DIFFUSION CONTROLLED BUILDUP OF SURFACE ACTIVE MATERIAL AT THE AIR—WATER INTERFACE DURING EVAPORATION

1963 ◽  
Vol 67 (11) ◽  
pp. 2355-2360 ◽  
Author(s):  
F. L. Jackson ◽  
F. P. Krause
Keyword(s):  
Active Material ◽  
Water Interface ◽  
Diffusion Controlled ◽  
Air Water Interface ◽  
Surface Active ◽  
Surface Active Material

Application of the Langmuir trough to the Study of Rubber Latex

1942 ◽  
Vol 15 (1) ◽  
pp. 107-114 ◽  
Author(s):  
W. G. Wren
Keyword(s):  
Active Material ◽  
Close Packing ◽  
Metal Salts ◽  
Dilute Solution ◽  
Langmuir Trough ◽  
Rubber Latex ◽  
Air Water Interface ◽  
Cent Sodium ◽  
Surface Active ◽  
Surface Active Material

Abstract When a drop of ammoniated latex is allowed to touch a cleaned water surface, it spreads rapidly and evenly at the air-water interface, none entering the bulk of the water. Microscopic examination of such a film shows that, given sufficient spreading area, the latex globules are clearly separate one from another, and form a layer one particle thick. On reducing the area occupied by the globules by compressing the film between waxed glass straight edges lying in the surface of the water, the particles are forced together until visible spaces or voids disappear. The film still appears to be one particle thick, and remains in the surface of the water. Further compression results in irregularities of the surface, which can be seen to consist of folds in the film and, on expansion, a proportion of the latex globules is found to have been forced from the surface into the bulk of the water. If a dilute solution of certain substances is used in place of water, the latex particles all remain on the surface, even under conditions of high compression. Dilute acids and solutions of divalent metal salts are found to be effective in keeping the particles in the surface but, on compression to the point where close packing of the particles occurs, the film sometimes forms a continuous coagulum and on release of the pressure, it does not expand. Solutions of a creaming agent, such as 0.1 per cent sodium alginate (Manucol V), are adequate, not only to prevent particles being forced out of the surface, but also to give films which expand readily on release of the pressure. The fact that the latex is instantly swept to one side by a trace of surface active material, such as oleic acid, confirms that the particles have not penetrated into the interior of the water.

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.

Letter to the Editor

PEDIATRICS ◽  
1974 ◽  
Vol 54 (4) ◽  
pp. 519-519
Keyword(s):  
Amniotic Fluid ◽  
Active Material ◽  
Hyaline Membrane Disease ◽  
Clinical Entity ◽  
Letter To The Editor ◽  
Hyaline Membrane ◽  
Surface Active ◽  
Surface Active Material

Dr. Stevenson's observations concerning the association of amniotic fluid aspiration and hyaline membrane disease is quite interesting. Very little work, that we are aware of, has been done since these articles were published (1955 to 1958) to follow tip this theory. However, much work has been done to clarify the etiology of hyaline membrane disease. It is now well accepted that this clinical entity is directly related to the degree of immaturity of the lungs and the presence or absence of surface active material.

336. Surface activity and proteins of milk

1946 ◽  
Vol 14 (3) ◽  
pp. 316-329 ◽  
Author(s):  
R. Aschaffenburg
Keyword(s):  
Milk Fat ◽  
Chemical Nature ◽  
Active Material ◽  
Milk Proteins ◽  
Residual Fraction ◽  
Total Milk ◽  
Surface Active ◽  
Surface Active Material ◽  
Dilution Curves

As moderate dilution causes little change in the surface tension of milk, it is shown to be advantageous to use σ-dilution curves in place of the σ-values of the undiluted fluid as a characteristic of the surface properties of milk. The complications arising from the presence of the milk fat are described, and it is suggested that the influence of the fat is of a physical rather than of a chemical nature. A study of the role of the various milk proteins shows the casein to be of great importance, whilst the heat-coagulable proteins have little influence. The serum obtained after removal of the casein and heat-coagulable proteins contains a residual fraction of protein-like material which is markedly surface active though constituting only about 3% of the total milk proteins. The surface-active material (σ-proteose) has been concentrated and isolated, and its properties are described in some detail.

