Polymer Science and Engineering

Biography

Biography: Hiroshi Jinnai

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. In order 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.