Novel coatings for transmission electron microscopy sample preparation

Sample preparation of TEM grids can require adaptation of the surface polarity to allow for easy spread of aqueous solutions. This can be done using plasma enhanced chemical vapour deposition (PECVD), but little research has been carried out on modelling the movement of the vapour through a vacuum chamber. This a challenging concept, but one which could be utilised in improving process efficiency and coating quality. Methanol is know
n to produce a hydrophobic coating when deposited using a glow discharge, but how methanol moves through a vacuum has not previously been modelled.
A model of the processes using the Computational Fluid Dynamics software ANSYS CFD has been developed. A 2D compressible flow of chamber species defined by the methanol chemical reactions follows the methodology proposed in [1]. The flow domain is shown in fig. 1 where the distribution of electron density is taken as in [2].