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Though massive efforts have been devoted to exploring Br‐based batteries, the highly soluble Br2/Br3− species causing rigorous "shuttle effect", leads to severe self‐discharge and low Coulombic efficiency. Conventionally, quaternary ammonium salts such as methyl ethyl morpholinium bromide (MEMBr) and tetrapropylammonium bromide (TPABr) are used to fix Br2 and Br3−, but they occupy the mass and volume of battery without capacity contribution. Here, we report an all‐active solid interhalogen compound, IBr, as a cathode to address the above challenges, in which the oxidized Br0 is fixed by iodine (I), thoroughly eliminating cross‐diffusing Br2/Br3− species during the whole charging and discharging process. The Zn||IBr battery delivers remarkably high energy density of 385.8 Wh kg−1, which is higher than those of I2, MEMBr3, and TPABr3 cathodes. Our work provides new approaches to achieve active solid interhalogen chemistry for high‐energy electrochemical energy storage devices. [ABSTRACT FROM AUTHOR]

In order to develop multifunctional quaternary ammonium salts and explore their advantages as modifiers for wastewater treatment, castor oil-based quaternary ammonium salts were synthesised and subsequently used as modifiers for attapulgite treatment. The structures of untreated and treated attapulgite were compared by Fourier transform infrared spectra and X-ray diffraction. The mechanism of modification was speculated. Various factors such as the amount of modified attapulgite, temperature and pH were also investigated in the batch experiments on the removal rates of acetone and phenol from wastewaters. The synthesis conditions were set as follows: the reaction temperature was 80 °C, the reaction time was 8 h, the molar ratio of castor oil to N,N-dimethyl-1,3-propanediamine was 1:5, the catalyst was 6% NaOH and the product yield was about 64.72%. The grafting rate of the castor oil-based quaternary ammonium salt was about 99.6% when the amount of modifier was 0.69 g per 5 g of attapulgite, the ultrasound treatment time was 11 min and the pH was 5. The quaternary ammonium salt was only associated with the surface of attapulgite and did not change the rod-like crystal structure of the silicate. The modified attapulgite is much more fibrous and exhibits a good distribution of crystal bundles. The removal rates were found to be less favourable under strongly acidic and strongly alkaline conditions. Under suitable conditions, for 50 mL industrial wastewaters (phenol: 100–160 mg/L; acetone: 680–800 mg/L), the amount of modified attapulgite was 1 g, the temperature was 80 °C and the pH was 7, and the maximum removal rates of acetone and phenol after 80 min reached about 65.71% and 78.72%, respectively, which were higher than those of ATP. [ABSTRACT FROM AUTHOR]

A series of phosphorylated quaternary ammonium salts (QASs) containing isobutyl substituents on the phosphorus atom and higher alkyl substituents on the nitrogen atom were prepared in two steps. The QASs containing octyl to tetradecyl substituents on the nitrogen atom showed high antimicrobial activity against B. cereus, S. aureus, and E. coli bacterial strains, as well as C. albicans fungal strain, whereas hexa- and octadecyl-substituted QASs were inactive against the test pathogenic strains of microorganisms. As shown by 31Р NMR spectroscopy, the synthesized QASs underwent hydrolysis in air to form the corresponding phosphorylated betaines. [ABSTRACT FROM AUTHOR]

In this paper, a novel hydroxyl-containing quaternary ammonium surfactant N-(2-Hydroxyethyl)-N, N-dimethyl-3-[(1-oxododecyl)amino]-1-propanaminium (LPDC) was synthesized and introduced as a collector for the reverse cationic flotation separation of apatite from quartz; the adsorption mechanisms between LPDC and two mineral surfaces were investigated by Fourier transform infrared spectrometer (FTIR), zeta potential measurements and X-ray photoelectron spectroscopy (XPS) analysis. The micro-flotation tests showed that LPDC exhibited excellent flotation performance. When the pulp was at natural pH and LPDC concentration was 25 mg/L, the apatite concentrate with a P2O5 recovery of 95.45% and P2O5 grade of 38.94% could be obtained from artificially mixed minerals. FTIR, zeta potential, and XPS analysis indicated that the adsorption of LPDC onto quartz surface is stronger than that onto apatite surface; meanwhile, the adsorption of LPDC onto quartz surface is mainly provided by electrostatic force and hydrogen bonding. [ABSTRACT FROM AUTHOR]

There is an urgent requirement to advance ecofriendly antimicrobial polymers for solving the bacterial infections. Polymers with quaternary ammonium/phosphonium salts are considered one of the most promising materials for the antibacterial efficacy. Thus, in this trend, pluronic F68 was modified with chloroacetyl chloride, followed by treating with triethyl amine (TEA), triphenyl phosphine (TPP) and tributyl phosphine (TBP) to insert quaternary ammonium and phosphonium salts onto the polymer chain. The structural characterization of the modified polymers was determined by FT-IR, NMR spectroscopy, elemental analysis and TGA. The pluronic F68 and modified pluronic F68 were electrospun to fabricate nanofibers using cellulose acetate as a co-spinning agent and acetone/DMF (2:1) as a solvent. The morphology of the electrospun nanofibers is observed by scanning electron microscope (SEM). The antibacterial activities of the pluronic F68 and its derivatives against gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae, and Proteus vulgaris) and gram-positive bacteria (Staphylococcus aureus) were evaluated. All polymers exhibited high antibacterial activity against all the tested microorganisms. Chloroacetylated pluronic F68 (II) exhibited the highest activity against Staphylococcus aureus. On the other hand, tributyl phosphonium salt (V) showed the highest activity against Proteus vulgaris. The minimal inhibitory concentrations (MICs) studies showed that polymer (II) exhibited the highest activity against S. aureus and E. coli. Polymer (V) showed a moderate activity against E. coli. For cytotoxic activity, polymers showed moderate to strong effect against MCF-7 and Hela. [ABSTRACT FROM AUTHOR]

The analysis of the influence of dehydration and solvation (by proton-donor reagents) of halide anions in the organic phase on the processes of their solvent extraction separation with salts of quaternary ammonium bases has been carried out. The possibility of a significant increase in the separation factors of anions in the F-Cl-Br-I series due to endothermic dehydration of amine salts (Aliquat 336) in systems with "weak" proton-donor reagents, such as chloroform has been shown. In particular, the separation factors of the Cl/F pair increase by almost 15 times when going from Aliquat 336 solutions in toluene to extractant solutions in chloroform, for the Br/Cl pair, this increase is up to 5 times, and for I/Cl, about 3 times. In similar systems with additions of alcohols and phenols to the extractant (exothermic dehydration), there is a significant deterioration in the separation parameters of halides. The conclusions are confirmed by the data of 1H NMR studies, which also made it possible to establish some details of the processes of dehydration of amine salts in the studied systems. [ABSTRACT FROM AUTHOR]

Eight N-[2-(2′,3′,4′-tri-O-acetyl-α/β-d-xylopyranosyloxy)ethyl]ammonium bromides, a new class of d-xylopyranosides containing a quaternary ammonium aglycone, were obtained. Their complete structure was confirmed using NMR spectroscopy (1H, 13C, COSY and HSQC) and high-resolution mass spectrometry (HRMS). An antimicrobial activity against fungi (Candida albicans, Candida glabrata) and bacteria (Staphylococcus aureus, Escherichia coli) and a mutagenic Ames test with Salmonella typhimurium TA 98 strain were performed for the obtained compounds. The greatest activity against the tested microorganisms was shown by glycosides with the longest (octyl) hydrocarbon chain in ammonium salt. None of the tested compounds exhibited mutagenic activity in the Ames test. [ABSTRACT FROM AUTHOR]

