Wetting spontaneous

DOT CLASSIFICATION 4.3 Label Dangerous When Wet (UN 2950) DOT Class 4.1 Label Flammable Solid (UN 1869) DOT Class 4.3 Label Danger When Wet, Spontaneously Combustible SAFETY PROFILE Inhalation of dust and fumes can cause metal fume fever. The powdered metal ignites readily on the skin causing burns. Particles embedded in the skin can produce gaseous blebs that heal slowly. 

DOT CLASSIFICATION 4.3 Label Dangerous When Wet, Spontaneously Combustible DOT Class 4.3 Label Dangerous When Wet (UN 1435)... 

Spontaneous Imbibition Index. The Spontaneous Imbibition Index (SII), as a quantifiable measure of wettability to one fluid component, was defined by Spinier [17] as the ratio of measured spontaneous water imbibition to highly water-wet spontaneous imbibition, ASws-ww ... 

Electro wetting on dielectric (EWOD) Electrowetting on insulator coated electrodes (EICE) Electrowetting on line electrodes (ELE) Static electro wetting Spontaneous electrowetting... 

Like many other combustible Hquids, self-heating of ethyleneamines may occur by slow oxidation in absorbent or high-surface-area media, eg, dumped filter cake, thermal insulation, spill absorbents, and metal wine mesh (such as that used in vapor mist eliminators). In some cases, this may lead to spontaneous combustion either smoldering or a flame may be observed. These media should be washed with water to remove the ethyleneamines, or thoroughly wet prior to disposal in accordance with local and Eederal regulations. 

Regeneration with air can be done with continuous or periodic addition of small amounts of air. Both must be done carefully because of exothermic reaction. Regeneration is never complete, so the beds must be eventually changed out. This must be done carefully because of the pyrophoric (spontaneously combustible) nature of the iron sulfide. The entire bed is wetted first. 

Complete wetting, i.e. spontaneous spreading should always be sought to maximize adhesion. This condition occurs when, with reference to Fig. 4, it is not possible to satisfy the horizontal force balance, i.e. ys > Vl + Ysl- The thermodynamic driving force for the spreading process is the spreading coefficient. 

Flammable solids Spontaneously combustible materials and Materials that are dangerous when wet... 

The reaction starts spontaneously and is mildly exothermic. Moderating the temperature by use of a water bath diminishes the amount of bromine and product carried off by the carbon dioxide evolved. The reaction can be followed by use of a tetra-chloroethane bubbler, and at the end of the reaction the solvent in the bubbler can be used to wash the mercuric bromide. The checkers followed the reaction with a wet test meter presaturated with carbon dioxide 52-60% of the theoretical amount of carbon dioxide was evolved. 

Besides the spontaneous, complete wetting for some areas of application, e.g., washing and dishwashing, the rewetting of a hydrophobic component on a solid surface by an aqueous surfactant solution is of great importance. The oil film is thereby compressed to droplets which are released from the surface. Hydrophobic components on low-energy surfaces (e.g., most plastics) are only re wetted under critical conditions. For a complete re wetting of a hydrophobic oil on polytetrafluoroethylene (PTFE) by an aqueous solution, the aqueous solution-oil interface tension must be less than the PTFE-oil interface tension... 

Let us consider a circular puddle of liquid, L, on solid, S, in the presence of liquid vapor, V. The puddle is of radius Rq and small initial thickness Bq. We assume that holes nucleate spontaneously in the puddle and grow with radius r(t) as time t passes because the equilibrium contact angle. Go, is nonzero. The liquid is unstable as a wetting film. Equilibrium thickness of a film, < is given by [27,28]... 

A surface whose physicochemical properties gradually change as a function of the position is called a gradient surface. While the gradient surface has potential applications as a substrate for combinatorial studies [29-31], the gradient of surface wetting is of particular interest because spontaneous motions of a droplet are induced on the surface [32]. 

Manipulation of a droplet on a solid surface is of growing interest because it is a key technology to construct lab-on-a-chip systems. The imbalance of surface tensions is known to cause spontaneous motion of a droplet on the surface, as mentioned above. The wetting gradient causing liquid motion has been prepared by chemical [32], thermal [37], electrochemical [3] and photochemical [38-40] methods. 

Figure 16.4 Spontaneous motion of a droplet on wetting gradients.

T. Austad, B. Matre, J. Milter, A. Saevareid, and L. Oyno. Chemical flooding of oil reservoirs Pt 8 Spontaneous oil expulsion from oil-and water-wet low permeable chalk material by imbibition of aqueous surfactant solutions. Colloids Surfaces, Sect A, 137(1-3) 117-129, 1998. 

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