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You searched for: Subject "quaternary ammonium compounds" Remove constraint Subject: "quaternary ammonium compounds"
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1. An emerging deep eutectic solvent based on halogen-bonds

Author:
Ruifen Shi; Dongkun Yu; Fengyi Zhou; Jiangfeng Yu; Tiancheng Mu
Source:
Chemical communications 2022 v.58 no.29 pp. 4607-4610
ISSN:
1364-548X
Subject:
quaternary ammonium compounds,   etc   ; halogens; liquids; solvents;     Show all 4 Subjects
Abstract:
... A new deep eutectic solvent (DES) driven by halogen bonding (XB) was exploited. A family of eutectic mixtures in the liquid state was obtained by the combination of quaternary ammonium salts and dihalogens. The formation mechanism was discussed based on experiments and DFT calculations. It not only broadens the potential DES systems but unlocks the possibility of XB complexes as solvents. ...
DOI:
10.1039/d2cc00528j

2. Selective α-Methylation of Aryl Ketones Using Quaternary Ammonium Salts as Solid Methylating Agents

Author:
Johanna Templ; Michael Schnürch
Source:
Journal of organic chemistry 2022 v.87 no.6 pp. 4305-4315
ISSN:
1520-6904
Subject:
quaternary ammonium compounds,   etc   ; iodides; organic chemistry; regioselectivity; solvents;     Show all 5 Subjects
Abstract:
... We describe the use of phenyl trimethylammonium iodide (PhMe₃NI) as an alternative methylating agent for introducing a CH₃ group in α-position to a carbonyl group. Compared to conventional methylating agents, quaternary ammonium salts have the advantages of being nonvolatile, noncancerogenic, and easy-to-handle solids. This regioselective method is characterized by ease of operational setup, use o ...
DOI:
10.1021/acs.joc.1c03158

3. Studies on the Origin of the Stabilizing Effects of Fluorinated Alcohols and Weakly Coordinated Fluorine-Containing Anions on Cationic Reaction Intermediates

Author:
Feng-Xian Tian; Jin Qu
Source:
Journal of organic chemistry 2022 v.87 no.3 pp. 1814-1829
ISSN:
1520-6904
Subject:
quaternary ammonium compounds,   etc   ; hydrogen bonding; organic chemistry; thermodynamics;     Show all 4 Subjects
Abstract:
... Many synthetic methods that use fluorinated alcohols as solvents have been reported, and the fluorinated alcohols have been found to be crucial to the success of these methods. In addition, there have been reports indicating that adding a weakly coordinated fluorine-containing anion, such as BF₄–, PF₆–, or SbF₆–, to fluorinated alcohols can improve yields. The boosting effect of fluorinated alcoho ...
DOI:
10.1021/acs.joc.1c02361

4. Quaternary ammonium pesticides: A review of chromatography and non-chromatography methods for determination of pesticide residues in water samples

Author:
Ismael dos S. Belmonte; Tânia M. Pizzolato; Mariana R. Gama
Source:
Trends in environmental analytical chemistry 2022 v.35 pp. e00171
ISSN:
2214-1588
Subject:
quaternary ammonium compounds,   etc   ; analytical chemistry; chromatography; mass spectrometry; pesticides;     Show all 5 Subjects
Abstract:
... The monitoring of pesticide residues in water sources is essential because of their increased worldwide demand in agriculture and their subsequent detection in waters. Pesticide residues in water matrices are traditionally determined by multiresidue methodologies based on chromatography coupled to mass spectrometry. However, for quaternary ammonium pesticide residues, as highly polar compounds, th ...
DOI:
10.1016/j.teac.2022.e00171

5. Ma'edamines E and F, rare bromotyrosine alkaloids possessing a 1,2,3,5-tetrasubstituted pyridinium moiety from an Okinawan marine sponge Suberea sp.