Abstract Secondary Zn–based batteries are a valid alternative to Li for stationary storage, but commercial devices are not yet available, chiefly owing to anode shape‐change and passivation issues. Mildly acidic aqueous solutions are actively studied, since they seem to limit unstable growth of Zn, with respect to the alkaline ones, customary for primary batteries. Additives can further improve the performance of mildly acidic electrolytes. In this work we focus on the impact of a series of quaternary ammonium salts (TBAB, CTAB, DMDTDAB, BDMPAC, BPPEI, PDADMAC), selected to represent a comprehensive range of molecular functionalities. Electrochemical measurements (cyclic voltammetry, chronopotentiometry and galvanostatic‐cycling in split‐cells), combined with 2D and 3D imaging techniques (SEM, stereomicroscopy and in situ tomography) were adopted for the assessment Zn behaviour. This multi‐technique approach pinpointed TBAB as the single most effective additive for low‐current density operation, while at high current densities the additive‐free electrolyte allows better cycling performance, coherently with similar results for alkaline electrolytes.

The source of dyeing wastewater and the composition of pollutants are very complex, direct discharge will bring great harm to living environment, and cause waste of water resources. For the treatment of reactive dyeing wastewater, this work developed and synthesized a novel cationic flocculant called Poly (DMDAAC‐co‐DAMBAC), which was made by copolymerizing dimethyl‐diallyl‐ammonium chloride (DMDAAC) and methyl‐benzyl‐diallyl‐ammonium chloride (DAMBAC). To assess its flocculation effects, flocculation decolorization studies with 3RF reactive yellow, KN−R reactive blue, and 3BF reactive red were conducted. The copolymers′ lipophilicity considerably increased once atyl groups were added. The experimental results showed that Poly(DMDAAC‐co‐DAMBAC) had an optimal decolorization rate of over 94 % for three reactive dyes and a maximum decolorization rate of roughly 80 % for CODMn, both of which were significantly higher than those of PDMDAAC and nearly on par with those of PDAMBAC with a comparable viscosity. Instead, Theoretical calculations of the binding energy of the results demonstrated the accuracy of the findings. The study illustrated the flocculation mechanism and laid the foundation for further application of Poly(DMDAAC‐co‐DAMBAC). [ABSTRACT FROM AUTHOR]

A new synthetic material, namely, (3-(((4-((5-(((S)-hydroxyhydrophosphoryl)oxy)-2-nitrobenzylidene) amino) phenyl) imino) methyl)-4-nitrophenyl hydrogen (R)-phosphonate)), was subjected to a quaternary ammonium salt and named (HNAP/QA). Several characterizations, such as FTIR spectrometry, 1H-NMR analysis, 13C-NMR analysis, 31P-NMR Analysis, TGA analysis, and GC-MS analysis, were performed to ensure its felicitous preparation. HNAP/QA is capable of the selective adsorption of W(VI) ions from its solutions and from its rock leachate. The optimum factors controlling the adsorption of W(VI) ions on the new adsorbent were studied in detail. Furthermore, kinetics and thermodynamics were studied. The adsorption reaction fits the Langmuir model. The sorption process of the W(VI) ions is spontaneous due to the negative value of ∆G° calculated for all temperatures, while the positive value of ∆H° proves that the adsorption of the W(VI) ions adsorption on HNAP/QA is endothermic. The positive value of ∆S° suggests that the adsorption occurs randomly. Ultimately, the recovery of W(IV) from wolframite ore was conducted successfully. [ABSTRACT FROM AUTHOR]

The preparation technology of sustained release is a significant value of fragrance microcapsules. This article used quaternary ammonium chitosan (HACC) with antibacterial properties as the shell material. To research the factors affecting the density, encapsulation ratio and sustained‐release of the shell material of the coated fragrance microcapsules. According to the in‐situ polymerization method, fragrance microcapsules were prepared with aldehyde fragrance 7328 as the core material, TiO2 modified HACC as the shell material and glutaraldehyde as the crosslinking agent. During preparation, the effects of emulsification speed, pH and core‐shell ratio on the encapsulation ratio were explored. The results showed that under the conditions of the core‐shell ratio of 3:1 and emulsification speed of 1000 rad/min, when the shell material is modified with TiO2 and kh550, the encapsulation ratio can be reached 71.74%, which was increased by 41.5% compared with the unmodified microcapsules. And the sustained‐release time can last as long as 29 days, which was 18 days higher than that of unmodified microcapsules. [ABSTRACT FROM AUTHOR]

The solvent extraction of the 90Y/90Sr pair from carbonate media with mixtures of aromatic dihydroxy compounds and a quaternary ammonium salt—methyltrioctylammonium carbonate (MTOAC)—in toluene and butyl acetate was studied. It was found that MTOAC increases the distribution coefficients of both the extractant itself and its solvate with yttrium due to the formation of a mixed complex of yttrium and a dihydroxyaromatic ligand with MTOAC. During extraction from alkaline carbonate media in the pH range of 12–13.5 with mixtures of 0.01 M 2,3-dihydroxynaphthalene and 0.015 M MTOAC in butyl acetate or toluene, the distribution coefficients of yttrium exceed 80; the separation factors of the 90Y/90Sr pair under these conditions are more than 105. Dilute solutions of hydrochloric, nitric, and sulfuric acids can be used for the complete stripping of yttrium. The studied mixtures are chemically stable and do not change the extraction properties upon multiple extraction/stripping cycles. Model experiments on the leaching of yttrium from natural samples showed that the percentage of stable yttrium extraction from sand is 70–80%, while the percentage of yttrium extraction from soil is 50–60%. [ABSTRACT FROM AUTHOR]

Biological degradation of documentary heritage is a serious issue faced by libraries, museums and archives as it can lead to paper becoming brittle, fragile and discoloured, resulting in a loss of information. This study investigates the impact of didecyldimethylammonium bromide (DDAB) on the properties of pure or inked paper and the growth of different types of fungi. Three fungi species known for their ability to cause paper biodete-rioration in libraries and museums, Aspergillus clavatus Desm, Penicil-lium paneum Frisvald and Ulocladium chartarum Preuss, were selected for the DDAB salt antifungal activity test. The study measured the pH and degree of polymerization (DP), monitored colour changes and conducted scanning electron microscopy analyses (SEM) to confirm that DDAB can be used as a biocide for fungi on pure or inked paper. The study also investigated the antifungal effect of DDAB on paper treated with different types of ink, including black (iron-gall ink) and brown (copper ink). Didecyldi-methylammonium bromide (DDAB) can be used as a biocide for cleaning and preserving paper documents, with active concentrations of 0.7 and 1%. [ABSTRACT FROM AUTHOR]

Six quinoline derivatives containing quaternary ammonium salts and acyl chloride groups were synthesized from ethyl 8-chloro-[1,3]dioxolo[4,5-g]quinoline-7-carboxylate in several step. With berberine as the positive control, three human cancer cell lines (HCT-116, Hela and A549) and human normal liver L-02 cell lines were used to evaluate the cytotoxicity of the newly synthesized compounds in vitro. Compound (V–X) showed good antitumor activity, and the test result of compound (VII) was better than that of positive control group. In terms of antibacterial activity, compound (V–X) has obvious inhibitory effect on Staphylococcus aureus (ATCC 29213) and Escherichia coli (ATCC 8739), and its antibacterial activity is about 1–4 times that of positive control amoxicillin and 1–2 times that of ciprofloxacin. Among them, the most effective compounds (VII) and (X) have 4-fold the antibacterial activity of amoxicillin and 2-fold the antibacterial activity of ciprofloxacin. [ABSTRACT FROM AUTHOR]

