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Quaternary ammonium salts (QAS) commonly occur as active substances in disinfectants. QAS have the important property of coating abiotic surfaces, which prevents adhesion of microorganisms, thus inhibiting biofilm formation. In this study, a group of nine monomeric QAS, differing in the structure and length of the aliphatic chain (C12, C14, C16) and the counterion (methylcarbonate, acetate, bromide), were investigated. The study included an analysis of their action against planktonic forms as well as bacterial biofilms. The compounds were tested for their anti-adhesion properties on stainless steel, polystyrene, silicone and glass surfaces. Moreover, mutagenicity analysis and evaluation of hemolytic properties were performed. It was found that compounds with 16-carbon hydrophobic chains were the most promising against both planktonic forms and biofilms. Tested surfactants (C12, C14, C16) showed anti-adhesion activity but it was dependent on the type of the surface and strain used. The tested compounds at MIC concentrations did not cause hemolysis of sheep blood cells. The type of counterion was not as significant for the activity of the compound as the length of the hydrophobic aliphatic chain. [ABSTRACT FROM AUTHOR]

Gemini surfactants are advantageous over conventional surfactants as they find applications as antimicrobial agents, corrosion inhibitors, enhanced oil recovery, capping agents for nanoparticle synthesis, drug delivery agents, etc. This article provides a detailed overview of synthetic procedures for various types of geminis and the fundamental physicochemical parameters of these systems. This includes a discussion on the cationic geminis based on various groups such as biphenyl, amide (with/without alkane tail), binol, quaternary ammonium (with/without hydroxyl group as a spacer), morpholinium, pyridinium, amide (with/without alkane tail), ester quaternary ammonium, and imidazolium (spacer with/without hydroxyl group and thioether/ester) types. Further, it is focused on anionic geminis with carboxylate, borate, and sulfonate head groups. Zwitterionic geminis such as betaine surfactants, cocogem surfactants based on dodecylisopropylol amine and dicarboxylic acid, diester type, sulphobetaine gemini based on S‐triazine, zwitterionic hetero gemini containing ammonium and carboxylate head groups, zwitterionic gemini containing quaternary ammonium and a sulfate group, gemini containing phosphodiester anion and quaternary ammonium salt are also reviewed. Lastly, synthesis of nonionic geminis from sunflower oil, amide‐based nonionic, sulfonamide nonionic, N,N'‐diethylaminedialkyldiamide nonionic gemini, sugar‐based gemini, and nonionic gemini with sulfonate spacer have been discussed. [ABSTRACT FROM AUTHOR]

The formation of inherently chiral calix[4]arenes by the intramolecular cyclization approach suffers from a limited number of suitable substrates for these reactions. Here, we report an easy way to prepare one class of such compounds: calixquinolines, which can be obtained by the reaction of aldehydes with easily accessible aminocalix[4]arenes in acidic conditions (Doebner–Miller reaction). The synthetic procedure represents a very straightforward approach to the inherently chiral macrocyclic systems. The complexation studies revealed the ability of these compounds to complex quaternary ammonium salts with different stoichiometries depending on the guest molecules. At the same time, the ability of enantioselective complexation of chiral N-methylammonium salts was demonstrated. [ABSTRACT FROM AUTHOR]

Composite corrosion inhibitor PyCR-OPW for well production water was developed, using pyridine derivatives (PY-2), quaternary ammonium salts (QS-3), and imidazoline derivatives (IM-4) as raw materials, the corrosion inhibition properties and electrochemical mechanism of PyCR-OPW were studied by applying the static hanging experiment and the dynamic potential polarization curve. The results showed, PyCR-OPW had the best corrosion suppression when the optimal combination was 7g PY-2, 4g QS-3, and 1g IM-4,, and pyraternary ammonium had the greatest effect on the results; the corrosion rate of J55 was less than 0.076mm/a, and the corrosion rate was more than 70% when the mass concentration of PyCR-OPW was greater than 125 mg/L; PyCR-OPW was showed good temperature resistance when the system temperature was 80 ℃, the corrosion rate of J55 was 0.0719mm/a, and the corrosion rate was 70.41%; PyCR-OPW was a mixed inhibitor mainly by cathode; the daily dosing concentration and the corrosion prevention cost of well production waters were greatly reduced with the combination of periodic injection and continuous dosing methods. [ABSTRACT FROM AUTHOR]

Equine piroplasmosis has become a global problem of the equine husbandry sector. Haemoprotozoans evolved very quickly and developed resistance against most of the current available drugs. Phospholipid membrane synthesis by choline kinase enzyme is vital for propagation of intra-erythrocytic protozoa parasites. This pathway was targeted in the present study. Quaternary ammonium salts (QAS) and their analogues act against choline and hamper the biosynthesis process for phosphatidylcholine. We analysed anti- T. equi activity of three QAS - decamethonium bromide (DMB), decyl trimethyl ammonium bromide (DTAB) and dodecyl trimethyl ammonium bromide (DDTAB). Theileria equi parasites in vitro treated with different concentrations of DMB, DDTAB and DTAB. Drug treated T. equi failed to multiply further in the viability test. The IC 50 value of DMB, DDTAB and DTAB for growth inhibition of T. equi was 14.0 μM, 469.51 nM and 558.40 nM, respectively. DMB, DDTAB and DTAB treated T. equi parasites were observed to be devoid of internal structures, showing pyknotic and degenerative appearances. Various concentration of DMB, DDTAB and DTAB were analysed for their cytotoxicity and haemolytic activity on horse's PBMCs and RBCs. DMB was less than 10% cytotoxic to PBMCs, while DDTAB and DTAB were 40%–50% cytotoxic at 1000 μM concentrations. The respective CC 50 values were 7202.96 μM, 1026.26 μM and 1263.95 μM. DMB and DTAB showed least haemolytic activity (<3%); whereas DDTAB was more haemolytic to RBCs at highest concentration of 2000 μM. The respective CC 50 values of these drugs were 224495.3 μM, and 39101.35 μM; 713.54 μM. Specific selective index for DMB, DDTAB and DTAB values with respect to host's PBMC and RBC cells, were 514.50, 2185.81, 2263.52 and 16035.38, 1519.75, 70023.91, respectively. These data indicated its non-toxicity to host's cells and selective potential of anti- T. equi in vitro activity. [Display omitted] • In vitro anti- Theileria equi efficacy of QAS - DMB, DDTAB and DTAB as choline kinase inhibitor was investigated. • DMB, DDTAB and DTAB potentially and selectively arrested the in vitro growth of T. equi. • These drug molecules have very high SSI values and are non-toxic to host's PBMC and RBC cell lines. [ABSTRACT FROM AUTHOR]

