Supplemental material for Kynos Through Time: Decorated Pottery Sherds from Eleven Strata of a Homeric Greek Site

<p>Supplemental material for Kynos Through Time: Decorated Pottery Sherds from Eleven Strata of a Homeric Greek Site by Agoritsa Tsiachri, Georgios P. Mastrotheodoros, Harrisis Zoubos, Dimitrios F. Anagnostopoulos and Konstantinos G. Beltsios in Applied Spectroscopy</p

Grafting of Imidazolium Based Ionic Liquid on the Pore Surface of Nanoporous MaterialsStudy of Physicochemical and Thermodynamic Properties

Supported ionic liquid phase (SILP) systems were prepared by immobilizing a methylimidazolium cation based ionic liquid onto the pore surface of two types of support, MCM-41 and Vycor. The “grafting to” method was applied, involving (3-chloropropyl)-trialkoxysilane anchoring on the supports’ silanol groups, followed by treatment with 1-methylimidazole and ion exchange with PF6−. Optimum surface pretreatment procedures and reaction conditions for enhanced ionic liquid (IL) loading were properly defined and applied for all modifications. A study on the effect of different pore sizes on the physical state of the grafted 1-(silylpropyl)-3-methylimidazolium-hexafluorophosphate ([spmim][PF6−]) was also conducted. The [spmim][PF6−] crystallinity under extreme confinement in the pores was investigated by modulated differential scanning calorimetry (DSC) and X-ray diffraction (XRD) and was further related to the capacity of the developed SILP to preferentially adsorb CO2 over CO. For this purpose, CO2 and CO absorption measurements of the bulk ionic liquid [bmim][PF6−] and the synthesized alkoxysilyl-IL were initially performed at several temperatures. The results showed an enhancement of the bulk IL performance to preferentially adsorb CO2 at 273 K. The DSC analysis of the SILPs revealed transition of the melting point of the grafted alkoxysilyl-IL to higher temperatures when the support pore size was below 4 nm. The 2.3 nm MCM-41 SILP system exhibited infinite CO2/CO separation capacity at temperatures below and above the melting point of the bulk IL phase, adsorbing in parallel significant amounts of CO2 in a reversible manner. These properties make the developed material an excellent candidate for CO2/CO separation with pressure swing adsorption (PSA) techniques

Ionic Liquid-Modified Porous Materials for Gas Separation and Heterogeneous Catalysis

This work examines important physicochemical and thermophysical properties of ultrathin ionic liquid (IL) layers under confinement into the pore structure of siliceous supports and brings significant advances toward understanding the effects of these properties on the gas separation and catalytic performance of the developed supported ionic liquid phase (SILP) and solid catalysts with ionic liquid layers (SCILL). SILPs were developed by making use of functionalized and nonfunctionalized ILs, such as 1-(silylpropyl)-3-methyl-imidazolium hexafluorophosphate and 1-butyl-3-methyl-imidazolium hexafluorophosphate ILs, whereas the SCILL was prepared by effectively dispersing gold nanoparticles (AuNPs) onto the IL layers inside the open pores of the SILP. The information derived from the gas absorption/diffusivity and heterogeneous catalysis experiments was exemplified in relation to the liquid crystalline ordering and orientation of the IL molecules, investigated by X-ray diffraction (XRD) and modulated differential scanning calorimetry (MDSC). The extent of pore blocking was elucidated with small angle neutron scattering (SANS) and was proven to be a decisive factor for the gas separation efficiency of the SILPs. CO₂/CO separation values above 50 were obtained in cases where liquid crystalline ordering of the IL layers and extended pore blocking had occurred. The presence of the IL layer in the developed SCILL assisted the formation of ultrasmall (2–3 nm) and well-stabilized AuNPs. The low-temperature CO oxidation efficiency was 22%. The catalytic experiments showed an additional functionality of the IL, acting as an “in-situ trap” that abstracts the product (CO₂) from the reaction site and improves yield

CO₂ Capture Efficiency, Corrosion Properties, and Ecotoxicity Evaluation of Amine Solutions Involving Newly Synthesized Ionic Liquids

The CO₂ capture efficiency of nine newly synthesized ionic liquids (ILs), both in their pure states as well as in binary and ternary systems with water and amines, was investigated. The study encompassed ILs with fluorinated and tricyanomethanide anions as well as ILs that interact chemically with CO₂ such as those with amino acid and acetate anions. Compared to amines, some of the novel ILs exhibited a majority of important advantages for CO₂ capture such as enhanced chemical and thermal stabilities and negligible vapor pressure; the previous features counterbalance the disadvantages of lower CO₂ absorption capacity and rate, making these ILs promising CO₂ absorbents that could partially or totally replace amines in industrial scale processes. In addition to their ability to capture CO₂, important issues including corrosivity and ecotoxicity were also examined. A thorough investigation of the capture efficiency and corrosion properties of several solvent formulations proved that some of the new ILs encourage future commercial-scale applications for appropriate conditions. ILs with a tricyanomethanide anion confirmed a beneficial effect of water addition on the CO₂ absorption rate (ca. 10-fold) and capacity (ca. 4-fold) and high efficiency for corrosion inhibition, in contrast with the negative effect of water on the CO₂ absorption capacity of ILs with the acetate anion. ILs with a fluorinated anion showed high corrosivity and an almost neutral effect of water on their efficiency as CO₂ absorbents. ILs having amino acid anions presented a reduced toxicity and high potential to completely replace amines in solutions with water but, in parallel, showed thermal instability and degradation during CO₂ capture. Tricyanomethanide anion-based ILs had a beneficial effect on the capture efficiency, toxicity, and corrosiveness of the standard amine solutions. As a consolidated output, we propose solvent formulations containing the tricyanomethanide anion-based ILs and less than 10 vol % of primary or secondary amines. These solvents exhibited the same CO₂ capture performance as the 20−25 vol % standard amine solutions. The synergetic mechanisms in the capture efficiency, induced by the presence of the examined ILs, were elucidated, and the results obtained can be used as guidance for the design and development of new ILs for more efficient CO₂ capture