Metal ions adsorption from ethanol solutions on ethylenediamine-modified poly(dimethylsiloxane) elastomeric network

Influence of the Nanotube Morphology and Intercalated Species on the Sorption Properties of Hybrid Layered Vanadium Oxides: Application for Cesium Removal from Aqueous Streams

The present paper examines the impact that the nanotube morphology and organic or inorganic intercalated species may have on the cesium sorption by layered vanadium oxides prepared with the use of hexadecylamine as a structure-directing agent. The hybrid material represented by a chemical formula of (V₂O₅)(VO₂)_1.03(C₁₆H₃₆N)_1.46(H₂O)_x was achieved through accelerated microwave-assisted synthesis carefully optimized to ensure the best compromise between the scroll-like morphology and the hydrophobic character. To enhance its dispersibility in water, this sample was subsequently modified by progressive replacement of the C₁₆H₃₆N⁺ units by NH₄⁺ cations. The final materials represented a stacking of lamellar sheets with a worse scroll-like morphology. Both the optimization procedure and the template removal were monitored on the basis of scanning and transmission electronic microscopy, X-ray diffraction, infra-red spectroscopy, inductively coupled plasma-optical emission spectrometry, X-ray photoelectron spectroscopy, and elemental analysis, supplemented by adequate simulations methods providing the reference IR spectra and XRD patterns for comparison or the textural parameters of the samples. The comparison of the cesium sorption from either a 4:1 ethanol–water mixture or aqueous solutions pointed toward the solubility of intercalated cations in the bulk solution as the main factor limiting their displacement from the interlayer space by the oncoming cesium ones. The sample obtained after 70% exchange with NH₄⁺ exhibited a maximum sorption capacity of 1.4 mmol g⁻¹ from CsNO₃ aqueous solutions and its retention efficiency remained significant from low-concentration Cs solutions in river or sea water.

Organic-Inorganic Hybrid Polymers as Adsorbents for Removal of Heavy Metal Ions from Solutions: A Review

Over the past decades, organic-inorganic hybrid polymers have been applied in different fields, including the adsorption of pollutants from wastewater and solid-state separations. In this review, firstly, these compounds are classified. These compounds are prepared by sol-gel method, self-assembly process (mesopores), assembling of nanobuilding blocks (e.g., layered or core-shell compounds) and as interpenetrating networks and hierarchically structures. Lastly, the adsorption characteristics of heavy metals of these materials, including different kinds of functional groups, selectivity of them for heavy metals, effect of pH and synthesis conditions on adsorption capacity, are studied.