Chemical stability of olefin carrier based on silver cations and metallic silver nanoparticles against the formation of silver acetylide for facilitated transport membranes

Rational Design of Mixed Matrix Membranes Modulated by Trisilver Complex for Efficient Propylene/Propane Separation

The application of membrane-based separation processes for propylene/propane (C₃ H₆ /C₃ H₈ ) is extremely promising and attractive as it is poised to reduce the high operation cost of the established low temperature distillation process, but major challenges remain in achieving high gas selectivity/permeability and long-term membrane stability. Herein, a C₃ H₆ facilitated transport membrane using trisilver pyrazolate (Ag₃ pz₃ ) as a carrier filler is reported, which is uniformly dispersed in a polymer of intrinsic microporosity (PIM-1) matrix at the molecular level (≈15 nm), verified by several analytical techniques, including 3D-reconstructed focused ion beam scanning electron microscropy (FIB-SEM) tomography. The π-acidic Ag₃ pz₃ combines preferentially with π-basic C₃ H₆ , which is confirmed by density functional theory calculations showing that the silver ions in Ag₃ pz₃ form a reversible π complex with C₃ H₆ , endowing the membranes with superior C₃ H₆ affinity. The resulting membranes exhibit superior stability, C₃ H₆ /C₃ H₈ selectivity as high as ≈200 and excellent C₃ H₆ permeability of 306 Barrer, surpassing the upper bound selectivity/permeability performance line of polymeric membranes. This work provides a conceptually new approach of using coordinatively unsaturated 0D complexes as fillers in mixed matrix membranes, which can accomplish olefin/alkane separation with high performance.

Graphene oxide nanoslit-confined AgBF4/ionic liquid for efficiently separating olefin from paraffin

Facilitated transport membrane for separating light olefins, using transition metals like silver and copper as carriers, is a promising way to replace traditional energy-consuming methods. Here, we construct ionic liquid (IL) to fill the nanoslits of laminated graphene oxide (GO) membrane with silver ions as a carrier to separate ethylene/ethane. The nanoslits of GO membrane efficiently prevent the loss of silver ion IL solution. The IL further slows down the reduction of silver ions. The membrane with silver concentration of 0.25 M shows the best performance with a selectivity of 54 for ethylene/ethane and ethylene permeance of 2.9 GPU. This performance is superior to other silver ion IL solution membranes and competitive among the reported facilitated transport membranes.

Synthesis and Characterization of Gold-Silver Nanoparticles in Deionized Water by Pulsed Laser Ablation (PLAL) Technique at Different Laser Parameter

Gold and silver nanoparticles (NPs) are physically synthesized using Q-switched neodymium-doped yttrium aluminum garnet (Nd:YAG)-pulsed laser ablation in liquid (PLAL) technique which is a rapid, simple and efficient one-step synthesis. The gold and silver colloidal solutions are separately prepared by 1064[Formula: see text]nm of pulsed laser ablation of metallic target (gold and silver) which is immersed in deionized water. Ultraviolet–visible spectroscopy (UV–Vis) analysis shows the absorption band of gold and silver NPs at [Formula: see text][Formula: see text]nm and [Formula: see text][Formula: see text]nm, respectively. The absorption spectra and color variations of gold and silver NPs at three different laser parameters (output laser energies, target distances from focal point and laser time exposures). High-resolution transmission electron microscopy shows the spherical shape of gold and silver NPs with 34[Formula: see text]nm and 33[Formula: see text]nm diameter of size, respectively, are reported. The aggregation and particle sizes of gold and silver NPs due to minimum energy (75[Formula: see text]mJ) and maximum energy (311[Formula: see text]mJ) are observed.