The reaction of octakis(3-chloropropyl)octasilsesquioxane with four equivalents of 1-hexylimidazole or 1-decylimidazole gave two products labelled as HQ-POSS (hexyl-imidazolium quaternized POSS) and DQ-POSS (decyl-imidazolium quaternized POSS) as regioisomer mixtures. An investigation of the biological activity of these two compounds revealed the higher antimicrobial performances of HQ-POSS against Gram-positive and Gram-negative microorganisms, proving its broad-spectrum activity. Due to its very viscous nature, HQ-POSS was adsorbed in variable amounts on the surface of biologically active oxides to gain advantages regarding the expendability of such formulations from an applicative perspective. Titania and 5 wt% Cu on titania were used as supports. The materials 10HQ-POSS/Ti and 15HQ-POSS/5CuTi strongly inhibited the ability of Pseudomonas PS27 cells—a bacterial strain described for its ability to handle very toxic organic solvents and perfluorinated compounds—to grow as planktonic cells. Moreover, the best formulations (i.e., 10HQ-POSS/Ti and 15HQ-POSS/5CuTi) could prevent Pseudomonas PS27 biofilm formation at a certain concentration (250 μg mL−1) which greatly impaired bacterial planktonic growth. Specifically, 15HQ-POSS/5CuTi completely impaired cell adhesion, thus successfully prejudicing biofilm formation and proving its suitability as a potential antifouling agent. Considering that most studies deal with quaternary ammonium salts (QASs) with long alkyl chains (>10 carbon atoms), the results reported here on hexylimidazolium-based POSS further deepen the knowledge of QAS formulations which can be used as antifouling compounds. [ABSTRACT FROM AUTHOR]

Objective Benzyl quinolinium quaternary ammonium salt (BQC) is a common acidizing corrosion inhibitor, but a derivative, benzyl quinoline quaternary ammonium salt dimer (BQD) was found in the synthesis process of BQC, which has more efficient corrosion inhibition effect on metal corrosion. In order to determine the effective content of BQD in the synthesis, a quantitative nuclear magnetic resonance hydrogen spectrum method was established for the determination of BQD content. Methods BQD was synthesized and purified, and its structure was characterized by elemental analysis, HPLC-HRMS, NMR and FT-IR. The effective content of the synthesized BQD product was studied by using CDCl3 as solvent, and the proton signals peaked at around δ12 for BQD and around δ5 for CH2Br2 were selected as the quantification peaks. By comparing the area of the two peaks, the effective content of BQD in the product was calculated. Results The sample test results showed that the content of BQD was 11.6%, which was basically consistent with the experimental results of adding pure BQD. Conclusion The ¹H NMR internal standard method established in this paper is a simple, rapid, and reliable method for determining BQD content in BQC. [ABSTRACT FROM AUTHOR]

The influence of eight different quaternary ammonium and phosphonium salts on the vulcanization of natural rubber was investigated. The central atom (P or N) of the cation was of minor importance, but the nature of the organic chains greatly affected the rheometrical parameters of the process and the mechanical properties of the vulcanizates. Some of the salts, especially the tetrabutylphosphonium and tetrabutylammonium bromides, reduced the optimum cure time and provided greater resistance to the vulcanized rubber. Studies of rubber compositions containing binary mixtures of a quaternary salt and the commercial accelerators ZDEC, TBBS, TMTD and MBTS showed a synergistic effect, mainly with TBBS and MBTS. With such binary systems, it is possible to reduce the amount of accelerator and improve the vulcanization parameters and the quality of the vulcanized rubber. The anionic complex bis(N-phenylsulfonyldithiocarbimato)zincate(II) (Z), one amine-free experimental accelerator, was prepared and isolated as tetrabutylammonium (B2Z) and benzyltriphenylphosphonium (H2Z) salts. The H2Z complex salt is a new substance and behaved as an ultra-accelerator, being faster than ZDEC and TMTD. B2Z was a medium rate accelerator, being faster than TBBS and similar to MBTS. In addition, the tensile and tear strength of the specimens vulcanized with the zinc-dithiocarbimate salts were superior when compared to compositions containing the commercial accelerators. The differences in the behavior of B2Z and H2Z showed that the zinc-dithiocarbimates are versatile accelerators for natural rubber as the process and the quality of the vulcanizate can be modulated by the choice of the cation. [ABSTRACT FROM AUTHOR]

The P(CS-CO-EGDE) was synthesized with cysteamine hydrochloride, glycol diglycidyl ether as raw materials. The structure was characterized by infrared spectrometer. And the corrosion behaviours of Q235 carbon steel in sulfamic acid with the P(CS-CO-EGDE) were studied by means of corrosion weight-loss measurement, polarization curve measurement and electrochemical impedance spectroscopy. The results showed that the poly(CS-CO-EGDE) was a hybrid inhibit with the same performance as heptadie- nylamine ethyl imidazoline quaternary ammonium salt. When the dosing concentration of synthetic product was 40 mg/L,the corrosion rate of Q235 carbon steel was 0.8155g/(m²·h),which was lower than the control index requirement of GB/T 25146—2010 that the laboratory verification result of carbon steel cor- rosion rate had to be lower than 2g/(m²·h). [ABSTRACT FROM AUTHOR]

Copyright of Polimery is the property of Industrial Chemistry Research Institute 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.)

Copyright of Polimery is the property of Industrial Chemistry Research Institute 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.)

A highly efficient biocide and an easily applicable procedure are two keys for antibacterial modification of cotton cellulose. A quaternized di-N-chloramine silicone that contains complementary functionalities of one quaternary ammonium salt (QAS) and two N-chloramine sites (an amidic one and an imidic one) in each composite unit was synthesized to better contact with bacteria to exert super biocidability. Briefly, Knoevenagel condensation between hydantoin with 4-dimethylaminobenzaldehyde produced a compound with one amidic and one imidic nitrogens and one tertiary amine. The tertiary amine of the Knoevenagel product was quaternized with 3-chloro-1-propanol whose hydroxyl group was subsequently bonded to poly(methylhydrosiloxane) via silane alcoholysis. The silane alcoholysis product was interpenetrated into cotton cellulose at 50 °C and 28 MPa in supercritical CO2 (scCO2) and its amidic and imidic nitrogens were then chlorinated to form a 76 nm quaternized di-N-chloramine silicone layer. Biocidal assay proved that QAS and N-chloramine sites functioned synergistically, eliminating ~ 7 log of S. aureus and E. coli at a much faster rate (in 3 min) than each functionality. The scCO2 interpenetration produced a durable modification layer as shown by stability tests without the reliance upon chemical linkages and hence can be transferable to substrates with different components. [ABSTRACT FROM AUTHOR]

