Effects of Iron Layer Thickness and Growth Time on Carbon-Infiltrated Carbon Nanotube Growth Heights on Ti6Al4V Medical Grade Titanium

Abstract Carbon-infiltrated carbon nanotubes (CICNT) have been discovered to have an antibacterial effect on medical grade metallic surfaces. In order to improve materials used for antimicrobial experiments, the primary aim of this investigation was to provide a more thorough understanding of the effects of controlling the height of carbon nanotubes by changing the iron catalyst layer thickness prior to carbon nanotube growth, and changing the time of the growth phase of the carbon nanotubes via chemical vapor deposition (CVD) on Ti6Al4V. All samples were coated with a barrier layer of alumina (Al2O3) of 200 nm between the Ti6Al4V and an iron growth catalyst layer. Three different groups of iron deposited thicknesses (2 nm, 4 nm, and 6 nm) were used, along with four separate growth times: 40 s, 80 s, 160 s, and 320 s. Samples were grown at 750 C for each setting of the variables, with each trial repeated three times. A subsequent infiltration period of one minute at 900 C was implemented on all batches. The samples were then analyzed under a 3D profilometer to observe the varying heights. Results show that there is a statistically significant increase in growth height with increasing growth time. Analysis of the variation in height shows that samples with 6 nm of iron and a 40 s growth time have the smallest height variation. To promote more repeatable nanotube growths, we recommend that these settings should be used for growth of nanotube films for future experiments on bacterial resistance.