Temperature effects on structural properties of pluronic P104 and F108 PEO-PPO-PEO block copolymer solutions

Journal Article · Mon May 01 04:00:00 EDT 1995 · Langmuir

DOI:https://doi.org/10.1021/la00005a011· OSTI ID:62440

Alexandridis, P; Nivaggioli, T; Hatton, T A ^[1]

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1. Massachusetts Inst. of Technology, Cambridge, MA (United States)

The effects of temperature on the micellization properties and the structure of the micelles for two poly(ethylene-oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (PEO-PPO-PEO) copolymers, having similar size hydrophobic (PPO) blocks and different size hydrophilic (PEO) blocks, are reported. Critical micellization concentration (CMC) and temperature (CMT) values for aqueous copolymer solutions were obtained from a dye solubilization method and corroborated with differential scanning calorimetry, surface tension, density, light scattering intensity, and fluorescence spectroscopy experiments; very good agreement among the different techniques is observed. The extraction of CMC and CMT values from the characteristic features of the data obtained from the various techniques is discussed. The hydrodynamic radii of the copolymer micelles, determined using dynamic light scattering, remained constant over the temperature range investigated; the polydispersity of the micelle size decreased with temperature. The micropolarity in aqueous copolymer solutions was probed as a function of temperature using the I{sub 1}/I{sub 3} intensity ratio of the pyrene vibrational fine structure recorded in fluorescence emission spectra. The decreasing values for the intensity ratio, following the formation of micelles, were considered to be a linear combination of the temperature effects on polarity observed in bulk PEO and PPO homopolymers, and in water. 59 refs., 10 figs., 2 tabs.

• Sponsoring Organization: USDOE
• DOE Contract Number: FG02-92ER14262
• OSTI ID: 62440
• Journal Information: Langmuir, Journal Name: Langmuir Journal Issue: 5 Vol. 11; ISSN LANGD5; ISSN 0743-7463
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
40 CHEMISTRY
ABUNDANCE
AQUEOUS SOLUTIONS
COPOLYMERS
EMISSION SPECTRA
LIGHT SCATTERING
MICELLAR SYSTEMS
PHASE DIAGRAMS
PHYSICAL CHEMISTRY
PLURONICS
POLYETHYLENE GLYCOLS
POLYPROPYLENE
STRUCTURAL CHEMICAL ANALYSIS
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES