Plasma - Aided Modification of Nonwoven Filters for Wastewater Treatment

In this study, needle punched polyethyleneterephthalate (PET) nonwoven material which is used for filtration of hot acid gases was modified by grafting with polyethylenimine (PEI) after normal glow discharge (NGD) plasma-chemical surface activation. NGD-plasma treatments induce chemical changes at the fiber surface. It was shown that using epoxyimine treatment after NGD air plasma is possible to obtain surface modification of needle felted nonwovens for ion-exchange filter applications for cleaning up contaminated with heavy metal ions and waste water. To obtain a functional polymer film on PET fibers, glyoxal hydrate has been used, as a bridge between the PEIand the newly created post-plasma processing new active sites. The density of the samples is 400 g/m2 and never does not create any problem occurred at any plasma condition. The advantage of such NGD plasma treatments is that the modification turns out to be restricted in the uppermost layers of the substrate, thus not affecting the overall desirable bulk properties. The effectiveness of the NGD plasma and plasma -chemical modification of nonwovens was analysed by examining the fiber surface layer with FTIR spectroscopies, SEM surface morphology, wettability tests and air permeability tests. It's proven the deposition of solid polymeric film with desired properties on the textile substrates. The advantage of such NGD treatments is that the modification leads to the formation of a film which wraps the fibers and slightly changes the permeability of the filter barrier.