wetting

wet

W0104300 (wĕt)adj. wet·ter, wet·test 1. Covered or soaked with a liquid, such as water: a wet towel.2. Not yet dry or firm: wet paint.3. a. Stored in or prepared with water or other liquids.b. Characterized by the use or presence of water or liquid reagents: wet chemistry.c. Involving the performance of experiments rather than the design or analysis of them: a wet lab.4. a. Rainy, humid, or foggy: wet weather.b. Characterized by frequent or heavy precipitation: a wet climate.5. Informal Allowing the sale of alcoholic beverages: a wet county.n.1. Something that wets; moisture.2. Rainy or snowy weather: go out into the wet.3. Informal One who supports the legality of the production and sale of alcoholic beverages.v. wet or wet·ted, wet·ting, wets v.tr.1. To make wet; dampen: wet a sponge.2. To make (a bed or one's clothes) wet by urinating.v.intr.1. To become wet.2. To urinate.Idioms: all wet Slang Entirely mistaken. wet behind the ears Inexperienced; green. wet (one's) whistle Informal To take a drink.

[Middle English, from Old English wǣt; see wed- in Indo-European roots.]

wet′ness n.wet′ta·ble adj.wet′ter n.

wetting

(ˈwɛtɪŋ) n1. the act or an instance of making something wet2. (Physiology) the act or an instance of urinating (on something)

Thesaurus

Noun	1.	wetting - the act of making something wet change of state - the act of changing something into something different in essential characteristicsdousing, ducking, submersion, immersion - the act of wetting something by submerging itdrenching, sousing, soaking, souse - the act of making something completely wet; "he gave it a good drenching"dampening, moistening - the act of making something slightly wetsplashing, splash - the act of scattering water about haphazardlywatering - wetting with water; "the lawn needs a great deal of watering"
	2.	wetting - a euphemism for urination; "he had to take a leak"making water, passing water, leakeuphemism - an inoffensive or indirect expression that is substituted for one that is considered offensive or too harshmicturition, urination - the discharge of urine

Translations

bagnatabagnatura

Wetting

wetting

[′wed·iŋ] (electronics) The coating of a contact surface with an adherent film of mercury. (metallurgy) Spreading liquid filler metal or flux on a solid base metal.

Wetting

a phenomenon arising upon contact of a liquid with the surface of a solid or other liquid. In particular, wetting is seen in the spreading of a liquid over a solid surface in contact with a gas (vapor) or other liquid, in the impregnation of porous bodies and powders, and in the change in shape of the surface of a liquid at the surface of a solid. Thus, wetting results in the formation of a spherical meniscus in a capillary tube and determines the shape of a droplet on a solid surface or the shape of a gas bubble on the surface of an object immersed in a liquid. Wetting is often regarded as a result of intermolecular (van der Waals’) interactions in the zone of contact of three phases (bodies, media). However, in many cases, for example, in the contact of liquid metals with solid metals, oxides, diamond, and graphite, wetting is caused more by the formation of chemical bonds, solid and liquid solutions, and diffusion processes in the surface layer of the wetted body than by intermolecular interactions. The heat effect accompanying the contact of a liquid with the surface being wetted is called the heat of wetting.

The contact angle θ between the surface being wetted and the surface of the liquid at the periphery usually serves as a criterion of wetting (Figure 1). The angle θ is measured through the liquid. For steady-state (equilibrium) wetting, this angle is related to the surface tension of the liquid (σ_L), the surface tension of the solid (σ_s), and the interphase tension at the solid-liquid boundary (σ_SL) by the Young equation: cos θ = (σ_s – σ_SL)/σ_L. The lyophily and lyophoby of surfaces relative to various liquids are determined by the magnitude of θ. On a lyophilic surface, a liquid spreads; that is, there is incomplete (0° < θ < 90°) or complete (θ → 0°) wetting. Spreading does not occur (θ > 90°) on a lyophobic surface (Figure 2).

Figure 1. Droplet on the surface of a solid

The contact angle depends on the relationship between the forces binding the molecules of the liquid to the molecules or atoms of the body being wetted (adhesion) and the forces binding the molecules of the liquid to each other (cohesion). The reversible work of adhesion and work of cohesion, respectively, are calculated from the equations W_Ad = σ_L(I + cos θ) and W_Co= 2σ_L. Since θ is always > 0° when W_Ad < W_Co, wetting will improve with an increase in the ratio W_Ad/W_Co. The term S = W_Ad/W_Co is called the spreading coefficient. The delay often observed in establishing equilibrium contact angles is called wetting hysteresis. A distinction is made between kinetic (dynamic) and static hysteresis. Possible causes of hysteresis include roughness of the surface, structural features of the surface layer, and relaxation processes in the liquid phase. Selective wetting occurs when a solid comes into contact simultaneously with two immiscible liquids. Surfactants are efficient regulators of wetting, being able to either improve or impede the process.

Figure 2. Position of a droplet (bubble) on a solid under various conditions of wetting: (G) gas, (L) liquid, and (S) solid

Wetting has great significance in nature, technology, and daily life. Good wetting is necessary in dyeing and washing, in processing photographic materials, and in applying paints and varnishes. Wetting also figures in the impregnation of fiber materials and in gluing, soldering, and amalgamation. An attempt to reduce wetting to a minimum is made in producing hydrophobic coatings and waterproofing materials. In some cases, for example, in flotation and emulsification using solid emulsifying agents, the contact angle must be kept within a set range of values. Wetting plays a vital role in metallurgical processes and in the dispersion of solids in a liquid medium. It affects the distribution of groundwater, the moistening of soils, and a variety of biological and other natural processes. P. A. Rebinder, A. N. Frumkin, and B. V. Deriagin made significant contributions to the theory and applications of wetting.

REFERENCES

Goriunov, Iu. V., and B. D. Summ. Smachivanie. Moscow, 1972.
Fridrikhsberg, D. A. Kurs kolloidnoi khimii. Leningrad, 1974. Page 60.
Naidich, Iu. V. Kontaktnye iavleniia v metallicheskikh rasplavakh. Kiev, 1972.
Zimon, A. D. Adgeziia zhidkosteii smachivanie. Moscow, 1974.

L. A. SHITS

wetting

In soldering or brazing, the spreading of a liquid filler metal or flux on a solid base metal.

wetting

wet

wetting

Wetting

wetting

Wetting

REFERENCES

wetting

wetting

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Patient discussion about wetting

wetting

Synonyms for wetting

noun the act of making something wet

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noun a euphemism for urination

Synonyms

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