PFASs are called “forever chemicals” because they do not fully degrade. They have become so ubiquitous in the environment that it is difficult to prevent exposure. This review aims to provide a set of improved technologies to remove PFASs from water.
19 August 2013 in Journal of the American Chemical Society
This work validates a sustainable way to produce customized PVDF membranes, suitable for contactors applications, in which DMSO is employed as nonhazardous solvent, in place of substances of very high concern (SVHC), by a combination of vapor-induced and liquid-induced phase separation (VIPS and LIPS) stages, and without using any chemical additive as pore forming. The experimental results highlight the key role of the kinetic and thermodynamic parameters of the phase separation processes involved in the control of the surface and transport properties of the PVDF membranes. Namely, combining VIPS and LIPS techniques in a controlled way, allowed to produce symmetric porous membranes with customized rough surface topography (root-mean-square roughness up to 0.67 μm) and hydrophobicity (water contact angle up to 140°) according to a biomimetic behavior as that of lotus leaves surfaces, through an environmental friendly fabrication process. The resulting membranes are characterized by a high porosity (total porosity ≥70%, mean pore size 0.08–0.4 μm), with well interconnected pores, despite no pore former additives were included in the dope solution, making them ideal candidates for application in membrane contactors. The quality of the produced membrane (permeate flux up to 12.1 kgh1–m–2 with salt rejection 99.8%) is assessed by MD tests and results showed comparable performance to commercial PVDF membranes having similar mean pore size, porosity and surface roughness, but produced using SVCH solvents.
16 February 2007 in Journal of the American Chemical Society
Two new heteroleptic Zn(II) complexes of the 4,4′-bis(hydroxymethyl)-2,2′-bipyridine have been synthesized by using different stoichiometric ratios of tropolone. In an attempt to induce the formation of metal complex co-crystals, liquid assisted solid state reaction followed by solvent crystallization has been conducted by using the new Zn(II) tropolonate derivatives 1 and 2 with saccharin. The novel Zn(II) species obtained exhibits different structures and properties with respect to their precursors, due to a hydrogen exchange between saccharin and the tropolonate coordinated ligand.