Surface tension, surfactants

Surface active agents (surfactants) are active (adsorb) at surfaces and reduce surface tensions. Surfactants work because they are amphiphilic they have opposing solubility tendencies in one molecule, such as a hydrocarbon chain and a polar end. Because of this disparity in solubility, they tend to form concentration gradients at dissimilar phase interfaces. Surfactant additives are classified according to the interface at which they are active. 

The open surface of a liquid tends to contract inwards towards the bulk of the liquid, as if it were covered with an elastic skin. This phenomenon is termed surface tension. Surfactant... 

Here we consider a solution of a nonionic surfactant, whose concentration, q = c (z,t), depends on the position and time because of the diffusion process. (As before, z denotes the distance to the interface, which is situated in the plane z = 0.) Correspondingly, the surface tension, surfactant adsorption and the subsurface concentration of surfactant vary with time o = o(t), r, = r,(t), Cjj = CiXO- The surfactant concentration obeys the equation of diffusion ... 

Styrenics/PA/PPE Styrenics/PBT Sulfonyl azide Surface finish Surface free energy Surface resistivity Surface tension Surfactant... 

Surface chemistry and thermodynamics, Surface Tension Surfactants. Defoamers, antifoams, anti flood and float, wetting aids, emulsifiers, levelling agents, pigment dispersants. Colorant acceptor Water repellents. Numerous aniottic, non-ioruc, cationic and an hoteric agents. Silicones an hipafhic polymers. Polysiloxanes... 

In engineering applications where surface tension can create problems, molecules called surfactants are often added to decrease the surface tension. Surfactants also rely on an understanding ofintermolecular forces in their design. 

Carry-over can be caused by dirty wash liquid or particulates in the hydrocarbon feed. Caustic strengths in excess of 15%-20% can contribute to carry-overs. Extraneous chemicals that reduce surface tension (surfactants) and thus promote foaming are obvious culprits. 

Keywords Aerosol Cloud condensation nuclei Surface tension Surfactant... 

The simple fact that critical micelle concentration can be obtained from the surface tension-surfactant concentration isotherm is the best proof thit micellization prevents adsorption proceeding to completion and is not the result of surface saturation. Real situations are similar to the cases depicted by Figs. 7 and 8 (probably closer to Fig. 8). This is not too surprising, as both micellization and adsorption at the water-air surface or at a water-low-polarity solid or liquid result from the same driving force the exclusion of the fatty chains by water molecules ... 

Figure 9.10 Surface tension-surfactant concentration curves for alkaline extracts from waste biomass. The data from Garcia-Becerra was obtained in an electrolyte solution containing 1 g NaCI/IOOml. The sodium dodecyl benzene sulfonate data (SDBS) was obtained at a pH of 6 [43, 661...

Uses Low foam wetting agent and low surface tension surfactant for hard-surface cleaning, metal cleaning and degreasing, rinse aids syn. lubricant base fluid for metalworking... 

---