Quatsomes: Vesicles Formed by Self-Assembly of Sterols and Quaternary Ammonium Surfactants

Langmuir ◽  
2013 ◽  
Vol 29 (22) ◽  
pp. 6519-6528 ◽  
Author(s):  
Lidia Ferrer-Tasies ◽  
Evelyn Moreno-Calvo ◽  
Mary Cano-Sarabia ◽  
Marcel Aguilella-Arzo ◽  
Angelina Angelova ◽  
...  
Keyword(s):  
Quaternary Ammonium ◽  
Self Assembly ◽  
Quaternary Ammonium Surfactants

scholarly journals The surface adsorption, aggregate structure and antibacterial activity of Gemini quaternary ammonium surfactants with carboxylic counterions

2019 ◽  
Vol 6 (8) ◽  
pp. 190378 ◽  
Author(s):  
Xiqin Zhou ◽  
Siqi Hu ◽  
Yu Wang ◽  
Sana Ullah ◽  
Jun Hu ◽  
...  
Keyword(s):  
Surface Tension ◽  
Antibacterial Activity ◽  
Quaternary Ammonium ◽  
Self Assembly ◽  
High Surface ◽  
Surfactant Molecule ◽  
Counterion Binding ◽  
High Antibacterial Activity ◽  
Transmission Electron ◽  
Quaternary Ammonium Surfactants

A group of Gemini quaternary ammonium surfactants with the formula C n H 2 n +1 CONH(CH 2 ) 2 N + (CH 3 ) 2 (CH 2 ) 2 N + (CH 3 ) 2 (CH 2 ) 2 NHCOC n H 2 n +1 · 2Y ( n = 11, 13 and 15, Y = HCOO − , CH 3 COO − and CH 3 CHOHCOO − ) have been synthesized by a counterion conversion process and characterized by Fourier transform infrared spectroscopy and mass spectroscopy. Their adsorption and self-aggregation properties are investigated by surface tension, conductivity, dynamic light scattering and transmission electron microscopy (TEM) measurements. The results show that these surfactants reduce the surface tension of water to a minimum value of 26.51 mN m −1 at a concentration of 5.72 × 10 −2 mmol l −1 . Furthermore, the increased alkyl chain length of the carboxylic counterions leads to the increased critical micelle concentration, the decreased degree of counterion binding ( β ) and the decreased self-assembly tendency, but the minimum area per surfactant molecule ( A min ) adsorbed at the air–aqueous solution are similar. TEM images reveal that these surfactants self-assemble spontaneously into aggregates with vesicle or bilayer structures. It is also found that they have superior antibacterial activity at a concentration of 0.1 g l −1 . The high surface activity and high antibacterial activity of the Gemini quaternary ammonium salt surfactants containing different carboxylic counterions bring more possibilities for the application in the field of biomedicine.

Successful complete digestion of well lithified shale and extraction of microfossils from Devonian beds in western New York

Stratigraphy ◽  
2020 ◽  
pp. 205-212
Author(s):  
Kimberly C. Meehan ◽  
Cody Kowalski ◽  
Kimberly Bartlett ◽  
Isabelle Li ◽  
Paul Bembia
Keyword(s):  
New York ◽  
Quaternary Ammonium ◽  
Sedimentary Rock ◽  
Complete Analysis ◽  
Late Devonian ◽  
Thin Sections ◽  
Devonian Shale ◽  
Complete Digestion ◽  
Quaternary Ammonium Surfactants ◽  
Traditional Approaches

ABSTRACT: Researchers in paleontological and paleoecological sciences often need complete disaggregation of rock materials for certain lines of investigation. However, complete disaggregation of more lithified sedimentary rock is known to be problematic. A complete shale disaggregation method implementing quaternary ammonium surfactants,widely used in paleontological sciences for poorly lithified shale and mudstone, was successfully used on well lithified Devonian shale in the Appalachian Basin ofWestern New York. Over 50 Devonian gray and black shale samples were collected from multiple localities in western New York (Cashaqua, Rhinestreet, Skaneateles, Windom, and Ludlowville), coarsely crushed, and fully immersed in a quaternary ammonium surfactant until complete disaggregation was achieved (5–14 days); aliquots were run through a series of nested sieves. The sieved sediments contained hundreds of well-preserved microfossils released from the shale: ostracods, dacryoconarids, and previously unreported palymorphs, charophytes, agglutinated foraminifera, miospores, and other microspherules. These microfossils were easily found within disaggregated and sieved samples but were unrecognizable on the shale surface and destroyed in prior investigations of whole rock thin sections. In addition to more traditional approaches, inclusion of this complete rock disaggregation method may assist in a more complete analysis of material, increase our understandings of ancient basin systems and have important implications on our understanding of the paleoecology during the Late Devonian marine biotic crises.

Synthesis and Properties of Quaternary Ammonium Surfactants Based on Alkylamine, Propylene Oxide, and 2-Chloroethanol

2018 ◽  
Vol 21 (2) ◽  
pp. 247-254 ◽  
Author(s):  
Ziyafaddin H. Asadov ◽  
Gulnara A. Ahmadova ◽  
Ravan A. Rahimov ◽  
Aygul Z. Abilova ◽  
Sevda H. Zargarova ◽  
...  
Keyword(s):  
Propylene Oxide ◽  
Quaternary Ammonium ◽  
Quaternary Ammonium Surfactants

Colorimetric detection of quaternary ammonium surfactants using citrate-stabilized gold nanoparticles (Au NPs)

2014 ◽  
Vol 6 (7) ◽  
pp. 2031-2033 ◽  
Author(s):  
Li-Qing Zheng ◽  
Xiao-Dong Yu ◽  
Jing-Juan Xu ◽  
Hong-Yuan Chen
Keyword(s):  
Gold Nanoparticles ◽  
Quaternary Ammonium ◽  
Low Cost ◽  
Colorimetric Detection ◽  
Hydrophobic Effect ◽  
Colorimetric Method ◽  
Au Nps ◽  
Quaternary Ammonium Surfactants

Based on the hydrophobic effect inducing the aggregation of Au NPs, a rapid and low-cost colorimetric method for detection of quaternary ammonium surfactants using citrate-stabilized AuNPs was developed.

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