Institutionen för fysikalisk kemi vid Åbo Akademi

Postal address:
Department of physical chemistry
Åbo Akademi University
Porthansgatan 3
FIN-20500 Åbo
Finland

Phone:
+358 2 215 4253 (Secretary, Ms. Christina Luojola)
Facsimile:
+358 2 233 0228

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THERMODYNAMIC MODELING OF MATERIALS

Modern processing of materials can be visualized as a string where molecular assemblies are synthesized from dissolved liquid species. These aggregates condense to so-called1–10 nm nano-particles, which hold particular electro-magnetic, optical, chemical and biofunctionalities, which exceed those of the corresponding larger particles by orders of magnitude. By joining different material groups to hybrid or composite materials the functionalities can be maintained, combined or enforced in nano-particle assemblies of particulate meso-structures in the 10–1000 nm size range. This specialized processing is heuristically denoted nano-technology.

Surface-active solutions

The first step when synthesizing molecular precursors and further the growth of the primary nuclei to larger particles is to control the properties of the solution from which the first (nano) particles are nucleated. The primary tools beside of the raw materials are the use of surfactants and polymers as solution additives, which are themselves able to self-assemble to supermolecular structures.

Particle suspensions (sols)

The stability of particle suspensions (sols) may be controlled by the solution (surfactant) chemistry (colloidal interaction forces) or by steric (polymer) stabilisation. However, if the suspension (sol) is unstable, an aggregation is induced to mesoaggregates. If the aggregate size is extensive or continuous the synthesis is denoted a sol-gel process.

Liquid wetting

Upon shaping the final material wet processes (coating, slip casting, etc.) of the particle suspensions are frequently used due to their costefficiency and the availability of low (environmentally friendly) processing temperatures. The wetting properties of the surfaces and particulate matrices are then of key importance.

Surface functionalisation

In order to control the suspension interactions or after consolidation of the precipitate the product material surfaces can be chemically modified to be suitable for composite integration into hybrid materials.

Thermodynamic modelling of material processing

Thermodynamics provides the ideal framework for modelling all these process steps. Initially, solution thermodynamics is a self-evident starting point. Upon formation of the particles the wetting properties are related to the dispersability of the particles into suspensions. Here the thermodynamic theory for colloidal systems and irreversible thermodynamics (flux models) provides the framework for the characterisation of the suspension properties (e.g. the sol-gel transition).


		Åbo Akademi University
	Contact us Personnel Newcomers Good to know Research Education Instruments News & events Intranet Publications History Home page Contact us: Postal address: Department of physical chemistry Åbo Akademi University Porthansgatan 3 FIN-20500 Åbo Finland Phone: +358 2 215 4253 (Secretary, Ms. Christina Luojola) Facsimile: +358 2 233 0228 E-mail: fysikalisk.kemi@abo.fi Disclaimer Search in this site:	THERMODYNAMIC MODELING OF MATERIALS Modern processing of materials can be visualized as a string where molecular assemblies are synthesized from dissolved liquid species. These aggregates condense to so-called1–10 nm nano-particles, which hold particular electro-magnetic, optical, chemical and biofunctionalities, which exceed those of the corresponding larger particles by orders of magnitude. By joining different material groups to hybrid or composite materials the functionalities can be maintained, combined or enforced in nano-particle assemblies of particulate meso-structures in the 10–1000 nm size range. This specialized processing is heuristically denoted nano-technology. Surface-active solutions The first step when synthesizing molecular precursors and further the growth of the primary nuclei to larger particles is to control the properties of the solution from which the first (nano) particles are nucleated. The primary tools beside of the raw materials are the use of surfactants and polymers as solution additives, which are themselves able to self-assemble to supermolecular structures. Particle suspensions (sols) The stability of particle suspensions (sols) may be controlled by the solution (surfactant) chemistry (colloidal interaction forces) or by steric (polymer) stabilisation. However, if the suspension (sol) is unstable, an aggregation is induced to mesoaggregates. If the aggregate size is extensive or continuous the synthesis is denoted a sol-gel process. Liquid wetting Upon shaping the final material wet processes (coating, slip casting, etc.) of the particle suspensions are frequently used due to their costefficiency and the availability of low (environmentally friendly) processing temperatures. The wetting properties of the surfaces and particulate matrices are then of key importance. Surface functionalisation In order to control the suspension interactions or after consolidation of the precipitate the product material surfaces can be chemically modified to be suitable for composite integration into hybrid materials. Thermodynamic modelling of material processing Thermodynamics provides the ideal framework for modelling all these process steps. Initially, solution thermodynamics is a self-evident starting point. Upon formation of the particles the wetting properties are related to the dispersability of the particles into suspensions. Here the thermodynamic theory for colloidal systems and irreversible thermodynamics (flux models) provides the framework for the characterisation of the suspension properties (e.g. the sol-gel transition).
		Last updated August 7, 2009 by Matti Hotokka.