PEO Units Research Articles

Application of Pluronics for Enhancing Aqueous Solubility of Lipophilic Microtubule Destabilizing Compounds on the Sea Urchin Embryo Model.

In screening, the dilution of DMSO stock solution of a lipophilic molecule with an assay medium often causes compound precipitation. To overcome the issue, the application of Pluronics as cosolvents was examined using a phenotypic sea urchin embryo assay that allows for the quick and facile evaluation of the antiproliferative effect together with systemic toxicity. Maximum tolerated concentration values for Pluronics L121, P123, and F127 were 1.4 μM, 8.6 μM, and 39.7 μM, respectively, and correlated directly with their hydrophilicity. Pluronics L121 and P123 suppressed cleavage and blastomeres retained the round shape, unlike hydrophilic Pluronic F127, which induced fertilization envelope creasing and embryo deformation that could be associated with the interaction of hydrophilic PEO units with mucopolysaccharides at the surface of sea urchin embryos. The toxicity of P123, but not of L121 and F127, was temperature-dependent and markedly increased at lower temperatures. CMC values obtained at different temperatures confirmed that the toxic effect of P123 was associated with both unimers and micelles, whereas F127 toxicity was related mainly to micelles. Evaluation using phenotypic sea urchin embryo assay revealed that potent microtubule destabilizers, namely albendazole, diarylisoxazole, and two chalcones, retained antimitotic activity after the dilution of their DMSO or 2-pyrrolidone stock solutions with 1.25% w/v Pluronic P123 or 5% w/v Pluronic F127. It was suggested that Pluronic P123 and Pluronic F127 could be used as cosolvents to improve the solubility of lipophilic molecules in aqueous medium.

Discovery of Kinetic Trapping of Poloxamers inside Liposomes via Thermal Treatment.

Poloxamers, a class of biocompatible, commercially available amphiphilic block polymers (ABPs) comprising poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) blocks, interact with phospholipid bilayers, resulting in altered mechanical and surface properties. These block copolymers are useful in a variety of applications including therapeutics for Duchenne muscular dystrophy, as cell membrane stabilizers, and for drug delivery, as liposome surface modifying agents. Hydrogen bonding between water and oxygen atoms in PEO and PPO units results in thermoresponsive behavior because the bound water shell around both blocks dehydrates as the temperature increases. This motivated an investigation of poloxamer-lipid bilayer interactions as a function of temperature and thermal history. In this study, we applied pulsed-field-gradient NMR spectroscopy to measure the fraction of chains bound to 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC) liposomes between 10 and 50 °C. We measured an (11 ± 3)-fold increase in binding affinity at 37 °C relative to 27 °C. Moreover, following incubation at 37 °C, it takes weeks for the system to re-equilibrate at 25 °C. Such slow desorption kinetics suggests that at elevated temperatures polymer chains can pass through the bilayer and access the interior of the liposomes, a mechanism that is inaccessible at lower temperatures. We propose a molecular mechanism to explain this effect, which could have important ramifications on the cellular distribution of ABPs and could be exploited to modulate the mechanical and surface properties of liposomes and cell membranes.

Effective Optimization of High Voltage Solid‐State Lithium Batteries by Using Poly(ethylene oxide)‐Based Polymer Electrolyte with Semi‐Interpenetrating Network

AbstractSolid polymer electrolytes (SPEs) are promising candidates for the realization of lithium metal batteries. However, the popular SPE based on poly(ethylene oxide) (PEO) reveals a “voltage noise”‐failure during charge, for example, with high energy/high voltage electrodes like LiNi0.6Mn0.2Co0.2O2 (NMC622), which can be attributed to short‐circuits via penetrating Li dendrites. This failure disappears when integrating PEO‐based SPE in a semi interpenetrating network, which mainly consists of PEO units, as well. In this work, it is shown that this SPE allows performance improvement via elimination of the crystalline domains without significant sacrifice of mechanical integrity. Hence, a highly amorphous SPE can be obtained by a simple increase of plasticizing Li salts, which overall is beneficial, not only for the ionic conductivity, but also the homogeneity, while remaining mechanically stable and solid in its original shape even after storage at 60 °C for 7 days. These aspects are crucial for the performance of the modified SPE as they can suppress the failure‐causing Li dendrite penetration while the electrochemical aspects, that is, anodic stability, are rather unaffected by the modification and remain stable (4.6 V vs Li│Li+). Overall, this optimized SPE enables stable cycling performance in NMC622│SPE│Li cells, even at 40 °C operation temperature.

