显然，将固体颗粒浸于液体中(一种分散方法)时所消耗的能堂，可以用一个1×1×1厘米的立方体(固体的表面张力=oa)浸入液体（液体的表面张力=σ1）中的情况来加以解释，其过程就是将这些囹体立方体自液体外放入液体内，可以看出，有三个过程（见图21-6)，即粘附功，漫渍功和铺展功，这些功的总和就相等于分散功。
图21-6在三个过程中固体立方体的位置
第一个与立方体有关的能量是在它与液体接触以前：一个立方体有六个面，每一个面的表面积为一厘米²，对一厘米的表面积来说，固体σs的表面张力和在固体表面中的能量，其数字大小是相等的。所以与固体立方体任何一个面有关的表面能都等于σs。同样，在一厘米²液体表面中的表面能则相等于σ1。
1.粘附。当将立方体的一个面与液体表面接触（粘附）时，就会发生消耗能量，其情况是：原在一厘米²固体表面(σs)和一厘米²液体表面(σ1)中储存的能，在它们接触后，存在的能量就只有一厘米²的固-液界面(σs1)了。由干只有在接触过程(粘附)中能景才发生变化。故
式中：Wa=粘附功。
2. Dipping. When the cube is put into the liquid to be level with the liquid surface (but not beyond the liquid surface), another energy change ( immersion) will occur, which can be seen in Figure 21-6. Before the cube is not immersed in the liquid, it has the energy of four faces (4 σs〉. After being immersed in the liquid, these energies are finally lost, but the generated surface energy is the same as that of the newly generated liquid on the four sides of the cube- The solid interface (4 σs1 ) is similar. Therefore
In the formula: Wi = impregnation work.
3. Spread. The last process is to immerse the top surface of the cube in the liquid, which is spreading, and its phenomenon can be seen in Figure 21-6. In this process, the top surface of the cube is replaced by two new surface areas, a liquid surface and a liquid-solid interface. The energy consumption associated with spreading is:
In the formula: Ws = spreading work.
4. Scatter. The total work of a solid submerged by a liquid (same as dispersion) is the sum of the above three works, namely
In the formula: Wd=dispersion work
Although a one centimeter cube is used here to illustrate the various stages in the dispersion process, it applies to all solids dispersed in liquids (including pigments dispersed in vehicles).
