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1不是气体亦非液体的奇特液体 如果从气体与液体之间的连续性来考虑,可认为存在既非气体亦非液体的过度态,即超临界流体,如果取来20cm长的细玻璃管,先将一端封闭,此时温度为20℃装入三氟甲烷CF_3H,再将另一端管口封闭。因此时温度较CF_3H的临界温度(25.9℃)为低,因而呈透明的液体可见明显的液柱弯月液面,随后将此玻璃管握在手中,以体温使之升温,则可见逐渐有气泡生出而且液面随之模糊起来,不久液柱的弯月面消失.这就是超临界流体。用冷水将玻璃管降温冷却,则弯月液面重新出现。假如装入封口玻璃管的液体仅占其容积的十分之七,可知升温后液体将消失,依经验我们说是生成了气体,此气体是处于异常高的密度状态。近年来,超临界流体以其特殊的提取,溶解性能以及反应介质的有效性,而被化学与化工领域广泛应用。
1 A peculiar liquid that is neither a gas nor a liquid Considering the continuity between a gas and a liquid, it is considered that there is an excessive state that is neither a gas nor a liquid, that is, a supercritical fluid. If a 20 cm-long fine glass tube is taken, One end of the first closed, then the temperature of 20 ° C into the CF3H3, then the other end of the nozzle closed. Therefore, when the temperature is lower than the critical temperature of CF_3H (25.9 ℃), so clear liquid visible liquid column meniscus, then the glass tube in the hand to body temperature to make it warm, we can see the gradual bubble Born and liquid will be blurred, soon disappeared meniscus liquid column.This is the supercritical fluid. Cool the glass tube with cold water cooling, the meniscus reappears. If the liquid contained in the sealed glass tube accounts for only about seven-tenths of its volume, it can be known that the liquid will disappear after the temperature is raised. According to experience, we say that gas is generated and the gas is in an abnormally high density state. In recent years, the supercritical fluid is widely used in the fields of chemistry and chemistry for its special extraction and dissolution properties as well as the effectiveness of the reaction medium.