Bonding mechanisms and conformation of poly(ethylene oxide)-based surfactants in interlayer of smectite

Deng, Youjun; Dixon, J. B.; White, G. Norman

doi:10.1007/s00396-005-1388-0

Cited by 98 publications

(76 citation statements)

References 28 publications

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“…In this contest, the use of nonionic surfactants (Ghiaci et al 2007; Guégan 2013, Guégan et al 2009) is increasingly replacing the traditional cationic surfactants (Koh and Dixon 2001;Mortland et al 1986) which revealed less versatile in the Electronic supplementary material The online version of this article (doi:10.1007/s10450-015-9697-1) contains supplementary material, which is available to authorized users. adsorption of both non-ionic organic compound and cationic species (Shen 2001;Deng et al 2003Deng et al , 2006.…”

Section: Introductionmentioning

confidence: 99%

Preparation and characterization of bio-organoclays using nonionic surfactant

et al. 2015

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The present study was aimed at the preparation and characterization of tailor made hybrid materials, whose peculiar hosting capability could be exploited in biotechnological applications. With this purpose, the modification of K10 montmorillonite by intercalation of Tween 20 surfactant, was accomplished. The influence of two internal parameters, namely pH and surfactant/clay ratio, on the surfactant uptake ability by clay was investigated. The adsorption mechanism was elucidated on the basis of complementary kinetic and equilibrium studies and, then, corroborated by the useful information provided by the FT-IR, TGA and XRD characterization. The gathered results allow to draw the conclusion that the whole surfactant uptake is the result of two contributions: a site-limiting component, governed by negative cooperative interactions, which takes into account for the Tween 20 adsorption onto the pristine clay, and a non-specific linear partitioning component, related to the adsorption of the surfactant onto the in situ prepared organo-clay. Moreover, at strongly acidic pH, a mechanism consisting of two-steps pathways involving two non-energetically equivalent binding sites of the clay surfaces, was proposed, while, on increasing the pH, the clay interlayer becomes the sole available site for the surfactant uptake. In the light of the interesting results obtained, among the plethora of potential biotechnological applications, the present paper suggests the exploitation of the prepared organo-clays to improve the performance of either hydrophilic or hydrophobic drug carriers systems

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Section: Introductionmentioning

confidence: 99%

Preparation and characterization of bio-organoclays using nonionic surfactant

et al. 2015

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“…The assigning for CHCl 3 was easy as it and its IR spectrum are well known and widely published [Silverstein & Webster, 1998]. The assigning for PEO was helped by [Ratna et al, 2006] and [Deng et al, 2006]. The work for C 22 H 44 O 4 Sn was the most difficult: it is rarely reported and its IR spectrum is unavailable in the literature.…”

Section: Comments On the Experimental Resultsmentioning

confidence: 99%

Diversity of Nanofibers from Electrospinning: from Graphitic Carbons to Ternary Oxides.

Wang¹,

Ramos²,

Santiago-Avilés³

2010

Nanofibers

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“…20 They showed that POE chains in oleth-type surfactants adsorbed to smectite surfaces through hydrogen bonding between oxygen atoms in the POE chain and water molecules in the hydration layers of exchangeable cations such as calcium and magnesium, and ion-dipole interactions between the POE oxygens and the cations. Furthermore, it was proposed that the POE chain would assume an extended helical conformation that would maximize exposure of the oxygen atoms to both the water molecules and the cations.…”

Section: Resultsmentioning

confidence: 99%

“…Furthermore, it was proposed that the POE chain would assume an extended helical conformation that would maximize exposure of the oxygen atoms to both the water molecules and the cations. 20 Based on the interlayer spacing (determined by their X-ray diffraction data), Deng et al 20 concluded that no more than 2 layers of POE chains intercalated between the clay platelets. Intercalation of the surfactants between the platelets in the current study would assist the further delamination of undissociated platelets and increase the number of potential contact points between platelets.…”

Section: Resultsmentioning

confidence: 99%

Effect of selected non-ionic surfactants on the flow behavior of aqueous veegum suspensions

Kennedy

2007

AAPS PharmSciTech

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The aim of this work was to investigate the influence of some non-ionic surfactants, Tween 80 and Brij 98, on the viscosity and flow behavior of a commercial montmorillonite clay, Veegum Granules. The effect of different concentrations of the surfactants on the shear stress-shear rate rheograms of hydrated concentrated clay suspensions was determined by shear viscometry. The addition of either surfactant increased the plastic viscosity and the yield stress of the suspensions. Furthermore, both surfactants altered the thixotropy of the suspensions to an extent that depended on both the surfactant concentration and the time of equilibration of the surfactant and Veegum. Brij 98 had a greater and more rapid effect. It is proposed that the surfactant polar head-groups anchor at the tetrahedral sheet surface, leaving the alkyl chains extending away from the edges and faces. Consequently, the alkyl chains undergo hydrophobic interactions that facilitate the association between the platelets and increase the physical structure within the suspension. Stereochemical differences between the polar groups may lead to differences in the way the surfactants associate with the tetrahedral sheet and hence their ultimate effect on the rheological behavior. There is a significant interaction between these surfactants and montmorillonite clays, and the rheological changes that occur could have a major impact on any pharmaceutical formulation that uses these ingredients.

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Bonding mechanisms and conformation of poly(ethylene oxide)-based surfactants in interlayer of smectite

Cited by 98 publications

References 28 publications

Preparation and characterization of bio-organoclays using nonionic surfactant

Preparation and characterization of bio-organoclays using nonionic surfactant

Diversity of Nanofibers from Electrospinning: from Graphitic Carbons to Ternary Oxides.

Effect of selected non-ionic surfactants on the flow behavior of aqueous veegum suspensions

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