Hyunsook Jung1, Min-Kun Kim2, Seongon Jang2. 1. Agency for Defense Development, Yuseong-Gu, Daejeon 305-600, South Korea. Electronic address: junghs@add.re.kr. 2. Agency for Defense Development, Yuseong-Gu, Daejeon 305-600, South Korea.
Abstract
HYPOTHESIS: The development of clothing that protects soldiers in the battlefield against wetting and chemical/biological (CB) warfare agents is of utmost importance. There are many examples in nature where the structures of some surfaces render them resistant to particular liquids. Hence, it should be possible to prepare an omniphobic textile surface that repels both water and liquid chemical warfare agents by combining a zirconium (Zr)-based porous metal-organic framework (MOF) or metal oxide and a polyhedral oligomeric silsesquioxane (POSS) to control the surface structure. EXPERIMENTS: Hierarchical micro/nanostructures were generated on a textile surface by growing UiO-66-NH2 or Zr(OH)4 on cotton fabric. This was followed by a coating of a hydrophobic aminopropylisooctyl polyhedral oligomeric silsesquioxane (O-POSS) on the surface of the textile. FINDINGS: UiO-66-NH2 or Zr(OH)4 particles were well grown on the surface of the cotton fabric with micro/nano surface structures. Less than a monolayer coating of O-POSS preserved the surface feature of UiO-66-NH2 or Zr(OH)4. The O-POSS coated UiO-66-NH2 on cotton fabric thus formed exhibited resistance towards wetting with water and the chemical warfare agent, sulfur mustard (HD). The static contact angles are >150° for a 5 μL water droplet and 107° for a 3 μL HD droplet. The roll-off angle is 7° for a 50 μL water droplet. Thus, this method may provide fabric developers (military or ordinary) with strategies to design and fabricate better omniphobic fabrics with optimal liquid-repellent properties.
HYPOTHESIS: The development of clothing that protects soldiers in the battlefield against wetting and chemical/biological (CB) warfare agents is of utmost importance. There are many examples in nature where the structures of some surfaces render them resistant to particular liquids. Hence, it should be possible to prepare an omniphobic textile surface that repels both water and liquid chemical warfare agents by combining a zirconium (Zr)-based porous metal-organic framework (MOF) or metal oxide and a polyhedral oligomeric silsesquioxane (POSS) to control the surface structure. EXPERIMENTS: Hierarchical micro/nanostructures were generated on a textile surface by growing UiO-66-NH2 or Zr(OH)4 on cotton fabric. This was followed by a coating of a hydrophobic aminopropylisooctyl polyhedral oligomeric silsesquioxane (O-POSS) on the surface of the textile. FINDINGS: UiO-66-NH2 or Zr(OH)4 particles were well grown on the surface of the cotton fabric with micro/nano surface structures. Less than a monolayer coating of O-POSS preserved the surface feature of UiO-66-NH2 or Zr(OH)4. The O-POSS coated UiO-66-NH2 on cotton fabric thus formed exhibited resistance towards wetting with water and the chemical warfare agent, sulfur mustard (HD). The static contact angles are >150° for a 5 μL water droplet and 107° for a 3 μL HD droplet. The roll-off angle is 7° for a 50 μL water droplet. Thus, this method may provide fabric developers (military or ordinary) with strategies to design and fabricate better omniphobic fabrics with optimal liquid-repellent properties.