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Dattani R, Cabral JT. Polymer fullerene solution phase behaviour and film formation pathways. SOFT MATTER 2015; 11:3125-3131. [PMID: 25739808 DOI: 10.1039/c5sm00053j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We report the phase behaviour of polymer/fullerene/solvent ternary mixtures and its consequence for the morphology of the resulting composite thin films. We focus particularly on solutions of polystyrene (PS), C60 fullerene and toluene, which are examined by static and dynamic light scattering, and films obtained from various solution ages and thermal annealing conditions, using atomic force and light microscopy. Unexpectedly, the solution phase behaviour below the polymer overlap concentration, c*, is found to be described by a simple excluded volume argument (occupied by the polymer chains) and the neat C60/solvent miscibility. Scaling consistent with full exclusion is found when the miscibility of the fullerene in the solvent is much lower than that of the polymer, giving way to partial exclusion with more soluble fullerenes (phenyl-C61-butyric acid methyl ester, PCBM) and a less asymmetric solvent (chlorobenzene), employed in photovoltaic devices. Spun cast and drop cast films were prepared from PS/C60/toluene solutions across the phase diagram to yield an identical PS/C60 composition and film thickness, resulting in qualitatively different morphologies in agreement with our measured solution phase boundaries. Our findings are relevant to the solution processing of polymer/fullerene composites (including organic photovoltaic devices), which generally require effective solubilisation of fullerene derivatives and polymer pairs in this concentration range, and the design of well-defined thin film morphologies.
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Affiliation(s)
- Rajeev Dattani
- Department of Chemical Engineering, Centre for Plastic Electronics, Imperial College London, London, SW7 2AZ, UK.
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Dattani R, Michels R, Nedoma AJ, Schweins R, Westacott P, Huber K, Cabral JT. Conformation and Interactions of Polystyrene and Fullerenes in Dilute to Semidilute Solutions. Macromolecules 2014. [DOI: 10.1021/ma501015s] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Rolf Michels
- Physikalische
Chemie, Universität Paderborn, 33098 Paderborn, Germany
| | | | - Ralf Schweins
- Institut Laue-Langevin, DS/LSS, F-38042 Grenoble, France
| | | | - Klaus Huber
- Physikalische
Chemie, Universität Paderborn, 33098 Paderborn, Germany
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Annunziata MA, Pelissetto A. Fluid–fluid demixing curves for colloid–polymer mixtures in a random colloidal matrix. Mol Phys 2011. [DOI: 10.1080/00268976.2011.622724] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Magida MM, Gad YH, El-Nahas HH. The use of compatible blend of styrene-vinylacetate copolymer/natural rubber latex in pressure-sensitive adhesive applications by using irradiation and chemical initiation. J Appl Polym Sci 2009; 114:157-165. [DOI: 10.1002/app.30175] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/05/2023]
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Myakonkaya O, Eastoe J. Low energy methods of phase separation in colloidal dispersions and microemulsions. Adv Colloid Interface Sci 2009; 149:39-46. [PMID: 19371853 DOI: 10.1016/j.cis.2009.03.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2009] [Revised: 03/31/2009] [Accepted: 03/31/2009] [Indexed: 12/17/2022]
Abstract
The majority of work on phase separation of colloidal systems has been concerned with the energy intensive approaches such as ultracentrifugation, solvent evaporation, changes of temperature and pressure etc. However, in modern nanotechnology it is desirable to minimize environmental impact in order to achieve separation and recovery of colloidal products. In this review recent research on phase separation methods, requiring relatively lower energy consumption are summarized. These include polymer-, solvent- and photo-induced approaches to phase separation.
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Mutch KJ, van Duijneveldt JS, Eastoe J, Grillo I, Heenan RK. Testing the scaling behavior of microemulsion-polymer mixtures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:3944-3952. [PMID: 19007255 DOI: 10.1021/la802488f] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The phase behavior and structural properties of "protein limit" mixtures of small (radius 20-30 A) water-in-oil microemulsion droplets (colloids) and large (radius 130-580 A) nonadsorbing polymer chains have been investigated. Accepted theoretical scaling relations for describing correlations have been applied and do not account fully for the observations; solvency effects may account for the deviations. The polymer/colloid size ratio has been varied from around 4 to 19 by using three different molecular weights of polyisoprene. Small-angle neutron scattering (SANS) has been used to determine partial structure factors (PSF) through contrast variation. The structure factors describing colloid-colloid interactions for the three polymers at fixed polymer concentration are shown to exhibit the same scaling behavior as the phase boundaries, provided that samples are sufficiently far from the demixing phase transition. The structure factors show a dramatic increase at low wavevectors on approaching the phase boundary, and behavior in this region does not obey expected scaling relations. By calculating effective polymer Flory-Huggins parameters, the effect of apparent solvent properties on adding microemulsion are shown to be less dramatic for the higher molecular weight polymers. This study extends previous work carried out on microemulsion-polymer mixtures.
