Search

[Display omitted] • Electrospinning hydrophilic/hydrophobic photothermal membranes for SDMD is proposed. • The membrane shows strong photothermal conversion properties and anti-fouling properties. • The membrane exhibits superstable and high flux in long-term desalination of SDMD. Low permeate flux and membrane fouling are major limiting factors for solar-driven membrane distillation (SDMD) industrial applications. Here, we report a Janus nanofiber membrane with electrospinning CB/PVA as hydrophilic photothermal layer and electro-blown spinning PTFE nanofiber membrane as hydrophobic layer, which exhibits excellent photothermal conversion performance, anti-fouling performance and durability. The hydrophilic photothermal layer simultaneously captures solar energy and performs photothermal conversion, repels chemical/oil-based pollutants and promotes steam flow. At the same time, the low surface of PTFE layer can guarantee the long-term durability of the composite nanofiber membrane. Under the light intensity of 1 kW·m−2, the Janus nanofiber membrane can obtain a permeate flux of 1.05 L·m−2·h−1 and a salt rejection of > 99.99 %. And the photothermal conversion efficiency reached 71.4 %. More importantly, the permeate flux of the Janus nanofiber membrane was still stable at 1.035 L·m−2·h−1 after continuous treatment of pollutant-containing feed solutions for 60 h, and the salt rejection was > 99.98 %. This indicates that the efficient photothermal conversion performance and anti-fouling properties make the CB-PVA/PTFE photothermal nanofiber membrane promising for generating fresh water from feed solutions containing various pollutants in SDMD systems. [ABSTRACT FROM AUTHOR]

• Stearate and hindered amine light stabilizer were compounded as electret additives. • Water electret melt-blown nonwovens with great filtration performance was fabricated. • The excellent durability was proven through various tests. • Surface friction and ion migration mechanisms were elucidated. • The good charge stability at high temperature and humidity was verified. Water electret (WE) technology is a current research hotspot in the field of high-efficiency and low-resistance melt-blown filter materials. The electret is an important factor affecting the filtration performance and durability of WE melt-blown nonwovens. In this paper, WE melt-blown nonwovens were prepared with stearate compounded with hindered amine light stabilizer (HALS) as the electret additives, which exhibited excellent performance and the filtering efficiency of DEHS oily particles exceeding 99%. The charge formation and storage mechanism of WE melt-blown nonwoven were also elucidated by using the thermally stimulated discharge technique. Benefiting from the inherent amino group of HALS and the synergistic effect with stearate, positively charged hydrated protons were attracted and migrated to the interior of the fiber to form durable space charges, which led to a significant enhancement of the filtration/charge storage performance of melt-blown nonwoven. The charge stability performance of WE melt-blown nonwoven was also investigated under the treatment of solvents such as constant temperature and humidity, high-temperature hot water, alcohol, and isopropyl alcohol. These studies help to improve the product quality of WE melt-blown nonwovens, as well as provide a systematic guide to an in-depth understanding of the electret mechanism of WE technology. [ABSTRACT FROM AUTHOR]