Electrically conductive adhesives with a focus on adhesives that contain carbon nanotubes

Abstract

On the basis of an analysis of results presented in the literature, the currently existing knowledge about relationships between the microstructural and physical properties of hard coatings is discussed. Particular emphasis is placed on the role of microstructural features, such as grain boundaries, nonequilibrium structures, impurities, and texture, in controlling the film hardness. On the basis of an analysis of results presented in the literature, the currently existing knowledge of electrically conductive adhesives (ECAs) is discussed. Particular focus is placed on the results obtained with ECAs that contain carbon nanotubes (CNTs) as conductive fillers. The review is divided in curable ECAs based on epoxy resins, and noncurable conductive hot melts and pressure-sensitive adhesives based on thermoplastic polymers. More literature results were found for epoxy/conductive filler ECAs than for other adhesives. Confirming the assessments made in a book by Li et al., which refers to nanotechnologies in ECAs, we found that only a reduced number of articles allude to polymer/CNT ECAs. Our analysis of the results includes a study of the balance between the viscosity, immediate adhesion, solidification process, electrical conductivity, and mechanical properties of the adhesives.

Nano‐Engineering of SWNT Networks for Enhanced Charge Transport at Ultralow Nanotube Loading

“…[ 1,2 ] Polymer composites with inclusion of CNTs have been recently demonstrated to produce electrically conductive adhesives, and to strongly enhance the piezoresistive properties of a polymer material when a percolated network of interconnected nanotubes was formed. [ 3,4 ] Hybrid single wall carbon nanotube (SWNT) devices such as broadband photodetectors, hybrid and all-carbon solar cells, electrically conductive photonic crystals and photothermal nanotube/ polymer composites for biomedical applications have also been demonstrated. [5][6][7][8][9][10][11][12][13] In many of these applications, formation of a continuous (percolated) network of interconnected nanotubes inside a polymer fi lm is essential to prevent nanotube aggregation, to promote charge transport through the fi lm and increase performance.…”

Electrically conductive nanocomposite adhesives based on epoxy or chloroprene containing polyaniline, and carbon nanotubes

“…In this respect, electrically conductive adhesives (ECAs) have recently received a lot of attention, on the basis of their importance in basic scientific research and potential industrial applications. Electrically conductive adhesives made from a polymeric matrix (such as, an epoxy, a silicone, or polyimide) that provides adhesion, mechanical strength, impact strength, and metallic filler (such as silver, gold, nickel or copper) that conducts electricity [6][7][8][9][10]. However, the main drawback of these electrically conductive adhesives is the high filler loading to achieve desired conductivity and hence reducing the mechanical properties of the resultant materials.…”

The effect of flow on the physical properties of polyurethane/carbon nanotubes nanocomposites: Repercussions on their use as electrically conductive Hot-Melt adhesives

“…Most of the investigated and produced ECAs are epoxy‐based composites, which follow a curing process to reach permanent adhesion. It can be stated that the field of Hot Melt and Pressure Sensitive electrically conductive adhesives, based on non curing polymers, is still in its beginnings . But the industrial interest on these materials seems to be increasing, according to the attention paid by some companies.…”