Diagnostics of microwave assisted electron cyclotron resonance plasma source for surface modification of nylon 6

Abstract

Looking at the increasing scope of plasma processing of materials surface, here we present the development and diagnostics of a microwave assisted Electron Cyclotron Resonance (ECR) plasma system suitable for surface modification of polymers. Prior to the surface-treatment, a detailed diagnostic mapping of the plasma parameters throughout the reactor chamber was carried out by using single and double Langmuir probe measurements in Ar plasma. Conventional analysis of I-V curves as well as the elucidation form of the Electron Energy Distribution Function (EEDF) has become the source of calibration of plasma parameters in the reaction chamber. The high energy tail in the EEDF of electron temperature is seen to extend beyond 60 eV, at much larger distances from the ECR zone. This proves the suitability of the rector for plasma processing, since the electron energy is much beyond the threshold energy of bond breaking in most of the polymers. Nylon 6 is used as a representative candidate for surface processing in the presence of Ar, H + N, and O plasma, treated at different locations inside the plasma chamber. In a typical case, the work of adhesion is seen to almost get doubled when treated with oxygen plasma. Morphology of the plasma treated surface and its hydrophilicity are discussed in view of the variation in electron density and electron temperature at these locations. Nano-protrusions arising from plasma treatment are set to be responsible for the hydrophobicity. Chemical sputtering and physical sputtering are seen to influence the surface morphology on account of sufficient electron energies and increased plasma potential.

Structural and morphological tuning of iron oxide polymorphs by ECR plasma-assisted thermal oxidation

“…The detailed mapping of the ECR plasma properties was reported elsewhere. 20 The axial mapping of the spectroscopic measurement conrmed the presence of different plasma species, viz., atomic, molecular and ionic species. The M-Fe or N-Fe lms were kept 23 cm away from the ECR zone, where the focal points of the RH coincide and the estimated n e was found to be of the order of 10 17 m À3 as determined using the electrostatic probe method.…”

“…The presently used ECR plasma reactor is a modied version of the 1 st generation ECR plasma reactor that was reported earlier 20 with detailed diagnostics of the ECR plasma system for the spatial distribution of plasma properties, mainly the electron temperature (T e ), plasma density (n e ), etc., using a Langmuir probe. Knowledge of plasma properties is quite an important factor that is used to understand the materials processing.…”

“…Further, the effects of the plasma species generated using Ar, O 2 and HN on nylon 6 have been studied. 20 Further, the ECR plasma reactor was used to modify the surface of UHMWPE (ultra high molecular weight polyethylene) using O 2 and HN plasma in order to study the adhesion and proliferation of bone-associated cells. The results demonstrate that the plasma treatment time was a sensitive parameter for dening the bone cell proliferation.…”

Enhancement of metal adhesion, owing to the plasma texturing of PEEK

“…The kinetic energy of the incident ions is critical to allow this erosion and depends on the mean free path of the ionized particle, and therefore on the pressure. [ 33‐38 ] It is also necessary to take into account the localization of the treated surface in the chamber, [ 39,40 ] which influences the sputtering rate. The texture can also be formed by a preferential chemical erosion of the amorphous zones, which is reported to be more effective in the case of O 2 plasmas.…”