Background: Photodynamic antimicrobial therapy (PDAT) has been extensively studied because of its potential applications such as precise controllability, high spatiotemporal accuracy, and non-invasiveness. More importantly, it is difficult for bacteria to develop resistance to the aforementioned PDATs. However, the selectivity of traditional PDAT methods to bacteria is generally poor, so it has been proposed to introduce positively charged components such as quaternary ammonium salts to enhance the targeting of bacteria; however, they always possess high toxicity to normal cells. As a result, measures should be taken to enhance the targeting of bacteria and avoid side effects on normal cells. Methods and Results: In our work, we creatively design a nanoplatform with high anti-bacterial efficiency, low side effects and its size is approximately 121 nm. BSA, as a nanocarrier, encapsulates the photosensitizer (E)-4-(4-(diphenylamino)styryl)-1-methylpyridin-1-ium with AIE properties named as BSA-Tpy, which increases its circulation time in vivo and improves the biocompatibility. Under acidic conditions (pH = 5.0), the surface positive charge of the BSA-Tpy is increased to +18.8 mV due to protonation of amine residues to achieve the targeting effect on bacteria. Besides, under the irradiation of white light, the BSA-Tpy will produce ROS to kill bacteria efficiently about 99.99% for both Gram-positive and Gram-negative bacteria, which shows the potential application value for the treatment of infected wounds. Conclusion: We have developed a feasible method for photodynamic antibacterial therapy, possessing excellent biocompatibility and high antibacterial efficiency with good fluorescence imaging property. [ABSTRACT FROM AUTHOR]

Copyright of Basic Sciences Journal of Textile Universities / Fangzhi Gaoxiao Jichu Kexue Xuebao is the property of Basic Sciences Journal of Textile Universities and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We synthesized ionic liquids with 2-(alkyldimethylamino)ethanol cation and inorganic anions and studied the electrical conductivity of their solutions in acetonitrile. The ion association constants (Ka), limiting molar electrical conductivities (λ0), and standard Gibbs association energies (ΔG°) in acetonitrile solutions at 25°С were calculated by the Lee–Wheaton equation. [ABSTRACT FROM AUTHOR]

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

During the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) pandemic, scientists from different areas are looking for alternatives to fight it. SARS‐CoV‐2, the cause of the infectious respiratory disease COVID‐19, is mainly transmitted through direct or indirect contact with infected respiratory droplets. The integrity of the virus structure is crucial for its viability to attack human cells. Quaternary ammonium salts are characterized by having antiviral capabilities which alter or destroy the structure of the viral capsid. In this work, polypropylene (PP)/(1‐Hexadecyl) trimethyl‐ammonium bromide (CTAB) composites have been prepared in order to create an antiviral material. The composites were melt processed and blown to produce thin films. The CTAB content on the antiviral effect was evaluated using antibodies and serum from infected patients with the SARS‐CoV‐2 virus. In addition, the mechanical and thermal properties of blown films were investigated, and CTAB release kinetics from the films was followed by UV–Vis. The results indicate that the virus tends to remain less on the polymer surface by increasing the amount of CTAB in the PP matrix. [ABSTRACT FROM AUTHOR]

Herein, the synthesis of a new type of catalyst, SBA−M (Schiff complex of different metal types grafted on SBA‐15) based on a quaternization reaction, is described. Various amounts of ionic liquid were grafted into the pore channels of SBA‐15 using the post‐grafting method, which allowed the ionic liquid to be grafted into the pore channels restrictively. Notably, over six cycles, SBA−Mn (0.2) has been shown to maintain its catalytic activity and stability. In addition, a reaction mechanism for the cycloaddition of CO2 with epoxides based on density‐functional theory is proposed. The cycloaddition reaction of CO2 and epoxides is an efficient way of carbon fixation. It is demonstrated that the metal coordinated with the oxygen atom of the epoxides and that a halogen attacked the carbon of epoxides. Moreover, theoretical calculations and synthesis strategy provide a new approach for CO2 conversion. [ABSTRACT FROM AUTHOR]

In this study, hydrophobic quaternary ammonium intermediate was synthesized by epichlorohydrin (ECH) and oleamide propyl dimethyl tertiary amine (PKO). Sodium carboxymethylcellulose (CMC) was chemically modified by introducing a large number of hydrophobic quaternary ammonium branched chains to improve CMC's salt resistance, thickening ability, and solubility. The quaternary ammonium salt structure can partially offset the compression double-layer effect of linear polymers in a low-price salt ion solution, which makes CMC more stretchable and helps it obtain a higher viscosity and greater drag-reduction performance. The experiment was mainly divided into three parts: Firstly, we performed an epichlorohydrin and oleic acid PKO reaction, generating an oleic acid chain quaternary ammonium chlorine atom intermediate. Secondly, the etherification reaction between intermediate –Cl and –OH groups of CMC was completed. Finally, the modified CMC was characterized by IR, SEM, and XPS, and the viscosity and the drag-reduction rate were evaluated. After CMC and the intermediate were reacted at a mass ratio of 9:1.8 at 80 °C for 5 h, the new CMC with enhanced thickening ability, salt resistance, and drag-reduction performance was obtained. We found that the apparent viscosity increased by 11%, the drag reduction rate increased by 3% on average, and the dissolution rate was also significantly accelerated, which was ascribed to the introduction of quaternary ammonium cation. Moreover, the oleic acid amide chain increased the repulsive force of the CMC chain to low-priced metal cations in solution and intermolecular repulsive force, which is beneficial to increase the viscosity, salt resistance, and drag-reduction performance. [ABSTRACT FROM AUTHOR]

