Contribution of 1H NMR to the investigation of the adsorption of cationic Gemini surfactants with oligooxyethylene spacer group onto silica

Bendjeriou‐Sedjerari, Anissa; Derrien, Gaëlle; Charnay, Clarence; Zając, Jerzy; Menorval, L. C. De; Lindheimer, Marc

doi:10.1016/j.jcis.2008.12.007

Cited by 29 publications

(5 citation statements)

References 39 publications

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“…43 An alternative approach, often providing reliable results, consists of monitoring the variation of the chemical shift of both the surfactant and analyte for solution of increasing relative concentration. [44][45][46][47][48] To make sure that the peak shift is caused by close contact between the solute and the surfactant, the determination of the peak separation between methylene units belonging to the apolar portion of the surfactant is followed. This separation changes with the amount of the solute, clearly excluding other solvation effects and confirming the close contact between the most sensitive methylene unit and the solute.…”

Section: Instrumental Investigations On Micellar Systemsmentioning

confidence: 99%

Recent advances in catalysis in micellar media

2015

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Section: Instrumental Investigations On Micellar Systemsmentioning

confidence: 99%

Recent advances in catalysis in micellar media

2015

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“…[21][22][23][24] The aggregation properties of gemini lipids strongly depend on the nature and length of the spacer between the two head groups. [25][26][27][28][29] The introduction of oxygen into the spacer can affect the orientation in a different fashion; thus, the spacer chain containing oxyethylene functionalities folds in association with water molecules of the interfacial region, this additional hydration reduces the coulumbic repulsions between two cationic heads 30 and might improve the interaction between the GCLs and DNA. Such interfacial polarity has been found to inuence the membrane properties of lipid aggregates as well as many crucial biological events.…”

Section: Introductionmentioning

confidence: 99%

Cationic gemini lipids containing polyoxyethylene spacers as improved transfecting agents of plasmid DNA in cancer cells

Barrán-Berdón

Misra²,

Datta³

et al. 2014

J. Mater. Chem. B

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“…Notably, these γ CAC values were significantly lower than those of hydrocarbon-based surfactants (30-40 mN/m) [31] and were similar to those reported for other trisiloxane surfactants (20-25 mN/m) [7,8] and fluorosurfactants (18-28 mN/m) [9], which might be attributed to the two hydrophobic trisiloxane groups of the gemini surfactant molecules better facilitating the self assembly into aggregates and more efficiently decreasing the surface tension than the corresponding monomeric surfactants. Moreover, other physicochemical parameters (Γ CAC , A CAC , △G θ mic , and △G θ ads ) related to surface activity were calculated according to previous studies [32][33][34][35]. The variables Г max and A CAC are also related to m and n, and an increase in the spacer group (CH 2 ) resulted in a slight decrease in Г max and an increase in A CAC .…”

Section: Surface Activities and Aggregation Properties Of Surfactantsmentioning

confidence: 99%

A gemini-type superspreader: Synthesis, spreading behavior and superspreading mechanism

Lin

Wang

Bai

et al. 2017

Chemical Engineering Journal

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Please cite this article as: A gemini-type superspreader: synthesis, spreading behavior and superspreading mechanism, Chemical Engineering Journal (2016), doi: http://dx.doi.org/10. 1016/j.cej.2016.12.132 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. ABSTRACTThis paper describes the facile microwave-assisted synthesis of a series of trisiloxane gemini superspreaders, as well as their surface and aggregation properties and superspreading behavior on plant leaf surfaces. The molecular structures of the trisiloxane gemini surfactants were characterized by Fourier transform infrared spectroscopy (FTIR) and 1 H nuclear magnetic resonance spectroscopy ( 1 H NMR). The obtained thermodynamic parameters showed that an increase in the spacer group (CH 2 ) resulted in decreases in the critical aggregation concentration (CAC), corresponding surface tension (γ CAC ), and surface excess concentration (Γ max ) but increases in the occupied area per surfactant molecule (A CAC ) and absolute values of the standard free energies of aggregation (△G θ mic ) and adsorption (△G θ ads ). An increase in ethoxy units (CH 2 -CH 2 -O-) resulted in increases in the CAC, γ CAC , and A CAC but decreases in Г max and the absolute values of △G θ mic and △G θ ads . The transmission electron microscopy and dynamic light scattering results showed that the average sizes of the aggregates of superspreader solutions increased with an increasing number of spacer units (CH 2 ) but decreased with an increasing number of ethoxy units (CH 2 -CH 2 -O-). The dynamic spreading behavior results demonstrated that the average spreading velocity increased with increasing spacer chain length, and the dependence of the maximum spreading velocity on the ethoxy chain length was nonmonotonous with a maximum at n(EO) = 8.68. The optimal HLB value was essential to obtaining good superspreading behavior, and the substrate wettability (hydrophobic rice plant and hydrophilic mango plant surfaces) greatly influenced the superspreading. The synergistic effects from the precursor film and Marangoni effect existed in the proposed superspreading model.

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Contribution of 1H NMR to the investigation of the adsorption of cationic Gemini surfactants with oligooxyethylene spacer group onto silica

Cited by 29 publications

References 39 publications

Recent advances in catalysis in micellar media

Recent advances in catalysis in micellar media

Cationic gemini lipids containing polyoxyethylene spacers as improved transfecting agents of plasmid DNA in cancer cells

A gemini-type superspreader: Synthesis, spreading behavior and superspreading mechanism

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