Due to the prohibitive cost of transporting raw materials into Space, in-situ materials along with cement-like binders are poised to be employed for extraterrestrial construction. A unique methodology for obtaining microstructural topology of cement samples hydrated in microgravity environment at the International Space Station (ISS) is presented here. Distinctive Scanning Electron Microscopy (SEM) micrographs of hardened tri-calcium silicate (CS) samples were used as exemplars in a deep learning-based microstructure reconstruction framework.
View Article and Find Full Text PDFHere we introduce the synthesis and thermal properties of a series of sophisticated imidazolium ionenes with alternating amide-amide or amide-imide backbone functionality, and investigate the structural effects of mono(imidazolium) and unprecedented tris(imidazolium) ionic liquids (ILs) in these ionenes. The new set of poly(amide-amide) (PAA) and poly(amide-imide) (PAI) ionenes represent the intersection of conventional high-performance polymers with the ionene archetype-presenting polymers with alternating functional and ionic elements precisely sequenced along the backbone. The effects of polymer composition on the thermal properties and morphology were analyzed.
View Article and Find Full Text PDFHere, we report the synthesis and thermophysical properties of seven primarily aromatic, imidazolium-based polyamide ionenes. The effects of varied -, -, and -connectivity, and spacing of ionic and amide functional groups, on structural and thermophysical properties were analyzed. Suitable, robust derivatives were cast into thin films, neat, or with stoichiometric equivalents of the ionic liquid (IL) 1-benzy-3-methylimidazolium bistriflimide ([Bnmim][TfN]), and the gas transport properties of these membranes were measured.
View Article and Find Full Text PDFIt is highly desirable to integrate the CO solubility benefits of ionic liquids (ILs) in polymeric membrane systems for effective CO separations. Herein, we are exclusively exploring a series of four novel imidazolium-mediated Tröger's base (TB)-containing ionene polymers for enhanced CO separation. The two diimidazole-functionalized Tröger's base monomers synthesized from "ortho"- and "para"-substituted imidazole anilines were polymerized with equimolar amounts of two different aromatic and aliphatic comonomers (α,α'-dichloro--xylene and 1,10-dibromodecane, respectively) via Menshutkin reactions to obtain four respective ionene polymers ([Im-TB(&)-Xy][Cl] and ([Im-TB(&)-C][Br], respectively).
View Article and Find Full Text PDFThree new isomeric 6FDA-based polyimide-ionenes, with imidazolium moieties and varying regiochemistry ( connectivity), and composites with three different ionic liquids (ILs) have been developed as gas separation membranes. The structural-property relationships and gas separation behaviors of the newly developed 6FDA polyimide-ionene + IL composites have been extensively studied. All the 6FDA-based polyimide-ionenes exhibited good compatibility with the ILs and produced homogeneous hybrid membranes with the high thermal stability of ~380 °C.
View Article and Find Full Text PDFThe anionic ring-opening copolymerization of N-( p-tolylsulfonyl)azetidine ( pTsAzet) and N-( o-tolylsulfonyl)azetidine ( oTsAzet) produces poly( pTsAzet- co- oTsAzet) as a statistical copolymer. The pTsAzet/ oTsAzet copolymerization is living and allows for the synthesis of poly(sulfonylazetidine) of target molecular weights with narrow dispersities. H NMR spectroscopy was used to monitor the kinetics of the polymerization and estimate the monomer reactivity ratios.
View Article and Find Full Text PDFA new family of six ionenes containing aromatic amide linkages has been synthesized from ready available starting materials at scales up to ~50 g. These ionene-polyamides are all constitutional isomers and vary only in the regiochemistry of the amide linkages (para, meta) and xylyl linkages (ortho, meta, para) which are present in the polymer backbone. This paper details the synthesis of these ionenes and associated characterizations.
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