Multi-techniques approach

Figure 5. Schematic description of a multi-technique approach to the assessment of molecular mobility inside swollen polymeric frameworks as a phenomenon dependent on their morphology at the nanometric scale [14, 21, 22, 108].

As is evident in the many examples selected in this chapter to illustrate the molecular characterisation and analysis of polymer degradation and oxidation processes, almost, without exception, each study or investigation cited has involved use of more than one analytical method or characterisation technique, often many more than two. This clearly emphasises the importance of using a multi-technique approach to provide supportive, complementary and confirmatory information, since each technique or method yields a different aspect of the degradation/oxidation process in polymers. 

In view of the complexity of heterogeneous systems, none of the above techniques will be able to supply, by itself, a complete atomic-level description of surface phenomena. A multi-technique approach has been perceived by many as most appropriate for fundamental studies in electrochemical surface science (30-2). Since none of the existing electrochemical laboratories are adequately equipped to perform a comprehensive experimental study, collaborative efforts between research groups of different expertise are burgeoning. Easier access to national or central facilities are also being contemplated for experiments which cannot be performed elsewhere. The judicious combination of the available methods in conjunction with the appropriate electrochemical measurements are permitting studies of electrocatalyst surface phenomena unparalleled in molecular detail. 

In this chapter we start with the methodology for the identification of the structure of a newly invented zeolite. To accomplish this task a multi-technique approach was necessary and is used as an example for the necessity of employing complementary techniques to solve a problem. If such a methodology had not been pursued, the structure would not have been correctly elucidated. 

Given the complex nature of the crystal structure and small crystal size with an anisotropic morphology of UZM-5, the normal X-ray diffraction patterns were not sufficient to deduce an unambiguous structure. Thus a multi-technique approach was required to successfully solve the structure, to explain the adsorption properties and by analogy to the structure of other zeolites in order to assess potential applications. 

IMPROVING OUR UNDERSTANDING OF GAS HYDRATE FORMATION PROCESSES THE IMPORTANCE OF MULTI-TECHNIQUE APPROACHES... 

To complete this chapter, we would like to mention that recent monographs have reviewed the use of in-situ spectroscopies for monitoring heterogeneously catalysed reaction under supercritical conditions, although very few studies in this field has been devoted to the study of the fluid-solid interface.182 The use of a multi-technique approach in order to maximise information under real, in-situ conditions has also been reviewed recently.183 The combined use of powerful spectroscopies with simultaneous on-line analysis of the catalytic activity of the sample will become more widespread in application allowing an interpretation of catalytic behaviour in terms of the physico-chemical properties of the solid. The next frontier in spectroscopic characterisation of metal catalysts will consist of time-dependent analysis of the gas/liquid-solid interface, particularly with a view to analyse short-lived intermediates during catalysed reactions and with the aim to determine the response of the catalyst surface and relate these responses to the physico-chemical properties of the solid. 

The chance that a different model also fits the experimental data can never be fully excluded. The multi-technique approach, however, reduces this chance considerably. 

Also, the result of any diffraction-based trial-and-error fitting is not necessarily unique it is always possible that there exists another untried structure that would give a better fit to experiment. Hence, a multi-technique approach that provides independent clues to the structure is very ffuitfiil and common in surface science such clues include chemical composition, vibrational analysis and position restrictions implied by other stmctural methods. This can greatly restrict the number of trial structures which must be investigated. 

Photographic behavior of the microcolumn imaging system parallels the microencapsulated system in many respects. Microcolumn provides a convenient sampling format for application of the multi-technique approaches in addressing the interdependence of the imaging characteristics, curing conditions, and the structure of the polymer formed. 

Vargas I, Pizarro G, Felis M, Corthom J, Acevedo S (2012) Multi-technique approach to understand the effects of bacterial communities involved in copper plumbing corrosion. Proceedings EUROCORR 2012. Istanbul, Turkey, pp 9-13... 

Productivity Comparison between ICP-MS and Other Multi-technique Approaches for the Determination of 12 Primary Contaminants in Drinking Water... 

We developed a multi-technique approach for a clear identification of the lamellar solid. XPS analysis showed the presence of B-N binding with a stochiometry close to pure h-BN. XANES analysis evidenced the sp hybridation of boron in these B-N bonds. On wear debris, these bonds are identified by EELS analysis. Finally, HRTEM depicted the crystal structure and the location of h-BN in the borate matrix. 

If pollutants abatement is performed using solid adsorbent or catalysts, the characterization of these substances is necessary. For that purpose, numerous methods have to be used those enabling information about structure the others that provide data concerning texture and those that reveal the existence of active sites for adsorption (conversion) of particular pollutants. Evidently, multi-technique approach has to be applied in order to perform full characterization of materials applied for pollutants abatement. Among the other techniques, calorimetry may be applied for the charac-... 

The volumetric-calorimetric data obtained by a Tian-Calvet heat-flow microcalorimeter connected to a gas-volumetric apparatus (as the one described in Chap. 1) being intrinsically molar quantities, their molecular interpretation often requires a multi-techniques approach. 

Estephane J, Groppo E, Vitillo JG, Damin A, Gianolio D, Lamberti C, Bordiga S, Quadrelli EA, Basset JM, Kervem G, Emsley L, Pintacuda G, Zecchina A (2010) A multi-technique approach to spin-flips for cp2Cr(ll) chemistry in confined state. J Phys Chem C 114 4451-4458... 

Mullei A. 2014. Porosity Characterisation across Different Cementitious Binders by a Multi-Technique Approach ( cole Polytechnique Federale de Lausanne, Switzerland, PhD thesis). 

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