Salt‐Induced Micellization of Pluronic F88 in Water

Patel, K.; Bahadur, Prashant; Chen, Guo; H., J.; Liu, H. Z.; Nakashima, Kenichi

doi:10.1080/01932690701757931

Cited by 20 publications

(23 citation statements)

References 14 publications

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“…The presence of additives like electrolytes and nonelectrolytes, hydrotropes or surfactants alters the surface activity, micellization, and thermo-reversible gel transition of these block copolymers. [14] Extensive work using several techniques on the effect of additives on micellization and phase behavior of EO-PO copolymers showing significant influence on CMC, CMT, cloud point (CP), and gelation region has been done by Bahadur et al [12,13,[15][16][17][18] High-sensitivity differential scanning calorimetry (HSDSC) has been used to identify phase transition and micellization of Pluronics. [19][20][21] Liu et al [22,23] used nuclear magnetic resonance (NMR) to study the micellization of these polymeric surfactants.…”

Section: Introductionmentioning

confidence: 99%

Calorimetric and Scattering Studies on Micellization of Pluronics in Aqueous Solutions: Effect of the Size of Hydrophilic PEO End Blocks, Temperature, and Added Salt

Khimani

Rao

Bahadur

et al. 2014

Journal of Dispersion Science and Technology

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Micellar behavior of five ethylene oxide-propylene oxide (EO-PO) triblock copolymers, called Pluronics, with similar molecular weights of middle block PPO ($2250 g/mol) and varied percentages of poly(ethylene oxide) (10%, 40%, 50%, 70%, and 80%, referred to as L81, P84, P85, F87, and F88, respectively) was examined by thermal (isothermal titration calorimetry and highsensitivity differential scanning calorimetry), spectral (UV-vis), and dynamic light scattering (DLS) techniques. Micellization was decreased with increasing hydrophilicity of copolymer but induced in the presence of salt. Critical micelle temperatures (CMTs) of copolymers at different concentrations, with and without sodium chloride, are reported. Viscosity and DLS results reveal that highly hydrophilic copolymers (F87 and F88) did not show significant change in micelle size even at temperatures close to cloud point, whereas micelle growth and sphere-to-rod transition occurred for P84 and P85. Surface tension of solutions in water and salt also show enhanced surface activity and salt-induced micellization. The CMTs for different systems using different methods are compared.

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Section: Introductionmentioning

confidence: 99%

Calorimetric and Scattering Studies on Micellization of Pluronics in Aqueous Solutions: Effect of the Size of Hydrophilic PEO End Blocks, Temperature, and Added Salt

Khimani

Rao

Bahadur

et al. 2014

Journal of Dispersion Science and Technology

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“…The strengh of this effect depends on the type and concentration of the anion. 17,18,23,24,32,[34][35][36][37] Moreover, it has also been shown that the usage of these lyotropic anions influences the type of aggregation and shape of the micelles. 23 The commonly used organic additives are trimethyl benzene, benzene, buthanol, alkanes, and cyclohexane.…”

Section: Introductionmentioning

confidence: 99%

“…[30][31][32] A similar impact could also be created by using the salts of the Hofmeister's series. 18,20,33,34 These salts can be collected into two main groups. The ones on the left-hand side, called lyotropic anions, decrease solubility and enhance aggregation; however the ones on the right-hand side, the hydrotropic anions, enhance the hydrophilicity and the solubility of the pluronics in an aquoues media.…”

Section: Introductionmentioning

confidence: 99%

“…4,10,[13][14][15][16] The pluronic surfactants are commanly used in many investigations because of their nontoxic, cheap and excellent aggregation properties. [17][18][19] These surfactants are triblock copolymers with a relatively hydrophobic group, poly(propylene oxide) (PPO), at the middle and relativly hydrophilic, poly(ethylene oxide) (PEO), head groups at both ends of the polymer (PEO x -PPO y -PEO x ). One of the characteristics of the mesoporous materials synthesized using the pluronic type surfactants is their thick walls that are typically around 3.0-7.0 nm.…”

Section: Introductionmentioning

confidence: 99%

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Role of Organic and Inorganic Additives on the Assembly of CTAB-P123 and the Morphology of Mesoporous Silica Particles

Poyraz

Dag

2009

J. Phys. Chem. C

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Mesoporous silica particles with various morphologies and structures have been synthesized by controlling the solubility, micellization, and assembly of a charged surfactant (cethyltrimethylammonium bromide, CTAB) and a pluronic (PEO 20 PPO 70 PEO 20 , P123) couple using an organic (benzene) or an inorganic (SO 4 2-, NO 3 -, or Cl -) additive. The effect of CTAB, with or without one of the Hofmeister ions or benzene in various concentrations, on the morphology, pore-size, pore-structure and the nature of the silica particles has been investigated. Increasing the lyotropic anion (SO 4 2-) or benzene concentration of the synthesis media creates wormlike particles with enlarged pores and reduced wall thickness. However, the hydrotropic anion (NO 3 -) influenced the solubility of the charged surfactant and increased the CTAB concentration in the CTAB-P123 micelles, and as a result, in the mesoporous silica particles. The surface area, unit cell, and pore size of the silica particles are diminished by increasing the nitrate ion centration. The effects of the Cl -ion are between the SO 4 2-and NO 3 -ions. It influenced the P123 at low and CTAB at high concentrations. At low CTAB/ P123 mol ratios, the Cl -ion affects mainly the P123, but at high CTAB/P123 it affects both the CTAB and P123. By carefully adjusting these ingredients (CTAB, SO 4 2-, Cl -, NO 3 -and benzene), not only the morphology of the particles, but also the pore-size and pore-structure of the mesoporous silica particles could be adjusted. The investigations were carried out by preparing a series of powder samples and, by varying the CTAB/P123 mol ratio (between 3.0 and 6.0) and the concentration of the organic (0.17 to 0.90 M) or inorganic (at 0.25, 0.50, or 1.00 M) additive in the synthesis media. The powder samples were analyzed using microscopy (SEM, TEM, and POM), diffraction (PXRD), and spectroscopy (FTIR, Raman, UV-vis, and EDS) techniques toward above goals.

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“…the most dense and optimized close-packed structure. 15 The microstructures of the emulsions with IL volume fractions outside 0.70-0.95 were also characterized by CLSM. 14 The colorized CLSM images shown in Fig.…”

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confidence: 99%