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Structural characterization using SAXS and rheological behaviors of pluronic F127 and methylcellulose blends. Polym Bull (Berl) 2020. [DOI: 10.1007/s00289-020-03154-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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2
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Effect of Hydrophobic Interactions on Lower Critical Solution Temperature for Poly( N-isopropylacrylamide-co-dopamine Methacrylamide) Copolymers. Polymers (Basel) 2019; 11:polym11060991. [PMID: 31167423 PMCID: PMC6630648 DOI: 10.3390/polym11060991] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 05/21/2019] [Accepted: 05/23/2019] [Indexed: 11/17/2022] Open
Abstract
For the preparation of thermoresponsive copolymers, for e.g., tissue engineering scaffolds or drug carriers, a precise control of the synthesis parameters to set the lower critical solution temperature (LCST) is required. However, the correlations between molecular parameters and LCST are partially unknown and, furthermore, LCST is defined as an exact temperature, which oversimplifies the real situation. Here, random N-isopropylacrylamide (NIPAM)/dopamine methacrylamide (DMA) copolymers were prepared under a systematical variation of molecular weight and comonomer amount and their LCST in water studied by calorimetry, turbidimetry, and rheology. Structural information was deduced from observed transitions clarifying the contributions of molecular weight, comonomer content, end-group effect or polymerization degree on LCST, which were then statistically modeled. This proved that the LCST can be predicted through molecular structure and conditions of the solutions. While the hydrophobic DMA lowers the LCST especially the onset, polymerization degree has an important but smaller influence over all the whole LCST range.
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3
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Seo JW, Kim KJ, Kim SH, Hwang KM, Seok SH, Park ES. Effect of Process Parameters on Formation and Aggregation of Nanoparticles Prepared with a Shirasu Porous Glass Membrane. Chem Pharm Bull (Tokyo) 2016; 63:792-8. [PMID: 26423035 DOI: 10.1248/cpb.c15-00297] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The objectives of this study were to prepare itraconazole (ITZ) nanoparticles using a Shirasu porous glass (SPG) membrane and to characterize the effects of diverse preparation parameters on the physical stability of nanoparticles. SPG membrane technology was used for the antisolvent precipitation method. The preparation of nanoparticles was carried out over a wide range of continuous-phase factors (type of surfactant, surfactant concentration), dispersed-phase factors (solvent type, solvent volume used to dissolve ITZ), and technical factors (pressure, membrane pore size, stirring speed in the continuous phase, temperature). Improved physical stability of nanoparticles was observed when surfactant with a lower molecular weight and higher hydrophilic segment ratio was used. The water miscibility of the solvent also had an effect on the physical stability. N,N-Dimethylacetamide contributed to creating a well-rounded shape and narrow size distribution due to high miscibility. Concentration of the surfactant and solvent volume used for dissolving ITZ were related to instability of nanoparticles, resulting from depletion attraction and Ostwald ripening. In addition to these factors, technical factors changed the environment surrounding ITZ nanoparticles, such as the physicochemical equilibrium between surfactant and ITZ nanoparticles. Therefore, the appropriate continuous-phase factors, dispersed-phase factors, and technical factors should be maintained for stabilizing ITZ nanoparticles.
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4
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Peng S, Guo Q, Hughes TC, Hartley PG. Reversible photorheological lyotropic liquid crystals. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:866-872. [PMID: 24011217 DOI: 10.1021/la4030469] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We describe novel lyotropic liquid-crystalline (LLC) materials based on photoresponsive amphiphiles that exhibit rapid photoswitchable rheological properties of unprecedented magnitude between solidlike and liquidlike states. This was achieved through the synthesis of a novel azobenzene-containing surfactant (azo-surfactant) that actuates the transition between different LLC forms depending on illumination conditions. Initially, the azo-surfactant/water mixtures formed highly ordered and viscous LLC phases at 20-55 wt % water content. Spectroscopic, microscopic, and rheological analysis confirmed that UV irradiation induced the trans to cis isomerization of the azo-surfactant, leading to the disruption of the ordered LLC phases and a dramatic, rapid decrease in the viscosity and modulus resulting in a 3 orders of magnitude change from a solid (20,000 Pa) to a liquid (50 Pa) at rate of 13,500 Pa/s. Subsequent exposure to visible light reverses the transition, returning the viscosity essentially to its initial state. Such large, rapid, and reversible changes in rheological properties within this LLC system may open a door to new applications for photorheological fluids.
