Zwitterionic Microcapsules as Water Reservoirs and Proton Carriers within a Nafion Membrane To Confer High Proton Conductivity under Low Humidity

Zwitterionic microcapsules (ZMCs) based on sulfobetaine with tunable hierarchical structures, superior water retention properties, and high proton conduction capacities are synthesized via precipitation polymerization. The incorporation of ZMCs into a Nafion matrix renders the composite membranes with significantly enhanced proton conductivity especially under low humidity. The composite membrane with 15 wt % ZMC-I displayed the highest proton conductivity of 5.8 × 10^–2 S cm^–1 at 40 °C and 20% relative humidity after 90 min of testing, about 21 times higher than that of the Nafion control membrane. The increased proton conductivity is primarily attributed to the versatile roles of ZMCs as water reservoirs and proton conductors for rendering a stable water environment and an additional proton conduction pathway within the membranes. This study may contribute to the rational design of water-retaining and proton-conducting materials

The elevated thinned ALT flap with three perforators surrounded by small cuffs of deep fascia.

<p>The elevated thinned ALT flap with three perforators surrounded by small cuffs of deep fascia.</p

Early postoperative view of the flap.

<p>Early postoperative view of the flap.</p

Three month follow-up with healed tissue envelope.

<p>Three month follow-up with healed tissue envelope.</p

Intraoperative view after elevation of the ALT musculocutaneous perforator flap with the deep fascia.

<p>Intraoperative view after elevation of the ALT musculocutaneous perforator flap with the deep fascia.</p

Preoperative view of extensive soft tissue defect over the hind foot and medial ankle.

<p>Preoperative view of extensive soft tissue defect over the hind foot and medial ankle.</p

The thinned ALT flap (25×16 cm) was designed according to a template made from the area of the defect.

<p>The thinned ALT flap (25×16 cm) was designed according to a template made from the area of the defect.</p

Appearance 15 days after operation with complete flap survival.

<p>Appearance 15 days after operation with complete flap survival.</p

Preoperative view of extensive soft tissue defect of the dorsal foot with exposed tendon and bone.

<p>Preoperative view of extensive soft tissue defect of the dorsal foot with exposed tendon and bone.</p

Appearance 14 months after debulking procedure.

<p>Appearance 14 months after debulking procedure.</p