Scrutinizing the tip of molecular probes

March 03, 2016

Studies of molecules confined to nano- or micropores are of considerable interest to physicists. That's because they can manipulate or stabilise molecules in unstable states or obtain new materials with special properties. In a new study published in EPJ Plus, Stefan Frunza from the National Institute of Materials Physics in Romania and colleagues have discovered the properties of the surface layer in probe molecules on the surface of oxide particles. These properties depend on the interaction at the interface. In this particular study, probes are formed by adsorption of rod-like cyanophenyl derivates on the surface of oxide particles. The authors found that their surface layers behave like glass-forming liquids.

What physicists already knew is that confinement of molecules may induce disorder. Confinement and disorder have a considerable influence both on the structure of the trapped molecule but also on its mobility. As a result, they also affect aspects such as molecular dynamics upon relaxation of the material. Such structurally well-defined monolayers on solid surfaces will allow researchers to model a large variety of interfacial phenomena.

The authors used data from infrared spectroscopy and thermogravimetry to identify the strength of the interaction between the probe and the oxide surface, which also helped them determine the type of bonding to the surface. They established two key parameters: firstly, the density of the adsorbed surface species used to characterise the interaction of the probe molecule with the surface. This parameter depends on the nature of the oxide nanoparticles and on the existence of nanopores. The second parameter expresses the ratio of the molecules contained in the surface layer having a glassy dynamic behaviour to the total number of the adsorbed molecules.

The study shows that the value of the surface density can be used to divide the composites into several groups. This helps to determine that the probe molecules applied to the surface of a given group can display similar interactions, as observed in surfaces of the same family.

Stefan Frunza, Ligia Frunza, Constantin Paul Ganea, Irina Zgura, Ana Rita Brás and Andreas Schönhals (2016), Rod-like cyanophenyl probe molecules nanoconfined to oxide particles: Density of adsorbed surface species, European Physical Journal Plus 131: 27, DOI 10.1140/epjp/i2016-16027-5


Related Molecules Articles from Brightsurf:

Finally, a way to see molecules 'wobble'
Researchers at the University of Rochester and the Fresnel Institute in France have found a way to visualize those molecules in even greater detail, showing their position and orientation in 3D, and even how they wobble and oscillate.

Water molecules are gold for nanocatalysis
Nanocatalysts made of gold nanoparticles dispersed on metal oxides are very promising for the industrial, selective oxidation of compounds, including alcohols, into valuable chemicals.

Water molecules dance in three
An international team of scientists has been able to shed new light on the properties of water at the molecular level.

How molecules self-assemble into superstructures
Most technical functional units are built bit by bit according to a well-designed construction plan.

Breaking down stubborn molecules
Seawater is more than just saltwater. The ocean is a veritable soup of chemicals.

Shaping the rings of molecules
Canadian chemists discover a natural process to control the shape of 'macrocycles,' molecules of large rings of atoms, for use in pharmaceuticals and electronics.

The mysterious movement of water molecules
Water is all around us and essential for life. Nevertheless, research into its behaviour at the atomic level -- above all how it interacts with surfaces -- is thin on the ground.

Spectroscopy: A fine sense for molecules
Scientists at the Laboratory for Attosecond Physics have developed a unique laser technology for the analysis of the molecular composition of biological samples.

Looking at the good vibes of molecules
Label-free dynamic detection of biomolecules is a major challenge in live-cell microscopy.

Colliding molecules and antiparticles
A study by Marcos Barp and Felipe Arretche from Brazil published in EPJ D shows a model of the interaction between positrons and simple molecules that is in good agreement with experimental results.

Read More: Molecules News and Molecules Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to