Effect of side-chain length in polycarboxylic superplasticizer on the early-age performance of cement-based materials

Abstract Varying the length of side-chain in Polycarboxylic superplasticizer (PCs) have been reported to greatly impact their molecular structure and their compatibility with other concrete raw materials. However, there is less study relating to the influence of side-chain length on early properties of cement-based materials. For this purpose, through a redox initiator system, five types of PCs with different side-chain lengths were synthesized by using 2-methyl allyl polyoxyethylene ether (HPEG) with different molecular weight and acrylic acid (AA) as monomers. The dispersing performance, hydration behavior, microstructure formation and cracking sensitivity in cement-based materials with these different types of PCs were thoroughly examined. The results showed that the initial fluidity of the cement paste increased first and then decreased but the fluidity losses decrease gradually with the increase of side-chain length in PCs. Compared to short side-chain PCs, the long ones can improve hydration heat peak value and shorten dissolution period, thus accelerating the hydration and microstructure formation of cement. The early-age strength increased, while 28-day strength and anti-cracking performance of cement-based materials increased first and then decreased with the increase of side-chain length in PCs. Such information also suggests that there exists a suitable side-chain length in PCs (53 PEO units) which makes cement-based materials have good dispersation, flow maintaining ability and the lowest crack sensitivity.

Closed-Loop Phase Behavior of Block Copolymers in the Presence of Competitive Hydrogen-Bonding and Coulombic Interaction

The closed-loop phase behavior, where a lower disorder-to-order transition (LDOT) takes place first, followed by an upper order-to-disorder transition (UODT) upon heating, is seldom observed in block copolymers (BCPs). In this work, we prepared a model BCP, LiClO4-doped poly(ethylene oxide)-b-poly(tert-butyl acrylate-co-acrylic acid) (PEO-b-P(tBA-co-AA)), in which the hydrogen (H)-bonding between the PEO and AA units and the Coulombic interaction in salt-doped PEO block have opposite effects on the miscibility of BCPs. The relative strength of the H-bonding and Coulombic interaction can be easily tuned by the hydrolysis degree (DH) of the PtBA block and the amount of doped salt. Various phase behaviors are observed by changing relative strength of different forces. Especially, the closed-loop phase behavior can be achieved when H-bonding, Coulombic interaction, and mixing entropy reach a delicate balance.

Reversible Protein Adsorption on Mixed PEO/PAA Polymer Brushes: Role of Ionic Strength and PEO Content.

Proteins at interfaces are a key for many applications in the biomedical field, in biotechnologies, in biocatalysis, in food industry, etc. The development of surface layers that allow to control and manipulate proteins is thus highly desired. In previous works, we have shown that mixed polymer brushes combining the protein-repellent properties of poly(ethylene oxide) (PEO) and the stimuli-responsive adsorption behavior of poly(acrylic acid) (PAA) could be synthesized and used to achieve switchable protein adsorption. With the present work, we bring more insight into the rational design of such smart thin films by unravelling the role of PEO on the adsorption/desorption of proteins. The PEO content of the mixed PEO/PAA brushes was regulated, on the one hand, by using PEO with different molar masses and, on the other hand, by varying the ratio of PEO and PAA in the solutions used to synthesize the brushes. The influence of ionic strength on the protein adsorption behavior was also further examined. The behavior of three proteins-human serum albumin, lysozyme, and human fibrinogen, which have very different size, shape, and isoelectric point-was investigated. X-ray photoelectron spectroscopy, quartz crystal microbalance, atomic force microscopy, and streaming potential measurements were used to characterize the mixed polymer brushes and, in particular, to estimate the fraction of each polymer within the brushes. Protein adsorption and desorption conditions were selected based on previous studies. While brushes with a lower PEO content allowed the higher protein adsorption to occur, fully reversible adsorption could only be achieved when the PEO surface density was at least 25 PEO units per nm2. Taken together, the results increase the ability to finely tune protein adsorption, especially with temporal control. This opens up possibilities of applications in biosensor design, separation technologies, nanotransport, etc.

