Dynamics of CO2 molecules confined in the micropores of solids as studied by 13C NMR

Omi, Hironori; Ueda, Takahiro; Miyakubo, Keisuke; Eguchi, Taro

doi:10.1016/j.apsusc.2005.02.048

Cited by 47 publications

(52 citation statements)

References 31 publications

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“…Among various chemical absorbents, metal oxides [9][10][11][12], Li-containing zirconates [13][14][15][16][17] and poly-ionic liquids [18,19] have been investigated. Numerous studies have explored methods of physisorption using functionalized/modified nanoporous solids for the abatement of CO 2 , for examples, microporous zeolites [20][21][22][23][24][25][26], activated carbons [27][28][29], porous coordination polymers or organic nanostructure materials [30][31][32]. However, these materials normally exhibit low CO 2 adsorption capacity (typically smaller to the benchmark value of ca.…”

Section: Introductionmentioning

confidence: 98%

Highly Stable Amine-modified Mesoporous Silica Materials for Efficient CO2 Capture

Liu

Lee

et al. 2009

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A highly efficient and stable solid adsorbent invoking a direct incorporation of tetraethylenepentamine (TEPA) onto the as-synthesized mesocelullar silica foam (MSF) has been developed for CO 2 capture. Unlike most amine-functionalized silicas, which typically exhibit CO 2 adsorption capacities less than 2.0 mmol/g, such organic template occluded mesoporous silica-amine composites exhibited remarkably high CO 2 uptake as high as 4.5 mmol/g at 348 K and 1 atm. Moreover, notable increases in CO 2 adsorption capacities of the composite materials were observed when in the presence of humidity. Durability test performed by cyclic adsorption-desorption revealed that such adsorbents also possess excellent stability, even though a slight decrease in adsorption capacity over time was observed.

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Section: Introductionmentioning

confidence: 98%

Highly Stable Amine-modified Mesoporous Silica Materials for Efficient CO2 Capture

Liu

Lee

et al. 2009

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“…In particular, a supercritical exfoliation method has been tested [30][31][32][33] . Due to molecular size of CO 2 and its polarizability, it has the potential to pass through the solid porous layers 34 and, when supercritical conditions are reached, CO 2 diffusivity can favor layers expansion and exfoliation [31][32][33] . It is also possible to add co-solvents (e.g., N-methylpyrrolidone (NMP), DMF and Isopropanol), to increase the polarity and the fluid-solid interaction 30 .…”

Section: Introductionmentioning

confidence: 99%

Formation of Cellulose Acetate–Graphene Oxide Nanocomposites by Supercritical CO₂ Assisted Phase Inversion

Baldino

Sarno

Cardea

et al. 2015

Ind. Eng. Chem. Res.

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(Stefano Cardea) Phone Number: +39089969365; msarno@unisa.it (Maria Sarno) Phone Number: +39089964057.KEYWORDS: Graphene oxide, Cellulose acetate, Nanocomposite, Supercritical CO 2 . ABSTRACTCellulose acetate (CA)/graphene oxide (GO) nanocomposite membranes were generated by an assisted phase inversion process, based on the use of SC-CO 2 as non-solvent, operating at 200 bar and 40 °C; loadings of GO up to 9% w/w were tested. The structures maintained the cellular morphology, characteristics of CA membranes, also at the highest GO loadings used, with a porosity of about 80%, but the presence of GO influenced the pore sizes, that ranged between about 9 and 16 µm. The starting GO and the nanocomposite structures were characterized by the combination of various techniques that evidences as Sulphur and Chlorinated impurities, that were present in the starting GO material, were completely eliminated by the interaction with SC-CO 2 during structures formation; moreover, a partial reduction of GO to graphene was also observed. . Compared to graphene, GO is heavily oxygenated and its basal plane carbon atoms are decorated with epoxide and hydroxyl groups and its edge atoms with carbonyl and carboxyl groups. Hence, GO is highly hydrophilic and the presence of these functional groups reduces interplanar forces, which can improve the interfacial interaction between GO and some polymers and, thus, the dispersion of GO in polymer matrices 2,3 . Many factors can affect the final properties and applications of GO/polymer nanocomposites 4 , among these: kind of GO used, its dispersion state in the polymeric matrix and interfacial interactions, the amount of wrinkling, its network structure in the matrix and its purity.Various attempts have been proposed in the literature to realize GO/polymers composite structures [5][6][7][8][9][10][11][12][13][14][15] . The processes proposed until now (i.e., phase inversion, casting, electrospinning) present several limitations; for example, residues of organic solvents of GO synthesis are typically found at the end of these processes, causing problems, in particular, for biomedical applications. Moreover, a homogeneous distribution of GO in the polymeric matrix is difficult to obtain, since the cohesive forces among GO layers tend to produce restacking. GO composites performance is strongly related to its level of exfoliation (i.e., separation of the layers). Exfoliated GO allows the largest interfacial contact with the polymer matrix, improving the properties of the composites. For this reason, several techniques have been implemented to increase the GO exfoliation degree. In particular, solvent-based exfoliation and thermal exfoliation techniques emerged as two preferred routes for this step [16][17][18][19] . [30][31][32][33] . Due to molecular size of CO 2 and its polarizability, it has the potential to pass through the solid porous layers 34 and, when supercritical conditions are reached, CO 2 diffusivity can favor layers expansion and exfoliation [31][32][33] . It is also possible to...