There are practically no disinfectants on the market of veterinary drugs that fully meet the requirements. This is due to the significant diversity and peculiarity of the structure of microorganisms and their ability to form resistance during long-term use of the same disinfectants. This is one of the reasons for the active search for effective active substances, the development of new drugs, and their registration, contributing to quite intensive changes in the range of disinfectants on the market. The work aimed to analyze the production, determine the share of domestic and imported disinfectants, determine the main active substances, and the range of disinfectants registered in Ukraine. The research material was a list of disinfectants registered in Ukraine used in animal husbandry, veterinary and humane medicine, and the food industry. It was established that from 2018 to 2022, 66 domestic and imported disinfectants were registered in Ukraine. Imported disinfectants are produced mainly in Great Britain, France, Belgium, Spain, Germany, Israel, Slovenia, Denmark, and the Netherlands. From among domestic companies, PP “Kronos Agro”, LLC “BioTestLab”, LLC “SANFORT-P”, LLC “Brovapharma”, LLC “Ukrvetprompostach”, LLC “Ukrainian-Polish joint enterprise “ZVK”, LLC “VetAgro” are engaged in the production of disinfectants, LLC “Inter-Syntez”, LLC “Ukrainian Chemical Technologies LTD”, LLC “GREENPAKS”, LLC NVK “Globus”, LLC “Vetsyntez”, PF “Termit”, LLC “ABM-Trade”, LLC “Dezsystema”, LLC “Tandem-2002”, NVPP “DEZO” and LLC “UKRTEK KO”. It was determined that manufacturers often use chlorine and oxygen as active ingredients, and the number of products with one active ingredient is relatively insignificant. Most often, the active substance of modern disinfectants is quaternary ammonium salts in combination with aldehydes. Their number is 33.4 % of all registered means. This means combining QAS and acids and QAS and oxygen compounds takes 3.2 times less time. Means containing other combinations of active substances are from 1.5 to 4.6 %. It was established that the leader in the production of imported “cleansing probiotics” (PIP – Probiotics In Progress) is the British company “Ingenious Probiotics”, which produces 66.7 % of registered products. Three companies produce this kind of disinfectant in our country; their assortment includes 23 names, and the largest share belongs to the company “Sirion”. [ABSTRACT FROM AUTHOR]

Archives, ancient books, and documents kept in museums and libraries are the carriers of historic and cultural information left by our ancestors. However, these paper cultural relics can show notorious signs of degradation, e.g., fungal development. Due to the organic components of paper objects, they suffer from fungal biodeterioration. The excreted substances of fungi and the fungi's structures themselves are often colored and interfere with the readability of the artifacts, diminishing their artistic and monetary values. In this study, we collected and separated the moldy archives collected in the Archives of Shaanxi Province (China) and obtained the identification results of eight kinds of molds. Clotrimazole (CTZ) and quaternary ammonium salt chitosan (HACC) were combined to prepare a microemulsion. Synergies of CTZ and HACC could enhance the antifungal effect and reduce the required concentration of a single drug. The composite emulsion could effectively improve the retention of drugs on the surface of paper cultural relics, improve the solubility of hydrophobic drugs, and provide a data basis for the anti-mold preservation of paper cultural relics. [ABSTRACT FROM AUTHOR]

Herein, we describe a one-step method for synthesizing cationic acrylate-based core-shell latex (CACS latex), which is used to prepare architectural coatings with excellent antimicrobial properties. Firstly, a polymerizable water-soluble quaternary ammonium salt (QAS-BN) was synthesized using 2-(Dimethylamine) ethyl methacrylate (DMAEMA) and benzyl bromide by the Hoffman alkylation reaction. Then QAS-BN, butyl acrylate (BA), methyl methacrylate (MMA), and vinyltriethoxysilane (VTES) as reactants and 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AIBA) as a water-soluble initiator were used to synthesize the CACS latex. The effect of the QAS-BN dosage on the properties of the emulsion and latex film was systematically investigated. The TGA results showed that using QAS-BN reduced the latex film's initial degradation temperature but improved its thermal stability. In the transmission electron microscopy (TEM) photographs, the self-stratification of latex particles with a high dosage of QAS-BN was observed, forming a core-shell structure of latex particles. The DSC, TGA, XPS, SEM, and performance tests confirmed the core-shell structure of the latex particles. The relationship between the formation of the core-shell structure and the content of QAS-BN was proved. The formation of the core-shell structure was due to the preferential reaction of water-soluble monomers in the aqueous phase, which led to the aggregation of hydrophilic groups, resulting in the formation of soft-core and hard-shell latex particles. However, the water resistance of the films formed by CACS latex was greatly reduced. We introduced a p-chloromethyl styrene and n-hexane diamine (p-CMS/EDA) crosslinking system, effectively improving the water resistance in this study. Finally, the antimicrobial coating was prepared with a CACS emulsion of 7 wt.% QAS-BN and 2 wt.% p-CMS/EDA. The antibacterial activity rates of this antimicrobial coating against E. coli and S. aureus were 99.99%. The antiviral activity rates against H3N2, HCoV-229E, and EV71 were 99.4%, 99.2%, and 97.9%, respectively. This study provides a novel idea for the morphological design of latex particles. A new architectural coating with broad-spectrum antimicrobial properties was obtained, which has important public health and safety applications. [ABSTRACT FROM AUTHOR]

The development of hydrogels as wound dressings has gained considerable attention due to their promising ability to promote wound healing. However, in many cases of clinical relevance, repeated bacterial infection, which might obstruct wound healing, usually occurs due to the lack of antibacterial properties of these hydrogels. In this study, we fabricated a new class of self-healing hydrogel with enhanced antibacterial properties based on dodecyl quaternary ammonium salt (Q12)-modified carboxymethyl chitosan (Q12-CMC), aldehyde group- modified sodium alginate (ASA), Fe3+ via Schiff bases and coordination bonds (QAF hydrogels). The dynamic Schiff bases and coordination interactions conferred excellent self-healing abilities to the hydrogels, while the incorporation of dodecyl quaternary ammonium salt gave the hydrogels superior antibacterial properties. Additionally, the hydrogels displayed ideal hemocompatibility and cytocompatibility, crucial for wound healing. Our full-thickness skin wound studies demonstrated that QAF hydrogels could result in rapid wound healing with reduced inflammatory response, increased collagen disposition and improved vascularization. We anticipate that the proposed hydrogels, possessing both antibacterial and self-healing properties, will emerge as a highly desirable material for skin wound repair. [ABSTRACT FROM AUTHOR]

[Display omitted] • PLA-based nanofibrous wound dressings were developed with organomodified nanoclay (OMMT) and various boron compounds. • Unlike the literature, different boron compounds, boron nitride, zinc borate and phenyl boronic acid were used. • The addition of OMMT and B compounds enhanced the thermal stability, antibacterial effect, and hydrolytic degradation rate of the PLA. • ATR-FTIR analysis supported the intercalated composite formation. • Matrices including zinc borate and phenyl boronic acid demonstrated both bacteriostatic and bactericidal effects. In this study, nanofibrous polymeric matrices were successfully developed with nanoclay, montmorillonite (MMT) and various boron (B) compounds, which were known to have positive effects on the wound healing with elevated antibacterial properties. For this purpose, MMT was modified with quaternary ammonium salt, trimethyl octadecyl ammonium bromide (TMOD), and boron compounds, boron nitride (BN), zinc borate (ZB), or phenylboronic acid (PBA) were adsorbed on organomodified MMT (OMMT). Then, poly (lactic acid) (PLA) based nanofibrous PLA-OMMT/B composites were fabricated via electrospinning. Modification of MMT nanoparticles with TMOD occurred through ion-exchange reaction and led to better homogenous fibrous structures which exhibited dramatic inhibition for gram-positive bacteria. Moreover, composites with ZB and PBA demonstrated both bacteriostatic and bactericidal effects for gram-positive and gram-negative bacteria. The chemical structures of the matrices were evaluated through ATR-FTIR and supported the intercalated composite formation. The thermal and mechanical stabilities of PLA matrices were also enhanced after OMMT and B incorporation. The lowest breaking strain value was recorded for PLA-OMMT/PBA composite compared to other B composites. The 100% and 50% extracts of the PLA-OMMT matrices showed modest cytotoxic effect on the human dermal fibroblasts (NHDF) on the second day culture that probably originated from TMOD. These results demonstrated that PLA-OMMT/B matrices, especially PBA including matrices, can be used as replaceable wound dressings that have limited interaction with cells but exhibit antibacterial activity and support the early stages of wound healing both morphologically and chemically. [ABSTRACT FROM AUTHOR]

