1.

Record Nr.

UNINA9910298644503321

Autore

Lüttschwager Nils Olaf Bernd

Titolo

Raman Spectroscopy of Conformational Rearrangements at Low Temperatures [[electronic resource] ] : Folding and Stretching of Alkanes in Supersonic Jets / / by Nils Olaf Bernd Lüttschwager

Pubbl/distr/stampa

Cham : , : Springer International Publishing : , : Imprint : Springer, , 2014

ISBN

3-319-08566-2

Edizione

[1st ed. 2014.]

Descrizione fisica

1 online resource (193 p.)

Collana

Springer Theses, Recognizing Outstanding Ph.D. Research, , 2190-5053

Disciplina

543.08584

Soggetti

Physical chemistry

Atomic structure  

Molecular structure 

Spectroscopy

Polymers  

Physical Chemistry

Atomic/Molecular Structure and Spectra

Spectroscopy/Spectrometry

Polymer Sciences

Lingua di pubblicazione

Inglese

Formato

Materiale a stampa

Livello bibliografico

Monografia

Note generali

"Doctoral Thesis accepted by the Georg-August-University G©œttingen, Germany."

Nota di bibliografia

Includes bibliographical references.

Nota di contenuto

Introduction -- Background -- Experimental -- Unbranched n-alkanes -- Perfluorinated alkanes -- Modulus of elasticity -- Summary and outlook -- Appendix.

Sommario/riassunto

This thesis identifies the turning point in chain length, after which alkanes self-solvate into a folded structure instead of an extended stretched conformation. After this turning point, London dispersion forces rearrange isolated n-alkanes into a particular hairpin-structure, while for shorter chain lengths, a simple stretched conformation is energetically preferred. This thesis can locate the experimental turning point for the first time in an interaction-free manner from measurements of unbranched alkanes at low temperatures in



supersonic jet expansions. It contains a detailed analysis of the vibrational Raman spectra of the chain molecules, which is supported by comprehensive quantum chemical simulations. In this way, the detailed balance between inter-chain attraction and conformational flexibility can be quantified.The investigations are complemented by measurements of perfluoroalkanes, and similarities and differences between the compounds are discussed. Furthermore, Nils Lüttschwager determines the stiffnesses (elastic moduli) of two of the most common industrial polymers: polyethylene and polytetrafluorethylene. He uses in this thesis a sophisticated extrapolation to calculate this value from quantities of their building blocks, showing that the single polymer molecules can be as stiff as a rod of steel.