Biomimetic Core–Shell-Structured Nanofiber Membranes for Rapid and Portable Water Purification

Abstract

Rapid and portable water purification (RPWP) technologies, helping travelers survive in the wild, have attracted increasing interest due to increasing activities, such as exploration, field hiking, and excursion. Field water is usually pathogenic because of various soluble and insoluble contaminants. In this study, fish-gilllike biomimetic core−shell-structured nanofiber membranes are designed and synthesized by an in situ oxidation polymerization coating process. A polyimide nanofiber membrane and a polypyrrole (PPy) coating layer are employed as a core and shell, respectively. The biomimetic membranes exhibit dual-functional capacities: a rapid removal of insoluble contaminants owing to the highly porous network and broad-spectrum adsorption of soluble contaminants enabled by the PPy shell. Model studies confirm the excellent ability of the membranes to purify Cr(VI)-contaminated water to drinkable water with a safe capacity of ∼1415 L m −2 . Actual application tests show that the membrane can efficiently remove coliform and suspended solids in a muddy water sample taken from a river in Suzhou, China. This study provides a promising route for the design of a single-layer membrane with dual functions for highly efficient RPWP.

Conformal Structured Ceramic Textiles with Passive and Active Heating Functionality

“…The optical photos of the synthetic PPy@Al 2 O 3 ceramic fiber fabric are shown in Figure c, in which the ceramic fiber fabric in Figure c (1–4) was Al 2 O 3 , PPy@Al 2 O 3 -10, PPy@Al 2 O 3 -20, and PPy@Al 2 O 3 -40 successively. The initial white Al 2 O 3 ceramic fiber fabric turned black during in situ oxidative polymerization, indicating the formation of black polypyrrole on the original Al 2 O 3 ceramic fiber Figure d shows the images of PPy@Al 2 O 3 -20 ceramic fiber fabric before and after synthesis, which can be scaled up for production.…”

“…The initial white Al 2 O 3 ceramic fiber fabric turned black during in situ oxidative polymerization, indicating the formation of black polypyrrole on the original Al 2 O 3 ceramic fiber. 34 Figure 1d shows the images of PPy@Al 2 O 3 -20 ceramic fiber fabric before and after synthesis, which can be scaled up for production. At the same time, one of the very important properties of textiles is their cutability and bendability; Figure S1a shows that the PPy@ Al 2 O 3 ceramic fiber fabric can be cut into complex patterns, and Figure S1b,c shows that it can be bent to varying degrees.…”

Cellulose nanocrystal/halloysite nanotube composite aerogels for water purification

“…These results confirmed that the adsorption process followed a pseudo-second-order model, suggesting that the adsorption mechanism is mainly controlled by chemical absorption, which can be associated to ion-ion interactions between the MB and CNC-HNT-0.4 aerogel. 55 Fig. 4 Effect of CNC-HNT-0.4 dosages on the adsorption capacity (A) and removal efficiency of MB (B).…”

A Tent‐Inspired Portable Solar‐Driven Water Purification Device for Wilderness Explorers

“…[1] As a result, solving the freshwater DOI: 10.1002/smll.202311731 problem becomes the first difficulty in the adventure process, especially in the extremely harsh scenarios such as seawaterdominated island, bacterial river waterdominated forest and waterless desert. [2] Therefore, many explorers are often in danger of dying due to extreme dehydration or drinking contaminated water. [3] Currently, many explorers solve freshwater problem mainly through filtration purification, cooking condensation and direct solar evaporation to purify seawater, bacterial river water and collected urine, but such methods are usually inefficient and laborious.…”