• Vähä-Nissi, Mika
• Heikkilä, Pirjo
• Sievänen, Jenni
• Koskinen, Jorma
• Harlin, Ali
• Salo, Erkki
• Johansson, L.-S.

Abstract

Atomic and molecular layer deposition (ALD and MLD,respectively) techniques are examples of self-assemblybased on repeated cycles of self-limiting gas-solidreactions. The precursors are pulsed into a reactoralternately, separated by inert gas pulses. During asingle cycle, only one molecular layer is deposited onthe surface, enabling tailored film composition inprinciple down to molecular resolution on ideal surfaces.These cycles are repeated until a layer with a specificthickness is achieved. Few materials are, however, ideal.During the early film growth precursors adsorb onto thesurface and absorb into the near-surface regionsdepending both on the substrate and the depositionparameters. These precursors can react with the substrateaffecting e.g. mechanical, barrier and surfaceproperties. The deposited material starts then to formclusters leading to nonuniform early film growth. Thepurpose of this presentation is to demonstrate that thinand non-uniform layers can be used to tailor the surfacecharacteristics of different substrates. For example,print quality (ink spreading and penetration) of inkjetprinting on polymer films can be adjusted with metaloxide. Secondly, this can be used to control waterpenetration into porous nonwovens. Third exampledemonstrates how adhesion of extrusion coated biopolymerto inorganic oxides can be improved with a novel hybridlayer based on lactic acid. As the amount of material tobe deposited is small, this will help to increase thespeed in ALD/MLD processes designed for moving webs.

Topics

• Deposition
• porous
• impedance spectroscopy
• surface
• cluster
• polymer
• extrusion
• self-assembly
• atomic layer deposition