Hydrogel molecular structure contained massive hydrophilic groups, which can capture water molecules to form the rejection layer of natural organic matter (NOM). Aiming at introducing the excellent properties of hydrogels into the water treatment separation membrane, a new kind of positive charged ambient self‐crosslinking chitosan quaternary ammonium salt (CQAS) hydrogel is designed and applied to prepare a hydrogel composite membrane via surface coating method. Effects of the amount of initiator on the ambient self‐cross‐linking time of CQAS hydrogels is discussed, as well as the impacts of coating amount of ambient self‐cross‐linking CQAS pre‐gel solution on the comprehensive properties of the composite membranes is also studied. The membrane structure and morphology is characterized by FT‐IR, FE‐SEM, AFM, and the membrane properties are evaluated by dynamic contact angle and membrane performance evaluation instrument. The obtained CQAS hydrogel composite membrane exhibited super hydrophilicity, high, and stable separation performance of monovalent and divalent cations, excellent long‐term tolerance, and resistance to NOM contaminants. Specifically, in the dynamic antifouling test, the stable flux recovery rate of the CQAS hydrogel membrane to the simulative contaminants BSA, HA, and SA are 82.95%, 92.89%, and 73.37%, respectively. [ABSTRACT FROM AUTHOR]

Waterborne polyurethane (WPU) antibacterial film was prepared by UV curing after introducing hydrophilic quaternary ammonium salts to polyurethane (PU) molecular chains via quaternization reaction between different alkyl chain haloalkanes and tertiary amine groups. PUs were bonded with tertiary amine group and unsaturated group, using 3-dimethylamino-1,2-propanediol as the chain extender and hydroxyethyl methacrylate as the capping agent. The structure and properties of WPU dispersion and light cured films were characterized by FT-IR, particle size analyzer, optical contact angle instrument, etc. The antibacterial properties of the materials were tested by shaking-flask method and zone of inhibition. And the effects of tertiary amine compounds on the properties of WPU were investigated. When the mass fraction of tertiary amine compound was 9% and the alkyl long chain was 12, the antibacterial rates of WPU against Gram-negative E. coli and Gram-positive S. aureus were more than 99.5%. Meanwhile, the longer the alkyl chain was, the better the effect was. Through UV-curable crosslinking, it could still maintain excellent antibacterial performance and reflect positive durability after 96 h water washing. The zone of inhibition test showed that the prepared quaternary ammonium salts WPU antibacterial film belonged to contact-killing material which avoided the pollution and adverse effects on the environment, human beings and other materials. With the increase of tertiary amine content, the quaternization degree of WPU system first increased and then decreased, and the variation of quaternization degree affected the antibacterial properties. Moreover, polyurethane material also exhibited good mechanical properties. The increase of hard segment content of the system enhanced the tensile strength of polyurethane. And when the alkyl long chain was 12, the waterborne polyurethane material had better toughness. [ABSTRACT FROM AUTHOR]

As a potent antibacterial, antifungal or antiviral material, synthesis of quaternarized epoxidized soybean oil was demonstrated in this work. The first step of the synthesis is the reaction of epoxidized soybean oil (ESO) with 2-chloroethyl maleic acid (Cl-MA-ESO). The last step is quaternarization of this condensate with triethylamine (Q-MA-ESO). All the synthesized monomers were characterized by FTIR and 1H NMR techniques. Homopolymer of the quaternarized derivative (Q-MA-ESO) was not obtained. However, styrene copolymers were obtained and characterized. Thermal properties of the copolymers were determined by TGA and DSC techniques. Additionally, swelling properties of the materials were also evaluated. The highest swelling ratio was observed in toluene. [ABSTRACT FROM AUTHOR]

In this work, nanoporous antireflective coatings on silicate glass were obtained from silicon dioxide sol compositions by the sol-gel method in the presence of quaternary ammonium salt (tetrabutylammonium bromide) at different annealing temperatures (200–250 °C). Varying the salt concentration from 3 to 5 wt.%, we achieved the transmittance of the coatings of about 97% at 250 °C in comparison with 91% for clean glass in the wavelength range from 400 to 1100 nm. The addition of gold nanoparticles to the composition containing 5 wt.% tetrabutylammonium bromide allowed us to decrease the annealing temperature to 200 °C, preserving the transmittance at the level of 96.5%. For this case, the optimal concentration of gold nanoparticles is determined (2.6 × 10−9 mol/mL). According to the SEM analysis, the obtained antireflective coatings contain pores with a minimum area size up to 4 nm2. [ABSTRACT FROM AUTHOR]

In this study, an antimicrobial packaging material was successfully developed with blends of high-density polyethylene (HDPE) and chitosan (CS) made by melt processing. In the different HDPE/CS composites, the CS content effect (up to 40%), and the addition of quaternary ammonium salt functionalized chitosan (CS-CTAB) as an additive were evaluated by X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analyses (TG), tensile strength, scanning electron microscopy (SEM) and antimicrobial activity. When analyzing the effect of the additive in the different HDPE/CS composites, it was observed that the compositions with 10 and 20 %wt of chitosan showed better elongation values (~13% and 10%) as well as a higher decomposition temperature at 20% mass loss (T20) varying from (321–332 °C and 302–312 °C), respectively, in relation to the other compositions, regardless of the type of additive used, it acted as an antimicrobial agent, promoting inhibition of microbial growth against the strains gram-positive and gram-negative used in this work, making the different HDPE/CS composites suitable candidates for use in food packaging. [ABSTRACT FROM AUTHOR]

