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Sagisaka M, Fujita Y, Nakanishi Y, Takahashi H, Tsuyoshi N, James C, Yoshizawa A, Mohamed A, Guittard F, Eastoe J. Periodic Formation/Breakdown of Lamellar Aggregates with Anionic Cyanobiphenyl Surfactants. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:13040-13047. [PMID: 26542352 DOI: 10.1021/acs.langmuir.5b03564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
This study reports unusual behavior of aqueous-phase lamellar aggregates with a new class of hybrid surfactant, CB-B2ES, having mesogenic units {6-[4-(4-cyanophenyl)phenyloxy]hexyl} and temperature-sensitive oxyethylated (butoxyethoxyethyl) tails. These tails are poorly miscible and likely to microsegregate if the surfactant molecules assemble. Lamellar aggregates appear at CB-B2ES concentrations higher than 5 wt % and were found to undergo repeat formation/breakdown periodically at 30 °C, with an average domain lifetime of ∼10 s. To investigate effects of the temperature-sensitive oxyethylene units on the hydrophilic/lipophilic balance (HLB) of the CB-B2ES bilayers, a fluorescence probe 1-pyrene-carboxaldehide was solubilized in the mixtures to sense the micro-environmental polarities. Fluorimetric measurements suggested that the polarity of CB-B2ES bilayers is very similar to that of the non-ethoxylated CB-B2ES analogue at high temperatures (≥65 °C). However, for CB-B2ES, polarity increased with a decreasing temperature, in contrast with the small decrease in polarity observed for analogous non-ethoxylated bilayers. This is consistent with increased hydration of the oxyethylene units in CB-B2ES bilayers at low temperatures. The periodic formation/breakdown and cooling-induced hydrophilicity of the CB-B2ES lamellar aggregates did not appear in the non-hybrid and/or non-ethoxylated surfactant systems. Therefore, the combination of two unsymmetrical tails, one containing oxyethylene units and the other containing cyanobiphenyl terminal tips, must play an important role promoting this unusual behavior.
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Affiliation(s)
- Masanobu Sagisaka
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Yayoi Fujita
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Yusuke Nakanishi
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Hisayuki Takahashi
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Narumi Tsuyoshi
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Craig James
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | - Atsushi Yoshizawa
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University , 3 Bunkyo-cho, Hirosaki, Aomori 036-8561, Japan
| | | | - Frédéric Guittard
- Equipe Surfaces et Interfaces, Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis , Parc Valrose, 06100 Nice, France
| | - Julian Eastoe
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, United Kingdom
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Unique liquid crystal behavior in water of anionic fluorocarbon–hydrocarbon hybrid surfactants containing oxyethylene units. J Colloid Interface Sci 2011; 357:400-6. [DOI: 10.1016/j.jcis.2011.02.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 02/06/2011] [Accepted: 02/08/2011] [Indexed: 11/19/2022]
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