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Septani CM, Kua MF, Chen CY, Lin JM, Sun YS. Micellization, aggregation, and gelation of polystyrene-block-poly(ethylene oxide) in cosolvents added with hydrochloric acid. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.129857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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2
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Septani CM, Shih O, Yeh YQ, Sun YS. Structural Evolution of a Polystyrene- Block-Poly(Ethylene Oxide) Block Copolymer in Tetrahydrofuran/Water Cosolvents. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:5987-5995. [PMID: 35507040 DOI: 10.1021/acs.langmuir.2c00041] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
This study aims to quantitatively investigate the effect of water content on the self-assembly behavior of polystyrene-block-poly(ethylene oxide) (PS-b-PEO) in tetrahydrofuran/water cosolvents by small-angle X-ray scattering. PS-b-PEO chains preferentially form fractal aggregates at a dilute concentration in neat tetrahydrofuran (THF). By adding a small amount of water into THF, PS-b-PEO forms gelled networks. The gelled networks have correlated inhomogeneities, which were generated through mesophase separation. These gelled networks are not present when PS-b-PEO is dissolved in THF/methanol and THF/ethanol cosolvents. The substitution of water with 12 M HCl reduces the viscosity of the gelled networks. Those results indicate that the gelled networks of PS-b-PEO need hydrogen bonds formed from surrounding water molecules to be bridging agents, which connect different PEO block chains together. Upon increasing the water content in THF/water cosolvents, dispersed micelles with a core-shell conformation or aggregated micelles preferentially coexist with fractal aggregates.
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Affiliation(s)
- Cindy Mutiara Septani
- Department of Chemical and Materials Engineering, National Central University, Taoyuan 32001, Taiwan
| | - Orion Shih
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Yi-Qi Yeh
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Ya-Sen Sun
- Department of Chemical and Materials Engineering, National Central University, Taoyuan 32001, Taiwan
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Kumi BC, Greer SC. Micelles of polybutadiene-b-poly(ethylene oxide) in deuterated methanol and deuterated cyclohexane. J Colloid Interface Sci 2012; 386:212-7. [PMID: 22921407 DOI: 10.1016/j.jcis.2012.06.091] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 06/26/2012] [Accepted: 06/27/2012] [Indexed: 11/30/2022]
Abstract
Micellization of the diblock copolymer poly(ethylene oxide)-b-polybutadiene, PEO(132)-PB(89), where the subscripts denote the number of monomers in each block, has been studied in solution in deuterated methanol and in deuterated cyclohexane, in order to compare the micellar assembly in deuterated solvents to that in protonated solvents. The methods used were dynamic light scattering and small angle neutron scattering. In CD(3)OD, PEO(132)-PB(89) forms only spherical micelles that change little in size or shape over the temperature range 21-68°C. In CH(3)OH, PEO(132)-PB(89) forms coexisting cylindrical and spherical structures over the entire temperature range. Thus cylindrical micelles form in CH(3)OH, but do not form in CD(3)OD. In C(6)D(12), the copolymer forms flexible, cylindrical micelles at lower temperatures; above about 40°C, spherical micelles and free copolymers appear and coexist with the cylindrical micelles. The behavior in C(6)H(12) is the same as in C(6)D(12), except that no free copolymers are observed in C(6)H(12). The stronger hydrogen bonding in deuterated methanol as compared to protonated methanol is assumed to be the source of the difference in assembly.
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Affiliation(s)
- Bryna C Kumi
- Department of Chemistry and Biochemistry, The University of Maryland College Park, College Park, MD 20742, United States.