Author:
Shin-ichiro Kurimoto; Ayano Okamoto; Satsuki Seino; Jane Fromont; Jun'ichi Kobayashi; Takaaki Kubota
Source:
Tetrahedron letters 2022 v.103 pp. 153985
ISSN:
0040-4039
Subject:
quaternary ammonium compounds,   etc   ; Suberea; alkaloids; cytotoxicity; leukemia; mice; moieties;     Show all 7 Subjects
Abstract:
... Two new bromotyrosine alkaloids, ma'edamines E (1) and F (2), were isolated from an Okinawan marine sponge Suberea sp., and their structures were elucidated by the analyses of spectroscopic (UV, IR, and NMR) and spectrometric (MS) data. Ma'edamines E (1) and F (2) are the second and third examples of natural products possessing an N-alkyl-3,5-diethyl-2-propylpyridinium moiety. Ma'edamine F (2) is ...
DOI:
10.1016/j.tetlet.2022.153985

6. Trifluoromethylation of dihydrocoptisines and the effect on structural stability and XBP1-activating activity

Author:
Xiang Li; Hai-Jing Zhang; Zhi-Hong Li; Lian-Qiu Wu; An-Jun Deng; Hai-Lin Qin
Source:
Journal of Asian natural products research 2022 v.24 no.4 pp. 388-396
ISSN:
1477-2213
Subject:
quaternary ammonium compounds,   etc   ; colitis; cytotoxicity; fluorine; research; transcription (genetics);     Show all 6 Subjects
Abstract:
... In order to obtain new dihydrocoptisine-type compounds with stable structure and activating XBP1 transcriptional activity, (±)-8-trifluoromethyldihydrocoptisine derivatives as target compounds were synthesized from quaternary ammonium chlorides of coptisine alkaloids as starting materials by a one-step reaction. The structures of the synthesized compounds were confirmed by ¹H-, ¹³C-, and ¹⁹F-NMR a ...
DOI:
10.1080/10286020.2021.1935895

7. Formation of Oxidation- and Acid-Sensitive Assemblies from Sterols and a Quaternary Ammonium Ferrocene Derivative: Quatsome- and Onion-like Vesicles and Extended Nanoribbons

Author:
William L. Odette; Janine Mauzeroll
Source:
Langmuir 2022 v.38 no.14 pp. 4396-4406
ISSN:
1520-5827
Subject:
quaternary ammonium compounds,   etc   ; cholesterol; extrusion; ferrocenes; oxidants; oxidation; sonication; surfactants;     Show all 8 Subjects
Abstract:
... Quatsomes are a class of nonphospholipid vesicles in which bilayers are formed from mixtures of quaternary ammonium (QA) amphiphiles and sterols. We describe the formation of oxidation and acid-sensitive quatsome-like vesicles and other bilayer assemblies from mixtures of a ferrocenylated QA amphiphile (FTDMA) and several cholesterol derivatives. The influence of the sterol and the preparation met ...
DOI:
10.1021/acs.langmuir.2c00128

8. A rapid way of preparing switchable bacteria-killing and bacteria-releasing cellulosic material with anti-bacteria adhesion capability

Author:
Li Dai; Jiangfei Lou; Na-won Baek; Xun Zhang; Jiugang Yuan; Jin Xu; Xuerong Fan
Source:
Cellulose 2022 v.29 no.9 pp. 5305-5323
ISSN:
0969-0239
Subject:
quaternary ammonium compounds,   etc   ; Escherichia coli; adhesion; cellulose; chemical bonding; zwitterions;     Show all 6 Subjects
Abstract:
... At present, some multifunctional and smart materials equipped with both “bacteria-killing” and “bacteria-defending” functions have been created to meet the demands of some particular application areas. However, most of these materials were either biologically incompatible or required intricate crafting. In this paper, a finishing agent containing quaternary ammonium lactone ring and NCO groups was ...
DOI:
10.1007/s10570-022-04589-4

9. Construction of N-spirocyclic cationic three-dimensional highly stable transport channels by electrospinning for anion exchange membrane fuel cells

