看到王晓明老师的一篇博文： 科学网—科学定义探讨：表面科学。文中提到，【按照我们物理化学课上学到的定义，表面（surface）是指物质与真空之间的边界】。

我查了下，教科书上对表面的定义是这样的：密切接触的两相之间的过渡区（约几个分子的厚度）称为界面（interface），如果其中一相为气体，这种界面通常称为表面（surface）。

 

我用的是高教出版社出版的《物理化学》第四版，傅献彩等编，883页。这本教材中，表面的定义和真空无关。

 

表面的定义是什么？和真空有关吗？

 

今天找了一下下载的书籍，刚好有一本英文书中提到表面和界面的问题。从这段话来看，有些书中表面的定义是和真空有关的。但是，在使用表面和界面的概念时，经常并不严格区分，也很容易“误解”。下面这段英文引自：Surface Chemistry
Of Solid and Liquid Interfaces，
Professor H. Yıldırım Erbil，First published 2006 by Blackwell Publishing Ltd

【1.1 Definition of a Surface and an Interface
A  phaseof a substance is a form of matter that is uniform throughout in chemical com-position and physical state. There are mainly three phases of matter namely solid, liquid
and gas. The word  fluid is used to describe both gas and liquid phases. We usually classify
the phase of a material according to its state at the normal ambient temperature (20–25°C),
w hich is well above the melting point of most fluids. We mostly deal with two or more
phases, which coexist, in equilibrium or non-equilibrium conditions. Phase diagrams are
used as a convenient method of representing the regions of stability of solid, liquid and
gas phases under various conditions of temperature and pressure. An  interface is the phys-ical boundary between two adjacent bulk phases. The interface must be at least one molec-ular diameter in thickness for the purpose of constructing a molecular model. In some
cases it may extend over several molecular thicknesses. We use the word  surface in order
to  define the physical boundary of only one of these phases, such as so lid surface and  liquid
surface etc. In reality, we deal with an  interface in all cases other than absolute vacuum con-ditions for solids, since every single phase is in contact with another phase such as solid–air,
liquid–air contacts. In many standard physical chemistry, surface chemistry and surface
physics textbooks, the words  surface and  interface are used interchangeably because the
authors neglect the small differences between the air phase and absolute vacuum condi-tions. On the other hand, some authors define and use the word  surface for only the
solid–gas and liquid–gas phase contacts, and the word  interface for all of other phase con-tacts, but this has no scientific basis and should be abandoned.】