The Menshutkin reaction represents the alkylation of tertiary amines by alkyl halide where the reactants are neutral and the products, quaternary ammonium salts, are two ions with opposite signs. The most commonly used organic solvents in quaternization reactions are volatile organic solvents (VOSs), namely acetone, anhydrous benzene, dry dichloromethane (DCM), dimethylformamide (DMF) and acetonitrile (ACN). The purpose of this work was to examine eutectic solvents as a "greener" alternative to conventional solvents so that quaternization reactions take place in accordance with the principles of green chemistry. Herein, sixteen eutectic solvents were used as replacements for volatile organic ones in quaternization reactions of isonicotinamide with substituted phenacyl bromides. The reactions were carried out at 80 °C by three synthetic approaches: conventional (4–6 h), microwave (20 min) and ultrasound (3 h). Microwave-assisted organic reactions produced the highest yields, where in several reactions, the yield was almost quantitative. The most suitable eutectic solvents were based on choline chloride (ChCl) as the hydrogen bond acceptor (HBA) and glycerol, oxalic or levulinic acid as hydrogen bond donors (HBDs). The benefits of these three deep eutectic solvents (DESs) as a medium for quaternization reactions are the simplicity of their preparation for large-scale production, with inexpensive, available and nontoxic starting materials, as well as their biodegradability. [ABSTRACT FROM AUTHOR]

Inspired by marine compounds isolated from sponges and the increased need for new effective antimicrobials, novel quaternary ammonium compounds with long alkyl chains (C8-C12) were designed and synthesized. Antibacterial and antibiofilm activity of new compounds was evaluated against six microbial strains (S. aureus, E. coli, and P. aeruginosa). All synthesized ammonium salts displayed antibacterial activity with MIC values ranging from 5.0 to 25.0 μg/mL. In addition, most compounds showed strong inhibition of biofilm formation of S. aureus ATCC 25923, P. aeruginosa PA01, and colistin-resistant P. aeruginosa (CRPA) at a concentration of 5.0 μg/mL. Ammonium salt 3 showed 100 % inhibitory activity against all tested bacterial biofilms except that of colistin-resistant S. aureus (CRSA)., (© 2024 Wiley-VCH GmbH.)

Multidrug-resistant (MDR) Gram-negative bacteria infections have gradually become a more serious health problem recently, and antibacterial drugs are urgently needed to tackle MDR Gram-negative bacteria. Herein, we synthesized a series of quaternary ammonium salt derivatives of hyperbranched polylysine (HPL- Cm - n ) with different alkyl chain lengths ( m = 4, 8, 12, 16) and grafting ratios ( n = 5.8-21.0) of alkyl quaternary ammonium salts ( Cm ). HPL- Cm - n s exhibited excellent antibacterial activities against drug-sensitive E. coli and P. aeruginosa , and specifically, HPL-C12- n s were also highly active against MDR E. coli and P. aeruginosa . The cytotoxicity and hemolytic activity of HPL- Cm - n s increased with the increase in the alkyl chain length and the grafting ratio of Cm . The killing study proved that HPL-C12-9.5 had fast killing kinetics and was bactericidal toward both drug-sensitive and MDR E. coli . The mechanistic studies showed that, similar to hyperbranched polylysine (HPL), HPL-C12-9.5 killed bacteria by disrupting the cell membranes and causing leakage of the cytoplasmic contents. HPL-C12- n s might have potential as an antibacterial agent to combat MDR Gram-negative bacteria.

The results of spontaneous polymerization of α-chloroacrylic and α-bromoacrylic acids with tertiary amines at a low temperature are presented. As a result of spontaneous polymerization during the interaction of α-halodacrylic acids with tertiary amines, polymers containing quaternary ammonium groups are formed. In order to confirm this assumption, nuclear magnetic resonance and infrared spectroscopic studies of the products of the spontaneous polymerization were carried out. Spontaneous polymerization proceeds, consisting of two stages: the quaternization reaction and the polymerization reaction. The kinetic regularities of the polymerization reaction were studied and it was shown that the quaternization reaction, which is the limiting stage of the spontaneous polymerization process, proceeds according to the SN2 - mechanism. It has described the first attempts to obtain new nanocomposite materials based on synthesized copolymers and modified montmorillonite. Analysis of the literature data shows that the features of the preparation of nanocomposites based on Na+ - montmorillonite and water-soluble copolymers have not been previously studied.

Biomedical device‐associated infection (BAI) is a common symptom in hospitals. To solve this problem, the biomedical device needs fast, efficient, and safe antibacterial methods to prevent infection. Herein, a strategy for surface antibacterial functionalization is proposed, using mild photothermal effect and quaternary ammonium salt to common sterilize. Au nanorods (NRs) and quaternized N,N′‐dimethylethylenediamine (QDED) (quaternary ammonium salt) are modified on the surface of polyurethane (PU) to fabricate PU‐Au‐QDED. First of all, stable and recyclable mild photothermal radiation is achieved by low‐power near‐infrared (NIR) light irradiation, and then in a shorter time of NIR irradiation, mild photothermal effect promotes the disturbance of the alkyl chain of quaternary ammonium salt to destroy the bacterial membrane, together with quaternary ammonium salt QDED that has fast and efficient antibacterial property, especially against multidrug‐resistant bacteria. Meanwhile, mild photothermal effects, together with quaternary ammonium salt QDED, have good biocompatibility. Among all of the samples, PU‐Au‐Q5 demonstrates fast, efficient, and safe antibacterial performances. At the same time, the antibacterial mechanisms are further studied. Finally, the in vivo antibacterial properties are verified by the subcutaneous implantation animal model. The present work provides a facile and promising approach to develop high‐performance antibacterial biomedical devices.

A novel doped system based on quaternary ammonium salts as hosts was established. Interestingly, it is the guest-activated hosts that emit room temperature phosphorescence, rather than the host-assisted guests in traditional doped systems. [ABSTRACT FROM AUTHOR]

Three novel polyaspartate derivatives with antibacterial properties and low hemolytic effects are synthesized by the reaction of sodium polyaspartate (PAspNa) with different quaternary ammonium salts with a carboxylic end‐group, subsequently these are tested in vitro against different cancer and normal cell lines. 1‐(carboxypentyl) pyridinium bromide, 1‐(carboxypentyl) benzalkonium bromide, and 1‐(carboxypentyl) quinolinium bromide are synthesized from a quaternization reaction between 6‐bromohexanoic acid and the respective tertiary amines (pyridine, N,N‐dimethylbenzylamine, and quinoline). Then, these ammonium salts are chemically grafted along the sodium polyaspartate macromolecular chains through an acid–base reaction. Three different polyaspartate derivatives are obtained and their chemical structures analyzed and confirmed by FT‐IR and 1H NMR, the corresponding thermal stability is analyzed by thermogravimetric analysis. The antibacterial efficiency of these PAspNa derivatives against Escherichia coli is determined by measuring the minimum inhibitory concentration and the minimum bactericidal concentration. Hemolysis assays are performed on isolated human erythrocytes and finally the cell proliferation is studied by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) analysis. All the PAspNa derivatives show antibacterial activities, low hemolytic effects, and antiproliferative effect in some concentrations evaluated in murine fibroblast (3T3), and cancer cell lines of cervix (HeLa), breast (4T1), and liver (HepG2) cells lines. [ABSTRACT FROM AUTHOR]