Author:
Song Wang; Zhe Wang; Jingmei Xu; Qian Liu; Zhiyan Sui; Xinming Du; Yinghe Cui; Yongjiang Yuan; Junjian Yu; Yan Wang; Yifang Chang
Source:
Journal of membrane science 2022 v.660 pp. 120852
ISSN:
0376-7388
Subject:
quaternary ammonium compounds,   etc   ; anion exchange; anion-exchange membranes; nanofibers; tensile strength;     Show all 5 Subjects
Abstract:
... A bead-on-string electrospinning strategy is proposed to solve the dilemma of unstable conduction channel while improving the OH⁻ conductivity of anion exchange membranes (AEMs). Here, poly (aryl ether ketone)-based AEMs are synthesized via N-spirocyclic quaternary ammonium modification, and then processed by electrospinning and sparingly soluble techniques. N-spirocyclic cations are induced to or ...
DOI:
10.1016/j.memsci.2022.120852

10. Lignin dissolution and lignocellulose pretreatment by carboxylic acid based deep eutectic solvents

Author:
Haitao Yu; Zhimin Xue; Ruifen Shi; Fengyi Zhou; Tiancheng Mu
Source:
Industrial crops and products 2022 v.184 pp. 115049
ISSN:
0926-6690
Subject:
quaternary ammonium compounds,   etc   ; Populus; hydrogen bonding; lactic acid; lignin; lignocellulose; solubility;     Show all 7 Subjects
Abstract:
... Deep eutectic solvents (DESs) composed by carboxylic acids and quaternary ammonium salts are potential candidate for lignocellulose dissolution and pretreatment. To both explore the most efficient DESs for lignocellulose dissolution and pretreatment as well as unveil the process mechanism, DESs composed by carboxylic acids as the hydrogen bond donors (HBDs) and quaternary ammonium salts as the hyd ...
DOI:
10.1016/j.indcrop.2022.115049

11. Novel poly(epichlorohydrin)-based matrix for monolithic ionogel electrolyte membrane with high lithium storage performances

Author:
Chunming Chen; Qiong Chen; Jian Xie; Zhonghua Chen
Source:
RSC advances 2022 v.12 no.19 pp. 12160-12165
ISSN:
2046-2069
Subject:
quaternary ammonium compounds,   etc   ; electrolytes; energy; epichlorohydrins; ionization; lithium; polymers; thermal stability;     Show all 8 Subjects
Abstract:
... Based on gelling matrices and ionic liquids (ILs), monolithic ionogel electrolyte membranes (MIEMs) have become a research focus. However, further application is limited by lack of functional matrices. Herein, we proposed the introduction of an ionized polymer, i.e., polyether polymer with side-chain ionic groups obtained via the reaction of quaternary ammonium with uncrystallizable poly (epichlor ...
DOI:
10.1039/d2ra00110a

12. Effect of functional group and structure on hydrophobic properties of environment-friendly lignin-based composite coatings

Author:
Xue Liu; Qi Liu; Shoujuan Wang; Zhongming Liu; Gaixiu Yang; Huan Wang; Wenlong Xiong; Peng Li; Feng Xu; Yuebin Xi; Fangong Kong
Source:
International journal of biological macromolecules 2022 v.215 pp. 132-140
ISSN:
0141-8130
Subject:
quaternary ammonium compounds,   etc   ; biomass; dispersibility; electrostatic interactions; hydrophilicity; hydrophobicity; lignin; straw;     Show all 8 Subjects
Abstract:
... Hydrophobic coatings are widely used in a variety of materials surfaces. However, it remains a great challenge for the non-toxic and environmentally-friendly production of hydrophobic coatings. Herein, two nano-scale spherical lignin/SiO₂ composite particles are synthesized based on the electrostatic interaction and the steric hindrance effect inspired by the self-protection of straw. Introduction ...
DOI:
10.1016/j.ijbiomac.2022.06.055

