Understanding the DLC film – Polyamide 12 substrate interrelation during pulsed laser deposition

Abstract

High-quality hydrogen-free diamond-like carbon (DLC) films that are free of any detectable signs of cracks and delamination are produced on polyamide 12 (PA) substrates using the Pulsed Laser Deposition (PLD) technique, resulting in subplantation of the polymeric substrate by carbon species and the formation of an interphase between the DLC film and the substrate. The interrelation between the DLC films and PA substrates of different crystallinity degree is investigated using spectroscopic (NMR, IR, XPS, and Raman) techniques and the morphology and topography of the films are evaluated using SEM and AFM. It is demonstrated that the laser fluence (16 and 20 J cm−2) directly affects the subplantation intensity and the DLC film structure. Additionally, it is shown that by changing the physical characteristics of the polymer substrate, such as the degree of crystallinity, the characteristics of the DLC layer and the response of the substrate to the energetic carbon species can be influenced. The studies open up new avenues for research aimed at understanding the interaction of energetic species with polymer substrates and enable the identification of parameters that are important in obtaining hard thin films of high quality on such substrates.