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Memesa M, Lenz S, Emmerling SGJ, Nett S, Perlich J, Müller-Buschbaum P, Gutmann JS. Morphology and photoluminescence study of titania nanoparticles. Colloid Polym Sci 2011; 289:943-953. [PMID: 21765580 PMCID: PMC3102206 DOI: 10.1007/s00396-011-2421-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 03/06/2011] [Accepted: 03/08/2011] [Indexed: 11/30/2022]
Abstract
Titania nanoparticles are prepared by sol–gel chemistry with a poly(ethylene oxide) methyl ether methacrylate-block-poly(dimethylsiloxane)-block-poly(ethylene oxide) methyl ether methacrylate triblock copolymer acting as the templating agent. The sol–gel components—hydrochloric acid, titanium tetraisopropoxide, and triblock copolymer—are varied to investigate their effect on the resulting titania morphology. An increased titania precursor or polymer content yields smaller primary titania structures. Microbeam grazing incidence small-angle X-ray scattering measurements, which are analyzed with a unified fit model, reveal information about the titania structure sizes. These small structures could not be observed via the used microscopy techniques. The interplay among the sol–gel components via our triblock copolymer results in different sized titania nanoparticles with higher packing densities. Smaller sized titania particles, (∼13–20 nm in diameter) in the range of exciton diffusion length, are formed by 2% by weight polymer and show good crystallinity with less surface defects and high oxygen vacancies.
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Affiliation(s)
- Mine Memesa
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
- Present Address: Materials Science and Technology of Polymers, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, the Netherlands
| | - Sebastian Lenz
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | | | - Sebastian Nett
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Jan Perlich
- Lehrstuhl für Funktionelle Materialien, Technische Universität München, Physik-Department E13, James-Franck-Str. 1, 85747 Garching, Germany
- Present Address: HASYLAB at DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - Peter Müller-Buschbaum
- Lehrstuhl für Funktionelle Materialien, Technische Universität München, Physik-Department E13, James-Franck-Str. 1, 85747 Garching, Germany
| | - Jochen S. Gutmann
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
- Present Address: Deutsches Textilforschungszentrum Nord-West e.V., Institut an der Universität Duisburg-Essen, Adlerstraße 1, 47798 Krefeld, Germany
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Ganguly R, Choudhury N, Aswal VK, Hassan PA. Pluronic L64 Micelles near Cloud Point: Investigating the Role of Micellar Growth and Interaction in Critical Concentration Fluctuation and Percolation. J Phys Chem B 2008; 113:668-75. [DOI: 10.1021/jp808304w] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- R. Ganguly
- Chemistry Division, Theoretical Chemistry Section, and Solid State Physics Division, Bhabha Atomic Research Center, Mumbai 400 085, India
| | - N. Choudhury
- Chemistry Division, Theoretical Chemistry Section, and Solid State Physics Division, Bhabha Atomic Research Center, Mumbai 400 085, India
| | - V. K. Aswal
- Chemistry Division, Theoretical Chemistry Section, and Solid State Physics Division, Bhabha Atomic Research Center, Mumbai 400 085, India
| | - P. A. Hassan
- Chemistry Division, Theoretical Chemistry Section, and Solid State Physics Division, Bhabha Atomic Research Center, Mumbai 400 085, India
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Bouilhac C, Cloutet E, Taton D, Deffieux A, Borsali R, Cramail H. Block copolymer micelles as nanoreactors for single-site polymerization catalysts. ACTA ACUST UNITED AC 2008. [DOI: 10.1002/pola.23142] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Chaibundit C, Ricardo NMPS, Ricardo NMPS, de M L L Costa F, Wong MGP, Hermida-Merino D, Rodriguez-Perez J, Hamley IW, Yeates SG, Booth C. Effect of ethanol on the micellization and gelation of pluronic p123. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:12260-12266. [PMID: 18844386 DOI: 10.1021/la8022425] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
In certain applications copolymer P123 (E21P67E21) is dissolved in water-ethanol mixtures, initially to form micellar solutions and eventually to gel. For P123 in 10, 20, and 30 wt % aqueous ethanol we used dynamic light scattering from dilute solutions to confirm micellization, oscillatory rheometry, and visual observation of mobility (tube inversion) to determine gel formation in concentrated solutions and small-angle X-ray scattering (SAXS) to determine gel structure. Except for solutions in 30 wt % aqueous ethanol, a clear-turbid transition was encountered on heating dilute and concentrated micellar solutions alike, and as for solutions in water alone (Chaibundit et al. Langmuir 2007, 23, 9229) this could be ascribed to formation of wormlike micelles. Dense clouding, typical of phase separation, was observed at higher temperatures. Regions of isotropic and birefringent gel were defined for concentrated solutions and shown (by SAXS) to have cubic (fcc and hcp) and hexagonal structures, consistent with packed spherical and elongated micelles, respectively. The cubic gels (0, 10, and 20 wt % ethanol) were clear, while the hex gels were either turbid (0 and 10 wt % ethanol), turbid enclosing a clear region (20 wt % ethanol), or entirely clear (30 wt % ethanol). The SAXS profile was unchanged between turbid and clear regions of the 20 wt % ethanol gel. Temperature scans of dynamic moduli showed (as expected) a clear distinction between high-modulus cubic gels (G'max approximately 20-30 kPa) and lower modulus hex gels (G'max<10 kPa).
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Affiliation(s)
- Chiraphon Chaibundit
- Polymer Science Program, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90112 Thailand.
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Kelarakis A, Castelletto V, Krysmann MJ, Havredaki V, Viras K, Hamley IW. Polymer-surfactant vesicular complexes in aqueous medium. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:3767-3772. [PMID: 18315019 DOI: 10.1021/la703745z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The introduction of ionic single-tailed surfactants to aqueous solutions of EO(18)BO(10) [EO = poly(ethylene oxide), BO = poly(1,2-butylene oxide), subscripts denote the number of repeating units] leads to the formation of vesicles, as probed by laser scanning confocal microscopy. Dynamic light scattering showed that the dimensions of these aggregates at early stages of development do not depend on the sign of the surfactant head group charge. Small-angle X-ray scattering (SAXS) analysis indicated the coexistence of smaller micelles of different sizes and varying polymer content in solution. In strong contrast to the dramatic increase of size of dispersed particles induced by surfactants in dilute solution, the d-spacing of corresponding mesophases reduces monotonically upon increasing surfactant loading. This effect points to the suppression of vesicles as a consequence of increasing ionic strength in concentrated solutions. Maximum enhancements of storage modulus and thermal stability of hybrid gels take place at different compositions, indicating a delicate balance between the number and size of polymer-poor aggregates (population increases with surfactant loading) and the number and size of polymer-surfactant complexes (number and size decrease in high surfactant concentrations).
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Affiliation(s)
- Antonios Kelarakis
- Physical Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, Athens, Greece.
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Kelarakis A, Castelletto V, Krysmann MJ, Havredaki V, Viras K, Hamley IW. Interactions of Bovine Serum Albumin with Ethylene Oxide/Butylene Oxide Copolymers in Aqueous Solution. Biomacromolecules 2008; 9:1366-71. [DOI: 10.1021/bm800046m] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Antonios Kelarakis
- National and Kapodistrian University of Athens, Department of Chemistry, Physical Chemistry Laboratory, Panepistimiopolis, 157 71 Athens, Greece, and School of Chemistry, The University of Reading, Post Office Box 224, Whiteknights, Reading RG6 6AD, United Kingdom
| | - Valeria Castelletto
- National and Kapodistrian University of Athens, Department of Chemistry, Physical Chemistry Laboratory, Panepistimiopolis, 157 71 Athens, Greece, and School of Chemistry, The University of Reading, Post Office Box 224, Whiteknights, Reading RG6 6AD, United Kingdom
| | - Marta J. Krysmann
- National and Kapodistrian University of Athens, Department of Chemistry, Physical Chemistry Laboratory, Panepistimiopolis, 157 71 Athens, Greece, and School of Chemistry, The University of Reading, Post Office Box 224, Whiteknights, Reading RG6 6AD, United Kingdom
| | - Vasiliki Havredaki
- National and Kapodistrian University of Athens, Department of Chemistry, Physical Chemistry Laboratory, Panepistimiopolis, 157 71 Athens, Greece, and School of Chemistry, The University of Reading, Post Office Box 224, Whiteknights, Reading RG6 6AD, United Kingdom
