Talk given by

Prof. Hiroshi Jinnai

IMRAM

Tohoku University

Sendai, Japan

Abstract:

In order to fabricate structures for many applications, e.g., nanotechnology, photovoltaic 
devices, drug delivery etc., choice of three-deimsnional (3D) structures is a key issue.　
Control of dispersion state of nano-particles in (polymeric) matrix, for example, is an 
important industrial problem. For more precise structural control, block copolymers (BCP) 
are often used because of their variety of periodic morphologies. Combining well-ordered 
3D morphologies of BCPs with nano-particles offers a way for well-controlled spatial 
arrangement of nano-particle inside materials. Transmission electron microscopy (TEM), 
electron tomography (3D TEM) in particular, plays an important role to characterize such 
nano-structures.

For better understanding and precise control of 3D structures, direct observation of 
ordering processes of nano-structures during phase transition are essential. Unfortunately, 
TEM has not been a useful method for such dynamical imaging. One of the biggest reasons 
for this is “staining” of (polymeric) samples is almost always necessary for contrast 
enhancement because of their weak contrast for electrons. Consequently, the staining 
“fixed” the nano-structure, which makes it impossible to perform “in-situ” dynamical 
observations. 

Here, we show some preliminary results of direct imaging of nano-structures from an 
unstained BCP that have never been observable without staining in the past. This new 
methodology in electron microscopy may open up a way of “in-situ” 3D imaging in the 
near future. In our talk, we will show some examples of structure control of polymeric 
materials and their characterization with TEM.