Chemical threat responsive carbon nanotube membranes

Abstract

Current research efforts are aimed at developing hybrid polymer-vertically aligned carbon nanotube (CNT) membranes that are breathable in their native state but become blocked upon exposure to low levels of chem. warfare agents (CWA). Our approach utilizes polymers formed by ring opening metathesis polymn. (ROMP) that have a highly non-planar structure in their neutral resting state to retain the high moisture vapor transport rate of the CNT membranes. Upon reacting with CWAs, these polymers can ionize and planarize, assuming a cationic, arom. structure. This π-stacking drives a gel collapse that will block the CNT pores. These types of polymers will be grafted from the membrane using surface initiated ROMP (SI-ROMP) on norbornene-substituted surfaces. In this approach, the surface will be functionalized with a reactive ruthenium catalyst, and subsequent addn. of norbornene-based monomers will result in a functional polymer grown from the membrane surface. It is envisioned that this hybrid material will be useful to protect soldiers from chem. and biol. threats.