Time-Resolved Simultaneous Detection of Structural and Chemical Changes during Self-Assembly of Mesostructured Films

Abstract

In situ and time-resolved simultaneous analysis by two different and complementary techniques, Fourier transform infrared spectroscopy (FTIR) and small-angle X-ray scattering (SAXS), has been developed. A conventional source for the infrared light and synchrotron radiation for the X-ray beam have been used. The new technique has been applied to the study of self-assembling mesostructured films during dip-coating. The combined FTIR and SAXS analytical approach has given the possibility of getting a direct correlation between the chemical processes and the structural changes occurring in the film during the deposition.

Time Resolved IR and X-Ray Simultaneous Spectroscopy: New Opportunities for the Analysis of Fast Chemical-Physical Phenomena in Materials Science

“…As showed in Ref. [1], IR simultaneous experiments make possible a semi-quantitative data analysis that can be later correlated to structural data provided by SAXS. Scrolling at the above list the formation of an ordered mesophase in films a process characterized by self--assembly of the supramolecular template induced by solvent evaporation is one of the most interesting process to be investigated and still poorly understood [19].…”

“…Recently, measurements have been performed at the Austrian SAXS beamline of the ELET-TRA electron storage ring at Trieste combining the SR X-ray radiation of Elettra with a conventional IR source. In these experiments the simultaneous technique was applied to the study of self-assembling mesostructured films during dip-coating processes [1]. A mother solution containing ethanol (EtOH), tetraethylorthosilicate (TEOS) water, HCl, and a templating solution were prepared to obtain a final precursor sol by a mixing of the two solutions.…”

“…However, the most diffused research technique and also widely used in the industry to characterize materials and processes is the Fourier transform infrared spectroscopy (FTIR), a well established method based on conventional sources. It is used to characterize all molecular systems and it is capable to follow fast chemical reaction kinetics and chemical changes occurring simultaneously [1]. It is then straightforward to image that the combination of the X-ray atomic and structural analysis with the IR molecular analysis will offer high rewards to materials science improving the understanding of complex materials and phenomena.…”

“…In the next sections we will present and discuss a few examples that may explain why the combination of infrared and X-ray simultaneous experiments may be usefully applied to understand dynamical processes and phase transitions. In particular, we will discuss applications in self-assembly phenomena [1] where the combination of two simultaneous spectroscopic analyses such as X-ray and IR spectroscopy may return complementary information on different aspects of the process, e.g., structural changes and chemical processes occurring during the ordering phenomena. Moreover, triggered by the booming of many research areas such as nanotechnologies and bio--engineering, in addition to a fast time-resolved analysis a demand of new advanced analytical techniques characterized by a high spatial resolution (micro-to nanoscale) and simultaneous analytical capabilities to characterize the complex structures and the different interplaying interactions is emerging.…”

Synchrotron radiation – a brilliant source for solid‐state research in the infrared energy domain

“…At the same time the complexity of the investigated phenomena demands for new experimental methods based on concurrent and possibly simultaneous time-resolved capabilities. The possibility offered by X-ray methods are well recognized in materials science, although, the most diffused research technique to characterize materials and processes, in particular in the industrial world, is the FTIR spectroscopy, a well established method used to characterize all molecular systems and suitable to follow fast chemical reaction kinetics and chemical changes [43]. Recently, to improve the understanding of complex materials and phenomena it has been proposed to combine the X-ray atomic and structural analysis with the IR molecular analysis in a new unique tool for materials science researches [44].…”