In the present study, gelatin (Ge) and polyvinyl alcohol (PVA) were used in order to synergize and strengthen as much as possible the various properties of the final matrix. To create antimicrobial properties in wound dressings, quaternary ammonium salt with silane was synthesized based on natural castor oil (CO), with the ability to bind to the polymer-siloxane network structure. The characterization and confirmation of the final structure and the detailed investigation of the chemical synthesis path of the antimicrobial agent were performed through the analysis of the data obtained from the ATR- FTIR methods. The high gel content values of the prepared films indicate the favorable cross-linking of the polymers in the structure of the wound dressings. Also, the observation of water absorption of wound dressings in the range of 220.1–351.6% confirms the high ability of polymer wound dressings to retain and absorb wound secretions. The level of hydrophilicity of the wound dressing surface was investigated by measuring the contact angle. The contact angles of all the films were less than 90º, which indicates the hydrophilic nature of the prepared films. The water vapor transmission rate (WVTR) of the wound dressings prepared in the range of 2224–2243 g/ m2/ day showed that the samples have the necessary ability as absorbent wound dressings to create a moist environment in the bed of wounds with medium to heavy discharge. The results obtained from the tensile test in both dry and wet conditions showed that the tensile strength of the prepared films was in a suitable range and comparable to the tensile strength of the skin. This combination of antibiotic/inhibitor with appropriate charge density and hydrophobicity is able to interact favorably with the bacterial membrane and has sufficient antibiotic properties against Gram-positive and Gram-negative bacteria. [ABSTRACT FROM AUTHOR]

The objectives of this study were to incorporate dimethylaminohexadecyl methacrylate (DMAHDM) into resin-modified glass ionomer cement (RMGI) to develop a novel orthodontic cement which endowed RMGI with strong antibacterial ability and investigated its modulation biofilm equilibrium from cariogenic state to non-cariogenic state for the first time. Cariogenic Streptococcus mutans (S. mutans), and non-cariogenic Streptococcus sanguinis (S. sanguinis) and Streptococcus gordonii (S. gordonii) were selected to form a tri-species biofilm model. RMGI incorporated with different mass fraction of DMAHDM was examined: biofilm colony-forming units, metabolic activity, live/dead staining, lactic acid and exopolysaccharides productions. TaqMan real-time polymerase chain reaction was used to determine changes of biofilm species compositions. The results showed RMGI containing 3% DMAHDM achieved strong antibacterial ability and suppressed the cariogenic species in biofilm, modulating biofilm equilibrium from cariogenic state to non-cariogenic state tendency. The novel bioactive cement containing DMAHDM is promising in fixed orthodontic treatments and protecting tooth enamel. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher 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.)

In recent years, pathogenic infections have been a growing health threat due to the proliferation of drug-resistant bacteria, so photothermal therapy (PTT) has gained considerable interest in biological and medical fields, owing to its noninvasive and highly effective properties. However, it is hard to achieve selective bacteria targeting while generating a large amount of heat at infected sites. Cationic electrostatic interaction is considered to be a common antimicrobial strategy. Herein, an organic molecule named RT-MN was synthesized with four positively charged quaternary ammonium salts that can bind to negatively charged bacteria. Under near-infrared 808 nm laser irradiation, RT-MN could be efficiently converted into a large amount of heat to eradicate bacteria. In addition, its good water solubility and biological safety proved that RT-MN has excellent biological application prospects. Overall, four such positively charged photosensitizer RT-MN, as a non-antibiotic treatment for resistant bacteria, could be promising for the exploration of highly effective antibacterial agents. [ABSTRACT FROM AUTHOR]

Bacterial infection contributes to the bioburden of wounds, which is an essential factor in determining whether a wound can heal. Wound dressings with antibacterial properties that can promote wound-healing are highly desired for the treatment of chronic wound infections. Herein, we fabricated a simple polysaccharide-based hydrogel dressing encapsulating tobramycin-loaded gelatine microspheres with good antibacterial activity and biocompatibility. We first synthesised long-chain quaternary ammonium salts (QAS) by the reaction of tertiary amines with epichlorohydrin. The amino groups of carboxymethyl chitosan were then conjugated with QAS through the ring-opening reaction and QAS-modified chitosan (CMCS) was obtained. The antibacterial analysis showed that both QAS and CMCS could kill E. coli and S. aureus at relatively low concentrations. QAS with 16 carbon atoms has a MIC of 16 μg/mL for E. coli and 2 μg/mL for S. aureus. A series of formulations of tobramycin-loaded gelatine microspheres (TOB-G) were generated and the best formulation was selected by comparing the characters of the microspheres. The microsphere fabricated by 0.1 mL GTA was selected as the optimal candidate. We then used CMCS, TOB-G, and sodium alginate (SA) to prepare physically crosslinking hydrogels using CaCl2 and investigated the mechanical properties, antibacterial activity, and biocompatibility of the hydrogels. In summary, the hydrogel dressing we produced can be used as an ideal alternative for the management of bacteria-infected wounds. [ABSTRACT FROM AUTHOR]

In order to investigate the influence of γ-(2,3-epoxy-propyl oxygen) propyl trimethoxylsilane (KH 560) on the thermal storage stability of inorganic coatings, the inorganic coatings were prepared with silica sol, potassium silicate, quaternary ammonium salt and KH 560 as raw materials. The test results showed that KH 560 had synergistic effect with quaternary ammonium salt stabilizer in inorganic coating system, which could significantly improve the storage stability of inorganic coating. [ABSTRACT FROM AUTHOR]

The resistance of microorganisms' biofilms to antibacterials is a problem both for medicine and for many industries. Increasing the effectiveness of antimicrobial agents is an urgent task. The goal of the present work was to develop a new approach to development of anti-biofilm compositions based on conventional disinfectants in combination with enhancers (adjuvants). Methods of microbiology (viable cells count, model biofilms) and electron microscopy were employed. This research formulates the principles for selection of adjuvants. The adjuvants should: (1) increase the efficiency of decomposition of the biofilm matrix or/and (2) suppress the microbial protective mechanisms. For testing anti-biofilm compositions, two models of biofilms have been developed, on a solid surface at the interface with air or liquid. It was demonstrated that hydrogen peroxide, ethanol, isopropanol, and 4-hexylresorcinol enhanced the biocidal effect of disinfectants based on oxidants (peroxides and chlorine-containing) and quaternary ammonium salts by three to six orders of magnitude. Mechanisms of adjuvant action were mechanical decomposition of the matrix (by oxygen bubbles formed inside a biofilm in the case of hydrogen peroxide), coagulation of matrix polymers (in the case of alcohols), and a decrease in metabolism (in the case of 4-hexylresorcinol). The use of approved chemicals as adjuvants will accelerate the design of effective anti-biofilm antiseptics for medicine, social hygiene, and food manufactures and other industries. [ABSTRACT FROM AUTHOR]

