Effective Pretreatment Routes of Polyethylene Terephthalate Fabric for Digital Inkjet Printing of Enzyme

Abstract

A major number of studies used enzymes during pre-processing in the form of beads, pellets, otherwise during post-processing, for example, surface cleaning and effluent treatment. [2,3] A few studies used flat film and paper like supports, however, use of non-flat textile like surfaces for immobilization is very limited. [4] Textile fabrics can be a more suitable support for enzyme immobilization due to their inherent advantages of being strong, flexible, and lightweight, along with providing low pressure drop in chemical processes. Thus, they show potential to be used in a range of advanced applications, for example, controlled release, drug delivery, bacterial inhibition, and biosensing. [5] Such advanced application often requires highly controlled, precise, contactless, and customizable production method such as digital inkjet printing. [6] Compared to conventional production methods, for example, coating, finishing and screen printing, resource efficient inkjet technology minimizes use of water, energy, chemical and wastes of valuable functional materials, for example, enzymes. [7] Drop-on-demand (DOD) inkjet technology has been successfully used for printing of enzymes on textiles for various applications, compared to the continuous system. [8] Among two ejection mechanisms of DOD printheads, that is, thermal and piezoelectric, the latter one is preferred due to less possible influence on the protein structure of enzymes and resulting activity. [9,10] Along with printhead mechanics, inkjet printing of enzyme on textiles comes with challenges on ink recipe optimization for a specific enzyme-printhead combination and ensuring proper fabric-enzyme interaction. [11] Optimization strategy of ink-containing enzyme for rheological, ionic, and printhead parameters has been demonstrated in our previous work. [12] In this work, fabric surface characteristics necessary for efficient inkjet printing and retention of active enzymes are studied.Polyethylene terephthalate (PET) fiber based synthetic products are being used in applications ranging from apparel and home furnishing to medical textiles with rising market trend for more advanced applications. [13] This inert fiber offers superior physiochemical and mechanical properties. Nevertheless, such fibers retain challenges for printing because of their hydrophobic surface caused by lack of polar groups. Additionally, synthetic fiber surfaces may induce greater hydrophobic interaction with enzymes, for example, lysozyme to cause confirmation changes and denaturation. [14] Due to this fact, studies regarding immobilization of this enzyme on synthetic fiber Enzymes immobilized on synthetic polyethylene terephthalate (PET) textile surface by resource-efficient inkjet printing technology can promote developments for various novel applications. Synthetic fabrics often require adequate pretreatments to facilitate such printing process. This work discusses PETwoven fabric pretreatment routes to improve wettability by alkaline, enzymatic, and plasma processes for effective prin...