A new approach using water as the stripping phase for extraction and recovery of low-concentration Ga (III) from concentrated hydrochloric acid solutions by Aliquat 336-based supported liquid membrane (SLM) is suggested. Generally, the stripping of Ga (III) from the loaded organic phase during liquid-liquid two-phase stirring extraction using quaternary ammonium salt as an extractant is extremely difficult. However, in the present work, an efficient mass transfer of low-concentration Ga (III) through the SLM was observed by introducing a low acidity (pH=2) aqueous solution as the stripping phase of the SLM. It was revealed that dissociation of GaCl 4 - and HCl 2 - anions into Ga3+, Cl- and H+ ions at the stripping/membrane phase interface play an important role in driving the mass transfer of GaCl 4 - from the concentrated hydrochloric acid solutions towards stripping phases. Kinetic analysis suggests that the permeability coefficient of Ga (III) ions through the SLM is dependent on the reaction temperature, extractant Aliquat 336 concentrations, and the difference in Cl- concentrations between the two sides of the liquid membrane phase, but independent of H+ concentrations. In view of future's applications for selective separation and recovery of low-concentration Ga (III) from the concentrated hydrochloric acid leaching solutions of various gallium-containing solid wastes, separation selectivity of Ga (III) against other coexisting metal impurity ions, such as Fe (II), Al (III), Mg (II) and Cu (II), was also evaluated. [Display omitted] • Water as stripping phase for selective separation and recovery of Ga(III) in concentrated hydrochloric acid. • The difficulty during traditional solvent extraction for stripping Ga(III) from the loaded organic phase can be solved. • Dissociation of GaCl 4 - anions into Ga3+ cations at the interface is the driving force. • The permeability coefficient depends on Cl- concentrations but independent of H+ concentrations. • Low-concentration Ga(III) can be selectively separated from Fe(II), Al(III), Mg(II), and Cu(II) mixed solution. [ABSTRACT FROM AUTHOR]

A palladium-catalyzed Suzuki cross-coupling of benzyl ammonium triflates via activation of a Csp3–N bond to construct a Csp3–Csp2 bond is described. Various boronic acids can be coupled with a range of benzylamine-derived quaternary ammonium salts in 1:1 molar ratio by the bench-stable N-heterocyclic carbene palladium complex, SIPr-PdCl2-Py to afford diarylmethane derivatives. This reaction exhibits a wide substrate scope and functional group tolerance. Direct arylation of benzylamine in a one-pot process and the gram-scale reaction can be performed successfully. [ABSTRACT FROM AUTHOR]

The treatment of low-carbon steel items with hydrochloric acid solutions is used in many industrial technologies. This process is accompanied not only by metal corrosion losses, but also by hydrogen absorption by the metal. In this study, the kinetics of hydrogen cathodic reduction on low-carbon steel in 2 M HCl containing corrosion inhibitors, namely, quaternary ammonium salts and a 3-substituted 1,2,4-triazole, have been studied. Adsorption isotherms of corrosion inhibitors on cathodically polarized steel surface have been obtained. XPS data provide valuable information on the composition and structure of protective layers formed on steel in HCl solutions containing inhibitors. The main rate constants of the stages of gaseous hydrogen evolution and incorporation of hydrogen atoms into the metal have been determined. The addition of quaternary ammonium salts or 3-substituted 1,2,4-triazole inhibits the cathodic reduction of hydrogen and its penetration into steel in the HCl solution. 3-substituted 1,2,4-triazole is the most efficient inhibitor of hydrogen absorption. The inhibitory effect of this compound is caused by a decrease in the ratio of the hydrogen concentration in the metal phase to the degree of surface coverage with hydrogen. The maximum decrease in hydrogen concentration in the metal bulk in the presence of the 3-substituted 1,2,4-triazole is 8.2-fold, which determines the preservation of the plastic properties of steel as it corrodes in HCl solutions. The high efficiency of the 3-substituted 1,2,4-triazole as an inhibitor of hydrogen cathodic reduction and absorption results from strong (chemical) adsorption of this compound on the steel surface and the formation of a polymolecular protective layer. [ABSTRACT FROM AUTHOR]

Chitosan (CS) derivatives with improved water solubility, antibacterial activity and adequate biocompatibility are attracting increasingly interest in medical application. Herein, we have successfully synthesized isocyanate terminated quaternary ammonium salt (IQAS) and sulfopropylbetaine (ISB) to be readily covalently bounded to CS skeleton by selective reaction with amino and hydroxyl groups. And their molecular structures and crystallinity were confirmed by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, and X-ray diffraction. The effect of the substitution degree, carbon chain length, content ratio of IQAS/ISB on their water solubility, antibacterial activity and cytotoxicity were systematically investigated, which shows that those properties of the CS derivatives can be tailored by adjusting the grafted antibacterial agents and their additive amount. The structure-property relationship of these CS derivatives may provide a solid guidance on the development of CS derivatives for more efficient practical applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Aims: To determine the antimicrobial potency of a surface‐anchored quaternary ammonium salt (SAQAS)‐based biocide during in vitro wet and dry fomite assays and to determine the mechanism of killing bacteria on the surface. Methods and Results: Wet and dry fomite assays were established in vitro for a commercially available biocide (SAQAS‐A) applied to glass and low‐density polyethylene (LDPE) surfaces. Both wet and dry fomite tests showed the active killing of Gram‐positive and Gram‐negative bacteria but not endospores. Assays measuring membrane permeability (ATP and DNA release), bacterial membrane potential and bacterial ROS production were correlated with the time‐to‐kill profiles to show SAQAS‐A activity in suspension and applied to a surface. Conclusions: SAQAS‐A is an effective biocide against model strains of vegetative bacteria. The killing mechanism for SAQAS‐A observed minimal membrane depolarization, a surge in ROS production and assessment of membrane permeability supported the puncture of cells in both suspension and surface attachment, leading to cell death. Significance and Impact of the study: SAQAS represents effective surface biocides against single challenges with bacteria through a mechanical killing ability that supports real‐world application if their durability can be demonstrated to maintain residual activity. [ABSTRACT FROM AUTHOR]