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Affiliation(s)
- Shuhua Peng
- Polymers Research Group, Institute for Frontier Materials, Deakin University , Locked Bag 2000, Geelong, Victoria 3220, Australia
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Vatankhah-Varnoosfaderani M, Hashmi S, GhavamiNejad A, Stadler FJ. Rapid self-healing and triple stimuli responsiveness of a supramolecular polymer gel based on boron–catechol interactions in a novel water-soluble mussel-inspired copolymer. Polym Chem 2014. [DOI: 10.1039/c3py00788j] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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6
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Martiel I, Sagalowicz L, Mezzenga R. A reverse micellar mesophase of face-centered cubic Fm3m symmetry in phosphatidylcholine/water/organic solvent ternary systems. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:15805-15812. [PMID: 24295511 DOI: 10.1021/la404307x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We report the formation of a reverse micellar cubic mesophase of symmetry Fm3m (Q(225)) in ternary mixtures of soy bean phosphatidylcholine (PC), water, and an organic solvent, including cyclohexane, (R)-(+)-limonene, and isooctane, studied by small-angle X-ray scattering (SAXS) and oscillatory shear rheology at room temperature. The mesophase structure consists of a compact packing of remarkably large reverse micelles in a face-centered cubic (fcc) lattice, a type of micellar packing not yet reported for reverse micellar mesophases. Form factor fitting in the pure L2 phase and in the Fm3m-L2 coexistence region yields quantitative estimations of the PC interface rigidity. The compact Fm3m structure results mainly from release of lipid tail frustration and hard-sphere interactions between monodisperse micelles, as suggested by a comparison with the Fd3m structure found in the PC/water/α-tocopherol system.
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Affiliation(s)
- Isabelle Martiel
- Food and Soft Materials Science, Institute of Food, Nutrition & Health, ETH Zurich , Schmelzbergstrasse 9, CH-8092 Zurich, Switzerland
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Ricardo NM, Ricardo NM, Costa FDM, Bezerra FW, Chaibundit C, Hermida-Merino D, Greenland BW, Burattini S, Hamley IW, Keith Nixon S, Yeates SG. Effect of water-soluble polymers, polyethylene glycol and poly(vinylpyrrolidone), on the gelation of aqueous micellar solutions of Pluronic copolymer F127. J Colloid Interface Sci 2012; 368:336-41. [DOI: 10.1016/j.jcis.2011.10.062] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 10/25/2011] [Accepted: 10/28/2011] [Indexed: 10/15/2022]
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8
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Basak R, Mukhopadhyay N, Bandyopadhyay R. Experimental studies of the jamming behaviour of triblock copolymer solutions and triblock copolymer-anionic surfactant mixtures. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2011; 34:103. [PMID: 21947900 DOI: 10.1140/epje/i2011-11103-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 07/14/2011] [Accepted: 08/01/2011] [Indexed: 05/31/2023]
Abstract
Photon correlation spectroscopy and rheological measurements are performed to investigate the microscopic dynamics and mechanical responses of aqueous solutions of triblock copolymers and aqueous mixtures of triblock copolymers and anionic surfactants. Increasing the concentration of triblock copolymers results in a sharp increase in the magnitude of the complex moduli characterising the samples. This is understood in terms of the changes in the aggregation and packing behaviours of the copolymers and the constraints imposed upon their dynamics due to increased close packing. The addition of suitable quantities of an anionic surfactant to a strongly elastic copolymer solution results in a decrease in the complex moduli of the samples by several decades. It is argued that the shape anisotropy and size polydispersity of the micelles comprising mixtures cause dramatic changes in the packing behaviour, resulting in sample unjamming and the observed decrease in complex moduli. Finally, a phase diagram is constructed in the temperature-surfactant concentration plane to summarise the jamming-unjamming behaviour of aggregates constituting triblock copolymer-anionic surfactant mixtures.
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Affiliation(s)
- R Basak
- Raman Research Institute, 560080 Bangalore, India.
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Chaibundit C, Ricardo NM, Ricardo NM, Muryn CA, Madec MB, Yeates SG, Booth C. Effect of ethanol on the gelation of aqueous solutions of Pluronic F127. J Colloid Interface Sci 2010; 351:190-6. [DOI: 10.1016/j.jcis.2010.07.023] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Revised: 07/09/2010] [Accepted: 07/10/2010] [Indexed: 10/19/2022]
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10
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Chaibundit C, Ricardo NMPS, Ricardo NMPS, O'Driscoll BMD, Hamley IW, Yeates SG, Booth C. Aqueous gels of mixtures of ionic surfactant SDS with pluronic copolymers P123 or F127. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:13776-13783. [PMID: 19572512 DOI: 10.1021/la901584u] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Gel diagrams based on tube inversion and oscillatory rheometry are reported for Pluronic copolymers F127 (E(98)P(67)E(98)) and P123 (E(21)P(67)E(21)) in mixtures with anionic surfactant sodium dodecyl sulfate (SDS). Total concentrations (c, SDS+copolymer) were as high as 50 wt % with mole ratios SDS/copolymer (mr) in the ranges 1-5 (F127) and 1-7 (P123). Temperatures were as high as 90 degrees C. Determination of the temperature dependences of the dynamic moduli served to confirm the gel boundaries from tube inversion and to reveal the high elastic moduli of the gels, e.g., compared at comparable positions in the gel phase, a 50 wt % SDS/P123 with mr = 7 had G' three times that of a corresponding gel of P123 alone. Small-angle X-ray scattering (SAXS) was used to show that the structures of all the SDS/F127 gels were bcc and that the structures of the SDS/P123 gels with mr = 1 were either fcc (c = 30 wt %) or hex (c = 40 wt %). Assignment of structures to SDS/P123 gels with values of mr in the range 3-7 was more difficult, as high-order scattering peaks could be very weak, and at the higher values of c and mr, the SAXS peaks included multiple reflections.
