PROJECT: HIGH-EFFICIENCY MATERIALS AND PROCESS TECHNOLOGIES FOR INNOVATIVE MICRO-FUSIONS (MATEMI)
Study of chemical-physical properties of ceramic slurries and development of advanced control techniques/methodologies (IR)
OBJECTIVES AND EXPECTED RESULTS
- Study of the physico-chemical properties of colloidal aqueous solutions, evaluation of their contribution to the stability of ceramic slurries for the production of shells, definition of effective control methods;
- In-depth study of the chemical-physical properties of colloidal aqueous solutions of ceramic slurries for the realization of the shells using very recent theoretical and experimental studies connected to systems far from equilibrium and quantum electrodynamics (analysis of the supermolecular structures of water and its impact on the dynamics of the slurries);
- Identification of the most critical parameters for the stability of ceramic slurries and their properties over time;
- Development and use of more effective control techniques and methodologies for ceramic suspensions.
As part of the PROMETE activities, a possible chemical-physical foundation was identified for the instability of the productive characteristics of the ceramic shells, which would have been even inconceivable until a few years ago for lack of both theoretical and experimental knowledge in this regard.
Such nanometric aggregates, having a changed electronic structure with respect to the free molecule, as it is well known to happen for nanometric structures, have the characteristic (of very recent experimental acquisition), at first glance unexpected, of remaining in the solid state at ordinary temperatures and pressures, once the remaining liquid water component ("bulk water") has been removed by evaporation (or freeze-drying).
It is clear that currently the methods that aim to study the stability of the "slurry" in order to optimize its performances surely suffer from a series of unexpressed problems; in practice, there is a large shaded area of which "no one knows not to know". Normally, the consequences of this "shadow area" are somehow attributed to an intrinsic instability of the phenomenon due to the fact that too many parameters have to be taken into account.
The time-varying activity of ceramic slurries, and of the other investigated systems (LUDOX and DEMINERALIZED WATER, and liquid part extracted from the slurries), reinforces the thesis that the so-called "aging" process of the slurry is due to the formation of aqueous supramolecular aggregates - and not instead to chemical reactions of various types, as currently taken for granted. The possibility of using this know-how will pave the way to measure in production the quantity of aggregates that have "naturally" formed in the slurry, so as to be able to decide with greater precision - and perhaps with online measurements - when the slurry can really be considered "old" and then replace it.
We can also individuate the future objective of being able to better understand, and therefore be able to act, on the causes of formation of the aggregates and on the variables that go to influence the dynamics of the aggregates, so as to be able to "control" them, is also identifiable. In fact, the relationship between these dissipative structures and external energy is certain, since these are structures far from thermodynamic equilibrium.
It should be emphasized, however, that we must not conclude that the aggregates are "harmful" due to the desired properties of the slurry; instead, the opportunity to study which are the optimal concentrations for the desired characteristics of the slurry (and therefore of the shells) is presented, so as to be able to remain in this identified interval, with techniques that will be developed ad hoc, but for which they are already interesting clues.
Project co-financed by Ministero dell'istruzione, dell'università e della ricerca with the PON Ricerca e competitività 2007-2013: http://www.ponricerca.gov.it/
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Ph. nr.: +39 081 056850
ph. nr.: +39 081 056851
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