In this study, eight hydrophobic supramolecular (SUPRA) solvents composed of tetrabutylammonium chloride and tetradecyltrimethylammonium bromide as amphiphiles and four perfluorinated compounds (hexafluoroisopropanol, trifluoroacetic acid, pentafluoropropionic acid and heptafluorobutyric acid) as coacervation-inducing agents were developed. The SUPRA phase volumes were determined as a function of individual concentrations of the system components. The extraction properties of the SUPRA solvents for the extraction of phthalates from the model aqueous solutions were investigated and their applicability as sample diluents for the reversed-phase HPLC separations of phthalates was tested. Finally, the solvent consisting of tetradecyltrimethylammonium bromide and hexafluoroisopropanol was applied for dispersive liquid-liquid microextraction of phthalates from wastewater samples prior to HPLC analysis. Under optimised extraction conditions, the enrichment factors were around 75. The calibration curves were linear (R² ≥ 0.9965) for the concentration level between 1.00 and 50.0 μg/L and the detection limits were in the range 0.3--0.6 μg/L. The recoveries of the phthalates of the developed method for the spiked wastewater samples were 93.1--104.4%, with the relative standard deviation values less than 7.4%. [ABSTRACT FROM AUTHOR]

The corrosion of industrial material is a costly problem associated with global economic losses reaching trillions of US dollars in the repair of failures. Injecting corrosion inhibitors is the most practically promising method for decelerating corrosion reactions and protecting surfaces. Recent investigations have focused on surfactants as corrosion inhibitors due to their amphiphilic nature, low cost, and simple chemical preparation procedures. This study aims to investigate the performance of an environment-friendly Quaternium-22 (Q-22) surfactant which is widely used in cosmetics for C-steel corrosion inhibition in a 5 M HCl medium. Weight loss experiments were performed at different concentrations and immersion times, presenting a maximum efficiency at 2.22 mmol·L−1. The influence of Q-22 on the corrosion behavior of C-steel was elucidated using non-destructive electrochemical measurements. The overall results revealed that adding varied concentrations of Q-22 significantly decreases the corrosion rate of C-steel. The results revealed the physisorption nature of Q-22 onto the C-steel surface, with adsorption following the Freundlich isotherm (∆ H ads = −16.40 kJ·mol−1). The relative inhibition performance of Q-22 was also evaluated by SEM and AFM analyses. Lastly, quantum chemical calculations based on density functional theory (DFT) demonstrated that Q-22 has promising molecular features concerning the anticorrosive mechanism. [ABSTRACT FROM AUTHOR]

Bifunctional solid acidic quaternary ammonium salts of Keggin-type vanadium-containing heteropoly acids, such as R3.5H0.5PVMo11O40 (R: (C2H5)4N, (C4H9)4N, (C6H13)4N), and [(C4H9)4N]4.5H0.5SiW11VO40, are capable of one-pot hydrolysis-oxidationconversion (OxFA-processing) of starch to biogenic formic acid. The impact of the reaction conditions and catalyst type was revealed. The highest formic acid yield of 50% was achieved over the best [(C2H5)4N]3.5H0.5PVMo11O40 catalyst, which was active and stable in seven reaction cycles. The kinetic computational model, which described formic acid formation well, was proposed in the presence of the most active [(C2H5)4N]3.5H0.5PVMo11O40 catalyst. [ABSTRACT FROM AUTHOR]

The activity towards superoxide anion radical (O2·−) generated in an enzymatic model system upon reduction of nitro blue tetrazolium (NBT test), as well as during non-enzymatic oxidation of adrenaline in an alkaline media, was revealed for water-soluble quaternary ammonium salts bearing 2,6-di-tert-butylphenol and pyridine moiety. An increased activity of superoxide dismutase of the Russian sturgeon liver homogenate in the presence of these salts was found. A moderate Fe2+-chelating activity relative to the EDTA standard is characteristic of these salts. Their inhibitory effect was demonstrated in model systems of non-enzymatic oxidation of cis-octadec-9-enoic acid and lipids of the Russian sturgeon liver homogenate. The highest gross antioxidant activity was found for a water-soluble quaternary ammonium salt containing the ortho-pyridinyl moiety. [ABSTRACT FROM AUTHOR]

The cationic modification technology for cotton could greatly enhance colour strength and fixation of reactive dyes. However, it is a two‐step method when cationic modification is applied to salt‐free dyeing. Cotton fabric is initially treated with a cationic compound through exhaust or pad‐cure, acid washing and drying process, then the cationic modified cotton is dyed with reactive dye. In this study, a single‐step pad‐steam cationisation and dyeing process was proposed to shorten the process and improve dye fixation. The fixation reaction between reactive dye and cotton fabrics was conducted at the temperature range 100–140°C and relative humidity range 40–90%. The effects of quaternary ammonium salt and inorganic salt as well as alkaline agent on K/S value and dye fixation were also studied. Furthermore, the drying kinetic of the wet cotton fabric was studied in this article. The result showed that the drying process fitted well to the Page model. The effective moisture diffusivity of wet cotton under different steaming conditions were calculated. An activation energy value of 32.25 kJ/mol was determined. Compared with the conventional process, a single‐step pad‐steam cationisation and dyeing process not only shortened the process but also increased K/S value and dye fixation. [ABSTRACT FROM AUTHOR]