The postharvest physiological and metabolic activities caused fruits and vegetables (F&V) quality deterioration. Therefore, developing an efficient preservation strategy is a promising approach to relieve this issue. In this study, a modified metal-organic framework (MOF; i.e., Cer@MHKUST-1) was encapsulated into a blended matrix of chitosan quaternary ammonium salt (CQAS)/gelatin to fabricate a multifunctional (water-locking, ethylene-removing, and antibacterial) packaging biopolymer-based film (i.e., CMCGF), the characteristics and preservative effects of the packaging were investigated. Results indicated that the physicochemical (e.g., mechanical, gas/light barrier, wettability) properties of CMCGF were improved compared with the control film (i.e., CGF). CMCGF have a higher ethylene adsorption performance of 65–69 cm3/g STP compared with CGF (7.8 cm3/g STP). Cu ions released from CMCGF destroyed the cell wall and membrane, resulting in the death of bacteria, and the antibacterial efficiency of CMCGF against E. coli and S. aureus was 97–100 % and 98–100 %, respectively. Postharvest storage experiments on tomato and winter jujube confirmed the high-efficiency preservation effect of CMCGF packaging. Therefore, CMCGF provides a multifunctional approach to extending the shelf-life of perishable products to decrease food wastage. [Display omitted] [ABSTRACT FROM AUTHOR]

Lately, ionic forms (namely, quaternary ammonium salts, QASs) of nicotinamide, widely known as vitamin B3, are gaining popularity in the sectors developing novel pharmaceuticals and agrochemicals. However, the direct influence of these unique QASs on the development of various terrestrial plants, as well as other organisms, remains unknown. Therefore, three compounds comprising short, medium, and long alkyl chains in N-alkylnicotinamide were selected for phytotoxicity analyses, which were conducted on representative dicotyledonous (white mustard) and monocotyledonous (sorghum) plants. The study allowed the determination of the impact of compounds on the germination capacity as well as on the development of roots and stems of the tested plants. Interestingly, independently of the length of the alkyl chain or plant species, all QASs were established as non-phytotoxic. In addition, QSAR simulations, performed using the EPI Suite™ program pack, allowed the determination of the products' potential toxicity toward fish, green algae, and daphnids along with the susceptibility to biodegradation. The obtained nicotinamide derivative with the shortest chain (butyl) can be considered practically non-toxic according to GHS criteria, whereas salts with medium (decyl) and longest (hexadecyl) substituent were included in the 'acute II' toxicity class. These findings were supported by the results of the toxicity tests performed on the model aquatic plant Lemna minor. It should be stressed that all synthesized salts exhibit not only a lack of potential for bioaccumulation but also lower toxicity than their fully synthetic analogs. [ABSTRACT FROM AUTHOR]

Hydroxides of alkali and alkaline earth metals are most widely used as catalysts for transesterification of triglycerides of fatty acids in biodiesel production. After biodiesel purification, the determination of catalyst residue is performed to prevent their excess accumulation. Catalysts can promote the degradation of biodiesel. In this research, a simple, fast, and environmentally friendly strategy for the sensitive determination of transesterification catalysts (sodium, potassium, calcium, and magnesium) in biodiesel samples by flame atomization atomic absorption spectrometry is developed. The developed procedure is based on ultrasound assistant dispersive liquid–liquid microextraction of the catalysts in a hydrophilic deep eutectic solvent prepared by mixing quaternary ammonium salt and carboxylic acid. The effect of the nature of the deep eutectic solvent on the mass transfer of catalysts is investigated; in addition, the microextraction procedure conditions are optimized to obtain high sensitivity. The limits of detection established for the proposed procedure are 0.03 mg kg–1 for all analytes. No hazardous and volatile organic solvents are required for sample pretreatment. Sample preparation time is less 15 min. [ABSTRACT FROM AUTHOR]

A nanostructured starch acetate–montmorillonite (SA–Mt) hybrid, where gelatinized SA was attached on the exfoliated Mt through Mt hydration expansion, ion exchange between Mt and quaternary ammonium salt, and SA intercalation, was designed and further used for reinforcing poly(lactic acid)/starch acetate (PLA/SA) composite films. Making use of the synergistic effect of SA and Mt, considerable enhancement in mechanical, thermal, and barrier properties for PLA/SA composite films was achieved. The effect of SA–Mt hybrids on structure–property relationships of PLA/SA composite films was investigated. Under an optimal loading of 7 wt% SA–Mt (SA:Mt = 1:1, w/w), the tensile strength, Young's modulus and elongation at break of SA–Mt‐filled composite films were significantly enhanced, about 104%, 73%, and 98% higher than those of PLA/SA, respectively, revealing the synergistic strengthening/toughening effect of SA and Mt; the thermal decomposition temperature and degradation activation energy of such composite film were also enhanced, implying their superior thermal stability. Moreover, the obtained PLA‐based composite films with good water/oxygen barrier performance and excellent biodegradability provide a potential for use as packaging materials. [ABSTRACT FROM AUTHOR]

Quaternary ammonium compounds (QACs) are among the most effective antimicrobial agents that have been used for more than a century. However, due to the growing trend of bacterial resistance and high toxicity of QACs, research in this field remains a pressing matter. Recent studies of the structure–activity relationship suggest that the introduction of the amide functional group into QAC structures results in soft variants that retain their antimicrobial properties while opening the possibility of fine-tuned activity regulation. Here, we report the synthesis and structure-function study of three structurally distinct series of naturally derived soft QACs. The obtained 3-amidoquinuclidine QACs showed a broad range of antibacterial activities related to the hydrophobic-hydrophilic balance of the QAC structures. All three series yielded candidates with minimal inhibitory concentrations (MIC) in the single-digit μ M range. Time-resolved growth analysis revealed subtle differences in the antibacterial activity of the selected candidates. The versatile MIC values were recorded in different nutrient media, suggesting that the media composition may have a dramatic impact on the antibacterial potential. The new QACs were found to have excellent potential to suppress bacterial biofilm formation while exhibiting low ability to induce bacterial resistance. In addition, the selected candidates were found to be less toxic than commercially available QACs and proved to be potential substrates for protease degradation. These data suggest that 3-amidoquinuclidine QACs could be considered as novel antimicrobial agents that pose a low threat to ecosystems and human health. [ABSTRACT FROM AUTHOR]

Ten novel bifunctional quaternary ammonium salt phase-transfer organocatalysts were synthesized in four steps from (+)-camphor-derived 1,3-diamines. These quaternary ammonium salts contained either (thio)urea or squaramide hydrogen bond donor groups in combination with either trifluoroacetate or iodide as the counteranion. Their organocatalytic activity was evaluated in electrophilic heterofunctionalizations of β-keto esters and in the Michael addition of a glycine Schiff base with methyl acrylate. α-Fluorination and chlorination of β-keto esters proceeded with full conversion and low enantioselectivities (up to 29% ee). Similarly, the Michael addition of a glycine Schiff base with methyl acrylate proceeded with full conversion and up to 11% ee. The new catalysts have been fully characterized; the stereochemistry at the C-2 chiral center was unambiguously determined. [ABSTRACT FROM AUTHOR]