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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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11
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Kloxin CJ, van Zanten JH. Microviscoelasticity of adhesive hard sphere dispersions: Tracer particle microrheology of aqueous Pluronic L64 solutions. J Chem Phys 2009; 131:134904. [DOI: 10.1063/1.3238570] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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12
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Hodges CS, Hammond RB, Gidalevitz D. Behavior of thin films of poly(oxyethylene)-poly(oxybutylene) copolymers studied by brewster angle microscopy and atomic force microscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:13470-13476. [PMID: 18991421 DOI: 10.1021/la802445q] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Surface films of two copolymers of ethylene oxide (E) and butylene oxide (B), namely E23B8 and E87B18, have been examined by Brewster angle microscopy (BAM) and atomic force microscopy (AFM). Isotherms taken on unsupported films of these copolymers at the air-water interface showed a clear gas to liquid phase transition for E57B18 and a barely discernible phase transition for E23B8. The BAM studies showed a gradual brightening of the films as the surface pressure was increased, which was associated with a film thickening and/or a film densification. Several bright spots were also observed within the films, with the number of spots increasing gradually as the film surface pressure was increased. AFM studies of these films did not show any localized ordering, which fits in with the results from our previous X-ray study of these copolymers [Hodges, C. S.; Neville, F.; Konovalov, O.; Gidalevitz, D.; Hamley, I. W.; Langmuir 2006, 22 (21), 8821-8825], where no long-range ordering was observed. AFM imaging showed two sizes of particulates that were irregularly spaced across the film. The larger particulates were associated with silica contaminants from the copolymer synthesis, whereas the smaller particulates were assumed to be aggregated copolymer. An analysis of the semidilute region of the isotherm showed that while both copolymers had intermixed ethylene oxide and butylene oxide units, the lower molecular weight E23B8 copolymer manifested significantly more intermixing than E87B18.
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Affiliation(s)
- Chris S Hodges
- Institute of Materials Research, and Institute of Particle Science and Engineering, University of Leeds, Leeds LS2 9JT, United Kingdom.
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Juárez J, Taboada P, Valdez MA, Mosquera V. Self-assembly process of different poly(oxystyrene)-poly(oxyethylene) block copolymers: spontaneous formation of vesicular structures and elongated micelles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:7107-7116. [PMID: 18547091 DOI: 10.1021/la8004568] [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
In the present work, we investigated the micellization, gelation, and structure of the aggregates of three poly(ethylene oxide)-polystyrene oxide block copolymers (E12S10, E10S10E10, and E137S18E137, where E denotes ethylene oxide and S styrene oxide and the subscripts the block length) in solution. Two of them have similar block lengths but different structures (E12S10 and E10S10E10) and the other has longer blocks (E137S18E137). For the first time, the spontaneous formation of vesicles by a poly(oxystyrene)-poly(oxyethylene) block copolymer is reported. These vesicular structures are present when copolymer E12S10 self-assembles in aqueous solution in coexistence with spherical micelles, as confirmed by the size distribution obtained by dynamic light scattering and pictures obtained by polarized optical microscopy, and transmission and cryo-scanning electron microscopies. Vesicle sizes vary between 60 and 500 nm. On the other hand, for copolymers E10S10E10 and E137S18E137, only one species is found in solution, which is assigned to elongated and spherical micelles, respectively. If we compare the high aggregation number derived by static light scattering for the triblock block copolymer micelles, with the maximum theoretical micellar dimensions compatible with a spherical geometry, we can see that the micellar geometry cannot be spherical but must be elongated. This is corroborated by transmission electron microscopy images. On the other hand, tube inversion was used to define the mobile-immobile (soft-hard gel) phase boundaries. To refine the phase diagram and observe the existence of additional phases, rheological measurements of copolymer E137S18E137 were done. The results are in good agreement with previous values published for other polystyrene oxide-poly(ethylene oxide) block copolymers. In contrast, copolymers E12S10 and E10S10E10 did not gel in the concentration range analyzed. Thus, only certain concentrations of copolymer E10S10E10 were analyzed by rheometry, for which an upturn in the low-frequency range of the stress moduli was observed, denoting an evidence of an emerging slow process, which we assign to the first stages of formation of an elastic network.
