (e.g., number of hydrophobically modified arms, f) were studied by means of dynamic light scattering (DLS), small-angle neutron scattering (SANS), and high frequency rheology measurements as a function of the polymer architecture and the amount of added polymer. For this purpose, we employed tailor-made hydrophobically end-capped poly(N,N-dimethylacrylamide) star polymers of a variable number of endcaps, f, of different alkyl chain lengths, synthesized by the reversible addition-fragmentation chain transfer method. The addition of the different end-capped polymers to an uncharged ME of O/W droplets leads to a large enhancement of the viscosity of the systems. SANS experiments show that the O/W ME droplets are not changed upon the addition of the polymer, and its presence only changes the interdroplet interactions. The viscosity increases largely upon addition of a polymer, and this enhancement depends pronouncedly on the alkyl length of the hydrophobic sticker as it controls the residence time in a ME droplet. Similarly, the high frequency modulus G(0) depends on the amount of added polymer but not on the sticker length. G(0) was found to be directly proportional to f - 1. The onset of network formation is shifted to a lower number of stickers per ME droplet with increasing f, and the network formation becomes more effective. Thus, the dynamics of network formation are controlled by the polymer architecture. The effect on the dynamics seen by DLS is even more pronounced. Upon increasing the polymer concentration, slower relaxation modes appear that become especially pronounced with increasing number of arms. The relaxation dynamics are correlated to the rheological relaxation, and both are controlled by the polymer architecture.
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Affiliation(s)
- Paula Malo de Molina
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, Berlin, Germany.
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Saetung N, Campistron I, Pascual S, Pilard JF, Fontaine L. One-Pot Synthesis of Natural Rubber-Based Telechelic cis-1,4-Polyisoprenes and Their Use To Prepare Block Copolymers by RAFT Polymerization. Macromolecules 2011. [DOI: 10.1021/ma102406w] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nitinart Saetung
- LCOM-Chimie des Polymères, UCO2M, UMR CNRS 6011, Université du Maine, Avenue Olivier Messiaen, 72085 Le Mans Cedex 09, France
| | - Irène Campistron
- LCOM-Chimie des Polymères, UCO2M, UMR CNRS 6011, Université du Maine, Avenue Olivier Messiaen, 72085 Le Mans Cedex 09, France
| | - Sagrario Pascual
- LCOM-Chimie des Polymères, UCO2M, UMR CNRS 6011, Université du Maine, Avenue Olivier Messiaen, 72085 Le Mans Cedex 09, France
| | - Jean-François Pilard
- LCOM-Chimie des Polymères, UCO2M, UMR CNRS 6011, Université du Maine, Avenue Olivier Messiaen, 72085 Le Mans Cedex 09, France
| | - Laurent Fontaine
- LCOM-Chimie des Polymères, UCO2M, UMR CNRS 6011, Université du Maine, Avenue Olivier Messiaen, 72085 Le Mans Cedex 09, France
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Sarraguça JMG, Pais AACC, Linse P. Structure of microemulsion-ABA triblock copolymer networks. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:11153-11163. [PMID: 18729531 DOI: 10.1021/la801658k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Structural equilibrium properties of transient networks formed by microemulsion droplets and ABA triblock copolymers in solution have been studied by Monte Carlo simulation. The droplets were represented by soft spheres, and the polymers were represented by junctions connected by harmonic bonds with an angular potential regulating the intrinsic chain stiffness. The interaction parameters were selected such that the end A-blocks were localized inside the droplets and the middle B-block in the continuous phase. The influence of (i) the polymer concentration, (ii) the polymer stiffness, and (iii) the contour length of the middle B-block on the formation and the structure of the microemulsion-polymer network were investigated using polymer end-to-end separation probability distribution functions, droplet radial distribution functions, droplet-droplet nearest-neighbor probability distribution functions, and network connectivity indicators. An increase of the polymer-droplet number ratio had a strong impact on the network formation. Under typical conditions and at an intermediate polymer-droplet number ratio, (i) the fraction of polymers forming bridges between droplets increased from essentially zero to unity and (ii) the fraction of polymers that were forming loops decreased as the ratio of the polymer end-to-end separation and the surface-to-surface separation between neighboring droplets for a hypothetical homogeneous droplet distribution was increased from 0.5 to 2. For long and flexible polymers, a mesoscopic segregation triggered by a depletion attraction between droplets appeared, and, furthermore, for sufficiently stiff chains, only bridge conformations occurred. The percolation probability could be represented as a function of the average droplet cluster size only, across all systems.
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Affiliation(s)
- J M G Sarraguça
- Department of Chemistry, University of Coimbra, 3004-353 Coimbra, Portugal.
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Wines TH, Somasundaran P, Turro NJ, Jockusch S, Ottaviani MF. Investigation of the mobility of amphiphilic polymer—AOT reverse microemulsion systems using electron spin resonance. J Colloid Interface Sci 2005; 285:318-25. [PMID: 15797429 DOI: 10.1016/j.jcis.2004.11.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2004] [Accepted: 11/04/2004] [Indexed: 10/26/2022]
Abstract
Amphiphilic polymers can be used as tools to manipulate the behavior of reverse microemulsions. EPR spectroscopy employing the spin probe 5-doxyl stearic acid was used to study the adsorption of a comb type polymer (polymaleic anhydride octyl vinyl ether) and a diblock polymer (polybutadiene-ethylene oxide) onto reverse microemulsion droplets formed from Aerosol-OT/heptane/water. The findings indicate that the comb type polymer was adsorbed by the reverse microemulsion drops at low polymer concentrations causing a structural change of the micelle.
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Affiliation(s)
- Thomas H Wines
- Columbia University, 1140 Amsterdam Avenue, New York, NY, USA.
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Liu T, Schuch H, Gerst M, Chu B. Laser Light Scattering Study of Microemulsion-like Polymerization Processes with Block Copolymers as Dispersants. Macromolecules 1999. [DOI: 10.1021/ma990403n] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tianbo Liu
- Polymers Laboratory, BASF AG, D-67056, Ludwigshafen, Germany, Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794-3400, and Department of Materials Science and Engineering, State University of New York at Stony Brook, Stony Brook, New York 11794-2275
| | - Horst Schuch
- Polymers Laboratory, BASF AG, D-67056, Ludwigshafen, Germany, Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794-3400, and Department of Materials Science and Engineering, State University of New York at Stony Brook, Stony Brook, New York 11794-2275
| | - Matthias Gerst
- Polymers Laboratory, BASF AG, D-67056, Ludwigshafen, Germany, Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794-3400, and Department of Materials Science and Engineering, State University of New York at Stony Brook, Stony Brook, New York 11794-2275
| | - Benjamin Chu
- Polymers Laboratory, BASF AG, D-67056, Ludwigshafen, Germany, Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794-3400, and Department of Materials Science and Engineering, State University of New York at Stony Brook, Stony Brook, New York 11794-2275
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Affiliation(s)
- Wolfgang Meier
- Institut für Physikalische Chemie, Departement Chemie, Universität Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
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