Spin-Trapping Analysis and Characterization of Thermal Degradation of Thermoplastic Poly(ether–ester) Elastomer

We investigated the thermal degradation of poly(butylene terephthalate)-co-poly(ethylene oxide) (PBT-co-PEO), a thermoplastic poly(ether–ester) elastomer (TPEE), through proton nuclear magnetic resonance (NMR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), gel permeation chromatography (GPC), and spin-trapping electron spin resonance (ESR) analysis to detect radical intermediates present during degradation. Three kinds of PBT-co-PEO with different component ratios of PBT/PEO were synthesized. The thermal degradation process of PBT-co-PEO was divided into four weight-loss stages. In the first stage from room temperature to 120 °C, we confirmed the production of two radical intermediates, O–•CH–CH2 and •CH2–, by the spin-trapping method. This suggested that the initial decomposition occurred at the OCH2–CH2O bond in the PEO units. Upon annealing at 120 °C, PBT-co-PEO showed a small degree of random degradation, while higher PBT con...

Crystallization study and morphology behaviour of calcium carbonate crystals in aqueous Surfactant-Pluronics® prototype

A facile procedure to fabricate the hydrophobic surfaces of calcium carbonate-polymer composites has been well described. Nano-sized highly ordered CaCO3 clusters i.e. calcite/vaterite have been synthesized by simple precipitation in the presence of template made of cationic surfactant: cetyl trimethyl ammonium bromide (CTAB) and different non-ionic amphiphilic triblock copolymers comprising of PEO–PPO–PEO units: F98 and F127 commercially known as Pluronics® or Synperonics® or Poloxamers. The morphology of these nano-composites so formed was characterized in detail using spectroscopy, microscopy, diffraction, and scattering techniques. It was found that the surfactant-polymer prototype turned out to be an important parameter to tune and understand the shape-controlled morphology and crystallization in precipitated calcium carbonate (PCC). Our diffraction pattern depicted the presence of calcite/vaterite, while the microscopic investigations indicated the bunch/clusters of calcite (nano-flakes) arranged in stacks which could be attributed to the attractive hydrophobic interaction between the alkyl group of cationic surfactant and -PPO unit of the block copolymer. Similar assumptions were inferred by structural optimization using Gauss View 5.0.9. The scattering measurements described the polydispersity of nano-aggregates based on the scattering intensity. Results expounded the growth mechanism of CaCO3 crystals to be a step-by-step build process with respect to the polarity.

Poloxamers, poloxamines and polymeric micelles: Definition, structure and therapeutic applications in cancer

Research for new therapies to treat diseases like cancer, it is one of the focus of Health Sciences. Nowadays, the available therapeutic strategies have in many cases limitations and undesired side effects, which shows a need to find new therapies with a higher efficacy. In this regard, over the past few years, poloxamers and poloxamines have been gaining more attention in the pharmaceutical field, mainly due to their advantages as potential nanosystems. Therefore, poloxamers and poloxamines are amphiphilic block of copolymers constituted by PEO units, poly(ethylene oxide), and PPO units, poly(propylene oxide), presenting the capability to self-assembly in micellar structures in aqueous medium forming polymeric micelles, which improve theirs potential as drug and genetic material nanocarriers. Thereby, in order to create new alternative treatments for current pathologies, like cancer, alterations in the poloxamines and poloxamers, the combination of these with other polymers and the conjugation with ligands are being introduced as a viable option to allow the combination of therapies, such as the simultaneous delivery of a gene and a drug in the same system. These intelligent stimuli-sensitive systems, with well-defined structures and functionalities, make possible the development of a safe, specific and effective therapeutic strategy. Thus, this article intends to review several aspects of poloxamines and poloxamers concerning their general properties and their applications in drug and gene delivery. Also, are reviewed the preparation and characterization techniques of polymeric micelles with a focus in micelleplexes which can be used as a simultaneous drug and nucleic acid carrier.

Soft segment length controls morphology of poly(ethylene oxide) based segmented poly(urethane-urea) copolymers in a binary solvent