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Affiliation(s)
- Josué Juárez
- Departamento de Investigación en Polímeros y Materiales y Departamento de Física, Universidad de Sonora, Sorales Resales y Transversal, 83000 Hermosillo Sonora, Mexico
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14
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Mohan PH, Bandyopadhyay R. Phase behavior and dynamics of a micelle-forming triblock copolymer system. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2008; 77:041803. [PMID: 18517648 DOI: 10.1103/physreve.77.041803] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2007] [Indexed: 05/26/2023]
Abstract
Synperonic F-108 (generic name, "pluronic") is a micelle forming triblock copolymer of type ABA , where A is polyethylene oxide (PEO) and B is polypropylene oxide (PPO). At high temperatures, the hydrophobicity of the PPO chains increase, and the pluronic molecules, when dissolved in an aqueous medium, self-associate into spherical micelles with dense PPO cores and hydrated PEO coronas. At appropriately high concentrations, these micelles arrange in a face centered cubic lattice to show inverse crystallization, with the samples exhibiting high-temperature crystalline and low-temperature fluidlike phases. By studying the evolution of the elastic and viscous moduli as temperature is increased at a fixed rate, we construct the concentration-temperature phase diagram of Synperonic F-108. For a certain range of temperatures and at appropriate sample concentrations, we observe a predominantly elastic response. Oscillatory strain amplitude sweep measurements on these samples show pronounced peaks in the loss moduli, a typical feature of soft solids. The soft solidlike nature of these materials is further demonstrated by measuring their frequency-dependent mechanical moduli. The storage moduli are significantly larger than the loss moduli and are almost independent of the applied angular frequency. Finally, we perform strain rate frequency superposition experiments to measure the slow relaxation dynamics of this soft solid.
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15
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Barbosa S, Cheema MA, Taboada P, Mosquera V. Effect of Copolymer Architecture on the Micellization and Gelation of Aqueous Solutions of Copolymers of Ethylene Oxide and Styrene Oxide. J Phys Chem B 2007; 111:10920-8. [PMID: 17718470 DOI: 10.1021/jp073481i] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The micellar properties and solubilization capacity of poorly water soluble drugs of several micellar and gel solutions of diblock and triblock copolymers of styrene oxide/ethylene oxide have been measured and compared with block copolymers of butylene oxide/ethylene oxide, showing that the solubilization capacity of the styrene oxide block is approximately four times that of a butylenes oxide block for dilute solutions. To continue establishing the correlation between micellar characteristics and solubilization capacity, we have found it interesting to compare the micellar and gelation properties of the diblock and triblock copolymers PSO10PEO135 and PEO69PSO8PEO69 (subindexes are the number-average block lengths), with different architecture but similar average block lengths. Surface tension measurements allowed the determination of the critical micelle concentrations at several temperatures and, so, to calculate standard enthalpies of micellization. Static and dynamic light scattering data permitted us to determine micellar parameters and to obtain qualitatively the extent of hydration of the copolymer micelle. A tube inversion method was used to define the mobile-immobile (soft-hard gel) phase boundary. To refine the phase diagram and observe the existence of additional phases, rheological measurements were done. The results are in good agreement with previous values published for PSOnPEOm and PEOmPSOnPEOm copolymers.
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Affiliation(s)
- Silvia Barbosa
- Grupo de Sistemas Complejos, Laboratorio de Física de Coloides y Polímeros, Departamento de Física de la Materia Condensada, Facultad de Física, Universidad de Santiago de Compostela 15782, Spain.
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16
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Fundin J, Castelletto V, Yang Z, Hamley IW, Waigh TA, Price C. A Light and X‐Ray Scattering Study of Aqueous Micellar Solutions of a Diblock Copolymer of Propylene Oxide and Ethylene Oxide with Solubilized Alkylcyanobiphenyl Liquid Crystals. J MACROMOL SCI B 2007. [DOI: 10.1081/mb-200033253] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Johan Fundin
- a Department of Chemistry , University of Leeds , Leeds , LS2 9JT , UK
| | | | - Zhuo Yang
- b Department of Chemistry , University of Manchester , Manchester , UK
| | - Ian W. Hamley
- a Department of Chemistry , University of Leeds , Leeds , LS2 9JT , UK
| | | | - Colin Price
- b Department of Chemistry , University of Manchester , Manchester , UK
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17
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Matteucci ME, Hotze MA, Johnston KP, Williams RO. Drug nanoparticles by antisolvent precipitation: mixing energy versus surfactant stabilization. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:8951-9. [PMID: 17014140 DOI: 10.1021/la061122t] [Citation(s) in RCA: 214] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Organic itraconazole (ITZ) solutions were mixed with aqueous solutions to precipitate sub-300 nm particles over a wide range of energy dissipation rates, even for drug loadings as high as 86% (ITZ weight/total weight). The small particle sizes were produced with the stabilizer poloxamer 407, which lowered the interfacial tension, increasing the nucleation rate while inhibiting growth by coagulation and condensation. The highest nucleation rates and slowest growth rates were found at temperatures below 20 degrees C and increased with surfactant concentration and Reynolds number (Re). This increase in the time scale for growth reduced the Damkohler number (Da) (mixing time/precipitation time) to low values even for modest mixing energies. As the stabilizer concentration increased, the average particle size decreased and reached a threshold where Da may be considered to be unity. Da was maintained at a low value by compensating for a change in one variable away from optimum conditions (for small particles) by manipulating another variable. This tradeoff in compensation variables was demonstrated for organic flow rate vs Re, Re vs stabilizer concentration, stabilizer feed location (organic phase vs aqueous phase) vs stabilizer concentration, and stabilizer feed location vs Re. A decrease in the nucleation rate with particle density in the aqueous suspension indicated that secondary nucleation was minimal. A fundamental understanding of particle size control in antisolvent precipitation is beneficial for designing mixing systems and surfactant stabilizers for forming nanoparticles of poorly water soluble drugs with the potential for high dissolution rates.
