Search

A systematic series of industrial‐relevant polystyrene‐based anion exchange resins that are functionalized with hydro‐ or fluorocarbon chains are compared regarding their adsorption behavior toward perfluorocarboxylic acids (PFCA) in respect to their charge, chain length, and type of chain. The results clearly show the dominance of electrostatic interactions in the adsorption process as uncharged adsorber materials showed no adsorption at all. In contrast, the charged adsorber materials showed in general a PFCA removal of 80% to 30% over the experiment depending on effluent fraction. Unexpectedly, for perfluorobutanoic acid (PFBA) the highest removal rate is found with consistently >90%. Despite observing significant benefits in the adsorption of PFCA for fluoroalkylated adsorbers in comparison to their non‐fluorinated counterparts, this effect of fluoroalkylation is comparatively small and can not be clearly attributed to fluorophilic interactions between the fluoroalkyl chains. These findings help clarifying that the introduction of fluorocarbon moieties in adsorber materials is not necessary in order to remove fluorocarbon molecules from the environment. [ABSTRACT FROM AUTHOR]

The adsorption of viruses from aqueous solution is frequently performed to detect viruses. Charged filtration materials capture viruses via electrostatic interactions, but lack the specificity of biological virus‐binding substances like heparin. Herein, we present three methods to immobilize heparin‐mimicking, virus‐binding polymers to a filter material. Two mussel‐inspired approaches are used, based on dopamine or mussel‐inspired dendritic polyglycerol, and post‐functionalized with a block‐copolymer consisting of linear polyglycerol sulfate and amino groups as anchor (lPGS‐b‐NH2). As third method, a polymer coating based on lPGS with benzophenone anchor groups is tested (lPGS‐b‐BPh). All three methods yield dense and stable coatings. A positively charged dye serves as a tool to quantitatively analyze the sulfate content on coated fleece. Especially lPGS‐b‐BPh is shown to be a dense polymer brush coating with about 0.1 polymer chains per nm2. Proteins adsorb to the lPGS coated materials depending on their charge, as shown for lysozyme and human serum albumin. Finally, herpes simplex virus type 1 (HSV‐1) and severe acute respiratory syndrome coronavirus type 2 (SARS‐CoV‐2) can be removed from solution upon incubation with coated fleece materials by about 90% and 45%, respectively. In summary, the presented techniques may be a useful tool to collect viruses from aqueous environments. [ABSTRACT FROM AUTHOR]

Molybdenum disulfide (MoS2) holds great promise for antibacterial applications owing to its strong photothermal performance and biocompatibility. Most of its antibacterial explorations have sought enhanced antibacterial potency through designing new hybrid inorganic materials, the relationship between its physiochemical properties and antibacterial activities has yet to be explored. This work is the first to investigate the combination effects of different sized and functionalized MoS2 sheets on their antibacterial activities. The bacterial capture abilities of 3 µm mannosylated, galactosylated, and glucosylated sheets, as well as 300 nm mannosylated sheets, all with similar sugar densities, are compared. Only mannosylated MoS2 sheets are found to agglutinate normal Escherichia coli (E. coli) and large mannosylated MoS2 sheets show the strongest E. coli agglutination. Despite slightly weaker photothermal performance under near‐infrared (NIR) laser irradiation, large mannosylated MoS2 sheets exhibit higher antibacterial activity than the smaller sheets. By much stronger specific multivalent binding, large sheets capture E. coli more efficiently and compensate for their reduced photothermal activity. Besides providing a facile approach to eliminate E. coli bacteria, these findings offer valuable guidance for future development of 2D nanomaterial‐based antibacterial agents and filter holder materials, where large‐functionalized sheets can capture and eliminate bacteria powerfully. [ABSTRACT FROM AUTHOR]

Mucus is the first defense barrier against viruses in the human immune system. Inspired by the mucus structure, we designed a highly sulfated hydrogel to bind viruses and prevent infection of the underlying cells. The hydrogel was formed by gelation of sulfated cellulose nanofiber (SCNF) with Ca 2+ . SCNF exhibited a mucin-like nanofiber structure with high numbers of sulfated groups. Based on the electrostatic interactions with a virus, SCNF could efficiently inhibit herpes simplex virus-1 (HSV-1) infection with a half-maximal inhibitory concentration (IC 50 ) of 0.43 μg/mL, which is comparable to that of heparin (IC 50 = 0.30 μg/mL). Benefiting from the multiporous structure and sulfate groups, the Ca 2+ -SCNF hydrogel could efficiently trap HSV-1 and inhibit the virus from attacking the underlying cells in a transwell model. Furthermore, SCNF also inhibited SARS-CoV-2 infection in a similar experimental setting. By integrating the advantages of high and broad-spectrum virus inhibitory activity as well as low toxicity, it is believed that the Ca 2+ -SCNF hydrogel can promote the development of highly biocompatible and efficient antiviral material with "binding and inhibition" capability and other diverse strategies.