The increasing pressure for lithium resources from the
electric
vehicle and nuclear energy industries means that new technologies
to separate Mg2+ from Li+ from salt water are
in demand. To address this need, we fabricated lithium pyrene squarate
covalent organic frameworks (Li-SQCOFs) to separate Mg2+/Li+ mixtures from salt water. We optimized the effect
of the electrolyte and the amount of the adsorbent and then carried
out a kinetics study on the adsorbent recovery at various pH levels
using both batch and continuous flow adsorption methods. Li-SQCOF
was found to have excellent selectivity for solutions containing a
mixture of Mg2+/Li+ ions. This work represents
a unique path for the separation of Mg2+/Li+ through direct adsorption using a covalent organic framework (COF).
The COF-supported ultrafiltration bed made in this study gave a Mg2+ separation flux of 60.5 h–1 m–2.
The presence of perfluorooctanoic acid, a perfluoralkyl
substance,
in water sources has raised health concerns due to its toxicity. Finding
effective adsorbents is essential to ensure healthy sources of water
for consumption. In this study, a heptazine-based polymer network
(Py-HPOP) was synthesized using a one-pot nucleophilic substitution
of 2,5,8-trichloro-s-heptazine (TCH) with 4,4′,4″,4‴-(pyrene-1,3,6,8-tetrayl)
tetraaniline (Py-TA). For comparison, a triazine-based polymeric network
(Py-TPOP) was also prepared using 2,4,6-trichloro-1,3,5-triazine under
similar conditions. Both polymers were used to treat aqueous solutions
containing 1 mg/L PFOA. Py-TPOP exhibited superior adsorption capacity
(98.4% PFOA removal) relative to Py-HPOP (80.8% PFOA removal) despite
Py-HPOP’s higher Brunauer–Emmett–Teller (BET)
surface area S
BET at 205 m2 g–1. The effect of electrostatic interactions
was also observed as a critical factor for PFOA adsorption as demonstrated
by the change in PFOA adsorption by both polymers under basic, neutral,
and acidic conditions. This investigation illustrates a facile synthesis
of amorphous covalent frameworks as strong, competitive adsorbents
for PFOA removal from water.
PEPy‐COF, a new covalent organic framework (COF), exhibits a shiny blue fluorescence under UV and visible light. In article number 2300412, Amin Zadehnazari, Alireza Abbaspourrad, and colleagues built PEPy‐COF via a one‐pot condensation reaction using perylene and pyrene building blocks. PEPy‐COF features temperature‐dependent and solvent‐independent fluorescence and a semiconductor band gap making it an excellent candidate for temperature sensing devices.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.