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Affiliation(s)
- Michal E Matteucci
- Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, USA
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18
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Hodges CS, Neville F, Konovalov O, Hammond RB, Gidalevitz D, Hamley IW. Structural analysis of PEO-PBO copolymer monolayers at the air-water interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:8821-5. [PMID: 17014123 DOI: 10.1021/la060632k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
X-ray reflectivity (XR) and grazing incidence X-ray diffraction (GIXD) have been used to examine an oxyethylene-b-oxybutylene (E(23)B(8)) copolymer film at the air-water interface. The XR data were fitted using both a one- and a two-layer model that outputted the film thickness, roughness, and electron density. The best fit to the experimental data was obtained using a two-layer model (representing the oxyethylene and oxybutylene blocks, respectively), which showed a rapid thickening of the copolymer film at pressures above 7 mN/m. The large roughness values found indicate a significant degree of intermixing between the blocks and back up the GIXD data, which showed no long range lateral ordering within the layer. It was found from the electron density model results that there is a large film densification at 7 mN/m, possibly suggesting conformational changes within the film, even though no such change occurs on the pressure-area isotherm at the same surface pressure.
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Affiliation(s)
- Chris S Hodges
- Institute for Materials Research, University of Leeds, Leeds, LS2 9JT, UK.
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Castelletto V, Hamley IW, Triftaridou AI, Patrickios CS. SAXS Investigation of ABC Triblock Star Terpolymers in Aqueous Solution. J MACROMOL SCI B 2006. [DOI: 10.1081/mb-120027750] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- V. Castelletto
- a Department of Chemistry , University of Leeds , Leeds , LS2 9JT , UK
| | - I. W. Hamley
- a Department of Chemistry , University of Leeds , Leeds , LS2 9JT , UK
| | | | - C. S. Patrickios
- b Department of Chemistry , University of Cyprus , Nicosia , Cyprus
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Kreutzer G, Ternat C, Nguyen TQ, Plummer CJG, Månson JAE, Castelletto V, Hamley IW, Sun F, Sheiko SS, Herrmann A, Ouali L, Sommer H, Fieber W, Velazco MI, Klok HA. Water-Soluble, Unimolecular Containers Based on Amphiphilic Multiarm Star Block Copolymers. Macromolecules 2006. [DOI: 10.1021/ma060548b] [Citation(s) in RCA: 146] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Georg Kreutzer
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire des Polymères, Bâtiment MX-D, CH-1015 Lausanne, Switzerland; Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire de Technologie des Composites et Polymères, Bâtiment MX-G, CH-1015 Lausanne, Switzerland; Department of Chemistry, University of Reading, Reading, RG6 6AD, United Kingdom; Department of Chemistry, University of North Carolina at Chapel Hill, CB# 3290, Chapel Hill, North
| | - Céline Ternat
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire des Polymères, Bâtiment MX-D, CH-1015 Lausanne, Switzerland; Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire de Technologie des Composites et Polymères, Bâtiment MX-G, CH-1015 Lausanne, Switzerland; Department of Chemistry, University of Reading, Reading, RG6 6AD, United Kingdom; Department of Chemistry, University of North Carolina at Chapel Hill, CB# 3290, Chapel Hill, North
| | - Tuan Q. Nguyen
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire des Polymères, Bâtiment MX-D, CH-1015 Lausanne, Switzerland; Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire de Technologie des Composites et Polymères, Bâtiment MX-G, CH-1015 Lausanne, Switzerland; Department of Chemistry, University of Reading, Reading, RG6 6AD, United Kingdom; Department of Chemistry, University of North Carolina at Chapel Hill, CB# 3290, Chapel Hill, North
| | - Christopher J. G. Plummer
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire des Polymères, Bâtiment MX-D, CH-1015 Lausanne, Switzerland; Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire de Technologie des Composites et Polymères, Bâtiment MX-G, CH-1015 Lausanne, Switzerland; Department of Chemistry, University of Reading, Reading, RG6 6AD, United Kingdom; Department of Chemistry, University of North Carolina at Chapel Hill, CB# 3290, Chapel Hill, North
| | - Jan-Anders E. Månson
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire des Polymères, Bâtiment MX-D, CH-1015 Lausanne, Switzerland; Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire de Technologie des Composites et Polymères, Bâtiment MX-G, CH-1015 Lausanne, Switzerland; Department of Chemistry, University of Reading, Reading, RG6 6AD, United Kingdom; Department of Chemistry, University of North Carolina at Chapel Hill, CB# 3290, Chapel Hill, North
| | - Valeria Castelletto
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire des Polymères, Bâtiment MX-D, CH-1015 Lausanne, Switzerland; Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire de Technologie des Composites et Polymères, Bâtiment MX-G, CH-1015 Lausanne, Switzerland; Department of Chemistry, University of Reading, Reading, RG6 6AD, United Kingdom; Department of Chemistry, University of North Carolina at Chapel Hill, CB# 3290, Chapel Hill, North
| | - Ian W. Hamley
