Discovered a new state of soft matter
Lightweight and biocompatible materials to be used, for example, in biomedicine for the transport of drugs. It is one of the possible applications of a study published in Nature Materials and produced by the Institute for chemical and physical processes (IPFC-CNR) and the Institute of Complex Systems (ISC-CNR) of CNR in collaboration with the University of Rome Wisdom and the European Synchrotron Radiation Facility (ESRF) in Grenoble.
“Working on a solution of colloidal clay we observed the first experimental evidence of the existence of extremely stable gel (so-called gel balance), never previously reported, confirming the above theory in recent years by a team led by Francesco Sciortino,” says Barbara Ruzicka, co-author of the study.
“We had noticed – Sciortino says – that in models with directional interactions (models used in studying the interactions between water and proteins), could generate were arrested without the aid of a thermodynamic phase separation.”
Normally, the precise Ruzicka, “the two-phase separating colloidal suspensions and dense phase stops forming a stable gel, which is a substance that changes its characteristics over time. These gels do not allow to control their final state, a necessary condition for applications in industry and technology. ”
This new state of soft matter observed by the researchers of the CNR in synthetic clay used for the construction of nanocomposites and also as a thickener in paints, and cosmetics and household cleaning, the Laponite, presents characteristics suitable for technological applications .
“The clay dissolved in water forming a colloidal solution of nano-sized discs with a net negative charge on the positive sides and edges. This charge distribution results in a highly directional interaction potential. In fact, we observed a very slow phase separation, which generates a liquid phase that, contrary to the standard is very thin and that this has been defined liquid void. ”
These particles in this liquid “freezes in a gel state at low density, which is made up of little matter, then occupying only a small fraction of the space available,” says Emanuela Zaccarelli, co-author of the study. “Under appropriate conditions these ‘empty liquid’ is therefore of crucial materials for the construction of extremely light and ultra-stable over time, to be used, for example, as nano compounds in biomedicine.”