It is known that morphology and structure-property behavior of poly(ethylene oxide) (PEO) based poly(urethane-urea) copolymers are affected by soft segment (SS) chain length. Here, a multi-scale computational study is carried out to determine the origins of this behavior, supported by atomic force microscopy (AFM) imaging. First, single PEO chains of varying lengths are comparatively examined by molecular dynamics and dissipative particle dynamics (DPD) simulations in THF:DMF solvent mixture to verify that the coarse graining strategy is applicable to the system at hand. In the second step, hard segment (HS) beads are attached to PEO chains to study their effect on the overall morphology. We find that the critical chain length of PEO plays a key role on the structure-property behavior of these copolymers. Density fields obtained from DPD calculations reveal a stable channel formation by SS beads in the copolymers if their length is below a threshold value. HS-SS interactions drive this behavior by promoting phase mixing. The role of the binary solvent is essential as the channel-like structures are not stable in the pure solvents. In contrast, for chains having long enough PEO segments, spontaneous clustering of the PEO units controls morphology development. This behavior gives rise to the formation of globular SS clusters surrounded by HS units. The dual solvent acts as a lubricant, with THF preferring the PEO clusters. Results obtained from DPD studies are corroborated by AFM images obtained for the corresponding copolymers. The strategy employed lays the foundations for developing systems having novel morphologies and macroscopic-properties using designs based on HS-SS cooligomers.

A facile strategy to synthesize mesoporous aluminosilicates with reduced particle size

We report a facile strategy for synthesis of hydrothermally stable mesoporous aluminosilicates (MAs) from zeolite Y precursors by adding small amount of Tween-20. By the addition of suitable amount of Tween-20, P123-Tween complex micelles formed due to the interaction between hydrophobic chain of Tween and PPO units of P123. The hydrophilicity of the complex micelles was enhanced due to the incorporation of PEO units of Tween. As a result of this, the micelles could be well dispersed and MAs with reduced particle size could be readily obtained.

Aggregation behaviors of mixed systems for imidazole based ionic liquid surfactant and Triton X-100

Abstract The adsorption and aggregation of mixed systems for ionic liquid (ILs) surfactants (1-decyl-3-methylimidazolium bromide, C 10 mimBr, 1-dodecyl-3-methylimidazolium bromide, C 12 mimBr, 1-hexadecyl-3-methylimidazolium bromide, C 16 mimBr) and non-ionic surfactant Triton X-100 in aqueous media have been investigated by surface tension measurements, electrical conductivity, 1 H NMR and FTIR technologies. Surface properties have been determined such as critical micelle concentration (CMC), surface saturation adsorption ( Γ max ), minimum surface area per surfactant molecule ( A min ), surface tension at the CMC (γ CMC ), adsorption efficiency ( pC 20 ), and surface pressure at the CMC ( Π CMC ) as well as thermodynamic parameters of micellization. The surface tension measurements revealed that the addition of Triton X-100 into ILs can decrease CMC of ILs, suggesting that it is beneficial to the mixed micelle formation. Consistent with the results of surface tension, electrical conductivity measurement demonstrate a small degree of counter-ion binding to form mixed micelles, which may increase with the addition of TX-100. The 1 H NMR data and FT-IR analysis demonstrated the presence of hydrogen-bond between the imidazolium cation of ILs and the PEO units of Triton X-100 and hydrophobic interactions between the alkyl chain of the imidazolium cation and the hydrophobic chain with phenyl of Triton X-100.

Sequential Structure, Crystallization, and Properties of Biodegradable Poly(ethylene Terephthalate-Co-Ethylene Oxide-Co-Lactide) Copolyester

The sequential structure, isothermal crystallization, tensile property, and degradation behavior of poly(ethylene terephthalate-co-ethylene oxide-co-lactide) (ETOLA) copolyester based on melt transesterification of poly(ethylene terephthalate) with poly(ethylene oxide) and oligo(lactic acid) was investigated. The degree of randomness was calculated to be 0.38, showing the incorporation of poly(ethylene oxide) (PEO) blocks into the homogeneous sequences of ethylene terephthalate (ET) and lactide (LA) units. The isothermal crystallization kinetics results revealed that the crystallization activation energy of the copolyester calculated using the Arrhenius’ equation was lower than that reported for poly(ethylene terephthalate) (PET), indicating that the addition of PEO and LA units into PET retarded the crystallization of PET. The copolyester exhibited the same crystal structure at different crystallization temperatures, similar to that of PET homopolymer, based on wide angle X-ray diffraction results. The size of the spherulites of ETOLA increased with crystallization temperature. The increase of crystallization temperature reduced the elongation at break of the copolyesters, as well as the enzymatic degradation.

Liquid Carbazole Substituted with a Poly(ethylene oxide) Group and Its Application for Liquid Organic Light-emitting Diodes

Abstract We report efficient carrier injection characteristics in liquid organic light-emitting diodes (OLEDs). The use of a liquid carbazole substituted with a poly(ethylene oxide) (PEO) chain provided a substantial improvement in carrier injection compared to devices constructed with carbazoles without PEO units. The external electroluminescence quantum efficiency (ΦEL) of an OLED with the liquid carbazole as an emitting layer resulted in ΦEL = 0.75%, 25 times higher ΦEL than that of our previous liquid OLED without electrolyte.