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“…Miliani et al [72] applied Fourier Transform Infrared Spectroscopy (FTIR) to investigate the presence of adsorbed species on synthetic and natural ultramarine pigments. Their data indicated the presence of CO 2 in natural Afghan ultramarine, and suggested that CO 2 molecules, although not free to rotate, were loosely physisorbed to the sodalite cage [73].…”

Section: Detection Of Co 2 In Lapis Lazuli By 13 C Mas Nmrmentioning

confidence: 99%

“…In particular, the 13 C NMR spectrum has been successfully used to investigate the local structure and dynamics of absorbed CO2 in porous materials such as zeolites with micro-or mesopores [73]. We exploited 13 C MAS NMR spectroscopy to ascertain the presence of CO2 in natural abundance included into the structure of a sample of Afghan lapis lazuli.…”

Section: Detection Of Co2 In Lapis Lazuli By 13 C Mas Nmrmentioning

confidence: 99%

Nuclear Magnetic Resonance, a Powerful Tool in Cultural Heritage

2018

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In this paper five case studies illustrating applications of NMR (Nuclear Magnetic Resonance) in the field of cultural heritage, are reported. Different issues were afforded, namely the investigation of advanced cleaning systems, the quantitative mapping of moisture in historic walls, the investigation and evaluation of restoration treatments on porous stones, the stratigraphy of wall paintings, and the detection of CO 2 in lapis lazuli. Four of these case studies deal with the use of portable NMR sensors which allow non-destructive and non-invasive investigation in situ. The diversity among cases reported demonstrates that NMR can be extensively applied in the field of cultural heritage.

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Dynamics of CO2 molecules confined in the micropores of solids as studied by 13C NMR

Cited by 47 publications

References 31 publications

Highly Stable Amine-modified Mesoporous Silica Materials for Efficient CO2 Capture

Highly Stable Amine-modified Mesoporous Silica Materials for Efficient CO2 Capture

Formation of Cellulose Acetate–Graphene Oxide Nanocomposites by Supercritical CO₂ Assisted Phase Inversion

Nuclear Magnetic Resonance, a Powerful Tool in Cultural Heritage

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Dynamics of CO2 molecules confined in the micropores of solids as studied by 13C NMR

Cited by 47 publications

References 31 publications

Highly Stable Amine-modified Mesoporous Silica Materials for Efficient CO2 Capture

Highly Stable Amine-modified Mesoporous Silica Materials for Efficient CO2 Capture

Formation of Cellulose Acetate–Graphene Oxide Nanocomposites by Supercritical CO2 Assisted Phase Inversion

Nuclear Magnetic Resonance, a Powerful Tool in Cultural Heritage

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Formation of Cellulose Acetate–Graphene Oxide Nanocomposites by Supercritical CO₂ Assisted Phase Inversion