Physicochemical characterization of green sodium oleate-based formulations. Part 3. Molecular and collective dynamics in rodlike and wormlike micelles by proton nuclear magnetic resonance relaxation.

Autor: Calucci L; Istituto di Chimica dei Composti OrganoMetallici (ICCOM), Consiglio Nazionale delle Ricerche - CNR, via G. Moruzzi 1, 56124 Pisa, Italy; Centro per l'Integrazione della Strumentazione Scientifica dell'Università di Pisa - CISUP, Lungarno Pacinotti 43/44, 56126 Pisa, Italy. Electronic address: lucia.calucci@pi.iccom.cnr.it., Borsacchi S; Istituto di Chimica dei Composti OrganoMetallici (ICCOM), Consiglio Nazionale delle Ricerche - CNR, via G. Moruzzi 1, 56124 Pisa, Italy; Centro per l'Integrazione della Strumentazione Scientifica dell'Università di Pisa - CISUP, Lungarno Pacinotti 43/44, 56126 Pisa, Italy. Electronic address: silvia.borsacchi@pi.iccom.cnr.it., Balzano F; Dipartimento di Chimica e Chimica Industriale, Università di Pisa, via G. Moruzzi 13, 56124 Pisa, Italy. Electronic address: federica.balzano@unipi.it., Volpi R; Dipartimento di Chimica e Chimica Industriale, Università di Pisa, via G. Moruzzi 13, 56124 Pisa, Italy. Electronic address: r.volpi94@gmail.com., Tatini D; Dipartimento di Chimica 'Ugo Schiff', Università di Firenze, 50019 Sesto Fiorentino, Italy; Consorzio per lo Sviluppo dei Sistemi a Grande Interfase - CSGI, Università di Firenze, 50019 Sesto Fiorentino, Italy. Electronic address: duccio.tatini@unifi.it., Uccello Barretta G; Dipartimento di Chimica e Chimica Industriale, Università di Pisa, via G. Moruzzi 13, 56124 Pisa, Italy. Electronic address: gloria.uccello.barretta@unipi.it., Lo Nostro P; Dipartimento di Chimica 'Ugo Schiff', Università di Firenze, 50019 Sesto Fiorentino, Italy; Consorzio per lo Sviluppo dei Sistemi a Grande Interfase - CSGI, Università di Firenze, 50019 Sesto Fiorentino, Italy. Electronic address: pierandrea.lonostro@unifi.it., Geppi M; Istituto di Chimica dei Composti OrganoMetallici (ICCOM), Consiglio Nazionale delle Ricerche - CNR, via G. Moruzzi 1, 56124 Pisa, Italy; Centro per l'Integrazione della Strumentazione Scientifica dell'Università di Pisa - CISUP, Lungarno Pacinotti 43/44, 56126 Pisa, Italy; Dipartimento di Chimica e Chimica Industriale, Università di Pisa, via G. Moruzzi 13, 56124 Pisa, Italy. Electronic address: marco.geppi@unipi.it.
Jazyk: angličtina
Zdroj: Journal of colloid and interface science [J Colloid Interface Sci] 2023 Apr 15; Vol. 636, pp. 279-290. Date of Electronic Publication: 2023 Jan 04.
DOI: 10.1016/j.jcis.2023.01.012
Abstrakt: Hypothesis: Sodium oleate (NaOL) self-aggregates in water forming rodlike micelles with different length depending on NaOL concentration; when KCl is added wormlike micelles form, which entangle giving rise to a viscoelastic dispersion. It is expected that aggregates with different size and shape exhibit different internal and overall molecular motions and collective dynamics.
Experiments: Two low viscosity NaOL/water and two viscoelastic NaOL/KCl/water formulations with different NaOL concentration (0.23 and 0.43 M) were investigated by 1 H fast field cycling NMR relaxometry over broad temperature and Larmor frequency ranges, after a first screening by 1 H and 13 C NMR spectroscopy at high frequency.
Findings: The analysis of the collected data indicated that fast conformational isomerization and rotation of NaOL about its long molecular axis and lateral diffusion of NaOL around the axis of the cylindrical aggregates are slightly affected by the aggregate shape and length. On the other hand, fluctuations of the local order director are quite different in the fluid and viscoelastic systems, reflecting the shape and size of the aggregates. Quantitative information was obtained on activation energy for fast internal and overall motions, correlation times and activation energy for lateral diffusion, and coherence length for collective order fluctuations.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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