Steric and Counterion Effects on Cationic Surfactant Self-Assembly into Micelles and Liquid Crystals

2003 ◽  
Vol 56 (10) ◽  
pp. 1065 ◽  
Author(s):  
Marta A. Cassidy ◽  
Gregory G. Warr
Keyword(s):  
Liquid Crystals ◽  
Cationic Surfactant ◽  
Group Size ◽  
Self Assembly ◽  
Cationic Surfactants ◽  
Head Group ◽  
Ion Flotation ◽  
Head Groups ◽  
Aggregate Morphology ◽  
Spherical Micelles

The roles of head-group size and counterion association on aggregate morphology in solution and lyotropic phases of cationic surfactants (tetradecyl trimethyl-, tetradecyl triethyl-, and tetradecyl tripropylammonium) are examined, using salicylate as a strongly binding counterion. Larger head groups are found to inhibit the formation of low-curvature structures such as bilayers, and salicylate binding excludes spherical micelles, so that both effects tend to favour locally cylindrical aggregates. Interfacial probes and ion flotation show that the binding of salicylate is reduced by increasing head-group size. In addition, a novel demixing is observed with features similar to lower consolute behaviour of other cationic surfactant systems.

Contrasting effect of 1-butanol and 1, 4-butanediol on the triggered micellar self-assemblies of C16-type cationic surfactants

2021 ◽  
Author(s):  
Vinod Kumar ◽  
Rajni Verma ◽  
Dwarkesh Satodia ◽  
Debes Ray ◽  
Ketan Kuperkar ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Cationic Surfactant ◽  
Self Assembly ◽  
Cationic Surfactants ◽  
Alkyl Chain ◽  
Cetylpyridinium Bromide ◽  
Quaternary Salts ◽  
Head Groups ◽  
Contrasting Effect ◽  
Cetyltrimethylammonium Tosylate

Self-assembly in aqueous solutions of three quaternary salts based C16-type cationic surfactant with different polar head groups and identical carbon alkyl chain viz., cetylpyridinium bromide (CPB), cetyltrimethylammonium tosylate (CTAT), and...

Effect of Nonionic Head Group Size on the Formation of Worm-Like Micelles in Mixed Nonionic/Cationic Surfactant Aqueous Systems

2004 ◽  
Vol 37 (5) ◽  
pp. 622-629 ◽  
Author(s):  
Carlos Rodriguez ◽  
Durga P. Acharya ◽  
Alicia Maestro ◽  
Koheita Hattori ◽  
Kenji Aramaki ◽  
...  
Keyword(s):  
Cationic Surfactant ◽  
Group Size ◽  
Head Group ◽  
Aqueous Systems

Antimicrobial Study of Symmetrical Gemini Cationic Surfactant Based on N-Hexadecyldimethylamine

2013 ◽  
Vol 575-576 ◽  
pp. 245-248 ◽  
Author(s):  
Zong Cheng Miao ◽  
Yi Wei Wang ◽  
Xing Zhang ◽  
Lei Zhang ◽  
Zhi Xue Wang ◽  
...  
Keyword(s):  
Cationic Surfactant ◽  
Cationic Surfactants ◽  
Chemical Structure ◽  
Gemini Surfactants ◽  
Head Group ◽  
Single Chain ◽  
H Nmr ◽  
Ft Ir ◽  
Gemini Cationic Surfactant ◽  
Ammonium Compounds

Gemini surfactants generally exhibit superior properties to those of their single-chain analogues with a similar chain length and head group, especially for gemini cationic surfactants. Gemini cationic surfactants have recently attracted considerable attention due to the increasing microbial resistance to common quaternary ammonium compounds. A novel symmetrical gemini cationic surfactant based onn-hexadecyldimethylamine was synthesized through epichlorohydrin andn-hexadecyldimethylamine as rude materials. The chemical structure of the product was confirmed using1H-NMR and FT-IR. The minimum inhibitory concentration of the surfactant toescherichia colirises to 100 ppm, and a higher concentration surely contributes to increase its effect, butstaphylococcus aureusis immune to this surfactant.

scholarly journals Cationic Surfactants: Self-Assembly, Structure-Activity Correlation and Their Biological Applications