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire des Polymères, Bâtiment MX-D, CH-1015 Lausanne, Switzerland; Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire de Technologie des Composites et Polymères, Bâtiment MX-G, CH-1015 Lausanne, Switzerland; Department of Chemistry, University of Reading, Reading, RG6 6AD, United Kingdom; Department of Chemistry, University of North Carolina at Chapel Hill, CB# 3290, Chapel Hill, North
| | - Frank Sun
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire des Polymères, Bâtiment MX-D, CH-1015 Lausanne, Switzerland; Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire de Technologie des Composites et Polymères, Bâtiment MX-G, CH-1015 Lausanne, Switzerland; Department of Chemistry, University of Reading, Reading, RG6 6AD, United Kingdom; Department of Chemistry, University of North Carolina at Chapel Hill, CB# 3290, Chapel Hill, North
| | - Sergei S. Sheiko
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire des Polymères, Bâtiment MX-D, CH-1015 Lausanne, Switzerland; Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire de Technologie des Composites et Polymères, Bâtiment MX-G, CH-1015 Lausanne, Switzerland; Department of Chemistry, University of Reading, Reading, RG6 6AD, United Kingdom; Department of Chemistry, University of North Carolina at Chapel Hill, CB# 3290, Chapel Hill, North
| | - Andreas Herrmann
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire des Polymères, Bâtiment MX-D, CH-1015 Lausanne, Switzerland; Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire de Technologie des Composites et Polymères, Bâtiment MX-G, CH-1015 Lausanne, Switzerland; Department of Chemistry, University of Reading, Reading, RG6 6AD, United Kingdom; Department of Chemistry, University of North Carolina at Chapel Hill, CB# 3290, Chapel Hill, North
| | - Lahoussine Ouali
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire des Polymères, Bâtiment MX-D, CH-1015 Lausanne, Switzerland; Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire de Technologie des Composites et Polymères, Bâtiment MX-G, CH-1015 Lausanne, Switzerland; Department of Chemistry, University of Reading, Reading, RG6 6AD, United Kingdom; Department of Chemistry, University of North Carolina at Chapel Hill, CB# 3290, Chapel Hill, North
| | - Horst Sommer
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire des Polymères, Bâtiment MX-D, CH-1015 Lausanne, Switzerland; Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire de Technologie des Composites et Polymères, Bâtiment MX-G, CH-1015 Lausanne, Switzerland; Department of Chemistry, University of Reading, Reading, RG6 6AD, United Kingdom; Department of Chemistry, University of North Carolina at Chapel Hill, CB# 3290, Chapel Hill, North
| | - Wolfgang Fieber
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire des Polymères, Bâtiment MX-D, CH-1015 Lausanne, Switzerland; Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire de Technologie des Composites et Polymères, Bâtiment MX-G, CH-1015 Lausanne, Switzerland; Department of Chemistry, University of Reading, Reading, RG6 6AD, United Kingdom; Department of Chemistry, University of North Carolina at Chapel Hill, CB# 3290, Chapel Hill, North
| | - Maria Inés Velazco
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire des Polymères, Bâtiment MX-D, CH-1015 Lausanne, Switzerland; Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire de Technologie des Composites et Polymères, Bâtiment MX-G, CH-1015 Lausanne, Switzerland; Department of Chemistry, University of Reading, Reading, RG6 6AD, United Kingdom; Department of Chemistry, University of North Carolina at Chapel Hill, CB# 3290, Chapel Hill, North
| | - Harm-Anton Klok
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire des Polymères, Bâtiment MX-D, CH-1015 Lausanne, Switzerland; Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire de Technologie des Composites et Polymères, Bâtiment MX-G, CH-1015 Lausanne, Switzerland; Department of Chemistry, University of Reading, Reading, RG6 6AD, United Kingdom; Department of Chemistry, University of North Carolina at Chapel Hill, CB# 3290, Chapel Hill, North
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21
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Harrison WJ, Aboulgasem GJ, Elathrem FAI, Nixon SK, Attwood D, Price C, Booth C. Micelles and gels of mixed triblock copoly(oxyalkylene)s in aqueous solution. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:6170-8. [PMID: 15982018 DOI: 10.1021/la050297k] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The micellization in dilute aqueous solution of a 50/50 wt% mixture of two triblock copolymers, E45B14E45 and E62P39E62, and the gelation of concentrated micellar solutions have been investigated over a range of temperatures. Here E, B, and P denote oxyethylene, oxubutylene, and oxypropylene chain units. Comparison is made with aqueous solutions of the individual copolymers. The results of light scattering measurements are consistent with effectively separate micellization of the two copolymers in the mixture. Hard gel formed when the extent of micellization was high for both copolymers. Because of the relatively high critical micellization temperatures of copolymer E62P39E62, the low-temperature boundary of the hard gel was high for this copolymer and for the mixture. The minimum concentration for hard-gel formation was higher for the mixture than for either of the individual copolymers, as would be expected for packing of two distributions of micelles of different average size.
