Hofmeister Salt Effects on Surface Tension Arise from Partitioning of Anions and Cations between Bulk Water and the Air−Water Interface

2007 ◽  
Vol 111 (19) ◽  
pp. 5411-5417 ◽  
Author(s):  
Laurel M. Pegram ◽  
M. Thomas Record
Keyword(s):  
Surface Tension ◽  
Bulk Water ◽  
Water Interface ◽  
Salt Effects ◽  
Air Water Interface ◽  
Anions And Cations

From Surface Tension to Molecular Distribution: Modeling Surfactant Adsorption at the Air–Water Interface

Langmuir ◽  
2021 ◽  
Vol 37 (7) ◽  
pp. 2237-2255 ◽  
Author(s):  
Mengsu Peng ◽  
Timothy T. Duignan ◽  
Cuong V. Nguyen ◽  
Anh V. Nguyen
Keyword(s):  
Surface Tension ◽  
Surfactant Adsorption ◽  
Water Interface ◽  
Molecular Distribution ◽  
Distribution Modeling ◽  
Air Water Interface

Surface active properties at the air–water interface of β-casein and its fragments derived by plasmin proteolysis

1989 ◽  
Vol 56 (3) ◽  
pp. 487-494 ◽  
Author(s):  
Michael Wilson ◽  
Daniel M. Mulvihill ◽  
William J. Donnelly ◽  
Brian P. Gill
Keyword(s):  
Surface Tension ◽  
Water Interface ◽  
Active Protein ◽  
Drop Volume ◽  
V Protein ◽  
Proteose Peptone ◽  
Rate Determining Step ◽  
Surface Active Properties ◽  
Air Water Interface ◽  
Surface Active

Summaryβ-Casein, was enzymically modified by incubation with plasmin to yield γ-caseins and proteose peptones. Whole γ-, γ1-, γ2/γ3-caseins and whole proteose peptone (pp) were isolated from the hydrolysate mixture. The time dependence of surface tension at the air-water interface of solutions of β-casein and its plasmin derived fragments, at concentrations of 10−1 to 10−4% (w/v) protein, pH 7.0, was determined, at 25 °C, using a drop volume apparatus. The ranking of the proteins with respect to rate of reduction of surface tension, during the first rate determining step, at 10-2% (w/v) protein, was γ2/γ3 ≫ pp > whole γ- > γ1- > β-casein. The ranking of the proteins with respect to surface pressures attained after 40 min (π40) was concentration dependent. γ2/γ3-Caseins were found to be very surface active, decreasing surface tension rapidly and giving a high π40. γ1 Casein decreased surface activity somewhat faster than β-casein, but generally reached a lower π40. Whole γ-casein reflected the properties of both γ1 and γ2/γ3-caseins. Proteose peptone was found to decrease surface tension rapidly during the initial rate determining step; it gave a relatively high π40 at a bulk phase concentration of 10−3% (w/v) protein, but, it was the least surface active protein at 10−1 and 10−2% (w/v) protein.

scholarly journals Effect of a surface tension gradient on the slip flow along a superhydrophobic air-water interface

2018 ◽  
Vol 3 (3) ◽  
Author(s):  
Dong Song ◽  
Baowei Song ◽  
Haibao Hu ◽  
Xiaosong Du ◽  
Peng Du ◽  
...  
Keyword(s):  
Surface Tension ◽  
Slip Flow ◽  
Surface Tension Gradient ◽  
Water Interface ◽  
Air Water Interface

Observations on the locomotion of post-larval and juvenile flying fish

1990 ◽  
Vol 70 (2) ◽  
pp. 311-320 ◽  
Author(s):  
John Davenport
Keyword(s):  
Surface Tension ◽  
Surface Roughness ◽  
Reynolds Numbers ◽  
Maximum Speed ◽  
Tail Flick ◽  
Horizontal Distance ◽  
Water Interface ◽  
Flying Fish ◽  
Air Water Interface ◽  
Air Penetration