13. Quaternary ammonium engineered polyamide membrane with high positive charge density for efficient Li+/Mg2+separation

Author:
Tianrun Gu; Runnan Zhang; Shiyu Zhang; Benbing Shi; Junhui Zhao; Zhen Wang; Mengying Long; Guangzhe Wang; Ting Qiu; Zhongyi Jiang
Source:
Journal of membrane science 2022 v.659 pp. 120802
ISSN:
0376-7388
Subject:
quaternary ammonium compounds,   etc   ; ammonium; ammonium salts; lithium; nanofiltration; polyamides; salt lakes;     Show all 7 Subjects
Abstract:
... The efficient separation of Li⁺/Mg²⁺ is the key to lithium extraction from salt lake brine. Herein, a multi-amino quaternary ammonium salt (3,5-dimethylhydrazide-benzyl trimethyl ammonium bromide, DHTAB) was designed and synthesized to modify pristine polyamide (PA) nanofiltration membranes. DHTAB was grafted on the surface of the PA nanofiltration membrane to construct a positively selective laye ...
DOI:
10.1016/j.memsci.2022.120802

14. Chemical modifications in the structure of seaweed polysaccharides as a viable antimicrobial application: A current overview and future perspectives

Author:
Caroline Santinon; Deise Ochi; Marisa Masumi Beppu; Melissa Gurgel Adeodato Vieira
Source:
Algal research 2022 v.66 pp. 102796
ISSN:
2211-9264
Subject:
quaternary ammonium compounds,   etc   ; biopolymers; derivatization; esterification; macroalgae; pandemic; polysaccharides; research; toxicity;     Show all 9 Subjects
Abstract:
... The global pandemic that started at the end of 2019 highlighted the need to create new biocidal products. Seaweeds are highly available non-toxic macromolecules of great interest in several industries and have remarkable biological properties, but still underexplored. Chemical modification in the structure of these biopolymers significantly improves their properties and confers high efficiency aga ...
DOI:
10.1016/j.algal.2022.102796

15. Ionic Liquid Assisted α–γ′ Phase Transition of Poly(vinylidene fluoride) Thin Films

Author:
Zixiong Liu; Haijun Wang; Kun Liu; Huihui Li; Xiaoli Sun; Jian Hu; Shaojuan Wang; Chunlei Yuan; Shouke Yan
Source:
Macromolecules 2022 v.55 no.6 pp. 2160-2170
ISSN:
1520-5835
Subject:
quaternary ammonium compounds,   etc   ; films (materials); fluorides; ionic liquids; phase transition; temperature;     Show all 6 Subjects
Abstract:
... In this work, a simple and efficient approach has been developed for preparing γ-PVDF films with a wide range of thickness based on the spontaneous diffusion of ionic liquids (ILs) into the α-PVDF matrix. It involves three steps: (i) preparation of α-PVDF films, (ii) surface coating of the resultant α-PVDF films with ionic liquids or quaternary ammonium solution, and (iii) annealing the surface mo ...
DOI:
10.1021/acs.macromol.1c02653

16. Microscopic insight into anion conduction in covalent−organic framework membranes: A molecular simulation study

Author:
Bohui Lyu; Mao Wang; Zhongyi Jiang; Jianwen Jiang
Source:
Journal of membrane science 2022 v.658 pp. 120754
ISSN:
0376-7388
Subject:
quaternary ammonium compounds,   etc   ; chlorides; ethyl ether; ion exchange; molecular dynamics; porosity;     Show all 6 Subjects
Abstract:
... Recently there has been considerable interest in the utilization of covalent-organic frameworks (COFs) as ion-exchange membranes. While rapid ion conduction is experimentally observed in COF membranes, the underlying mechanism remains elusive. Herein, we report a molecular simulation study on chloride ion (Cl⁻) conduction in four COF membranes functionalized with quaternary ammonium groups (QA-2, ...
DOI:
10.1016/j.memsci.2022.120754