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Affiliation(s)
- Wayne J Harrison
- School of Chemistry, University of Manchester, Manchester M13 9PL, UK
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22
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Castelletto V, Hamley IW, Yuan XF, Kelarakis A, Booth C. Structure and rheology of aqueous micellar solutions and gels formed from an associative poly(oxybutylene)-poly(oxyethylene)-poly(oxybutylene) triblock copolymer. SOFT MATTER 2005; 1:138-145. [PMID: 32521837 DOI: 10.1039/b419103j] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The structure and shear flow behaviour of aqueous micellar solutions and gels formed by an amphiphilic poly(oxybutylene)-poly(oxyethylene)-poly(oxybutylene) triblock copolymer with a lengthy hydrophilic poly(oxyethylene) block has been investigated by rheology, small angle neutron scattering (SANS) and small-angle X-ray scattering (SAXS). SANS revealed that bridging of chains between micelles introduces, in the micellar solution, an attractive long-range component which can be described through a potential of interaction corresponding to sticky soft spheres. The strength of the attractive interaction increases with increasing concentration. Rheology showed that the dependence of the storage modulus with temperature can be explained as a function of the micellar bridging, micellisation and phase morphology. SAXS studies showed that the orientation adopted by the system in the gel phase under shear is similar to that previously observed by us for the gel phase of a poly(oxyethylene)-poly(oxybutylene) diblock copolymer with a long poly(oxyethylene) chain, suggesting that the micellar corona/core length ratio and not the architecture of the block copolymer influences the alignment of the gel phase under shear.
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Affiliation(s)
- V Castelletto
- Dept of Chemistry and Centre for Self-Organising Molecular Systems, University of Leeds, Leeds LS2 9JT, UK.
| | - I W Hamley
- Dept of Chemistry and Centre for Self-Organising Molecular Systems, University of Leeds, Leeds LS2 9JT, UK.
| | - X-F Yuan
- School of Chemical Engineering and Analytical Science, University of Manchester, Manchester M60 1QD, UK
| | - A Kelarakis
- School of Chemistry, University of Manchester, Manchester M13 9PL, UK
| | - C Booth
- School of Chemistry, University of Manchester, Manchester M13 9PL, UK
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23
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Taboada P, Velasquez G, Barbosa S, Castelletto V, Nixon SK, Yang Z, Heatley F, Hamley IW, Ashford M, Mosquera V, Attwood D, Booth C. Block copolymers of ethylene oxide and phenyl glycidyl ether: micellization, gelation, and drug solubilization. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:5263-71. [PMID: 15924448 DOI: 10.1021/la0503808] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Three triblock copolymers of ethylene oxide and phenyl glycidyl ether, type E(m)G(n)E(m), where G = OCH2CH(CH2OC6H5) and E = OCH2CH2, were synthesized and characterized by gel-permeation chromatography, matrix-assisted laser desorption ionization time-of-flight mass spectrometry, and NMR spectroscopy. Their association properties in aqueous solution were investigated by surface tensiometry and light scattering, yielding values of the critical micelle concentration (cmc), the hydrodynamic radius, and the association number. Gel boundaries in concentrated micellar solution were investigated by tube inversion, and for one copolymer, the temperature and frequency dependence of the dynamic moduli served to confirm and extend the phase diagram and to highlight gel properties. Small-angle X-ray scattering was used to investigate gel structure. The overall aim of the work was to define a block copolymer micellar system with better solubilization capacity for poorly soluble aromatic drugs than had been achieved so far by use of block copoly(oxyalkylene)s. Judged by the solubilization of griseofulvin in aqueous solutions of the E(m)G(n)E(m) copolymers, this aim was achieved.
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Affiliation(s)
- Pablo Taboada
- Department of Physics of Condensed Matter, University of Santiago de Compostela, E-15706 Santiago de Compostela, Spain
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24
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Ji S, Ding J. Nonequilibrium Monte Carlo simulation of lattice block copolymer chains subject to oscillatory shear flow. J Chem Phys 2005; 122:164901. [PMID: 15945701 DOI: 10.1063/1.1884595] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
This paper has extended nonequilibrium Monte Carlo (MC) approach to simulate oscillatory shear flow in a lattice block copolymer system. Phase transition and associated rheological behaviors of multiple self-avoiding chains have been investigated. Stress tensor has been obtained based upon sampled configuration distribution functions. At low temperatures, micellar structures have been observed and the underlying frequency-dependent rheological properties exhibit different initial slopes. The simulation outputs are consistent with the experimental observations in literature. Chain deformation during oscillatory shear flow has also been revealed. Although MC simulation cannot account for hydrodynamic interaction, the highlight of our simulation approach is that it can, at small computing cost, investigate polymer chains simultaneously at different spatial scales, i.e., macroscopic rheological behaviors, mesoscopic self-assembled structures, and microscopic chain configurations.
