Properties of Hydrogen-Bonded Liquids at Interfaces

Buntkowsky, Gerd; Vogel, Michael; Winter, Roland

doi:10.1515/zpch-2018-1110

Cited by 19 publications

(21 citation statements)

References 193 publications

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“…As mentioned above these mesoporous silica materials permit the comparatively simple synthesis of surface functionalized host systems with well-defined tunable narrow pore diameters [175][176][177][178], employing a synthesis protocol, which is based on Grünberg et al [106] and Grün et al [179]. Details of the synthesis and characterization are given in [176,180] and will not be repeated here. The changes of porosity, specific surfaces and the modification of the surface sites of the material can be monitored by the combination of nitrogen adsorption (BET and BJH) analysis and 29 Si SSNMR spectroscopy.…”

Section: Preparation and Chemical Functionalization Of Mesoporous Silica; Nmr Characterizationmentioning

confidence: 99%

Small Molecules, Non-Covalent Interactions, and Confinement

Buntkowsky

Vogel

2020

Molecules

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This review gives an overview of current trends in the investigation of small guest molecules, confined in neat and functionalized mesoporous silica materials by a combination of solid-state NMR and relaxometry with other physico-chemical techniques. The reported guest molecules are water, small alcohols, and carbonic acids, small aromatic and heteroaromatic molecules, ionic liquids, and surfactants. They are taken as characteristic role-models, which are representatives for the typical classes of organic molecules. It is shown that this combination delivers unique insights into the structure, arrangement, dynamics, guest-host interactions, and the binding sites in these confined systems, and is probably the most powerful analytical technique to probe these systems.

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Section: Preparation and Chemical Functionalization Of Mesoporous Silica; Nmr Characterizationmentioning

confidence: 99%

Small Molecules, Non-Covalent Interactions, and Confinement

Buntkowsky

Vogel

2020

Molecules

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“…Recent experiments on the mobility of liquid glycerol under hard confinement have led to especially intriguing, but apparently contradictory, conclusions 20 . On the one hand, a breaking of the conventional free volume rules for molecular mobility was reported from spectroscopy measurements of glycerol in a mesoporous silica glass 21 .…”

Section: Introductionmentioning

confidence: 99%

Self-diffusion of glycerol in γ-alumina nanopores. The neglected role of pore saturation in the dynamics of confined polyalcohols

Campos-Villalobos¹,

Siperstein²,

D’Agostino³

et al. 2020

Applied Surface Science

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Molecular Dynamics simulations of glycerol confined in γ-Al 2 O 3 slit nanopores are used to explain controversial and inconsistent observations reported in the literature regarding the dynamics of viscous fluids in confined geometries. Analysing the effects of the degree of confinement and pore saturation in this system, we found that the presence of the solid/liquid interface and the liquid/gas interface in partially saturated pores are the main contributors for the disruption of the hydrogen bond network of glycerol. Despite the reduction of hydrogen bonds between glycerol molecules caused by the presence of the solid, glycerol molecules near the solid surface can establish hydrogen bonds with the hydroxyl groups of γ-Al 2 O 3 that significantly slow-down the dynamics of the confined fluid compared to the bulk liquid. On the other hand, the disruption of the hydrogen bond network caused by the liquid/gas interface in unsaturated pores reduces significantly the number of hydrogen bonds between glycerol molecules and results in a faster dynamics than in the bulk liquid. Therefore, we suggest that the discrepancies reported in the literature are a consequence of measurements carried out under different pore saturation conditions. J o u r n a l N a me , [ y e a r ] , [ v o l . ] , 1-8 | 1 arXiv:1905.05159v1 [cond-mat.soft]

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“…It is well established that nano-sized confinements strongly influence the structural and dynamical properties of liquids, including hydrogen-bonded compounds [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ]. Prominent observations are the suppression of crystallization and changes in the glass transition temperatures

.…”

Section: Introductionmentioning

confidence: 99%

“…We employ the mesoporous silica MCM-41 and SBA-15, which feature defined cylindrical pores with adjustable diameters d , as hard confinements and we use the branched, hydrophilic polysaccharide ficoll and the small, globular protein lysozyme at sufficiently high concentrations as soft confinements. Ficoll, which proved to be useful to mimic macromolecular crowding in cells [ 27 , 59 , 60 ], is a spherical molecule with a size of ∼10 nm and a conformation intermediate between a solid sphere and a random coil [ 61 , 62 ]. Lysozyme is a single polypeptide of 129 amino acids, which has a molecular weight of 14.3 kDa and is folded in a compact, ellipsoidal structure with a long cleft.…”

Section: Introductionmentioning

confidence: 99%

Confinement Effects on Glass-Forming Aqueous Dimethyl Sulfoxide Solutions

et al. 2020

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Combining broadband dielectric spectroscopy and nuclear magnetic resonance studies, we analyze the reorientation dynamics and the translational diffusion associated with the glassy slowdown of the eutectic aqueous dimethyl sulfoxide solution in nano-sized confinements, explicitly, in silica pores with different diameters and in ficoll and lysozyme matrices at different concentrations. We observe that both rotational and diffusive dynamics are slower and more heterogeneous in the confinements than in the bulk but the degree of these effects depends on the properties of the confinement and differs for the components of the solution. For the hard and the soft matrices, the slowdown and the heterogeneity become more prominent when the size of the confinement is reduced. In addition, the dynamics are more retarded for dimethyl sulfoxide than for water, implying specific guest-host interactions. Moreover, we find that the temperature dependence of the reorientation dynamics and of the translational diffusion differs in severe confinements, indicating a breakdown of the Stokes–Einstein–Debye relation. It is discussed to what extent these confinement effects can be rationalized in the framework of core-shell models, which assume bulk-like and slowed-down motions in central and interfacial confinement regions, respectively.

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Properties of Hydrogen-Bonded Liquids at Interfaces

Cited by 19 publications

References 193 publications

Small Molecules, Non-Covalent Interactions, and Confinement

Small Molecules, Non-Covalent Interactions, and Confinement

Self-diffusion of glycerol in γ-alumina nanopores. The neglected role of pore saturation in the dynamics of confined polyalcohols

Confinement Effects on Glass-Forming Aqueous Dimethyl Sulfoxide Solutions

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