2019 ◽  
Vol 20 (22) ◽  
pp. 5534 ◽  
Author(s):  
Zakharova ◽  
Pashirova ◽  
Doktorovova ◽  
Fernandes ◽  
Sanchez-Lopez ◽  
...  
Keyword(s):  
Self Assembly ◽  
Cationic Surfactants ◽  
Structural Diversity ◽  
Modern Trend ◽  
Biological Applications ◽  
Mixed Composition ◽  
Cleavable Surfactants ◽  
Amphiphilic Compounds ◽  
Head Groups ◽  
Main Emphasis

The development of biotechnological protocols based on cationic surfactants is a modern trend focusing on the fabrication of antimicrobial and bioimaging agents, supramolecular catalysts, stabilizers of nanoparticles, and especially drug and gene nanocarriers. The main emphasis given to the design of novel ecologically friendly and biocompatible cationic surfactants makes it possible to avoid the drawbacks of nanoformulations preventing their entry to clinical trials. To solve the problem of toxicity various ways are proposed, including the use of mixed composition with nontoxic nonionic surfactants and/or hydrotropic agents, design of amphiphilic compounds bearing natural or cleavable fragments. Essential advantages of cationic surfactants are the structural diversity of their head groups allowing of chemical modification and introduction of desirable moiety to answer the green chemistry criteria. The latter can be exemplified by the design of novel families of ecological friendly cleavable surfactants, with improved biodegradability, amphiphiles with natural fragments, and geminis with low aggregation threshold. Importantly, the development of amphiphilic nanocarriers for drug delivery allows understanding the correlation between the chemical structure of surfactants, their aggregation behavior, and their functional activity. This review focuses on several aspects related to the synthesis of innovative cationic surfactants and their broad biological applications including antimicrobial activity, solubilization of hydrophobic drugs, complexation with DNA, and catalytic effect toward important biochemical reaction.

scholarly journals The rheological characteristics for the mixtures of cationic surfactant and anionic–nonionic surfactants: the role of ethylene oxide moieties

RSC Advances ◽  
2017 ◽  
Vol 7 (22) ◽  
pp. 13032-13040 ◽  
Author(s):  
Liming Zhang ◽  
Wanli Kang ◽  
Derong Xu ◽  
Haishun Feng ◽  
Pengyi Zhang ◽  
...  
Keyword(s):  
Ethylene Oxide ◽  
Cationic Surfactant ◽  
Self Assembly ◽  
Cationic Surfactants ◽  
Nonionic Surfactants ◽  
Rheological Characteristics

Ethylene oxide moieties in various numbers regulate the rheological characteristics of anionic–nonionic/cationic surfactants solutions by affecting the molecular self-assembly.

scholarly journals Exchange Speed of Four-Component Nanorotors Correlates with Hammett Substituent Constants

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 116-125
Author(s):  
Yi-Fan Li ◽  
Amit Ghosh ◽  
Pronay Kumar Biswas ◽  
Suchismita Saha ◽  
Michael Schmittel
Keyword(s):  
Linear Correlation ◽  
Bond Cleavage ◽  
Head Group ◽  
Ligand Interaction ◽  
Exchange Frequency ◽  
Rate Determining Step ◽  
Head Groups ◽  
Substituent Constants ◽  
First Time ◽  
Determining Factor

Three distinct four-component supramolecular nanorotors were prepared, using, for the first time, bipyridine instead of phenanthroline stations in the stator. Following our established self-sorting protocol to multicomponent nanodevices, the nanorotors were self-assembled by mixing the stator, rotators with various pyridine head groups, copper(I) ions and 1,4-diazabicyclo[2.2.2]octane (DABCO). Whereas the exchange of a phenanthroline vs. a bipyridine station did not entail significant changes in the rotational exchange frequency, the para-substituents at the pyridine head group of the rotator had drastic consequences on the speed: 4-OMe (k298 = 35 kHz), 4-H (k298 = 77 kHz) and 4-NO2 (k298 = 843 kHz). The exchange frequency (log k) showed an excellent linear correlation with both the Hammett substituent constants and log K of the copper(I)–ligand interaction, proving that rotator–copper(I) bond cleavage is the key determining factor in the rate-determining step.

Redox-triggered changes in the self-assembly of a ferrocene–peptide conjugate

2014 ◽  
Vol 50 (42) ◽  
pp. 5551-5553 ◽  
Author(s):  
Bimalendu Adhikari ◽  
Heinz-Bernhard Kraatz
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Spherical Micelles

Redox and ultrasound directed self-assembly of a ferrocene–peptide conjugate was studied, showing redox-controlled reorganization between gel nanofibers and spherical micelles.

Sign in / Sign up

Export Citation Format

Share Document