| | - Kyriakos Viras
- National and Kapodistrian University of Athens, Department of Chemistry, Physical Chemistry Laboratory, Panepistimiopolis, 157 71 Athens, Greece, and School of Chemistry, The University of Reading, Post Office Box 224, Whiteknights, Reading RG6 6AD, United Kingdom
| | - Ian W. Hamley
- National and Kapodistrian University of Athens, Department of Chemistry, Physical Chemistry Laboratory, Panepistimiopolis, 157 71 Athens, Greece, and School of Chemistry, The University of Reading, Post Office Box 224, Whiteknights, Reading RG6 6AD, United Kingdom
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Norman AI, Ho DL, Greer SC. Partitioning, Fractionation, and Conformations of Star Poly(ethylene glycol) in Isobutyric Acid and Water. Macromolecules 2007. [DOI: 10.1021/ma071568w] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Alexander I. Norman
- Department of Chemical and Biomolecular Engineering and Department of Chemistry and Biochemistry, The University of Maryland College Park, College Park, Maryland, 20742, and The Electronic Materials Group, Polymers Division, National Institute of Standards and Technology, Gaithersburg, Maryland, 20899
| | - Derek L. Ho
- Department of Chemical and Biomolecular Engineering and Department of Chemistry and Biochemistry, The University of Maryland College Park, College Park, Maryland, 20742, and The Electronic Materials Group, Polymers Division, National Institute of Standards and Technology, Gaithersburg, Maryland, 20899
| | - Sandra C. Greer
- Department of Chemical and Biomolecular Engineering and Department of Chemistry and Biochemistry, The University of Maryland College Park, College Park, Maryland, 20742, and The Electronic Materials Group, Polymers Division, National Institute of Standards and Technology, Gaithersburg, Maryland, 20899
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Norman AI, Ivkov R, Forbes JG, Greer SC. The polymerization of actin: structural changes from small-angle neutron scattering. J Chem Phys 2007; 123:154904. [PMID: 16252969 DOI: 10.1063/1.2039088] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a new analysis of small-angle neutron-scattering data from rabbit muscle actin in the course of the polymerization from G-actin to F-actin as a function of temperature. The data, from Ivkov et al. [J. Chem. Phys. 108, 5599 (1998)], were taken in D2O buffer with Ca2+ as the divalent cation on the G-actin in the presence of ATP and with KCl as the initiating salt. The new analysis of the data using modeling and the method of generalized indirect fourier transform (O. Glatter, GIFT, University of Graz, Austria, http://physchem.kfunigraz.ac.at/sm/) provide shapes and dimensions of the G-actin monomer and of the growing actin oligomer in solution as a function of temperature and salt concentration. This analysis indicates that the G-actin monomer, under the conditions given above, is a sphere 50-54 A in diameter as opposed to the oblate ellipsoid seen by x-ray crystallography. The F-actin dimensions are consistent with x-ray crystal structure determinations.
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Affiliation(s)
- Alexander I Norman
- Department of Chemistry and Biochemistry, The University of Maryland College Park, College Park, Maryland 20742, USA.