Hydrophilic silica additives for disulfonated poly(arylene ether sulfone) random copolymer membranes

Hydrophilic silica (SiO 2) nanoparticles (average size = 7 nm), which act as inorganic acids at low pH (<2), were added together with a PEO–PPO–PEO triblock copolymer dispersant to a random disulfonated poly(arylene ether sulfone) copolymer in the potassium salt ( SO 3 −K +) form in order to control permeation and rejection characteristics of the homopolymer. The dispersants (shell) absorbed on the surface of SiO 2 nanoparticles (core) formed a distinctive core–shell structure. The PEO units located at the outside of the dispersant formed complexes with SO 3 −K + groups of BPS-20 via ion–dipole interactions. These interactions induced a compatible binary system following the Flory–Fox equation associated with glass transition temperature ( T g) depression and prevented extraction of the water-soluble dispersant even under aqueous conditions. The ion–dipole interaction, combined with hydrogen bonding between SiO 2 and the dispersant, caused SiO 2 nanoparticles to be well distributed within the BPS-20 matrix up to a limit of 1 wt.% of SiO 2 and minimized the formation of non-selective cavities within the matrix's hydrophilic water channels. The resulting BPS-20_SiO 2 nanocomposites showed improved salt rejection and reduced ionic conductivity. These trends are analogous to those of disulfonated copolymer systems, with polar groups creating hydrogen bonding or acid–base complexation with SO 3 −K + groups in BPS copolymers. Well dispersed SiO 2 nanoparticles in highly water-permeable desalination membranes are expected to result in an increase in salt rejection but very little change in water permeability. The addition of nanoparticles to desalination membranes may offset the permeability-selectivity tradeoff observed in polymer membranes. Above 1 wt.%, SiO 2 nanoparticles increased both the interchain distance between polymer chains and the water uptake. However, the increased hydrophilicity due to high SiO 2 content did not yield improved water permeation of the nanocomposite membranes. The SiO 2 nanoparticles acted as barriers, hindering water passage (restrictive diffusion) and lowering water permeability. Meanwhile, acidic hydroxyl groups (OH 2 +) on the SiO 2 surface in the sulfonate matrix led to improved ionic conductivity, but NaCl rejection capability decreased because the concentration of SO 3 −K + was diluted by highly absorbed water molecules, resulting in weakened Donnan exclusion. The mechanical properties and chlorine resistance of all BPS-20_SiO 2 nanocomposites were comparable to those of BPS-20.

Electrochemical behavior of hemoglobin in neutral surfactants with different poly(ethylene oxide) unit lengths adsorbed on an electrode

The direct electron transfer and adsorption behavior of hemoglobin (Hb) in a series of surfactants with different poly(ethylene oxide) (PEO) unit lengths on a glassy carbon electrode have been studied. With a surfactant of appropriate PEO unit length, the surfactant film-modified electrode exhibited a more stable adsorption state with a larger surface coverage of Hb and a more positive formal potential, which can be attributed to the effect of hydrogen bonding between proteins and surfactants. The electrochemical behavior of surfactants with different PEO unit lengths is discussed in detail. Moreover, UV-visible spectroscopy demonstrated that the structure of Hb was not destroyed in the surfactant films. The electrocatalytic activity of hydrogen peroxide on three neutral surfactant-modified electrodes has also been investigated.

Block Copolymer Micellisation in a Common Solvent Modeled by Self‐Consistent Field Calculations

AbstractSummary: Recently it was shown that it is possible that block copolymers form micellar solutions in non‐selective solvents. Such micellisation is the result of a pure form of self‐assembly. A molecular realisation is given by asymmetric Poly‐(methacrylic acid)‐block‐Poly(ethylene oxide) copolymers (PMAA‐b‐PEO) in water at a pH &lt; 5. As both the (short) methacrylic acid block and the (long) ethylene oxide are water soluble in the conditions used, it was concluded that the driving force is interchain hydrogen bonding between the PMAA and the PEO units. The mismatch in length of the blocks forces one block to accumulate at the micellar periphery and this eventually stops the phase separation process. We have performed self‐consistent field calculations to examine this scenario. With very reasonable parameters we are able to mimic the properties of these micelles, elaborate the pH dependence and confirm the trend found for the electrophoretic mobility. A nontrivial result of the calculations is that the ratio EO/MAA in the core is close to two.

