(386b) Stimuli-Responsive Carbon Nanotube Membranes for Chemical Warfare Protection

Stimuli responsive materials have many diverse uses in areas such as drug delivery, sensors, dynamic surfaces, and advanced textiles. For fabrics applications, smart protective garments that rapidly transport water vapor and autonomously block chemical threats are expected to enable effective personal protection without adding undue physiological stress to the user.¹ However, the incorporation of these seemingly incompatible properties into a single responsive system remains elusive. In this work, we demonstrate a bistable membrane that can rapidly, selectively, and reversibly transition from a highly breathable state in a safe environment to a chemically protective state when exposed to organophosphate threats such as sarin.² Autonomous response to chemical stimuli is achieved through the physical collapse of an ultrathin copolymer layer grafted to the membrane surface, which efficiently gates transport through membrane pores composed of single-walled carbon nanotubes (SWCNT). The adoption of nanometer-wide SWCNTs for ultrafast moisture conduction enables a simultaneous boost in size-sieving selectivity and water-vapor permeability by decreasing nanotube diameter, thereby overcoming the breathability/protection trade-off that limits conventional membrane materials. Moisture vapor transport rates that rival commercial breathable fabrics coupled with the ability to block both biological (by size sieving) and chemical threats make these membranes promising materials for next-generation protective garments for military, first responders, and medical personnel.

References

1. Bui, E. R. Meshot, S. Kim, J. Peña, P. W. Gibson, K. J. Wu, F. Fornasiero, Adv. Mater., 28 (2016) 5871.
2. Li, C. Chen, E. R. Meshot, S. F. Buchsbaum, M. Herbert, R. Zhu, O. Kulikov, B McDonald, N. Bui, M. L. Jue, S. J. Park, C. Valdez, S. Hok, C. J. Doona, K. J. Wu, T. M. Swager, F. Fornasiero, Adv. Funct. Mater, in press (2020)

This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.