scholarly journals Halogen‐Dependent Surface Confinement Governs Selective Alkane Functionalization to Olefins

2019 ◽  
Vol 58 (18) ◽  
pp. 5877-5881 ◽  
Author(s):  
Guido Zichittella ◽  
Matthias Scharfe ◽  
Begoña Puértolas ◽  
Vladimir Paunović ◽  
Patrick Hemberger ◽  
...  
Keyword(s):  
Alkane Functionalization ◽  
Surface Confinement

scholarly journals Cover Picture: Halogen‐Dependent Surface Confinement Governs Selective Alkane Functionalization to Olefins (Angew. Chem. Int. Ed. 18/2019)

2019 ◽  
Vol 58 (18) ◽  
pp. 5773-5773
Author(s):  
Guido Zichittella ◽  
Matthias Scharfe ◽  
Begoña Puértolas ◽  
Vladimir Paunović ◽  
Patrick Hemberger ◽  
...  
Keyword(s):  
Alkane Functionalization ◽  
Surface Confinement

Surface confinement induces the formation of solid-like insulating ionic liquid nanostructures

2017 ◽  
Author(s):  
Massimiliano Galluzzi ◽  
Simone Bovio ◽  
Paolo Milani ◽  
Alessandro Podestà
Keyword(s):  
Ionic Liquid ◽  
Electrical Properties ◽  
Electric Fields ◽  
Relative Dielectric Constant ◽  
Ionic Mobility ◽  
Electric Properties ◽  
Bulk Liquid ◽  
Structural Reorganization ◽  
Surface Confinement ◽  
Insulator Layers

We report on the modification of the electric properties of the imidazolium-based [BMIM][NTf2] ionic liquid upon surface confinement in the sub-monolayer regime. Solid-like insulating nanostructures of [BMIM][NTf2] spontaneously form on a variety of insulating substrates, at odd with the liquid and conductive nature of the same substances in the bulk phase. A systematic spatially resolved investigation by atomic force microscopy of the morphological, mechanical and electrical properties of [BMIM][NTf2] nanostructures showed that this liquid substance rearranges into lamellar nanostructures with a high degree of vertical order and enhanced resistance to mechanical compressive stresses and very intense electric fields, denoting a solid-like character. The morphological and structural reorganization has a profound impact on the electric properties of supported [BMIM][NTf2] islands, which behave like insulator layers with a relative dielectric constant between 3 and 5, comparable to those of conventional ionic solids, and significantly smaller than those measured in the bulk ionic liquid. These results suggest that in the solid-like ordered domains confined either at surfaces or inside the pores of the nanoporous electrodes of photo-electrochemical devices, the ionic mobility and the overall electrical properties can be significantly perturbed with respect to the bulk liquid phase, which would likely influence the<br>performance of the devices.<br>

Behaviors of Repaired Edge Column Slab Connections after Punching Failure Using Normal and Non-Shrinkable (CAH) Concrete

2016 ◽  
Vol 845 ◽  
pp. 166-174
Author(s):  
I. Ketut Sudarsana
Keyword(s):  
Flat Plate ◽  
Punching Shear ◽  
Normal Concrete ◽  
Plate Structures ◽  
Shear Damage ◽  
Concrete Mix ◽  
Surface Confinement ◽  
Strength And Stiffness ◽  
Original Strength ◽  
Punching Failure

Column slab connections in flat plate structures are critical part of the structure. Punching shear damage to the connections may occur during construction or post moderate earthquakes. To avoid demolishing overall structures with such damage, connections may be repaired to restore the original strength of the structures. This paper presents behavior of repaired edge column slab connections using normal concrete and non-shrinkable (CAH) concrete. Four edge connections of flat plate structure after failure were repaired using normal and non-shrinkable (CAH) concrete respectively for two connections. The connections were re-tested to fail under combined shear and moment. The results show that bonding agent Sika Top Armatec 110 Epocem gave an excellent bond between the old concrete and the repaired concrete in the tests of repaired edge column slab connection as there are no cracks observed along the concrete interface. The edge connections repaired using normal concrete can have similar strength and stiffness as the original connections when good curing is provided The edge connections repaired using an expansive CAH concrete exhibited less strength and stiffness compared to the original edge connections due to lack of surface confinement. The Superplasticizer used in CAH concrete (Mix. B) improves concrete expansion but reduce the strength of the repaired connections

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