Impact of Aromatic Counter-Ions Charge Delocalization on the Micellization Behavior of Surface-Active Ionic Liquids

The nature of counter-ions governs the micellar and structural characteristics of surface-active ionic liquids (SAILs). Especially, the introduction of aromatic counter-ions significantly increases their surface adsorption and induces the formation of various types of aggregates like prolate ellipso...

Ausführliche Beschreibung

Bibliographische Detailangaben
Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1992. - 35(2019), 45 vom: 12. Nov., Seite 14586-14595
1. Verfasser: Singh, Onkar (VerfasserIn)
Weitere Verfasser: Singla, Pankaj, Aswal, Vinod Kumar, Mahajan, Rakesh Kumar
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2019
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article
LEADER 01000naa a22002652 4500
001 NLM302277315
003 DE-627
005 20231225110400.0
007 cr uuu---uuuuu
008 231225s2019 xx |||||o 00| ||eng c
024 7 |a 10.1021/acs.langmuir.9b02695  |2 doi 
028 5 2 |a pubmed24n1007.xml 
035 |a (DE-627)NLM302277315 
035 |a (NLM)31621330 
040 |a DE-627  |b ger  |c DE-627  |e rakwb 
041 |a eng 
100 1 |a Singh, Onkar  |e verfasserin  |4 aut 
245 1 0 |a Impact of Aromatic Counter-Ions Charge Delocalization on the Micellization Behavior of Surface-Active Ionic Liquids 
264 1 |c 2019 
336 |a Text  |b txt  |2 rdacontent 
337 |a ƒaComputermedien  |b c  |2 rdamedia 
338 |a ƒa Online-Ressource  |b cr  |2 rdacarrier 
500 |a Date Revised 04.03.2020 
500 |a published: Print-Electronic 
500 |a Citation Status PubMed-not-MEDLINE 
520 |a The nature of counter-ions governs the micellar and structural characteristics of surface-active ionic liquids (SAILs). Especially, the introduction of aromatic counter-ions significantly increases their surface adsorption and induces the formation of various types of aggregates like prolate ellipsoidal micelles, rodlike micelles, vesicles, lamellars, etc. The present study reports the role of charge delocalization of two different aromatic counter-ions in the micellization behavior of their respective SAILs in aqueous medium. For this purpose, we have synthesized two SAILs, namely, 1-tetradecyl-3-methylimidzolium phenolate [C14mim][PO] and 1-tetradecyl-3-methylimidzolium benzoate [C14mim][BZ]. The O-atom of phenolate (PO-) possesses negative charge, which is delocalized on its phenyl ring. Conversely, the negative charge of benzoate (BZ-) is not delocalized on its phenyl ring. The more hydrophobic BZ- counter-ion increases the hydrophobic interactions and reduces the electrostatic repulsions more efficiently as compared to PO-, which results in a lower critical micelle concentration (cmc) of [C14mim][BZ] than that of [C14mim][PO]. Interfacial properties obtained by tensiometry reveal better surface activity and absorption efficiency of [C14mim][BZ] as compared to [C14mim][PO]. The increase of cmc and degree of counter-ion binding (β) with the rise of temperature for both SAILs has been observed by conductometry. The decrease in the polarity of pyrene microenvironment explains the higher compactness of [C14mim][BZ] aggregates than that of [C14mim][PO], observed by fluorimetry. The position of PO- and BZ- is in the stern and palisade layers of C14mim+ aggregates, respectively, located by 1H NMR. The existence of prolate ellipsoidal micelles for both SAILs has been established by small-angle neutron scattering measurements. Thus, the interfacial and bulk properties of [C14mim][PO] lie somewhere in between those of the SAILs having perfect aromatic counter-ions, [C14mim][BZ], and the SAILs having regular inorganic counter-ions like Cl-, Br-, etc 
650 4 |a Journal Article 
700 1 |a Singla, Pankaj  |e verfasserin  |4 aut 
700 1 |a Aswal, Vinod Kumar  |e verfasserin  |4 aut 
700 1 |a Mahajan, Rakesh Kumar  |e verfasserin  |4 aut 
773 0 8 |i Enthalten in  |t Langmuir : the ACS journal of surfaces and colloids  |d 1992  |g 35(2019), 45 vom: 12. Nov., Seite 14586-14595  |w (DE-627)NLM098181009  |x 1520-5827  |7 nnns 
773 1 8 |g volume:35  |g year:2019  |g number:45  |g day:12  |g month:11  |g pages:14586-14595 
856 4 0 |u http://dx.doi.org/10.1021/acs.langmuir.9b02695  |3 Volltext 
912 |a GBV_USEFLAG_A 
912 |a SYSFLAG_A 
912 |a GBV_NLM 
912 |a GBV_ILN_22 
912 |a GBV_ILN_350 
912 |a GBV_ILN_721 
951 |a AR 
952 |d 35  |j 2019  |e 45  |b 12  |c 11  |h 14586-14595