Objective. To explore the influence of resin modified glass ionomer cement (RMGIC) adhesives containing protein-repellent and quaternary ammonium salt agents on supragingival microbiome, enamel and gingival health around brackets. Materials and Methods. Ten patients (21.4 ± 3.5 years) about to receive fixed orthodontics were enrolled in this study. Unilateral upper teeth bonded with RMGIC incorporating 2-Methacryloyloxyethyl phosphorylcholine (MPC) and Dimethylamino-hexadecyl methacrylate (DMAHDM) were regarded as experimental group (RMD), while contralateral upper teeth bonded with RMGIC were control group (RMGIC), using a split-mouth design. Supragingival plaque was collected from both groups before treatment (T0), and at 1 month (T1) and 3 months (T2) of treatment. High-throughput sequencing was performed targeting v3-v4 of 16S rRNA gene. Streptococcus mutans and Fusobacterium nucleatum quantification was done by qPCR analysis. Bracket failures, enamel decalcification index (EDI), DIAGNODent scores (Dd), plaque index (PI) and gingival index (GI) were monitored at indicated time points. Results. Within 3 months, alpha and beta diversity of supragingival plaque had no difference between RMGIC and RMD groups. From T0 to T2, the relative abundance of Streptococcus depleted in RMD but remained steady in RMGIC group. Streptococcus, Prevotella, and Fusobacterium became depleted in RMD, Haemophilus and Capnocy-tophaga became depleted in RMGIC group but Prevotella enriched. Quantification of Fusbacterium nucleatum and Streptococcus mutans showed significant difference between RMGIC and RMD groups at T2. Teeth bonded with RMD had significant lower plaque index (PI) and DIAGNODent (Dd) score at T2, compared with teeth bonded with RMGIC (p < 0.05). No difference in bracket failure rate was examined between both groups (p > 0.05). Conclusion. By incorporating MPC and DMAHDM into RMGIC, the material could affect the supragingival microbial composition, inhibit the progress of plaque accumulation as well as the key pathogens S. mutans and F. nucleatum in the early stage of orthodontic treatment. [ABSTRACT FROM AUTHOR]

In this investigation, a novel sustainable approach was employed to combine the dyeing and antimicrobial finishing steps for nylon fabric in a decamethylcyclopentasiloxane (D5) non-aqueous media dyeing system. Nylon fabric was dyed with acid dye and quaternary ammonium salt (QAS). Dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride was employed in the dyebath as a fixing agent. The dyeing efficiency was assessed by measuring the color characteristics and colorfastness of the dyed fabric. The success of antibacterial treatment was analyzed by observing the reduction in bacteria colony forming units. These results showed that uniformly dyed samples with higher color strength than the aqueous bath and excellent colorfastness were obtained in the D5 non-aqueous media dyeing system. After five Launder-Ometer washing cycles, the treated samples still showed good antibacterial activity. These results showed that the acid dyeing and QAS finishing processes of nylon fabric can be carried out in a D5 solvent bath at the same time. [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.)

Coal face operations sometimes need to mine gangue, which is more dust-generating than coal, but there needs to be more research into the mechanism of gangue dust deposition. Spraying dust suppressants can improve the dust removal effect, but ignoring the water retention makes it easy to produce secondary dust. This study combined experiments and simulation to determine the surfactant that would reduce dust on gangue powder. The molecular orbital energy and electrostatic potential were obtained through MS simulation, and the molecular dynamics model for surfactant solutions was constructed. In the orbital energy level difference, ΔE RPT = 3.7895ev is the largest, the stability of RPT is high, and the activity is good. The three surfactants had a higher positive and negative potential difference than H 2 O, indicating good wetting properties. The diffusion coefficient of H 2 O is D RPT = 1.0011 >D LAB-35 = 0.2166 >D HEC = 0.0392. This suggests that RPT exhibits superior wettability for the gangue. The HEC had a lower diffusion degree of H 2 O and a better ability for water retention. The complex surfactant solution is good at holding water because the LAB-35 has quaternary ammonium salts (R 4 NX) and -COOH, and the -OH in the HEC can form ionic with R 4 NX and hydrogen bonds with the -COOH. This makes the solution more stable. Spraying experiments revealed that dust suppressants with settling time as an indicator have the best effect on dust reduction. The experimental scheme was 0.25 % LAB-35 + 0.30 % HEC + 0.20 % RPT. The dust reduction rate was 83 %, 1.7 times greater than pure water. • Innovatively propose dust reduction measures for coal gangue powder. • A multifunctional dust suppressant that combines wetting and water retention. • Using molecular simulation to analysis the microscopic properties of surfactants. • Verification of dust abatement effect using long-pressure, short-pumping devices [ABSTRACT FROM AUTHOR]

• A new quaternary ammonium magnetic bead was synthesized and used for enriching 5 folates in blood within 5 min. • The established method had good sensitivity (LOD = 1.04 ng/L). • Magnetic beads with a carbon chain length of 16 exhibited the best enrichment performance. • Acid scavenger was innovatively employed to protect magnetism. This study used quaternary ammonium functionalized magnetic beads (QAMBs) as magnetic solid-phase extraction (MSPE) sorbents and liquid chromatography-tandem mass spectrometry (LC-MS) to analyze five folates in a way that was both effective and sensitive. The developed magnetic beads had high BET surface areas up to 434.4 m2/g and strong positive zeta potentials above 40 mV. The conditions for MSPE were optimized. Under the chosen conditions, the linear ranges of the studied folates were 10–10000 ng/L, and the LODs were found to be 1 ng/L. This method was also successfully applied to analyze human plasma samples, giving satisfactory results (recovery of 86.4–98.8 %) and accomplishing it in a short time (i.e., 5 min). The proposed method would be employed for detecting other acids in blood. [ABSTRACT FROM AUTHOR]

The objective of this study was to develop a bio-nanocomposite coating (CQSC) by combining chitosan quaternary ammonium salt (CQAS) and sericin (SC) with biomass-derived carbon dots (CDs) to extend the shelf life of Chinese flowering cabbage (CFC). The effects of different concentrations of CDs (0.2, 0.4, 0.6, 0.8, and 1.0 mg/mL) on the physicochemical, structural, and functional activity of nanocomposite particles were evaluated. CQAS exhibited strong inhibitory effects against Escherichia coli and Bacillus subtilis. Moreover, the application of CQSC on CFC significantly reduced mass losses, slowed the increase in lignin content, maintained ascorbic acid and chlorophyll levels, inhibited the growth of microorganisms, and preserved the unique texture and aroma of CFC during storage at 10 °C compared with uncoated CFC. The results will contribute to the further development of CDs coatings to improve the postharvest preservation effect of fruits and vegetables. [Display omitted] • Preparation of bacteriostatic CDs from biomass. • CQAS-SC-CDs particles compounded primely that showed good antibacterial function. • CQSC nanoparticles increased the shelf life of Chinese flowering cabbage. [ABSTRACT FROM AUTHOR]