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Affiliation(s)
- Kevin J Mutch
- School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom, Institut Max-Von-Laue-Paul-Langevin, BP 156-X, F-38042 Grenoble Cedex, France
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Mutch KJ, Duijneveldt JSV, Eastoe J, Grillo I, Heenan RK. Small-angle neutron scattering study of microemulsion-polymer mixtures in the protein limit. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:3053-3060. [PMID: 18275227 DOI: 10.1021/la702913y] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Contrast variation small-angle neutron scattering (SANS) has been employed to study complex fluids comprising model microemulsions and polymers. The systems are water-in-oil microemulsions with added non-adsorbing polymer, under good polymer solvency conditions and semidilute polymer concentrations. The polymer/colloid size ratio was q approximately 11, which is well within the "protein limit". Four scattering contrasts were produced by selective deuteration of the dispersed and continuous phases and also the surfactant. In this way, the separate partial structure factors (PSF) for colloid-colloid (c-c), polymer-polymer (p-p), and colloid-polymer (c-p) have been obtained. The c-c PSF has been compared with theoretical predictions, allowing determination of a polymer correlation length. This is compared with a similar correlation length obtained from the p-p PSF, which is shown to increase with colloid concentration. In this sense, adding microemulsion has a similar effect on the dissolved polymer as reducing the solvent quality, and an effective Flory-Huggins chi parameter has been calculated. The cross-term PSF shows a distinct anti-correlation. This is the first time such structure factors have been determined experimentally for colloid-polymer systems in the protein limit and these allow a more detailed understanding of the structural interactions in these systems.
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Affiliation(s)
- Kevin J Mutch
- School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom, Institut Max-Von-Laue-Paul-Langevin, BP 156-X, F-38042 Grenoble Cedex, France
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Mutch KJ, van Duijneveldt JS, Eastoe J. Colloid-polymer mixtures in the protein limit. SOFT MATTER 2007; 3:155-167. [PMID: 32680259 DOI: 10.1039/b611137h] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
This review discusses the structure and phase behaviour of mixtures of colloidal particles and non-adsorbing polymers in the protein limit of large polymers and small colloids. The vast majority of work on colloid-polymer mixtures has been concerned with the colloid limit of large colloidal particles and small polymer chains. In this regime, the diameter of the colloidal particles, , is larger than the characteristic size of the polymer-taken as twice their radius of gyration, . The opposite limit, of size ratios , is called the protein limit due to the common practice of adding polymer to protein solutions in order to aid protein crystallisation. Theoretical predictions for systems in the protein limit are considered briefly and then the main focus is on recent experimental studies of mixtures in the protein limit.
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Affiliation(s)
- Kevin J Mutch
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, UKBS8 1TS.
| | | | - Julian Eastoe
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, UKBS8 1TS.
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Kramer T, Schweins R, Huber K. Coil Dimensions of Polystyrene Chains in Colloid−Polymer Mixtures at the Protein Limit: A SANS Study. Macromolecules 2005. [DOI: 10.1021/ma051308j] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Thomas Kramer
- Fakultät für Naturwissenschaften, Department Chemie, Universität Paderborn, Warburger Str. 100, D-33098 Paderborn, Germany
| | - Ralf Schweins
- Fakultät für Naturwissenschaften, Department Chemie, Universität Paderborn, Warburger Str. 100, D-33098 Paderborn, Germany
| | - Klaus Huber
- Fakultät für Naturwissenschaften, Department Chemie, Universität Paderborn, Warburger Str. 100, D-33098 Paderborn, Germany
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Kramer T, Schweins R, Huber K. Small-angle neutron scattering of dilute polystyrene chains at the protein limit of a colloid-polymer mixture. J Chem Phys 2005; 123:014903. [PMID: 16035865 DOI: 10.1063/1.1946751] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The present work investigates the structure of large polystyrene (PS) chains in solutions of small poly(ethyl methacrylate) (PEMA) microgel particles in toluene. Toluene is a good solvent for the PS chains. The PEMA colloids have an outer radius of R=11 nm which is much smaller in size than the radius of gyration Rg=58 nm of the PS chains. The system is considered to represent the protein limit of polymer-colloid mixtures. Structural investigation is performed by small-angle neutron scattering (SANS) using an appropriate contrast matching. This could be achieved by dissolving fully deuterated PS chains (D8-PS) in solutions of hydrogenated PEMA colloids in hydrogenated toluene (H-toluene). It is first demonstrated that PEMA colloids are satisfactorily contrast matched for SANS in H-toluene if the PEMA concentration does not exceed 200 g/l. Based on these findings, D8-PS is investigated by SANS in pure H-toluene and three different PEMA concentrations in H-toluene. The results indicate a drastic shrinking of D8-PS chain dimensions with increasing PEMA content. Comparison with model curves of star-branched Gaussian chains and Gaussian rings suggest a striking similarity of the respective density-density correlation of those models with the shrunken D8-PS chains. Along with this, a shrinking as large as 0.5 was estimated when the PEMA content reached 200 g/l.
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Affiliation(s)
- Thomas Kramer
- Department Chemie, Fakultät für Naturwissenschaften, Universität Paderborn, Warburger Strasse 100, D-33098 Paderborn, Germany
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Kramer T, Schweins R, Huber K. Silsesquioxane Molecules and Polystyrene Chains as a Model System for Colloid−Polymer Mixtures in the Protein Limit. Macromolecules 2004. [DOI: 10.1021/ma048766x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Thomas Kramer
- Universität Paderborn, Fakultät für Naturwissenschaften, Department Chemie, Warburger Str.100, D-33098 Paderborn, Germany
| | - Ralf Schweins
- Universität Paderborn, Fakultät für Naturwissenschaften, Department Chemie, Warburger Str.100, D-33098 Paderborn, Germany
| | - Klaus Huber
- Universität Paderborn, Fakultät für Naturwissenschaften, Department Chemie, Warburger Str.100, D-33098 Paderborn, Germany
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