Physico-chemical properties of gemini micelles studied by X-ray scattering and ESR spectroscopy

Autor:	Annarosa Arcangeli, Sara Falsini, Laura Ciani, Francesco Spinozzi, Sandra Ristori, E. Di Cola
Rok vydání:	2015
Předmět:	Ammonium bromide Scattering Small-angle X-ray scattering Chemistry X-ray Analytical chemistry Micelle law.invention chemistry.chemical_compound Colloid and Surface Chemistry law Spectroscopy Electron paramagnetic resonance Order of magnitude
Zdroj:	Colloids and Surfaces A: Physicochemical and Engineering Aspects. 472:101-108
ISSN:	0927-7757
DOI:	10.1016/j.colsurfa.2015.02.034
Popis:	Gemini surfactants have enhanced interfacial properties with respect to their single chain counter parts. Thus, their behavior in water is of great relevance for industrial applications and for nanodevice production. In this work we studied the shape evolution of α,ω-bis(N-dodecyl-N,N-dimethyl ammonium bromide) (i.e. 12- s -12) micelles as a function of spacer length ( s = 3, 6, 12) and concentration. Small angle X-rays scattering (SAXS) and electron spin resonance (ESR) spectroscopy were the methods used to obtain complementary information. SAXS curves were analyzed with the GENFIT software over two orders of magnitude in concentration. The fitting evidenced a shape evolution from globular objects, to worm like aggregates and finally to lamellae. The fluidity and polarity of molecular environment were investigated by appropriately tailored spin probes. The ESR spectral parameters changed in correspondence to the shape transition highlighted by SAXS. In addition, data on local polarity and motional freedom suggested that the longer spacers tend to fold toward the internal region of micelles.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::377971b927b4affc65c0a258d69cefc5 https://doi.org/10.1016/j.colsurfa.2015.02.034 Zobrazit plný text záznamu Full Text from ScienceDirect