17. “Brush-like” Amphiphilic Polymer for Environmental Adaptive Coating

Author:
Zhengfeng Ma; Yizhe Liu; Kai Feng; Jianteng Wei; Jianxi Liu; Yang Wu; Xiaowei Pei; Bo Yu; Meirong Cai; Feng Zhou
Source:
ACS applied materials & interfaces 2022 v.14 no.16 pp. 18901-18909
ISSN:
1944-8252
Subject:
quaternary ammonium compounds,   etc   ; air; ammonium; composite polymers; energy; friction; hydrophilicity; lubrication;     Show all 8 Subjects
Abstract:
... Multiple functional coating is urgently needed in complex service surroundings to meet various requirements. In this work, a brush-like amphiphilic copolymer of poly methacryloxyethyl dimethyl butyl ammonium bromide–polydimethylsiloxane (pMDBAB–PDMS) was synthesized to construct an environment-adaptive multifunctional coating based on the copolymer via the UV-curing method. The special molecule ch ...
DOI:
10.1021/acsami.2c01824

18. Advanced anion-selective membranes with pendant quaternary ammonium for neutral aqueous supporting redox flow battery

Author:
Yan Xiao; Junhui Xu; Lei Hu; Hui Wang; Li Gao; Shiqi Peng; Mengting Di; Xiaojun Sun; Jie Liu; Xiaoming Yan; Liuping Chen; Gaohong He
Source:
Journal of membrane science 2022 v.659 pp. 120748
ISSN:
0376-7388
Subject:
quaternary ammonium compounds,   etc   ; anion-exchange membranes; batteries; electric potential difference; hydrophilicity; hydrophobicity;     Show all 6 Subjects
Abstract:
... Neutral aqueous organic redox flow battery (NAORFB) stands out as one of the most prospective mass energy storage options. The main limitations of large-scale storage regarding the NAORFB lie in the low Na⁺/Cl⁻ conductivity of membrane in pH7 systems, which leads to a lower voltage efficiency. Herein, quaternary ammonium functionalized fluorinated poly (arylene ether) (QAFPAE-x) anion exchange mem ...
DOI:
10.1016/j.memsci.2022.120748

19. Critical In-Plane Density of Polyelectrolyte Brush for the Ordered Hydrogen-Bonded Structure of Incorporated Water

Author:
Kosuke Yamazoe; Yuji Higaki; Yoshihiro Inutsuka; Jun Miyawaki; Atsushi Takahara; Yoshihisa Harada
Source:
Langmuir 2022 v.38 no.10 pp. 3076-3081
ISSN:
1520-5827
Subject:
quaternary ammonium compounds,   etc   ; X-radiation; chlorides; electric field; hydrogen bonding; polymers; spectroscopy;     Show all 7 Subjects
Abstract:
... A polymer electrolyte brush is a reasonable platform to confine water molecules within a nanoscopic area to study their role in the function of interacting media because of their adjustable nanospace and charge by changing the in-plane density and side chains of the brush. Here, we demonstrate how the in-plane spacing of cationic polymer brush chains, poly[2-(methacryloyloxy)ethyltrimethylammonium ...
DOI:
10.1021/acs.langmuir.1c02895

20. Quaternary ammonium-biphosphate ion-pair based copolymers with continuous H+ transport channels for high-temperature proton exchange membrane

Author:
Junqiao Jiang; Zhen Li; Min Xiao; Shuanjin Wang; Kenji Miyatake; Yuezhong Meng
Source:
Journal of membrane science 2022 pp. 120878
ISSN:
0376-7388
Subject:
quaternary ammonium compounds,   etc   ; ammonium; composite polymers; durability; electric potential difference; phosphoric acid;     Show all 6 Subjects
Abstract:
... Phosphoric acid (PA)-doped polymer electrolyte membranes are the most promising materials for high-temperature proton exchange membranes (HT-PEMs). However, their development is subject to the compromise between proton conductivity and phosphoric acid (PA) doping level. Here, an ether-free QPAF-4 membrane (a copolymer containing perfluoroalkylene and fluorenyl groups with pendant ammonium groups) ...
DOI:
10.1016/j.memsci.2022.120878