Lightweight Ultra-High-Barrier Liners for Helium and Hydrogen

Abstract

Upcoming efficient air-borne wind energy concepts and communication technologies applying lighter-than-air platforms require high-performance barrier coatings, which concomitantly and nonselectively block permeation not only of helium but also of ozone and water vapor. Similarly, with the emergence of green hydrogen economy, lightweight barrier materials for storage and transport of this highly diffusive gas are very much sought-after, particularly in aviation technology. Here the fabrication of ultraperformance nanocomposite barrier liners by spray coating lamellar liquid crystalline dispersions of high aspect ratio (∼20 000) silicate nanosheets mixed with poly­(vinyl alcohol) on a PET substrate foil is presented. Lightweight nanocomposite liners with 50 wt % filler content are obtained showing helium and hydrogen permeabilities as low as 0.8 and 0.6 cm3 μm m–2 day–1 atm–1, respectively. This exhibits an improvement up to a factor of 4 × 103 as compared to high-barrier polymers such as ethylene vinyl alcohol copolymers. Furthermore, ozone resistance, illustrated by oxygen permeability measurements at elevated relative humidity (75% r.h.), and water vapor resistance are demonstrated. Moreover, the technically benign processing by spray coating will render this barrier technology easily transferable to real lighter-than-air technologies or irregular- and concave-shaped hydrogen tanks.

Review of the Hydrogen Permeability of the Liner Material of Type IV On-Board Hydrogen Storage Tank

“…At present, only a small number of experts and scholars have researched this, and there are few related references. Generally, the permeability of gas in polymers is mainly affected by external conditions (such as temperature [20,21], pressure [15,22]), material properties (such as crystallinity [23,24], fillers [25,26], etc. ), and the interaction between gas and material [27,28].…”

“…where 0 P P represents the ratio of polymer permeability coefficient after filling to before filling, and μ , α , and φ represent geometric factor, aspect ratio, and volume fraction related to the filling, respectively. According to this rule, Habel et al [26] used NaHec with a large aspect ratio as the nanofiller and optimized its arrangement in the polymer to produce a lightweight ultrahigh barrier liner for helium and hydrogen. Sun et al [45] comprehensively investigated the hydrogen permeability of PA6 filled with lamellar inorganic components (LIC).…”

Enhancing Hydrogen Storage Capacity of Pd Nanoparticles by Sandwiching between Inorganic Nanosheets

“…The flexible nanosheets [24] completely encapsulated individual nanoparticles (Figure 1a). Since the nanosheets are impermeable for H 2 , [25] the Pd nanoparticles at this low loading turned out to be not accessible for CO chemisorption or Ar (Figure S5a). More nanoparticles that are closer to each other were required to prevent the nanosheets from collapsing.…”

High Barrier Nanocomposite Film with Accelerated Biodegradation by Clay Swelling Induced Fragmentation

“…Previously in our group, synthetic sodium fluorohectorite (NaHec, [Na 0.5 ] inter [Mg 2.5 Li 0.5 ] oct [Si 4 ] tet O 10 F 2 ) clay has been used to create nanocomposite barrier coatings with various polymer matrices. [26][27][28] NaHec undergoes the rare phenomenon of repulsive osmotic delamination, which is a thermodynamically allowed process, resulting in gentle and quantitative delamination into a nematic liquid crystalline suspension. With an aspect ratio of 20000, rotation even in very dilute suspensions (<1 vol%) is sterically hindered.…”