Researchers Study Interaction of Probe Molecules Confined to Nanopores

Physicists are interested in studies relating to molecules confined to micro- or nanopores. This is due to the fact that molecules can be stabilized or manipulated in unstable states, or can acquire new materials with unique properties.

The characteristics of the surface layer in probe molecules on oxide particle surface were discovered by Stefan Frunza from the National Institute of Materials Physics, Romania and colleagues. These properties rely on the interaction at the interface.

In this specific research, rod-like cyanophenyl derivates were adsorbed on the surface of an oxide particle to form probes. The team discovered that the surface layers in the probes acted like glass-forming liquids.

Physicists are already aware that confining molecules is likely to stimulate disorder. Confinement and disorder have a significant impact on the structure of the trapped molecule as well as on its movement. They also impact other aspects such as molecular dynamics after the material is relaxed. Researchers will be able reproduce a number of diverse interfacial phenomena using these structurally distinct monolayers on solid surfaces.

The team used data obtained from thermogravimetry and spectroscopy to detect the interaction strength between the oxide surface and the probe. This also allowed them to establish the type of bonding to the surface. They came up with two major parameters: The density of the adsorbed surface species utilized to describe the probe molecule’s interaction with the surface. This parameter is based on the presence of nanopores and the type of the oxide nanoparticles. The other parameter focuses on the ratio of the molecules confined within the surface layer possessing a glassy dynamic characteristic to the overall number of the adsorbed molecules.

The research reveals that the value of the surface density can be applied to split the composites into many groups. This helps to establish that the probe molecules applied to the surface of a certain group can exhibit analogous interactions, as detected in surfaces of the same family.