Aggregation and clouding behavior of aqueous solution of EO–PO block copolymer in presence of n-alkanols

Bharatiya, Bhavesh; Chen, Guo; Ma, Jinyuan; Hassan, P. A.; Bahadur, Pratap

doi:10.1016/j.eurpolymj.2007.02.010

Cited by 78 publications

(52 citation statements)

References 42 publications

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“…Some reports on oil solubilization are available and clearly mention that the Pluronic micelles undergo remarkable phase transition under the effect of oils [49]. Previous studies on the effect of various alkanols [50], salts [51], diols [52] on TBCP micelles have shown similar results indicating that the micellar growth is not restricted to the partitioning of only aromatic oils.…”

Section: Cmts and Micellar Size Of Copolymers In Watermentioning

confidence: 50%

Solubilization of Aromatic Hydrocarbons in Ethylene Oxide‐Propylene Oxide Triblock Micelles: Location of Solubilizate and its Effect on Micelle Size from 2D NMR and Scattering Techniques

Parekh

Singh²,

Marangoni³

et al. 2011

J Surfact & Detergents

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The solubilization of benzene and toluene in micellar solutions and the effects on the micellization and micelle size of ethylene oxide-propylene oxide triblock copolymers were investigated by dynamic light scattering (DLS), small angle neutron scattering (SANS), and 2D NMR spectroscopy. The copolymeric surfactants have the same size as the middle hydrophobic polypropylene oxide block (Mol. Wt. 3250) and varying polyethylene oxide end blocks (30, 40 and 50%). The solubilization and the properties of the micelles in the presence of the solubilizates were investigated; the results reveal that the more hydrophobic copolymer showed better solubilization. The cloud points of the copolymers decreased in the presence of oils; the depression in the cloud point is due to the formation of an electron donor-acceptor complex. DLS shows that the effect of benzene is dominated at high oil concentration. SANS data show that the micelles remain spherical in shape and that the micellar core size does not change with higher benzene concentration; observed changes in the low scattering vector region could be because of some small amount of benzene clusters formed at higher benzene concentration. Finally, the locus of solubilization of the oils in the copolymer micelles was determined via 2D NMR experiments. In all cases, significant nuclear Overhauser effect spectroscopy (NOESY) cross peaks were observed that appeared to correlate well with the expected loci of these solubilizates in micelles. Hence, the noninvasive NOESY technique provides important information on the location of the aromatic solubilizates in these copolymer micelles that depends on the structure of the oils.

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Section: Cmts and Micellar Size Of Copolymers In Watermentioning

confidence: 50%

Solubilization of Aromatic Hydrocarbons in Ethylene Oxide‐Propylene Oxide Triblock Micelles: Location of Solubilizate and its Effect on Micelle Size from 2D NMR and Scattering Techniques

Parekh

Singh²,

Marangoni³

et al. 2011

J Surfact & Detergents

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“…It has been suggested that the presence of such "structured" water cages around ethanol decreases the hydration of the polymer chain resulting in decreased solubility and, thus, a lower cloud point [26]. A similar effect is described for longer n-alcohols (C4-C6) at low concentrations causing a decrease in cloud point for ethylene oxide-propylene oxide copolymers [49,50]. The different behavior between PropOx and i-PropOx upon increasing the ethanol fraction most likely arises from hydrophobic solvation of the side chain by ethanol molecules.…”

Section: Resultsmentioning

confidence: 86%

“…This peculiar solubility behavior is due to the clustering of water molecules in ethanol rich solutions. At 80 wt% ethanol, water is mostly present as individual water molecules driving the formation of a water hydration shells around the polymer by interactions with the amide groups [40,50] The resulting hydration shell acts as a compatibilizing layer between the solvent mixture and the polymer. When decreasing the amount of ethanol from 80 wt% to 60 wt% the water cluster size gradually increases [40] and, therefore, the driving force for polymer hydration decreases since hydration now competes with water-water hydrogen bonding in the clusters.…”

