Electrospun sheet materials from CA, PES and PLLA as supports for ALD coating

Electrospinning is a method that can be used in the production of polymeric nanofibres. Polymer solution is drawn into sub-µm to nanosized fibres utilizing electric field. The structure of electrospun web has intrinsic properties such as small fibre diameter, small pore size, and high specific surface area which are beneficial for various applications. In addition, fibres can be functionalized in various methods. Thin (nm scale), conformal coatings made by atomic layer deposition (ALD) can be used for functionalization. For example, metal oxides can provide interesting properties, such as electronic, antimicrobial, self-cleaning and hydrophobic properties among others, to fibrous materials. Combining electrospinning and thicker ALD layer enables also preparation of sub-µm tubes, if core fibres are removed. Aim of this work was to make electrospun fibres from three polymers, cellulose acetate (CA), polyether sulphone (PES) and poly-L-lactide (PLLA) to be used as substrates for ALD. In this presentation we will report preparation electrospun fibres using solvent mixtures, structure of electrospun sheets (PLLA shown as an example), and preliminary results of ALD carried out on electrospun sheets, as well as discuss the possibilities of ALD method in functionalization and processing of electrospun fibres.