Copyright of West China Journal of Stomatology is the property of Sichuan University, West China College of Stomatology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Compounds with antimicrobial activity have gained much attention in research due to the outbreak of coronavirus disease 2019 (COVID-19). Quaternary ammonium salts (QASs) are an emerging group of antibacterial agents that are used as disinfectants. Many studies have been carried out involving the applications of QASs as antifouling agents for the inhibition of biofilm growth on medical implants and antibacterials on surfaces and in an aquatic environment. In investigating the antibacterial activity of QASs, we addressed the structure-activity relationship and the physicochemical factors. This review is focused on the fine-tuning of the chemical structures of QASs for their applications as wide antibacterial agents. [ABSTRACT FROM AUTHOR]

For double network (DN) hydrogels, their performance can be tuned by adjusting the interaction between their two networks. A novel DN hydrogel toughening approach is proposed by employing Janus nanoparticles (JNs) as crosslinkers to gain a conjoined‐network hydrogel. First, a kind of JNs modified by amino groups and quaternary ammonium salt is synthesized, named R3N+‐JN‐NH2. The DN hydrogel is fabricated based on ionic coordination between calcium chloride (CaCl2) and sodium alginate (Alg), as well as covalent (benzoic imine) between glycol chitosan (GC) and benzaldehyde‐capped poly(ethylene oxide) (BzCHO−PEO−BzCHO). Based on the same covalent and ionic dynamic crosslinking mechanism, the added R3N+‐JN‐NH2 interacts with two networks to promote crosslinking to form a dually crosslinked structure. The R3N+‐JN‐NH2 effectively provides more energy dissipation, and the hydrogel with conjoined networks shows better compression resistance. [ABSTRACT FROM AUTHOR]

A method for the synthesis of 1-dialkylaminoalkyl-2-phenyl-4-arylidene-5-imidazolones from N-benzoyl-α,β-dehydroamino acid dialkylaminoalkylamides using trimethylchlorosilane and hexamethyldisilazane as dehydrating agents was proposed. The synthesized imidazolones were converted into the corresponding ammonium salts by reacting with various alkyl halides and acids. The anticholinesterase properties of 1-dialkylaminoalkyl-2-phenyl-4-arylidene-5-imidazolones and their quaternary ammonium salts were studied. It was found that the studied substances have anticholinesterase activity and are mainly specific for BuChE. [ABSTRACT FROM AUTHOR]

Deep eutectic solvent extraction for As, Mn, Pb, Cr, and Ni from spleen, kidney, and brain samples was investigated. The experimental parameters such as type and amount of deep eutectic solvent and sample/deep eutectic solvent ratio were optimized. The method optimization was conducted with the certified reference material (BCR 185-R). The analytical characteristics such as limits of detection and quantitation, relative standard deviation, and calibration equations were determined. Different deep eutectic solvent types were prepared and examined for better extraction. Choline chloride was used as a quaternary ammonium salt, and oxalic acid, urea, thiourea, and citric acid were used as hydrogen bond donors. Better results and recoveries higher than 90% were obtained with oxalic acid. The calculated LOD values for As, Mn, Pb, Cr, and Ni were 1.1, 0.3, 1.3, 1.4, 0.8, and LOQ values were 3.8, 1.1, 4.3, 4.7, 2.7 mg/kg, respectively. [ABSTRACT FROM AUTHOR]

In this study, environmentally friendly microcapsules with chitosan quaternary ammonium salt (HACC) and sodium alginate (SA) shells and rapeseed oil cores were used to harmlessly reduce the dangers of open pit coal mine dust to coal miners. Due to the electrostatic attraction between -NH3+ of HACC and -COOH- of SA, the complex coacervation method was used to coat the rapeseed oil core material to prepare a type of oil-based dust suppression microcapsules. Optical and scanning electron microscopy showed that the microcapsules had a spherical structure, smooth surface without holes, core-shell structure, and sustained release properties. Infrared spectroscopy and X-ray diffraction showed that HACC and SA were electrostatically attracted to form a kind of "eggshell" structure-coated core material. Thermogravimetric analysis showed that the microencapsulated rapeseed oil had good thermal stability. Performance tests showed that rapeseed oil adheres well to the dust, the shell material and the dust form a strong solid layer, and the core and shell materials work synergistically to suppress coal dust. The dust suppression rate reached up to 91.98 %. In addition, the dust suppression microcapsules have good water retention performance and degradability, which can reduce the harm to the environment. [Display omitted] [ABSTRACT FROM AUTHOR]

A new library of pinane-based 1,4-amino alcohols was synthesised and utilised as chiral ligands in enantioselective diethylzinc addition to benzaldehyde. Aldol condensation of (+)-nopinone, derived from (–)-β-pinene, with 2-pyridinecarboxaldehyde gave the key intermediate α,β-unsaturated ketone, which was transformed in diastereoselective reduction, followed by hydrogenation, resulting in 1,4-amino alcohols. On the other hand, epoxidation of the α,β-unsaturated ketone, followed by reduction and then hydrogenation of the pyridine ring, afforded a mixture of 4-amino-2,3-epoxy-1-ols. Stereoselective hydride reduction of the epoxy ketone and subsequent condensation of the resulting products with substituted benzyl bromides provided quaternary ammonium salts, which were subjected to hydride reduction and then hydrogenation, affording 4-amino-2,3-epoxy-1-ol derivatives containing an N -benzylpiperidine moiety. The inhibition of nucleophile-initiated opening of the oxirane ring was interpreted by a systematic series- of comparative Hartree–Fock modelling study using the 6-31+G(d,p) basis set. The antiproliferative activities of 4-amino-2,3-epoxy--1-ol derivatives were examined, and structure–activity relationships were studied from the aspects of the stereochemistry of the oxirane ring, saturation, and substituent effects on the piperidine ring system. [ABSTRACT FROM AUTHOR]

