Directional Water Transport Janus Composite Nanofiber Membranes for Comfortable Bioprotection

Abstract

The Janus membrane has a huge prospect for personal comfortable protection. However, there still is a huge imbalance between the comfort and protection of the existing Janus membrane. There is an urgent need to further improve the comprehensive performance of the protective membrane to realize both protection and comfort. Herein, we report the Janus membrane with directional water transport capacity and dust rejection performance by compounding the polyvinyl chloride hydrophobic nanofiber membrane and polyamide-6 blended polyvinyl pyrrolidone hydrophilic nanofiber membrane. This Janus composite nanofiber membrane exhibited an excellent dust rejection efficiency of 99.99%, air permeability of 42.15 mm/s, which was 76 times that of the commercial waterproof and breathable PTFE membrane, water vapor transmission rate of 4.89 kg/(m2 × 24 h), and accumulative one-way transport capacity of 888.7%. In addition, the breakthrough pressure of the Janus membrane in the reverse direction (i.e., hydrophilic layer to hydrophobic layer) was four times that in the positive direction (i.e., hydrophobic layer to hydrophilic layer), suggesting it to be a potential substrate for comfortable bioprotection with a comprehensive protection capability.

Multistage-Split Ultrafine Fluffy Nanofibrous Membrane for High-Efficiency Antibacterial Air Filtration

“…FTIR spectroscopy was performed to study the interaction between different molecule groups and prove the preparation of multicomponent electrospun nanofibers. The band at 3300 cm –1 was assigned to the vibration of O–H groups (Figure a) . The redshift and the broadening of the band demonstrated the enhancement of intermolecular hydrogen bonding .…”

“…The band at 3300 cm −1 was assigned to the vibration of O−H groups (Figure 2a). 57 The redshift and the broadening of the band demonstrated the enhancement of intermolecular hydrogen bonding. 57 The characteristic bands of PA6/PVP, PA6, and PA6/PEO nanofibrous membranes appeared at 3299.61, 3294.42, and 3292.38 cm −1 , respectively, and their widening indicated enhanced intermolecular hydrogen bonding.…”

“…57 The redshift and the broadening of the band demonstrated the enhancement of intermolecular hydrogen bonding. 57 The characteristic bands of PA6/PVP, PA6, and PA6/PEO nanofibrous membranes appeared at 3299.61, 3294.42, and 3292.38 cm −1 , respectively, and their widening indicated enhanced intermolecular hydrogen bonding. 58 The images of PA6/PVP, PA6, and PA6/PEO solutions also proved the enhanced hydrogen bonding of PA6/ PEO solution (Figure S2a), which made it more viscous and turbid.…”

High-performance multifunctional electrospun fibrous air filter for personal protection: A review

“…The purpose of water vapor transmission system is to achieve efficient directional transmission of water droplet and vapor, thus avoid the rising air resistance and wet–sticky feeling caused by exhaled water vapor to realize comfortable use [164] . Constructing hydrophobic/hydrophilic gradient structure (i.e., Janus membrane) is an effective method to realize directional water droplet or vapor transport, which has been widely used in wound dressing, protective clothing, oil–water separation and so on [165] , [166] , [167] , [168] . Water vapor will spontaneously transfer from hydrophobic surface to hydrophilic surface due to different wettabilities [169] .…”

Multi-Bioinspired Janus Copper Mesh for Improved Gravity-Irrelevant Directional Water Droplet and Flow Transport

“…Directional water transportation driven by geometric structures or asymmetric wettability without extra energy consumption is extremely important in efficient transportation and separation processes, including but not limited to fog harvesting and oil/water separation. − Inspired by the Namib desert beetle, cactus, and spider, diverse materials such as fibers or outer surfaces with chemical or structural anisotropy have been fabricated for efficient directional water transport. − In addition to these, guided by the Janus interface of the lotus leaf, Janus porous membranes with asymmetric interfacial wettability have drawn keen interest owing to their unique directional water penetration behavior. − Despite considerable progress, most of these materials generally focus on the relatively large water droplets, which are gravity-dependent. However, for separation and transportation processes, gravity-irrelevant minuscule water droplets and continuous water flow transport are considerably more important.…”