Manufacturing of polytetrafluoroethylene fine fibers by waterjet impacting.

Due to unique anti-erosion properties and excellent thermal stability, polytetrafluoroethylene (PTFE) fibers are regarded as an ideal material to manufacture filters for industrial dust purification. Based on weak interactions between PTFE molecular chains, we applied a high-pressure waterjet to cause normal PTFE split-film fibers to split fibers again. Four kinds of PTFE split-film fibers and sintered films with different molecular weights were produced.

Cr Migration Potential and Species Properties in the Soil Profile from a Chromate Production Site in the Groundwater Depression Cone Area.

The relationship between the migration process and speciation distribution of Cr is important for the risk assessment in the underground environment. In this work, soil columns were collected from the chromate production site, with a 40-year operation, in the groundwater depression cone area of North China plain. The relationship between chromium pollution features and the geochemical properties of soil was established, and the migration risk of Cr(VI) was assessed based on the Nemerow composite index and Hydrus-1D model.

Toxicokinetics and persistent thyroid hormone disrupting effects of chronic developmental exposure to chlorinated polyfluorinated ether sulfonate in Chinese rare minnow.

The abnormality in thyroid hormone modulation in developmental fish, vulnerable to per- and polyfluorinated substances, is of particular concerns for the alternative substances. Juvenile rare minnows, were exposed to chlorinated polyfluoroalkyl ether sulfonates (Cl-PFESAs), the novel alternatives to perfluorooctane sulfonate (PFOS), for 4 weeks followed by 12 weeks of depuration. Half lives were determined to be 33 d, 29 d, and 47 d for total Cl-PFESAs, C8 Cl-PFESA and C10 Cl-PFESA, respectively.

Polytetrafluoroethylene/Polyphenylene Sulfide Needle-Punched Triboelectric Air Filter for Efficient Particulate Matter Removal.

The demand for air filtration materials in recent years has been substantially increasing on a worldwide scale because people are paying extensive attention to particulate matter (PM) pollution. In this work, we report a type of needle-punched triboelectric air filter (N-TAF) consisting of polytetrafluoroethylene (PTFE) fibers modified by silica nanoparticles and polyphenylene sulfide (PPS) fibers. Compared to conventional electrostatic precipitators, the N-TAF can be charged online by a unique nonwoven processing technology without additional energy consumption and toxic ozone emission.