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Affiliation(s)
- Shichen Ji
- Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai 200433, China
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25
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Sommer C, Pedersen JS, Garamus VM. Structure and interactions of block copolymer micelles of Brij 700 studied by combining small-angle X-ray and neutron scattering. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:2137-49. [PMID: 15752000 DOI: 10.1021/la047489k] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Spherical micelles of the diblock copolymer/surfactant Brij 700 (C(18)EO(100)) in water (D(2)O) solution have been investigated by small-angle X-ray scattering (SAXS) and small-angle neutron scattering (SANS). SAXS and SANS experiments are combined to obtain complementary information from the two different contrast conditions of the two techniques. Solutions in a concentration range from 0.25 to 10 wt % and at temperatures from 10 to 80 degrees C have been investigated. The data have been analyzed on absolute scale using a model based on Monte Carlo simulations, where the micelles have a spherical homogeneous core with a graded interface surrounded by a corona of self-avoiding, semiflexible interacting chains. SANS and SAXS data were fitted simultaneously, which allows one to obtain extensive quantitative information on the structure and profile of the core and corona, the chain interactions, and the concentration effects. The model describes the scattering data very well, when part of the EO chains are taken as a "background"contribution belonging to the solvent. The effect of this becomes non-negligible at polymer concentrations as low as 2 wt %, where overlap of the micellar coronas sets in. The results from the analysis on the micellar structure, interchain interactions, and structure factor effects are all consistent with a decrease in solvent quality of water for the PEO block as the theta temperature of PEO is approached.
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Affiliation(s)
- Cornelia Sommer
- Department of Chemistry, University of Aarhus, Langelandsgade 140, DK-8000 Aarhus C, Denmark
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26
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Foroutan M, Jafarizadeh MA. Study on Effects of Polydispersity on the Form Factor and Depletion Interaction in Colloid-Polymer Mixtures with Laser Distribution. MACROMOL THEOR SIMUL 2004. [DOI: 10.1002/mats.200400038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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27
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Nicolai T, Laflèche F, Gibaud A. Jamming and Crystallization of Polymeric Micelles. Macromolecules 2004. [DOI: 10.1021/ma049101y] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Taco Nicolai
- Polymères, Colloïdes, Interfaces, UMR CNRS, Université du Maine, 72085 Le Mans Cedex 9, France
| | - Fabrice Laflèche
- Polymères, Colloïdes, Interfaces, UMR CNRS, Université du Maine, 72085 Le Mans Cedex 9, France
| | - Alain Gibaud
- Laboratoire de Physique de l'Etat Condensé, UMR CNRS, Université du Maine, 72085 Le Mans Cedex 9, France
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Castelletto V, Hamley IW, Pedersen JS. Small-angle neutron scattering study of the structure of superswollen micelles formed by a highly asymmetric poly(oxybutylene)-poly(oxyethylene) diblock copolymer in aqueous solution. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:2992-2994. [PMID: 15835187 DOI: 10.1021/la036231b] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Affiliation(s)
- V Castelletto
- Department of Chemistry, University of Leeds, Leeds LS2 9JT, United Kingdom
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30
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Castelletto V, Hamley IW, Waigh TA. Dynamic light scattering study of the dynamics of a gelled polymeric micellar system. J Chem Phys 2004; 121:11474-80. [PMID: 15634107 DOI: 10.1063/1.1818067] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The dynamics of the E(92)B(18)/water system are studied by dynamic light scattering (DLS) in the liquid, soft gel, and hard gel phases. Both the liquid and the soft gel phases are micellar phases, although the structural order is higher in the soft gel phase than in the liquid phase. The hard gel phase corresponds to a face-centered cubic arrangement of micelles. DLS results show that the dilute liquid phase is characterized by a single characteristic time tau(1) associated with the diffusion of the micelles. In addition, a second characteristic time tau(2) associated with the presence of micellar clusters in the system is identified in the concentrated liquid and in the soft gel phases. According to these results, DLS suggests that the structure of the soft gel phase comprises micellar clusters coexisting with micellar fluid, in good agreement with hypotheses from our previous work. The dynamics of the system slows down as the hard gel phase is approached and a plateau is observed in the DLS correlation function. The structure of the hard gel is "softened" upon increasing temperature and/or decreasing concentration.
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Affiliation(s)
- V Castelletto
- Department of Chemistry, University of Leeds, Leeds LS2 9JT, United Kingdom
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31
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Castelletto V, Hamley IW, Yang Z, Haeussler W. Neutron spin-echo investigation of the dynamics of block copolymer micelles. J Chem Phys 2003. [DOI: 10.1063/1.1609195] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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32
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Castelletto V, Hamley IW, Pedersen JS. A small-angle neutron scattering investigation of the structure of highly swollen block copolymer micelles. J Chem Phys 2002. [DOI: 10.1063/1.1509747] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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33
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Castelletto V, Hamley I. Modelling small-angle scattering data from micelles. Curr Opin Colloid Interface Sci 2002. [DOI: 10.1016/s1359-0294(02)00043-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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