Surface tension gradient driven spreading of trisiloxane surfactant solution on hydrophobic solid

Chengara, Anoop; Nikolov, Alex

doi:10.1016/s0927-7757(02)00060-2

Cited by 52 publications

(46 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is interesting that the maximum of the spread area for BT-278 and the mixture of DoTAB with SOcSare observed at the identical concentration 1 g/l. The maximum in the spread area of trisiloxane surfactant at concentration 1 g/l agrees with the results presented in [23] for Silvet L-77, which is similar to BT-278.…”

Section: Comparison Of Spreading Factors For Superspreader Bt-278 Andsupporting

confidence: 89%

Mixtures of catanionic surfactants can be superspreaders: Comparison with trisiloxane superspreader

Kovalchuk

Barton

Trybała

et al. 2015

Journal of Colloid and Interface Science

View full text Add to dashboard Cite

Section: Comparison Of Spreading Factors For Superspreader Bt-278 Andsupporting

confidence: 89%

Mixtures of catanionic surfactants can be superspreaders: Comparison with trisiloxane superspreader

Kovalchuk

Barton

Trybała

et al. 2015

Journal of Colloid and Interface Science

View full text Add to dashboard Cite

“…The spreading dynamic of surfactant solutions has been extensively investigated over last years [1][2][3][4][5][6][7] ; however an understanding of the mechanism of influence of surfactants on spreading of droplets of aqueous surfactant solutions is to be understood.…”

Section: Introductionmentioning

confidence: 99%

“…[9][10][11][12][13][14][15][16] Obviously the spreading of surfactant solutions is affected by adsorption of surfactant molecules at interfaces, which could drastically changes interfacial tensions and energy balance at a three-phase contact line, promote the spreading of aqueous surfactant solutions: the rate of adsorption of surfactant molecules and depletion of surfactant at the expanding interface during the spreading reflects on the changing of spreading rate of droplet. 17 The mechanisms proposed by a number of researchers [4][5][6][7]10 for spreading of surfactant solution over hydrophobic surfaces relayed only on the adsorption processes on (i) the liquid-vapor and/or (ii) the solid-liquid interfaces, and completely excluded the possibility of adsorption of surfactant on (iii) the solid-vapour interface in front of the moving three phase contact line. The latter phenomenon has been suggested as a driving force of spreading of aqueous surfactant solutions over hydrophobic substrates [18][19][20][21][22][23][24] .…”

Section: Introductionmentioning

confidence: 99%

Why do aqueous surfactant solutions spread over hydrophobic substrates?

Starov

Иванова

Rubio

2010

Advances in Colloid and Interface Science

View full text Add to dashboard Cite

Kinetics of spreading of aqueous surfactant solution droplets over highly hydrophobic substrates proceeds in one slow stage at concentration of surfactants below some critical value and in two stages if the surfactant concentration above the critical value: the fast and relatively short first stage is followed by a slower second stage. It is shown that the kinetics of spreading at concentrations below critical and the second stage at concentrations above critical are determined by a slow surfactant molecules transfer on a bare hydrophobic substrate in front of the moving three phase contact line (autophilic phenomenon). The latter process results in an increase of the interfgacial tension of the hydrophobic solid surface in front and the spreading as a result. It is proven that in spite of that the latter process results in a decrease of the total free energy of the droplet and, hence, the adsorption of surfactants molecules on a bare hydrophobic substrate in front of the moving three phase contact line is a spontaneous process. The duration of the first stage of spreading in the case of the surfactant concentration above the critical correlates well with the duration of adsorption of surfactant molecules onto liquid-air interface.The latter allows assuming that the adsorption on the liquid-air interface is the driving mechanism of spreading during the first fast stage of spreading at surfactant concentrations above the critical. It is discussed why the first stage does not present 2 in the case of surfactant concentrations below the critical concentration in spite of the longest duration of adsorption in this case.

show abstract

“…The central droplet surface therefore moved outwards and spread onto the substrate until the gradient reduced. A detailed discussion of theoretical arguments supporting the Marangoni effect mechanism together with experimental evidence has been given in previous studies [16,49,51]. The formation of surface tension gradients resulting in the Marangoni effect was also observed in numerical simulations [55].…”

Section: Dynamic Spreading Behavior Of the Surfactants On Plant Leaf mentioning

confidence: 70%

“…Furthermore, the role of bilayer aggregation in the bulk was elucidated by Ananthapadmanabhan [12] and Venzmer [15]. Additionally, Chengara et al [16] claimed that a surface tension gradient causing Marangoni flow was the driving force for the superspreading process. Lin et al [17] and Churaev [18] noted that the existence of a thin water precursor film in contact with the leading edge of the droplet plays a significant role.…”

Section: Introductionmentioning

confidence: 99%

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

Lin

Wang

Bai

et al. 2017

Chemical Engineering Journal

View full text Add to dashboard Cite

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.

show abstract

Surface tension gradient driven spreading of trisiloxane surfactant solution on hydrophobic solid

Cited by 52 publications

References 16 publications

Mixtures of catanionic surfactants can be superspreaders: Comparison with trisiloxane superspreader

Mixtures of catanionic surfactants can be superspreaders: Comparison with trisiloxane superspreader

Why do aqueous surfactant solutions spread over hydrophobic substrates?

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

Contact Info

Product

Resources

About