Electron Density Mapping of Triblock Copolymers Associated with Model Biomembranes: Insights into Conformational States and Effect on Bilayer Structure

One-dimensional electron-density profiles derived from synchrotron small-angle X-ray scattering (SAXS) have been constructed and used to determine the conformational state of selected poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers and the region of their association with a lipid bilayer. The number of molecular repeat units in the hydrophobic PPO block has been found to determine both the nature of triblock polymer-membrane association and the conformational state of the symmetric, flanking hydrophilic PEO units. For DMPC-based biomembranes, polymers whose PPO chain length is less than that of the bilayer thickness insert weakly into the membrane with the PEO blocks on the same side of the bilayer, leading to delocalization of the PEO at the membrane-water interface. This polymer architecture has been found not to alter the membrane fluidity and roughness. Conversely, polymers whose chain length is sufficient to span the lipid bilayer are tightly integrated, projecting their PEO chains into the water channels on opposing sides of the bilayer. The coiled conformational state of the PEO chains produces steric pressure on the bilayer, causing a thinning of the membrane and leading to a rigid, less-mobile bilayer than systems where the polymer is introduced as the lipid conjugate.

Ionic conductivity in polyethylene- b-poly(ethylene oxide)/lithium perchlorate solid polymer electrolytes

The ionic conductivity and phase arrangement of solid polymeric electrolytes based on the block copolymer polyethylene- b-poly(ethylene oxide) (PE- b-PEO) and LiClO 4 have been investigated. One set of electrolytes was prepared from copolymers with 75% of PEO units and another set was based on a blend of copolymer with 50% PEO units and homopolymers. The differential scanning calorimetry (DSC) results, for electrolytes based on the copolymer with 75% of PEO units, were dominated by the PEO phase. The PEO block crystallinity dropped and the glass transition increased with salt addition due to the coordination of the cation by PEO oxygen. The conductivity for copolymers 75% PEO-based electrolyte with 15 wt% of salt was higher than 10 −5 S/cm at room temperature and reached to 10 −3 S/cm at 100 °C on a heating measurement. The blend of PE- b-PEO (50% PEO)/PEO/PE showed a complex thermal behavior with decoupled melting of the blocks and the homopolymers. Upon salt addition the endotherms associated with PEO domains disappeared and the PE crystals remained untouched. The conductivity results were limited at 100 °C to values close to 10 −4 S/cm and at room temperature values close to 3 × 10 −6 S/cm were obtained for the 15 wt% salt electrolyte. Raman study showed that the ionic association of the highly concentrated blend electrolytes at room temperature is not significant. Therefore, the lower values of conductivity in the case of the blend with 50% PEO can be assigned to the higher content of PE domains leading to a morphology with lower connectivity for ionic conduction both in the crystalline and melted state of the PE domains.

Thermal transitions in associating aqueous block copolymers: light scattering, rheology and spectroscopy

Solutions containing a polyoxy-ethylene/polyoxy-propylene/polyoxy-ethylene (PEO–PPO–PEO) block copolymer, indicated as F68, in water were investigated as a function of composition and temperature. Hydrogen nuclear magnetic resonance (1H NMR) line width, chemical shift, self-diffusion, spin-lattice relaxation times, laser light scattering and rheological methods were used. The monomer–micelle equilibrium and the micelle–liquid crystalline phase transitions depend on the F68 content in the mixture and temperature. Significant changes in light scattering intensity and apparent hydrodynamic radius are associated to micelle formation above the critical micellar temperature (CMT). According to a Contin analysis, this behaviour is reflected in the presence of two populations in the intensity–intensity autocorrelation functions. The contributions due to molecules and micelles can be evaluated separately. No such effects are observed below the CMT. Micelle onset is also associated to variations in 1H NMR spectra, affecting the chemical shift, line width and spin-lattice relaxation time of the PPO methyl protons and self-diffusion, as well. Spin-lattice relaxation times of PEO chains, conversely, change significantly at temperatures close to the micelle–liquid crystalline thermal transition. Similar results were obtained from the line width of 2H NMR spectra as a function of T. Significant changes in both viscous and elastic modulus were also observed and ascribed to PPO dehydration, at the CMT, as well as to squeezing and dehydration of PEO units in liquid crystal formation, respectively.