Post-larval specimens of Hirundichthys affinis are capable of jumping out of water, but the pectoral and pelvic fins are not extended when in air. Penetration through the air/ water interface demands a force to overcome surface tension which is similar in magnitude to the force required for the jump itself. However, post-larvae do not produce the single propulsive tail flick which powers the jump until most of the animal has passed through the interface. The post-larva emerges at an angle close to 45°, thus maximising the horizontal distance travelled before re-entry.Whether swimming slowly (4 body lengths s-1), or at maximum speed (36 body lengths s-1), post-larvae swim with the pectoral and pelvic fins extended. Calculations show that fast swimming post-larvae operate at Reynolds’ numbers of about 4×103, where surface roughness and projections decrease rather than increase drag.

scholarly journals Aerosol microdroplets exhibit a stable pH gradient

2018 ◽  
Vol 115 (28) ◽  
pp. 7272-7277 ◽  
Author(s):  
Haoran Wei ◽  
Eric P. Vejerano ◽  
Weinan Leng ◽  
Qishen Huang ◽  
Marjorie R. Willner ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Bulk Water ◽  
Bulk Solution ◽  
Spatial Gradient ◽  
Water Interface ◽  
Atmospheric Reactions ◽  
Air Water Interface ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
2D And 3D

Suspended aqueous aerosol droplets (<50 µm) are microreactors for many important atmospheric reactions. In droplets and other aquatic environments, pH is arguably the key parameter dictating chemical and biological processes. The nature of the droplet air/water interface has the potential to significantly alter droplet pH relative to bulk water. Historically, it has been challenging to measure the pH of individual droplets because of their inaccessibility to conventional pH probes. In this study, we scanned droplets containing 4-mercaptobenzoic acid–functionalized gold nanoparticle pH nanoprobes by 2D and 3D laser confocal Raman microscopy. Using surface-enhanced Raman scattering, we acquired the pH distribution inside approximately 20-µm-diameter phosphate-buffered aerosol droplets and found that the pH in the core of a droplet is higher than that of bulk solution by up to 3.6 pH units. This finding suggests the accumulation of protons at the air/water interface and is consistent with recent thermodynamic model results. The existence of this pH shift was corroborated by the observation that a catalytic reaction that occurs only under basic conditions (i.e., dimerization of 4-aminothiophenol to produce dimercaptoazobenzene) occurs within the high pH core of a droplet, but not in bulk solution. Our nanoparticle probe enables pH quantification through the cross-section of an aerosol droplet, revealing a spatial gradient that has implications for acid-base–catalyzed atmospheric chemistry.

Influence of pH on the surface and foaming properties of aqueous silk fibroin solutions

Soft Matter ◽  
2020 ◽  
Vol 16 (15) ◽  
pp. 3695-3704 ◽  
Author(s):  
Xiuying Qiao ◽  
Reinhard Miller ◽  
Emanuel Schneck ◽  
Kang Sun
Keyword(s):  
Surface Tension ◽  
Silk Fibroin ◽  
Bubble Coalescence ◽  
Foaming Properties ◽  
Water Interface ◽  
Interfacial Layers ◽  
Air Water Interface ◽  
Influence Of Ph

Silk fibroin (SF) adsorbs at the air/water interface, reduces the surface tension, and forms interfacial layers suppressing bubble coalescence and stabilizing foam.

Molecular dynamics simulations predict an accelerated dissociation of H2CO3 at the air–water interface

2014 ◽  
Vol 16 (46) ◽  
pp. 25573-25582 ◽  
Author(s):  
Mirza Galib ◽  
Gabriel Hanna
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Molecular Dynamics Simulations ◽  
Carbonic Acid ◽  
Bulk Water ◽  
Water Interface ◽  
Air Water Interface ◽  
Dynamics Simulations ◽  
Dissociation Barrier

Ab initio molecular dynamics simulations of carbonic acid (H2CO3) at the air–water interface yield a lower dissociation barrier than in bulk water.

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