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Norman AI, Fei Y, Ho DL, Greer SC. Folding and Unfolding of Polymer Helices in Solution. Macromolecules 2007. [DOI: 10.1021/ma0622783] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alexander I. Norman
- Department of Chemical and Biomolecular Engineering and Department of Chemistry and Biochemistry, The University of Maryland College Park, College Park, Maryland 20742, and Polymers Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899
| | - Yiwei Fei
- Department of Chemical and Biomolecular Engineering and Department of Chemistry and Biochemistry, The University of Maryland College Park, College Park, Maryland 20742, and Polymers Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899
| | - Derek L. Ho
- Department of Chemical and Biomolecular Engineering and Department of Chemistry and Biochemistry, The University of Maryland College Park, College Park, Maryland 20742, and Polymers Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899
| | - Sandra C. Greer
- Department of Chemical and Biomolecular Engineering and Department of Chemistry and Biochemistry, The University of Maryland College Park, College Park, Maryland 20742, and Polymers Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899
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Norman AI, Ho DL, Lee JH, Karim A. Spontaneous Formation of Vesicles of Diblock Copolymer EO6BO11in Water: A SANS Study†. J Phys Chem B 2006; 110:62-7. [PMID: 16471500 DOI: 10.1021/jp0544336] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Small angle neutron scattering (SANS) is used to study the structures formed in water by a diblock copolymer EO6BO11 (having 6 ethylene oxide, EO, and 11 butylene oxide, BO, units). The data show that polymer solutions over a broad concentration range (0.05-20 wt %) contain vesicular structures at room temperature. Interestingly, these vesicles could be formed without any external energy input, such as extrusion, which is commonly required for the formation of other block copolymer or lipid vesicles. The EO6BO11 vesicles are predominantly unilamellar at low polymer concentrations, whereas at higher polymer concentrations or temperatures there is a coexisting population of unilamellar and multilamellar vesicles. At a critical concentration and temperature, the vesicular structures fuse into lyotropic arrays of planar lamellar sheets. The findings from this study are in broad agreement with the work of Harris et al. (Langmuir, 2002, 18, 5337), who used electron microscopy to identify the vesicle phase in the same system.
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Affiliation(s)
- Alexander I Norman
- Polymers Division, Stop 8542, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland, 20899, USA
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Booth C, Attwood D, Price C. Self-association of block copoly(oxyalkylene)s in aqueous solution. Effects of composition, block length and block architecture. Phys Chem Chem Phys 2006; 8:3612-22. [PMID: 16883389 DOI: 10.1039/b605367j] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The article deals with the association behaviour in dilute aqueous solution of block copoly(oxyalkylene)s in which hydrophilic poly(ethylene oxide) is combined with hydrophobic poly(propylene oxide), poly(1,2-butylene oxide) or poly(styrene oxide). Polymers with three simple architectures are considered, i.e. copolymers of type EmAn, EmAnEm and AnEmAn, where E denotes an oxyethylene unit, A denotes a hydrophobic oxyalkylene unit, and the subscripts m and n denote number-average block lengths in repeat units. The aim is to examine how composition, block length and block architecture govern two fundamental properties, critical micelle concentration (cmc) and micelle association number (N), for systems which are in dynamic equilibrium. Copolymers with properties known to be greatly affected by heterogeneity in composition are excluded from consideration. A uniform pattern of behaviour emerges when log(cmc) is plotted against reduced hydrophobic block length (x), consistent with the micellisation equilibrium changing from one between unimers and multimolecular micelles at low values of x, to one between unimolecular micelles and multimolecular micelles at high values of x. Support for this model is provided by the enthalpy of micellisation, values of which fall effectively to zero as x is increased. Values of the micelle association number are used to define a critical hydrophobic block length for micellisation (n(cr)) for each class of diblock copolymers, values of which apply equally well to the half-length of the central block of corresponding EmAnEm triblock copolymers. Given these values, and irrespective of block architecture, the overall scaling law for the weight-average association number of the micelles is shown to be Nw = n'(1.07)m(-0.63) where m is the length (or half-length) of the hydrophilic block, and n' is the effective length of the hydrophobic block, equal to its length (or half-length) minus the critical length, i.e. n' = n-n(cr).
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Affiliation(s)
- Colin Booth
- School of Chemistry, University of Manchester, Manchester, UK M13 9PL
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Fairclough JPA, Norman AI, Shaw B, Nace VM, Heenan RK. Small angle neutron scattering study of the structure and hydration of polyoxyethylene-block-polyoxybutylene in aqueous solution. POLYM INT 2006. [DOI: 10.1002/pi.2044] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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