Influence of section thickness

Ultrathin sections are somewhat difficult to prepare and reveal only a thin layer of the material, which gives more two-dimensional information on the morphology than a three-dimensional one. Thicker semithin sections often reveal much better the size and shape of particles in polymer blends, rubber-toughened polymers, and others. Additionally, semithin sections represent bulk-tike properties better than do ultrathin sections if they contain a representative volume of the material. 

Omega filter used in the global mode (a) and of the same area by zero-loss filtering (b)[l,2], 

---

A well-developed gyroid membrane can also be identified in the differentiating sieve elements of Nymphoides peltata investigated in [40], in which planes cut approximately normal to the 211 plane are evident (Fig. 7.6(c)). These and similar sections of the gyroid (see [57] for another example) are sometimes very difficult to assign, and can be confused with certain sections of the P-PCS structure. We have found it particularly important to investigate the influence of section thickness to avoid any confusion. 

---