Feasibility of Carbon Nanoparticle Coatings as Protective Barriers for Copper─Wetting Assessment

Abstract

Copper is extensively used in a wide range of industrial and daily-life applications, varying from heat exchangers to electrical wiring. Although it is protected from oxidation by its native oxide layer, when subjected to harsh environmental conditionssuch as in coastal regionsthis metal can rapidly degrade. Therefore, in this study, we analyze the potential use of carbon nanoparticle coatings as protective barriers due to their intrinsic hydrophobic wetting behavior. The nanocarbon coatings were produced via electrophoretic deposition on Cu platelets and characterized via scanning electron microscopy, confocal laser scanning microscopy, and sessile drop test; the latter being the primary focus since it provides insights into the wetting behavior of the produced coatings. Among the measured coatings, graphite flakes, graphene oxide, and carbon nanotube (CNT) coatings showed superhydrophobic behavior. Based on their wetting behavior, and specifically for electrical applications, CNT coatings showed the most promising results since these coatings do not significantly impact the substrate’s electrical conductivity. Although CNT agglomerates do not affect the wetting behavior of the attained coatings, the coating’s thickness plays an important role. Therefore, to completely coat the substrate, the CNT coating should be sufficiently thickabove approximately 1 μm.

Influence of topography on electrical contact resistance of copper-based materials

“…It was added to aid in the deposition process by promoting CNT dispersion. Furthermore, this additive gives the CNT a surface charge, therefore resulting in an anodic deposition [23,25]. Each counter electrode was coated via potentiostatic EPD at 300 V DC .…”

“…Observing the micrograph in figure 6(a), CNT agglomerates can be observed scattered pervasively through the rivet's surface. In our previous work [25], the area fraction of CNT agglomerate was determined by image analysis, resulting in a CNT-agglomerate area fraction of around 44%. The FIB cross section shown in figure 6(b) reveals an irregular, porous coating.…”

“…Therefore, sufficiently thick CNT coatings may be capable of limiting any undesirable topography-induced effects. These nanoparticle coatings also have the added advantage of providing wear protection due to their outstanding solid lubricity [24], as well as atmospheric protection because of their intrinsic hydrophobic wetting behavior [23,25]. Consequently, this simple, cost-effective, and quick post process could be implemented at the last stages of a manufacturing process.…”

Evaluating the effect of unidirectional loading on the piezoresistive characteristics of carbon nanoparticles

“…In our previous work, different CNP have been used as protective coatings due to their hydrophobic behavior 20 , 21 , as topography offsetting interfaces due to their elasticity 22 , as well as for wear protection 23 – 27 . Moreover, CNP-containing composites have been studied for tribological and electrical applications 28 – 33 .…”

Electrical Characterization of Carbon Nanotube Reinforced Silver and Copper Composites for Switching Contacts

“…Moreover, multiple studies have reported that the addition of CNT as a reinforcement phase in nickel matrices has significantly reduced friction and wear [21][22][23], as well as CNT coatings providing wear protection while having a marginal impact on ECR [24][25][26]. Furthermore, the incorporation of CNT into the system could provide the electrical switch with secondary advantages due to the chemical inertness and hydrophobic wetting behavior of this carbon nanostructure [27][28][29], in addition to their exceptional mechanical properties [30][31][32][33].…”