• Application of ten Tetraalkylammonium and phosphonium salt were evaluated as asphaltenes and dispersant. • The systematic study using UV–vis spectroscopy was done to investigate interactions between asphaltenes and organic salts based on the size and the shape of the cations and anions. • The length of alkyl chain in cations and hydrophobicity of anion have crucial role in preventing of asphaltene stacking interactions. • This mechanistic study was revealed that the role of anions on the stability of asphaltene aggregates is more important than cations. Asphaltenes deposition is one of the most severe problems in the petroleum industry, imposing high costs on oil producer companies. The use of chemical dispersants reduces the risk of asphaltene deposition. For this purpose, a variety of chemicals with different structures and functional groups were designed and synthesized. Organic quaternary salts, such as ionic liquids, have been widely used to control asphaltene deposition over the last two decades, but the mechanism of their interaction with asphaltene has not been studied in detail. In this study, the interaction of ten commercial quaternary ammonium and phosphonium salts with asphaltene molecules was investigated using ultraviolet-visible (UV-Vis) spectroscopy. It was observed that the size, shape, and hydrophobicity of their cations or anions play an essential role in the dispersion of asphaltene aggregations. The results showed that the interaction of these quaternary salts is strongly influenced by the hydrophobic nature of the salt, and salts with more hydrophobic cations and anions, such as tetrabutylammonium iodide, tetrabutylammonium hexafluorophosphate, and cetyltrimethylammonium bromide, can better disperse asphaltene aggregations. The results also revealed that the role of anions such as iodide, and hexafluorophosphate in the dispersion of asphaltene aggregates is more important than cations. In addition, the results showed that except for tetramethylammonium bromide, the efficiency of the salts was increased with increasing concentration. [ABSTRACT FROM AUTHOR]

Surface modification of fabrics is a powerful strategy that can endow fabrics with desired effects while keeping the intrinsic properties. Herein, an ordinary strategy, dipping-drying based layer-by-layer self-assembly (LbL) coating, is reported to functionalize fabrics' surfaces. Firstly, the novel cation waterborne polyurethanes (QAHDPU) and anion waterborne polyurethanes (HDPU) are successfully designed and synthesized. By incorporating targeted molecule, hydantoin diol (HD) and quaternary ammonium salt with long alkyl chain (DOQA), the QAHDPU are antibacterial and hydrophobically functionalized. Taking advantage of strong adhesion, waterborne polyurethanes (WPUs) are physically bonded to surfaces of fabrics to generate durable antibacterial and hydrophobic fabrics. The QAHDPU with long alkyl chain combined with rough and porous fabric surface fabricates hydrophobic fabric surface, which can prevent bacteria from adhering to the fabrics. Furthermore, the coated fabrics present excellent antibacterial properties after chlorination, forming a second barrier against bacteria. The chlorinated coated fabrics, can inactivate 85.0–99.9% of Staphylococcus aureus and 85.0–97.7% of Escherichia coli with contact time of 60 min. The hydrophobic properties of coated fabrics are greatly improved with water contact angles of 122.0°–141.1°. In addition, the proposed method is applicable for a variety of fibers and expected to be used for industrial production. [ABSTRACT FROM AUTHOR]

As an organic cation, quaternary ammonium salt was introduced as a control agent to synthesize silver nanowires. The important influence of quaternary ammonium salt on the preparation of silver nanowires was seriously investigated by varying the length of carbon chain and its amount. Results showed that using quaternary ammonium salt as the control agent can successfully control the growth of silver nanowires, of which the diameters ranging from 35.06 to 46.60 nm. The diameters of the as‐prepared silver nanowires tended to be smaller with a longer carbon chain. This work provides a new aspect for controllable preparation of silver nanowires. Furthermore, the as‐prepared silver nanowires were used to prepare transparent electrodes. They exhibited good optical performance with 95.6% transmittance at a low sheet resistance of 18 Ω/square, demonstrating their great potential in the application for touch screens. [ABSTRACT FROM AUTHOR]

Aqueous zinc-based rechargeable batteries, such as Zn-Ni and Zn-Air, have been increasingly re-investigated over the last decade due to the abundant and inexpensive nature of zinc, the high solubility of zinc ions, and rapid kinetics and most negative standard potential of the Zn(II)/Zn redox couple in aqueous media. However, the overwhelming challenge that has prevented the implementation of next-generation Zn batteries lies in their poor rechargeability—flowing electrolytes have proven to be of benefit to zinc deposition and dissolution cycling, but the rapid zinc deposition–dissolution at practical current densities of 100 mA cm2 or over is still questionable. Herein, we demonstrated that applying an optimal concentration of quaternary ammonium electrolyte additives with carefully selected cations' alkyl groups can effectively improve the high-rate zinc cycling performance at 100 mA cm2/20 mAh cm2. The resultant additives significantly reduced the initial coulombic efficiency loss to only 1.11% with coulombic efficiency decay rate of 0.79% per cycle, which is less than a quarter of the benchmark of 6.25% and 3.75% per cycle for no additives. [ABSTRACT FROM AUTHOR]

Background: Chloride measurement is crucial for calculating the anion gap. Bicarbonate can interfere with chloride measurements; however, there is no information on the specific types of electrodes affected or the changes in bicarbonate non-selectivity over time. We evaluated the interference of bicarbonate on chloride measurements using different electrodes and the stability of this interference over time. Methods: The effect of bicarbonate on chloride measured with electrodes of various manufacturers was assessed. When non-selectivity toward bicarbonate was observed, the stability of this interference during the electrode’s lifetime was explored. The impact of the bicarbonate concentration on the calibrator was also evaluated. Results: Non-selectivity was observed for electrodes using quaternary ammonium salts (Beckman Coulter, Siemens, and Roche), with overestimated or underestimated chloride values observed at high or low bicarbonate concentrations, respectively. The degree of selectivity varied among electrodes. With the Roche electrode, interference became more pronounced over time, whereas the Siemens electrode appeared to gain selectivity during its lifetime. For the Roche system, adjusting the calibrator’s bicarbonate concentration from 30 mmol/L to 20–24 mmol/L reduced the number of samples with unacceptable bias (>3%) from 77.3% to 12.6%. Lot-to-lot variations in the calibrator bicarbonate concentration increased the uncertainty of chloride measurements. Conclusions: The extent of bicarbonate-induced error varied accor [ABSTRACT FROM AUTHOR]

Copyright of Electroplating & Finishing is the property of Electroplating & Finishing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)