Surfactants immediate effects

Uses Spreader/activator surfactant improves effectiveness of certain post-emergence herbicides can also be used with certain insecticides, fungicides, acaricides, and miticides to enhance act. contains rain protectant which helps to reduce loss of act. from rainfall immediately after applic. 

Figure 4 Stabilized bromine antimicrobials are produced by eosinophils, a type of mammalian white blood cell. Bacteria are captured by phagocytosis and contained intracellularly within vesicles called phagosomes. Granules release cationic surfactants, lytic enzymes, and eosinophil peroxidase into the phagosome in a process known as degranulation. Eosinophil peroxidase, an enzyme that is structurally similar to the bromoperoxidases found in seaweed (Figure I), selectively catalyzes oxidation of bromide to hypobromite by reducing hydrogen peroxide to water. The hypobromite immediately reacts with nitrogenous stabilizers such as aminoethanesulfonic acid (taurine) to form more effective and less toxic antimicrobial agents.

Frosolono and Currie (1985) investigated the effect of phosgene on the pulmonary surfactant-system (PSS) in groups of six to 14 rats exposed to phosgene at 1 ppm for 4 h. The exposure system and parameters were similar to those described in Section 3.2.1 (Hatch et al. 1986). The actual chamber concentration was 1.0 0.06 ppm. Animals were sacrificed immediately after exposure, or on postexposure days 1, 2, or 3. Pulmonary edema was present immediately after exposure and persisted through day 3. Phosphatidylinositol levels were significantly (p<0.05) decreased compared with controls immediately after exposure only. Phosphatidylserine and phosphatidylethanolamine levels were significantly increased compared with controls on days 1, 2, and 3 postexposure. Phosphatidylcholine levels were increased at all time points compared with controls. 

Respiratory effects are more likely to occur after inhalation exposure to high concentrations of chloroform. It has been demonstrated that chloroform has a destructive influence on the pulmonary surfactant (Enhoming et al. 1986). This effect is probably due to the solubility of phospholipids in the surfactant monolayer and can cause collapse of the respiratory bronchiole due to the sudden increase in inhalation tension. Immediate death after chloroform inhalation may be due principally to this effect in the lungs (Fagan et al. 1977). It is unlikely that exposure levels of chloroform in the general environment or at hazardous waste sites would be high enough to cause these severe respiratory effects. 

The use of surfactants in hydrogenation and hydroformylation immediately followed the practical implementation of the original idea of aqueous biphasic catalysis [57, 118]. Not only the effect of well-known tenzides (SDS, CTAB, etc.) was studied, but new amphiphilic phosphine... 

One of the central questions in the stability of foams is why are liquid films between two adjacent bubbles stable, at least for some time In fact, a film of a pure liquid is not stable at all and will rupture immediately. Formally this can be attributed to the van der Waals attraction between the two gas phases across the liquid. As for emulsions, surfactant has to be added to stabilize a liquid film. The surfactant adsorbs to the two surfaces and reduces the surface tension. The main effect, however, is that the surfactant has to cause a repulsive force between the two parallel gas-liquid interfaces. Different interactions can stabilize foam films [570], For example, if we take an ionic surfactant, the electrostatic double-layer repulsion will have a stabilizing effect. 

In the same work, it is also supposed that colloidal stability, rather than monomer ripening, plays an effective role in determining the final droplet size. Such a conclusion was supported by two different experimental results. First, it was noticed that droplet size increases right after the emulsification process stops, and a stable situation is typically achieved after just a few hours. However, if surfactant is added immediately after, this growth in size does not occur. Second, it is shown that there is a clear correlation between final droplet size and amount of oil phase used in the recipe. In particular, when the oil fraction in the system increases, droplet size also increases. 

HERCULES 831 defoamer is a quick-dispersing, hydrocarbon oil-based antifoaming agent designed for use where immediate foam-control action is wanted. It is particularly suitable where addition adjacent to the foam-control point is required. Its efficiency is not adversely affected by temperature or pH, and it is effective in the presence of many surfactants. 

The effect of viscosity is important in the production of liquid membranes. These are, to a limited extent, employed in the extraction of non-ferrous metal salts (particularly Zn, Ni, Cu) from process efluents. In their manufacture a prepared water/oil emulsion (e.g. 1/3 kerosene with 2% of a surfactant and 2/3 aqueous NiSO4 with a homogenizing agent) is stirred into the non-ferrous metal salt containing effluent in a ratio of ca. 1 5. It emerged [404], that it is by no means unimportant, how the prepared water/oil emulsion is stirred into this solution. It can be carefully added layer-wise over the aqueous solution and then the stirrer switched on (A), or immediately added to the rotating stirrer (B). 

The common nonionic surfactants are often soluble in both water and oil phases. In the practice of emulsion preparation, the surfactant (the emulsifier) is initially dissolved in one of the liquid phases and then the emulsion is prepared by homogenization. In such a case, the initial distribution of the surfactant between the two phases of the emulsion is not in equilibrium therefore, surfactant diffusion fluxes appear across the surfaces of the emulsion droplets. The process of surfactant redistribution usually lasts from many hours to several days, until finally equilibrium distribution is established. The diffusion fluxes across the interfaces, directed either from the continuous phase toward the droplets or the reverse, are found to stabilize both thin films and emulsions. In particular, even films, which are thermodynamically unstable, may exist several days because of the diffusion surfactant transfer however, they rupture immediately after the diffusive equilibrium has been established. Experimentally, this effect manifests itself in phenomena called cyclic dimpling and osmotic swelling. These two phenomena, as well as the equilibration of two phases across a film,568.569 3j.g described and interpreted below. 

Difficulty in Translocating Brassinolide through Plant Tissue. The navel orange experiments revealed that brassinolide was only effective when polyethyleneglycol was added to the spray solution to prevent quick evaporation. Brassinosteroid is active at very low concentrations, such as 0.1 ppm. When such a low concentration was sprayed in solution on the plants with surfactant, the solution dried up immediately and did not be penetrated into the plant tissue. Thus, addition of chemicals to avoid quick evaporation is necessary for a successful treatment. 

Studies of diffusional phenomena have direct relevance to detergency processes. Experiments are reported which investigate the effects of changes in temperature on the dynamic phenomena, which occur when aqueous solutions of pure non-ionic surfactants contact hydrocarbons such as tetradecane and hexadecane. These oils can be considered to be models of non-polar soils such as lubricating oils. The dynamic contacting phenomena, at least immediately after contact, are representative of those which occur when a cleaner solution contacts an oily soil on a polymer surface. With Ci2E5 as non-ionic surfactant at a concentration of 1 wt.% in water, quite different phenomena were observed below, above, and well above the cloud point when tetradecane or hexadecane was carefully layered on top of the aqueous solution. Below the cloud point temperature of 31°C very slow solubilisation of oil into the one-phase micellar solution occurred. At 35°C, which is just... 

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