Multidisciplinary studies of structural and dynamic properties of glass forming compounds

Project leaders

Lucia Calucci, Miroslaw Galazka

Agreement

POLONIA - PAS (NUOVO ACCORDO) - Polish Academy of Sciences/Polska Akademia Nauk

Call

CNR-PAN 2017-2019

Department

Chemical sciences and materials technology

Thematic area

Chemical sciences and materials technology

Status of the project

New

Research proposal

This project aims at studying polymorphism, structural, and dynamic properties of selected organic materials showing a tendency to vitrify in peculiar conditions of temperature. In particular, the project will focus on soft materials showing liquid crystalline phases and/or orientationally (ODIC) or conformationally (CONDIS) disordered crystalline phases. Indeed, to gain knowledge about the vitrification of mesophases is important from the scientific point of view, as there are still some not-well described and comprehended universal features of glass formation from isotropic liquids. At the same time, understanding the relationship between molecular structure and polymorphism and the influence of temperature on the tendency of molecules to form a glassy phase is necessary in order to both gain fundamental knowledge and improve industrial processes, such as food preservation and drug formulation.
In this context, in the present project we will investigate the mechanism of vitrification/crystallisation phenomena in relation to molecular arrangement in different phases (isotropic liquid, ODIC, CONDIS and liquid crystalline phases) formed by selected organic compounds. On the basis of the results of a previous project realised by the same research groups (CNR-PAN 2014-2016 bilateral project "Studies of phase polymorphism and dynamics in selected soft materials"), we plan to study polymorphism, structural and dynamic properties of the following selected classes of organic materials in different temperature conditions:
- drugs for epilepsy (e.g. phenytoin and phenobarbital);
- branched alcohols (e.g. 2-methyl-2-pentanol and 3-methyl-3-pentanol);
- alcohols with one phenyl ring (e.g. n-(trifluoromethyl)phenethyl, with n = 2, 3, 4);
- fluorinated liquid crystals (e.g. 4-n-heptyl-2',3'-difluoro-4'-undecyloxybiphenyl, 4-n-heptyl-2',3'-difluoro-4'-nonyloxybiphenyl, 4-cyano-3-fluorophenyl-4-n-octylobenzoate, 4-cyano-3-fluorophenyl-4-butylbenzoate).
Information concerning polymorphism (temperature of phase transitions, influence of temperature scanning rate, entropy changes at phase transitions) will be obtained using Differential Scanning Calorimetry (DSC) and, when applicable, Polarising Optical Microscopy (POM); organization and degree of order of molecules within the different phases will be studied by X-ray diffraction (XRD), infrared (FT-IR) absorption spectroscopy, and multinuclear nuclear magnetic resonance (NMR) spectroscopy; internal and overall molecular motions will be investigated over a wide frequency range by broadband dielectric spectroscopy (BDS) and NMR spectroscopy and relaxometry. In particular DSC, POM, XRD, FT-IR, BDS and 2H NMR experiments will be carried out at IFJ-PAN, while 1H, 13C, and 19F NMR spectroscopy and 1H NMR relaxometry experiments will be performed at ICCOM-CNR. 2H NMR experiments will be applied to selectively deuterated isotopomers of some compounds to investigate the dynamic properties of specific moieties. Experimental studies will be complemented by ab initio quantum chemistry calculations and molecular modelling, which will be carried out exploiting computational resources of both the CYFRONET computer centre (Kraków) and the facilities of ICCOM-CNR. Moreover, proposals on neutron scattering measurements will be sent to European large-scale centres as JCNS and FRM II (Jüllich, Germany), ILL (Grenoble, France), or JINR (Dubna, Russia).
Theoretical analyses of dielectric relaxation processes (based on the Debye model and/or phenomenological Debye-like models, such as Cole-Cole, Cole-Davidson, Havriliak-Negami, and Dissado-Hill cluster models) will provide important information concerning the character of the relaxation processes. On the other hand, lineshape analysis of 2H NMR spectra and analysis of proton spin-lattice relaxation times in terms of suitable models will allow conformational dynamics, overall rotational and translational motions, and/or collective motions occurring in the different phases to be qualitatively and quantitatively characterized. Decisive factors for the universality of relaxation processes occurring at phase transitions may be revealed by comparing results of both macroscopic (dielectric, optic, calorimetric) and microscopic (long-range and local interactions, vibrations of atom bonds, orientational order, internal and overall molecular dynamics, etc.) physical properties of materials that differ significantly in molecular structure, from the elongated shape of calamitic liquid crystals to the almost globular shape of branched alcohols. For instance, such comparison was done for a cholesteric liquid crystal within the previous bilateral project [1].
The project offers outstanding opportunities for improving the existing scientific collaboration between the research groups at IFJ-PAN and ICCOM-CNR. It is worth mentioning that the two groups involved in the project largely share the same field of expertise (characterization of polymorphism, structural and dynamic microscopic properties of soft materials), while the experimental methods employed by the two groups are complementary. Moreover, expertise in the modelling of soft materials by computational chemistry methods is present in the ICCOM team.
The project will give the opportunity to young scientists involved to work in an international multidisciplinary research group. In particular, project findings will be included in the habilitation dissertations of two Polish researchers (dr. Natalia Osiecka and dr. Ewa Juszynska-Galazka).
The tightening of this Italian-Polish collaboration will constitute the basis for future applications to calls announced by European Union bodies or grants for international collaborations announced by the Polish National Science Centre.

[1] E. Carignani, L. Calucci, E. Juszynska-Galazka, M. Galazka, M. Massalska-Arodz, C. Forte, M. Geppi, J. Phys. Chem. B 120, 5083 (2016).

Research goals

The project has the following objectives:
1) To investigate polymorphism, structural, and dynamic properties of glass forming soft materials belonging to four different classes (i.e. drugs for epilepsy; branched alcohols; alcohols with one phenyl ring; fluorinated liquid crystals) in different temperature conditions by means of a plethora of experimental complementary techniques including DSC, POM, XRD, FT-IR, BDS and NMR spectroscopy and relaxometry and molecular modelling;
2) To investigate the mechanism of vitrification/crystallization processes in relation to molecular structure, molecular interactions and polymorphism;
3) To exploit the acquired data on both macroscopic and microscopic physical properties in order to highlight decisive factors for the universality of relaxation processes occurring at phase transitions of materials that differ significantly in molecular structure;
4) To strengthen the collaboration between IFJ-PAN and ICCOM-CNR and add value to the work of each group through the multidisciplinary approach to complex problems of common interest;
5) To present results of interest for the scientific community at national and international meetings and to publish them in peer reviewed high impact journals.
6) To train young researchers giving them the opportunity to work in an international research group with expertise in complementary fields of science.

Last update: 10/06/2025