Fabrication and Modification of Polymer Membranes via Ink-Jet Printing and Click Chemistry
Water desalination is currently a relatively expensive process that is done in most cases by RO technology and to a lesser extent utilizing nanofiltration (NF). The leading RO technology uses polymeric thin film composite (TFC) membranes that typically include a selective thin polyamide layer that is permeable to water but impermeable to larger molecules or salt ions, on an ultrafiltration support. They have a limited life span due to degradation by oxidants (hypochlorite), mineral scaling, and (bio)fouling.
However, new membrane compositions or modifications to the thin polyamide top layer may lead to more durable stable membranes, membranes with unique separation characteristics, or membranes with other enhanced performance or antifouling characteristics. Here we show interfacial polymerization methods for fabrication of TFC polyamide membranes using ink-jet printing. Patterned membranes were printed using different monomer solutions in the printer, which led to novel membranes of variable performance, stability and nanostructure. Surface modification with covalently attached antimicrobial peptides also gave surfaces with antimicrobial activity. Since water composition varies from location to location, and taylor made membranes to address unique needs would be desirable, these methods have the potential to be incorporated into current roll to roll fabrication techniques for adding unique functionality to commercial membranes.