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Wetting Phenomena of Mercury near the critical point

临界点附近汞的润湿现象

基本信息

批准号：
09440135
负责人：
YAO Makoto
金额：
$ 8.32万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

It is well known that liquid mercury is a non-wetting substance on solid non-metallic substrate under the ambient conditions. Indeed the closest example in common experience of a non-wetting substance is a mercury drop on a glass plate. However, at high temperatures and high pressures close to the liquid-vapor critical point of mercury, we found that sapphire substrate is wetted with mercury. This change from non-wetting to wetting takes place as a 1st order phase transition, and is called a wetting transition.In the present study, we tried to develop the above study further. We invented a new experimental technique for ellipsometric measurements, which can be applied to high temperature and high pressure conditions. By using this technique, we succeeded in determining important physical quantities, such as coverage Γ, which is the order parameter of the wetting transition. This technique makes us possible to study the physical properties of the wetting layer as an two-dimensional liqu … More id, and we concluded that the wetting layer has semiconducting properties. This result gives important information on the problem why the sapphire substrate is wetted by mercury. In addition, we found that the wetting phenomena can also be detected by measuring the thermal radiation intensity. Indeed, a sharp dip in the thermal radiation intensity is observed in the prewetting supercritical region, where the two-dimensional compressibility (αΓ/αμ)ィイD2τィエD2 is expected to show a maximum due to the critical fluctuations. Here μ is the chemical potential.As stated above, we invented new experimental techniques, by which we can determine experimentally both the mean values and the fluctuations of physical quantities characterizing the wetting phenomena with high accuracy. These techniques are expected to be applied not only to sapphire-mercury system but also to other systems. The results of the present research project are reported in "Adriatico research conference on wetting" (Treste, Italy) as an invited lecture. The head investigator of the present research project organized a symposium on "wetting phenomena" in the meeting of the physical society of Japan for the first time. Less

众所周知，液态汞在环境条件下是固体非金属基底上的非润湿物质。实际上，在一般经验中，与非润湿性物质最接近的例子是玻璃板上的汞滴。然而，在接近汞的液体-蒸气临界点的高温和高压下，我们发现蓝宝石衬底被汞润湿。这种从非润湿到润湿的转变是以一级相变的形式发生的，我们称之为润湿转变。我们发明了一种新的椭偏测量实验技术，可应用于高温高压条件下。通过使用这种技术，我们成功地确定了重要的物理量，如覆盖率Γ，这是润湿转变的序参量。这一技术使我们有可能研究润湿层作为二维液体的物理性质。 ...更多信息并且我们得出结论，润湿层具有半导体性质。该结果给出了关于蓝宝石衬底为什么被汞润湿的问题的重要信息。此外，我们发现润湿现象也可以通过测量热辐射强度来检测。实际上，在预润湿超临界区域中观察到热辐射强度的急剧下降，其中由于临界波动，二维可压缩性（α r/αμ）Δ D2τ Δ D2预期显示出最大值。如上所述，我们发明了新的实验技术，通过这些技术，我们可以用实验高精度地确定表征润湿现象的物理量的平均值和波动。这些技术不仅可以应用于汞-汞系统，还可以应用于其他系统。本研究项目的结果在“Adriatico润湿研究会议”（Treste，意大利）上作为特邀演讲报告。本研究项目的首席研究员首次在日本物理学会会议上组织了一次关于“润湿现象”的研讨会。少