Substantially Improving CO Permeability and CO/CH Selectivity of Matrimid Using Functionalized-TiCT.

Mixed-matrix membranes (MMMs) with favorable interfacial interactions between dispersed and continuous phases offer a promising approach to overcome the traditional trade-off between permeability and selectivity in membrane-based gas separation. In this study, we developed free-standing MMMs by embedding pristine and surface-modified TiCT MXenes into Matrimid 5218 polymer for efficient CO/CH separation. Two-dimensional TiCT with adjustable surface terminations provided control over these critical interfacial interactions.

Analysis of Metal-Organic Framework and Polyamide Interfaces in Membranes for Water Treatment and Antibacterial Applications.

Integrating biocidal nanoparticles (NPs) into polyamide (PA) membranes shows promise for enhancing resistance to biofouling. Incorporating techniques can tailor thin-film nanocomposite (TFN) membranes for specific water purification applications. In this study, silver-based metal-organic framework Ag-MOFs (using silver nitrate and 1,3,5-benzentricarboxylic acid as precursors) are incorporated into PA membranes via three different methods: i) incorporation, ii) dip-coating, and iii) in situ ultrasonic techniques.

MXenes Antibacterial Properties and Applications: A Review and Perspective.

The mutations of bacteria due to the excessive use of antibiotics, and generation of antibiotic-resistant bacteria have made the development of new antibacterial compounds a necessity. MXenes have emerged as biocompatible transition metal carbide structures with extensive biomedical applications. This is related to the MXenes' unique combination of properties, including multifarious elemental compositions, 2D-layered structure, large surface area, abundant surface terminations, and excellent photothermal and photoelectronic properties.

Glasses denser than the supercooled liquid.

When aged below the glass transition temperature, [Formula: see text], the density of a glass cannot exceed that of the metastable supercooled liquid (SCL) state, unless crystals are nucleated. The only exception is when another polyamorphic SCL state exists, with a density higher than that of the ordinary SCL. Experimentally, such polyamorphic states and their corresponding liquid-liquid phase transitions have only been observed in network-forming systems or those with polymorphic crystalline states.

Effect of Nanopore Geometry in the Conformation and Vibrational Dynamics of a Highly Confined Molecular Glass.

The effect of nanoporous confinement on the glass transition temperature () strongly depends on the type of porous media. Here, we study the molecular origins of this effect in a molecular glass, -bis(3-methylphenyl)--diphenylbenzidine (TPD), highly confined in concave and convex geometries. When confined in controlled pore glass (CPG) with convex pores, TPD's vibrational spectra remained unchanged and two 's were observed, consistent with previous studies.

Toward Sustainable Tackling of Biofouling Implications and Improved Performance of TFC FO Membranes Modified by Ag-MOF Nanorods.

In this work, nanorods with high antibacterial properties were synthesized with silver acetate as the metal source and 2-aminoterephthalic acid as the organic linker and were then embedded into thin-film composite (TFC) membranes to amend their performance as well as to alleviate biofouling. Silver metal-organic framework (Ag-MOF) nanorods with a length smaller than 40 nm were incorporated within the polyamide thin selective layer of the membranes during interfacial polymerization. The interaction of the synthesized nanorods with the polyamide was favored because of the presence of amine-containing functional groups on the nanorod's surface.

In Situ Ag-MOF Growth on Pre-Grafted Zwitterions Imparts Outstanding Antifouling Properties to Forward Osmosis Membranes.

In this study, a polyamide forward osmosis membrane was functionalized with zwitterions followed by the in situ growth of metal-organic frameworks with silver as a metal core (Ag-MOFs) to improve its antibacterial and antifouling activity. First, 3-bromopropionic acid was grafted onto the membrane surface after its activation with ,-diethylethylenediamine. Then, the in situ growth of Ag-MOFs was achieved by a simple membrane immersion sequentially in a silver nitrate solution and in a ligand solution (2-methylimidazole), exploiting the underlying zwitterions as binding sites for the metal.

Improving the Transport and Antifouling Properties of Poly(vinyl chloride) Hollow-Fiber Ultrafiltration Membranes by Incorporating Silica Nanoparticles.

Poly(vinyl chloride) (PVC)/SiO nanocomposite hollow-fiber membranes with different nano-SiO particle loadings (0-5 wt %) were fabricated using the dry-jet wet-spinning technique. Effects of SiO nanoparticles on the morphology of the prepared hollow-fiber membranes were investigated using scanning electron microscopy. Transport and antifouling properties of the fabricated membranes were evaluated by conducting pure-water permeation, solute rejection, and fouling resistance experiments.

Simultaneous Improvement of Antimicrobial, Antifouling, and Transport Properties of Forward Osmosis Membranes with Immobilized Highly-Compatible Polyrhodanine Nanoparticles.

This work shows that incorporating highly compatible polyrhodanine nanoparticles (PRh-NPs) into a polyamide (PA) active layer allows for fabricating forward osmosis (FO) thin-film composite (TFC)-PRh membranes that have simultaneously improved antimicrobial, antifouling, and transport properties. To the best of our knowledge, this is the first reported study of its kind to this date. The presence of the PRh-NPs on the surface of the TFC-PRh membranes active layers is evaluated using FT-IR spectroscopy, SEM, and XPS.

A New Pentiptycene-Based Dianhydride and Its High-Free-Volume Polymer for Carbon Dioxide Removal.

In addition to possessing excellent chemical, mechanical, and thermal stability, polyimides and polyetherimides have excellent solubility in many solvents, which renders them suitable for membrane preparation. Two new monomers [a pentiptycene-based dianhydride (PPDAn) and a pentiptycene imide-containing diamine (PPImDA)] and a pentiptycene-based polyimide [PPImDA-4,4'-hexafluoroisopropylidene diphthalic anhydride (PPImDA-6FDA)] have been synthesized and characterized by FTIR and H NMR spectroscopy, gel-permeation chromatography, mass spectrometry, X-ray photoelectron spectroscopy, thermogravimetric analysis, differential scanning calorimetry, BET surface area, and X-ray diffraction. High-molecular-weight PPImDA-6FDA has remarkable thermal stability and excellent solubility in common organic solvents.

Crystal structure of 5,7,12,14-tetra-hydro-5,14:7,12-bis-([1,2]benzeno)-penta-cene-6,13-dione.

The lattice of 5,7,12,14-tetra-hydro-5,14:7,12-bis-([1,2]benzeno)-penta-cene-6,13-dione, CHO, at 173 K has triclinic (-1) symmetry and crystallizes with four independent half-mol-ecules in the asymmetric unit. Each mol-ecule is generated from a CHO substructure through an inversion center at the centroid of the central quinone ring, generating a wide H-shaped mol-ecule, with a dihedral angle between the mean planes of the terminal benzene rings in each of the two symmetry-related pairs over the four mol-ecules of 68.6 (1) (), 65.

A review on chitosan-based adsorptive membranes.

Membrane adsorbents have emerged as powerful and attractive tools for the removal of hazardous materials such as dyes and heavy metal ions, mainly in trace amounts, from water resources. Among membrane adsorbents, those prepared from or modified with chitosan biopolymer and its derivatives are cases of interest because of chitosan advantages including biocompatibility, biodegradability, nontoxicity, reactivity, film and fiber forming capacity and favorable hydrophilicity. This review is oriented to provide a framework for better insight into fabrication methods and applications of chitosan-based adsorptive membranes.