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【答案】应助回帖
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刘亚君880530: 金币+20, 翻译EPI+1, ★有帮助, 一般 2012-12-07 09:07:56
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This is due to the contact of the both sides of the formed foam’s liquid film with the gas phase, the surface active molecules are adsorbed in the two-liquid interface, the SDS which is in the form of lauryl sulfate directionally arranges forming the surface diffusion electric double layer in the gas-liquid interface[17],as shown in Figure 6. When the two interfaces is close to a certain extent, the particles with the same charge each other and it will prevent the foam further thinning. In accordance with the principles of the second section, we can know when the foam through the sieve, the enhancement of mutual squeeze between the foam, the liquid discharge and the expansion of the foam will case the thinner liquid film. For the foam with larger liquid holdup, there is a certain thickness of the liquid film to maintain the stability of the foam after the sieve effect. For the foam with smaller liquid holdup, the thickness of the liquid film of its own is very thin, the role of the electric double layer cause the difficulties of its own liquid discharge, but the sieve will still force its liquid discharge, the liquid film further thinned. Therefore，by the sieve effect, the foam with the smaller liquid holdup will get the thinner liquid film, the foam in the direct contract with the air is more susceptible to evaporation induced leading to defoam; The internal foam is easier aggregating and forming a hole since the liquid film is too thin to maintain air bubbles stable, and thus prone to defoaming. |
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