Porous
materials have been of high scientific and technological
interest owing to their unique performances in many topical applications
related to multiphasic functional systems: gas separation and storage, heterogeneous catalysis, energy
conversion, etc. We review herein the synthetic strategies applied
for using functionalized adamantane derivatives as polyhedral (mainly
tetrahedral, Td-directing) building units of three-dimensional
(3-D) porous supramolecular structures and nanomaterials, either purely
organic or within metal hybrid frameworks. The resulting materials
are currently used in varied heterogeneous (or supported) transition
metal catalysis and organocatalysis, including recent high-value asymmetric
synthesis. Characterization, synthetic applications and recycling
properties of catalytic materials based on adamantane-scaffold are
discussed. This review highlights the structuring advantages of variously
functionalized-adamantanes to reach high surface area and controlled
porosity for exploiting both confinement effects related to modified
kinetics (compared to homogeneous) reactions, and pertinent chemo-
and enantioselectivity issues.
The influence of sliding velocity on the adhesion force in a nanometer-sized contact was investigated with a novel atomic force microscope experimental setup that allows measuring adhesion forces while the probe is sliding at continuous and constant velocities. For hydrophobic surfaces, the adhesion forces (mainly van der Waals forces) remain constant, whereas for hydrophilic surfaces, adhesion forces (mainly capillary forces) decrease linearly with a logarithmic increase of the sliding velocity. The experimental data are well explained by a model based on a thermally activated growth process of a capillary meniscus.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.