Merino Wool Surfaces Made Superhydrophobic

M.B. Herzog, J.H. Johnston
Victoria University of Wellington, New Zealand, NZ

Keywords: Merino wool fibres, superhydrophobicity, oleophobicity


Natural merino wool fibres have been used to fabricate wash-fast nonwoven textile surfaces with superhydrophobic and oleophobic properties. Wet felted samples were used to study the effect of the fibre diameter and the degree of felting on the static and dynamic contact angles. The influence of a subsequent chemical modification of the fibre surfaces, using perfluorohexylamine, perfluorooctylamine or Dynasylan® (F8815) on the contact angles of three different test liquids was also investigated. Static water contact angles exceeding 150°, corresponding contact angle hysteresis below 10° and a high oleophobicity of 138° for hexadecane were achieved. These surfaces also display antimicrobial activity. A commercial scale needling process was used as a second approach and the consequence of varying amounts of needle felting on the contact angles was studied. The subsequent chemical modifications via Dynasylan® led to superhydrophobic and oleophobic needle felted surfaces with good wash fastness. A water vapour transmission rate of 75-80 g m-2 24 h-1 was also established. This knowledge was then combined with previous research into hydrophilic and superhydrophilic surfaces and in an attempt to combine all the different surface properties a new multi-layered merino wool structure was created with promising initial results.