Analytical transmission electron microscopy at organic interfaces

Abstract

Organic materials are ubiquitous in all aspects of our daily lives. Increasingly there is a need to understand interactions between different organic phases, or between organic and inorganic materials (hybrid interfaces), in order to gain fundamental knowledge about the origin of their structural and functional properties. In order to understand the complex structure-propertyprocessing relationships in (and between) these materials, we need tools that combine high chemical sensitivity with high spatial resolution to allow detailed interfacial characterisation. Analytical transmission electron microscopy (TEM) is a powerful and versatile technique that can fulfil both criteria. However, the application of analytical TEM to organic systems presents some unique challenges, such as low contrast between phases, and electron beam sensitivity. In this review recent analytical TEM approaches to the nanoscale characterisation of two systems will be discussed: the hybrid collagen/mineral interface in bone, and the all-organic donor/acceptor interface in OPV devices.

Electronic Interaction of Epoxy Resin with Copper at the Adhered Interface

“…Sum frequency generation (SFG) spectroscopy − and soft X-ray absorption − have shown that functional groups of adsorbed chains are oriented at the outermost surface of the adherends. Real-space observation, such as electron microscopy, − has revealed the possibility of an interlocking or anchoring effect, , as described by the mechanical theory. Depth profiling techniques such as dynamic secondary ion mass spectroscopy (DSIMS), , X-ray/neutron reflectivity measurements, − and confocal Raman scattering have enabled us to examine the interfacial layer formed by the interdiffusion of polymers, of which the thickness directly affects the adhesion strength. − However, there seems to be very limited exploration of experimental approaches to electronic theory.…”

Analysis of complex, beam-sensitive materials by transmission electron microscopy and associated techniques

“…Complex materials often include a component of soft matter that is sensitive to structural or chemical alteration when imaged by electron microscopy. These electron beam sensitive components might be organic crystals, polymers, interfaces and hybrid organic-inorganic materials, even some inorganic materials such as hydrates and hydroxides, as well as multiphase solid/liquid and solid/gas systems (1,2). Arguably materials that contain such components constitute the majority of systems of current interest across a wide range of scientific and engineering disciplines including chemistry and chemical engineering, engineering materials, food science, biology and increasingly physics and electronic engineering.…”

Revealing structure and electronic properties at organic interfaces using TEM

“…This article and the accompanying one by Goode et al identifies some recent work showcasing progress within the field of interfacial characterization using spectroscopy. [28][29][30]…”