Isolation and assay of dipalmityl lecithin in lung extracts

1964 ◽  
Vol 207 (2) ◽  
pp. 402-406 ◽  
Author(s):  
Elwyn S. Brown
Keyword(s):  
Phosphatidyl Choline ◽  
Trichloroacetic Acid ◽  
Cadmium Chloride ◽  
Active Material ◽  
Weight Basis ◽  
Alcohol Extract ◽  
Wet Weight ◽  
Surface Active ◽  
Surface Active Material ◽  
Surface Balance

Lung extracts were obtained by either mincing the lungs in saline or by washing the lung with saline through the trachea. The surface tensions of the extracts on compression to 10% of the original area in a surface balance decreased to 7.5 ± 2.1 dynes/cm for rabbits, 10.0 ± 1.8 dynes/cm for dogs, and 6.8 ± 3.8 dynes/cm for man. The surface-active material in the extracts was completely precipitated with trichloroacetic acid. Ethyl or methyl alcohol extracted the activity from the precipitate. By concentrating and chilling the alcohol extract, a very surface-active white precipitate was obtained which was identified as dipalmityl phosphatidyl choline by melting point, chemical analysis, and paper chromatography. Cadmium chloride also precipitated a surface-active complex from the alcohol extract which was identified chemically as dipalmityl phosphatidyl choline. The quantity of hydrolecithin extracted from the lungs was 0.09–0.18% on a wet weight basis. No evidence of the presence of sphingomyelin or other surface-active phospholipid was obtained.

Beta-receptors and surface active material flux in fetal lamb lung: female advantage

1987 ◽  
Vol 63 (2) ◽  
pp. 828-833 ◽  
Author(s):  
D. Warburton ◽  
L. Parton ◽  
S. Buckley ◽  
L. Cosico ◽  
T. Saluna
Keyword(s):  
Pulmonary Surfactant ◽  
Binding Capacity ◽  
Active Material ◽  
Degree Polynomial ◽  
Beta Adrenergic ◽  
Female Advantage ◽  
Beta Agonists ◽  
Beta Receptors ◽  
Surface Active ◽  
Surface Active Material

We correlated the ontogeny of pulmonary beta-adrenergic receptors with the onset of surface active material (SAM) flux into tracheal fluid of male and female chronically catheterized fetal lambs. SAM flux began between 0.82 and 0.85 gestation in the females and between 0.85 and 0.89 gestation in the males and matured more rapidly thereafter in the females than in the males (P less than 0.01). beta-Adrenergic receptor binding, using [3H]dihydroalprenolol as the ligand, was saturable, linear, and stereospecific. The order of potency of competitive beta-agonists was isoproterenol greater than norepinephrine greater than epinephrine. The maximal binding capacity (Bmax) of pulmonary beta-receptors approximately doubled between 0.84 and 0.89 gestation, coinciding with the onset of SAM flux. Bmax matured as a third degree polynomial function of gestational age in females (r = 0.9, P less than 0.001) but as a linear function in males (r = 0.8, P less than 0.005). Between 0.86 and 0.93 gestation, Bmax was 1.45-fold greater in females than males (P less than 0.001). The dissociation constant of beta-receptors was not influenced significantly by gender or gestation. We conclude that maturation of pulmonary beta-receptors coincides with the onset of SAM flux in fetal lambs and that both mature more rapidly in females. We speculate that pulmonary beta-receptor maturation and SAM flux are coregulated by hormonal factors. More rapid maturation of pulmonary beta-receptors and SAM flux in females may be a factor in the female advantage with regard to pulmonary surfactant maturation and the survival of premature neonates.

Isolation and chemical composition of surface-active material from human lung lavage

Lipids ◽  
1988 ◽  
Vol 23 (6) ◽  
pp. 551-558 ◽  
Author(s):  
T. Sadana ◽  
K. Dhall ◽  
S. N. Sanyal ◽  
A. Wali ◽  
R. Minocha ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Human Lung ◽  
Active Material ◽  
Lung Lavage ◽  
Surface Active ◽  
Surface Active Material
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