Influence of hydrophilic groups and metal-ion adsorption on polymer-chain conformation of amidoxime-based uranium adsorbents.

This study focuses on the influence of hydrophilic groups and metal-ion loading on adsorbent polymer conformation, which controls access to adsorption sites and may limit adsorption capacity. Gaining a better understanding of the factors that influence conformation may yield higher-capacity adsorbents. Polyamidoxime (PAO), deuterated-PAO polyacrylic acid diblock copolymers (d-PAO-b-PAA), and randomly configured copolymers (PAO-co-PAA) were synthesized and characterized by neutron reflectometry in air and DO.

Accessing Siloxane Functionalized Polynorbornenes via Vinyl-Addition Polymerization for CO Separation Membranes.

The vinyl addition polymerization of norbornyl-based monomers bearing polar functional groups is often problematic, leading to low molecular weight polymers in poor yield. Herein, we provide proof-of-principle evidence that addition-type homopolymers of siloxane substituted norbornyl-based monomers may be readily synthesized using the catalyst -[Ni(CF)(SbPh)]. Polymerizations using this catalyst reached moderate to high conversion in just 5 min of polymerization and produced siloxane-substituted polymers with molecular weights exceeding 100 kg/mol.

Effect of Cross-Link Density on Carbon Dioxide Separation in Polydimethylsiloxane-Norbornene Membranes.

The development of high-performance materials for carbon dioxide separation and capture will significantly contribute to a solution for climate change. Herein, (bicycloheptenyl)ethyl-terminated polydimethylsiloxane (PDMSPNB) membranes with varied cross-link densities were synthesized via ring-opening metathesis polymerization. The developed polymer membranes show higher permeability and better selectivity than those of conventional cross-linked PDMS membrane.