Fatimah Edhaim

The design of high performance solid sorbent materials for CO2 capture is a technology which has been employed to mitigate global warming. However, the covalent incorporation of functionalities into polymeric supports usually involves multistep energy-intensive chemical processes. This fact makes the net CO2 balance of the materials negative even though they possess good properties as CO2 sorbents. Here we show a new family of polymers which are based on amines, amidoximes, and natural carboxylic acids and can be obtained using sustainable low energy processes. Thus, deep eutectic monomers based on natural carboxylic acids, amidoximes, and amines have been prepared by just mixing with cholinium type methacrylic ammonium monomer. The formation of deep eutectic monomers was confirmed by differential scanning calorimetry measurements. In all cases, the monomers displayed glass transition temperatures well below room temperature. Computational studies revealed that the formation of eutectic complexes lengthens the distance between the cation and the anion causing charge delocalization. The liquid nature of the resulting deep eutectic monomers (DEMs) made it possible to conduct a fast photopolymerization process to obtain the corresponding poly(ionic liquids). Materials were characterized by means of nuclear magnetic resonance, differential scanning calorimetry, thermogravimetric analysis, and X-ray diffraction to evaluate the properties of the polymers. The polymers were then used as solid sorbents for CO2 capture. It has been shown that the polymers prepared with citric acid displayed better performance both experimentally and computationally. The current endeavor showed that sustainable poly(ionic liquids) based on deep eutectic monomers can be easily prepared to produce low-energy-cost alternatives to the materials currently being researched for CO2 capture. © 2016 American Chemical Society.

Quantitative X-ray diffraction (XRD) analysis is performed on 172 samples mainly containing paleosol sections of Unayzah and Basal Khuff clastics taken from the core of one well drilled by Saudi Aramco. Quantitative XRD bulk mineralogical determination is achieved using the Rietveld refinement method whereas quantitative XRD clay mineralogical determination of clay-size fraction is obtained using the reference intensity ratio method. The XRD results indicate that the samples from paleosol sections consist mainly of quartz and feldspar (microcline and albite) as framework constituents. Cement minerals include dolomite, hematite, anhydrite, siderite, gypsum, calcite, and pyrite. Clay minerals are important constituents in paleosols. The XRD results show that clay minerals in the samples are illite, mixed-layer illite/smectite, kaolinite, and chlorite. No discrete smectite is present in the samples. The clay mineral associations in these samples of paleosol sections can be classified into three types: Type I predominantly consists of illite and a mixed layer of illite/smectite; Type II of kaolinite; and Type III of illite and a mixed layer of illite/smectite, but also significant amounts of kaolinite. The change of clay mineral association type with sample depth can indicate the change of paleoclimate and paleoenvironment. For example, kaolinite usually forms under strongly leaching conditions such as abundant rainfall, good drainage, and acid waters. Therefore, XRD mineralogical data of paleosol sections are important for petroleum geologists to study paleoclimate and paleoenvironment and to predict the reservoir quality of the associated rock formations.

The synthesis and characterization of the rare earth chalcogenide aerogels NaYSnS 4 , NaGdSnS 4 , and NaTbSnS 4 is reported. Rare earth metal ions like Y 3+ , Gd 3+ , and Tb 3+ react with the chalcogenide clusters [SnS 4 ] 4– in aqueous formamide solution forming extended polymeric networks by gelation. Aerogels obtained after supercritical drying have BET surface areas of 649 m 2 · g –1 (NaYSnS 4 ), 479 m 2 · g –1 (NaGdSnS 4 ), and 354 m 2 · g –1 (NaTbSnS 4 ). Electron microscopy and physisorption studies reveal that the new materials have pores in the macro (above 50 nm) and meso (2–50 nm) regions. These aerogels show higher adsorption of toluene vapor over cyclohexane vapor and CO 2 over CH 4 or H 2 . The notable adsorption capacity for toluene (NaYSnS 4 : 1108 mg · g –1 ; NaGdSnS 4 : 921 mg · g –1 ; and NaTbSnS4: 645 mg · g –1 ) and high selectivity for gases (CO 2 /H 2 : 172 and CO 2 /CH 4 : 50 for NaYSnS 4 , CO 2 /H 2 : 155 and CO 2 /CH 4 : 37 for NaGdSnS 4 , and CO 2 /H 2 : 75 and CO 2 /CH 4 : 28 for NaTbSnS 4 ) indicate potential future use of chalcogels in adsorption‐based gas or hydrocarbon separation processes.

Abstract The synthesis of metal chalcogenide aerogels Co 0.5 M 0.33 MoS 4 (M= Sb or Y) by the sol‐gel method is reported. In this system, the building blocks [MoS 4 ] 2− chelated with Co 2+ and (Sb 3+ ) or (Y 3+ ) salts in nonaqueous solvents forming amorphous networks with a gel property. The chalcogels obtained after supercritical drying have BET surface areas of 176 m 2 g −1 (Co 0.5 Sb 0.33 MoS 4 ) and 145 m 2 g −1 (Co 0.5 Y 0.33 MoS 4 ). Electron microscopy and physisorption studies reveal that the new materials are porous with wide pore size distribution and average pore width of 16 nm. These chalcogels show higher adsorption capacity of toluene vapor (Co 0.5 Sb 0.33 MoS 4 : 387 mg g −1 ) and (Co 0.5 Y 0.33 MoS 4 : 304 mg g −1 ) over cyclohexane vapor and high selectivity of CO 2 over CH 4 or H 2 , Co 0.5 Sb 0.33 MoS 4 (CO 2 /H 2 : 80 and CO 2 /CH 4 : 21), Co 0.5 Y 0.33 MoS 4 (CO 2 /H 2 : 27 and CO 2 /CH 4 : 15). We also demonstrated that the impregnation of various metal species like Li + , Mg 2+ , and Ni 2+ significantly enhanced the uptake capacity and selectivity of toluene and CO 2 adsorptions in the chacogels.