Section: Resultsmentioning

confidence: 99%

Temperature Induced Solubility Transitions of Various Poly(2-oxazoline)s in Ethanol-Water Solvent Mixtures

et al. 2010

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Abstract:The solution behavior of a series of poly(2-oxazoline)s with different side chains, namely methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, pentyl, hexyl, heptyl, octyl, nonyl, phenyl and benzyl, are reported in ethanol-water solvent mixtures based on turbidimetry investigations. The LCST transitions of poly(2-oxazoline)s with propyl side chains and the UCST transitions of the poly(2-oxazoline)s with more hydrophobic side chains are discussed in relation to the ethanol-water solvent composition and structure. The poly(2-alkyl-2-oxazoline)s with side chains longer than propyl only dissolved during the first heating run, which is discussed and correlated to the melting transition of the polymers.

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“…cationic, 34 gemini, 36,42 sugar surfactant, 43 Triton X-100 37 and Pluronics® with varying hydrophobicity. [38][39][40][41] Few studies demonstrate that addition of hydrophobic alcohol leads to growth of worm-like micelle 44,45 followed by vesicle formation. [46][47][48] Sreejith et al…”

Section: -33mentioning

confidence: 99%

“…It is generally noticed that short chain alcohols (C 1 -C 3 ) remain in the aqueous bulk phase, medium chain alcohols (C 4 -C 6 ) partition between the micellar and bulk phases and long chain alcohols (C 7 and above) are solubilized within the micelle with polar hydroxyl group protruding towards the micelle surface and inducing the microstructural changes in the system. Bahadur and coworkers [34][35][36][37][38][39][40][41] have extensively studied the effect of different alcohols on aqueous surfactant solutions. 1-Hexanol is a weakly amphiphilic alcohol with low aqueous solubility, which is known to penetrate into micelles and promote their growth.…”

Section: -33mentioning

confidence: 99%

1-Hexanol triggered structural characterization of the worm-like micelle to vesicle transitions in cetyltrimethylammonium tosylate solutions

et al. 2015

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The cationic surfactant cetyltrimethylammonium tosylate (CTAT) forms highly viscous/viscoelastic solutions and worm-like micelles at relatively low concentrations. The effect of 1-alkanols with short to long alkyl chains viz. ethanol, 1-butanol, 1-hexanol and 1-octanol on CTAT micelles was examined. In particular, a detailed study on the effect of 1-hexanol was carried out by viscosity, cryogenic transmission electron microscopy (cryo-TEM), nuclear magnetic resonance (NMR) and small-angle neutron scattering (SANS) to observe microstructural changes in CTAT micelles. 1-Hexanol displays a distinct interaction with CTAT micelles strongly dependent on CTAT concentration. Up to a certain critical CTAT concentration, 1-hexanol molecules penetrate into the micelles and show growth.Characterization by direct cryo-TEM imaging implies that upon progressive addition of 1-hexanol, worm-like CTAT micelles first grow and finally transform into vesicles. The course of vesicle formation was followed by SANS measurements. The site of 1-hexanol in the micelles close to the palisade layer was evaluated using 2D NMR. This study devotes a fundamental knowledge for controlling the shape and size of worm-like micelles that find many industrial applications particularly in personal-and home-care products.

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Aggregation and clouding behavior of aqueous solution of EO–PO block copolymer in presence of n-alkanols

Cited by 78 publications

References 42 publications

Solubilization of Aromatic Hydrocarbons in Ethylene Oxide‐Propylene Oxide Triblock Micelles: Location of Solubilizate and its Effect on Micelle Size from 2D NMR and Scattering Techniques

Solubilization of Aromatic Hydrocarbons in Ethylene Oxide‐Propylene Oxide Triblock Micelles: Location of Solubilizate and its Effect on Micelle Size from 2D NMR and Scattering Techniques

Temperature Induced Solubility Transitions of Various Poly(2-oxazoline)s in Ethanol-Water Solvent Mixtures

1-Hexanol triggered structural characterization of the worm-like micelle to vesicle transitions in cetyltrimethylammonium tosylate solutions

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