Benzyl quaternary ammonium salt is an effective collector of quartz from gypsum. To investigate the selective collection mechanism of tetradecyl dimethyl benzyl ammonium chloride (TDBAC) for quartz from a microscopic view, the adsorption experiments, first-principles calculations based on density functional theory (DFT), and molecular dynamics (MD) simulation were performed in this work. The adsorption experiment results show that the adsorption capacity of TDBAC on the quartz surface was 1.6 × 10−6 mol/m2, much larger than that on the gypsum surface (1.0 × 10−7 mol/m2). The interaction energy of TDBAC with quartz surface was −20202.98 kJ/mol, much smaller than that with gypsum surface (-78.37 kJ/mol). DFT calculation results indicate that the quartz surface was more likely to interact with TDBAC through electrostatic attraction since the average negative charge and exposure oxygen density of the quartz surface were both greater than those of the gypsum surface. After the adsorption of TDBAC, there were hydrogen bonds formed between the hydrogen atoms in TDBAC and the oxygen atoms on the quartz surface. This work confirmed that the highly selective adsorption of TDBAC on quartz surface was attributed to the strong electrostatic attraction and hydrogen-bond interaction. [Display omitted] • TDBAC had a higher adsorption capacity on quartz surface than that on gypsum surface. • The benzyl group of TDBAC enhanced the adsorption through hydrogen bonding. • The strong electronegativity of quartz strengthened the adsorption of TDBAC. [ABSTRACT FROM AUTHOR]

• "Introduction of ODD as an eco-friendly and economical surfactant for the flotation separation of the quartz-magnesite system." • "Superior flotation performance of ODD on quartz compared to magnesite." • "Analysis of the adsorption mechanisms of ODD on quartz and magnesite." • "Electrostatic forces and hydrogen bonding lead to the adsorption of ODD onto quartz surfaces." This study innovatively introduced heptadecenyl amine ethyl imidazoline quaternary ammonium salt (ODD) as a siliconophilic flotation collector, effectively facilitating the achievement of high-efficiency separation of magnesite from quartz. ODD exhibits unique properties such as high selectivity and environmental friendliness. Through a comprehensive series of experiments, including flotation tests, zeta potential characterization, atomic force microscopy (AFM) imaging, Fourier-transform infrared (FTIR) spectroscopy, and time-of-flight secondary ion mass spectrometry (ToF-SIMS), the flotation performance and selective adsorption mechanisms of ODD were thoroughly investigated. The experiments demonstrated that at a pH of 7.00 and an ODD concentration of 40 mg/L, quartz achieved a flotation recovery rate of 95.16 %, while magnesite was only 2.99 %, underscoring the high selectivity of ODD in mineral separation. Zeta potential measurements indicated that ODD exhibits strong adsorption interactions with quartz over magnesite. AFM observations confirmed that ODD forms significant adsorption structures on quartz surfaces, in contrast to weaker interactions with magnesite. FTIR analysis further revealed the robust interactions between ODD and quartz through hydrogen bonds and electrostatic forces, which were significantly diminished on magnesite surfaces. ToF-SIMS analysis provided direct evidence of ODD's selective adsorption on quartz, contributing to a better understanding of the flotation mechanisms involved. This research not only offers a novel approach for the purification of magnesite and effective removal of quartz but also demonstrates the potential of ODD as an eco-friendly collector in mineral processing, potentially advancing a green transformation in the industry. The findings provide a solid theoretical and experimental basis for future industrial applications and innovative development of flotation collectors. [ABSTRACT FROM AUTHOR]

Injecting anti-agglomerant hydrate inhibitors into subsea oil and gas pipelines is considered an effective method to prevent hydrate blockage during hydrocarbon transportation. It is desirable to design anti-agglomerants that are biodegradable, effective under high subcooling temperatures, and compatible with other production chemicals, in particular corrosion inhibitors. In this study, a cost-effective and solvent-free reaction is developed to synthesize novel bio-based quaternary ammonium salts (BQAs) using oleic acid as starting material. The inhibition efficiency of BQAs on methane hydrate agglomeration was evaluated using a high-pressure autoclave at a subcooling temperature of 15 °C. Moreover, a micromechanical force apparatus was employed to quantify cohesive forces among particles of cyclopentane hydrate in the presence of BQAs at 275 K and atmospheric pressure. The results showed that BQAs have the ability to prevent hydrate plugging for a duration of up to 1000 min. Furthermore, these compounds efficiently diminish cohesive forces between hydrate particles, resulting in a reduction of up to 33 %. This leads to a dispersal of hydrate particles that can be transported through pipes. To interpret the experimental results, all-atom molecular dynamics simulations were conducted. The computational results revealed strong BQAs adsorption on the methane hydrate surface, due to the carboxylate anion aligning its hydrocarbon tails parallel to the surface. Additional experiments showed that BQAs significantly lower carbon steel corrosion by 97 % and impede the diffusion of corrosive particles in water. Overall, these results suggest that BQAs derived from vegetable oils offer a practical alternative for oil-field applications, including biodegradability, affordability, anti-corrosion and anti-agglomerant properties at high subcooling temperatures. Their compatibility with other production chemicals needs to be tested. [Display omitted] • Novel bio-based quaternary ammonium salts were synthesized from oleic acid using a solvent-free method. • BQAs effectively inhibited methane hydrate agglomeration at a subcooling temperature of 15 °C. • BQAs reduced cohesive forces between the hydrate particles, resulting in a transportable hydrate slurry. • BQAs significantly lowered carbon steel corrosion and impeded the diffusion of corrosive particles in water. • BQAs offer a practical profile for field applications, including biodegradability, affordability, and dual inhibition effect. [ABSTRACT FROM AUTHOR]

Dental resin adhesive is a mixture of monomers used as an adhesive in resin-based composite tooth restoration. Methacrylate monomers used in these adhesives are susceptible to hydrolysis by bacterial enzymes, leading to limitation of their lifespan. To overcome this issue, in this research series of quaternary ammonium-containing methacrylamides, MDAB (m ethacrylamidoethyl d imethyl a mmonium b romide) and MDAF (m ethacrylamidoethyl d imethyl a mmonium f luoride), acrylamides, ADAB (a crylamidoethyl d imethyl a mmonium b romide) and bismethacrylamides, bis-MMAI (bis (2- m ethacrylamidoethyl) m ethyl a mmonium i odide) were synthesized. These new monomers exhibited antibacterial properties against common bacteria found in tooth cavities, which are S. mutans and E. faecalis. Extra methyl moiety on polymerizable group and long alkyl chain length increased antibacterial properties as well as cytotoxicity against MDPC.23 mouse dental papilla cell lines. Acrylamides, ADAB showed the least cytotoxicity with higher MBC values than the commonly used methacrylate monomer, bis-GMA and the only antibacterial methacrylate-based monomer currently used in commercial resin adhesives, MDPB (m ethacryloyl d odecyl p yridinium b romide). Steric hindrance and lipophilicity of bismethacrylamides in bis-MMAI series reduced antibacterial activities and also significantly enhanced cytotoxicity of the monomers. Moreover, bromide and fluoride counter ions in MDAB and MDAF , respectively, did not cause any difference in antibacterial effects. Additionally, all synthesized (meth)acrylamide monomers demonstrated greater stability against hydrolysis under acidic conditions compared to the methacrylate MDPB. Degree of conversions of synthesized monomers were lower than that of MDPB at the beginning of polymerization due to the higher viscosity, but were comparable at the latter stage. Methyl group on methacrylamides in MDAB and the highest viscosity of bismethacrylamides, bis-MMAI reduced degree of conversions of the monomers. TADAB (t etradecyl a crylamidoethyl d imethyl a mmonium b romide) incorporated in resin adhesive reduced water solubility of the cured resin under acidic condition. [Display omitted] • New synthetic routes for quaternary ammonium-containing (meth)acrylamides were proposed. • Some monomers were antibacterial and non-cytotoxic to mouse dental papilla cells. • All monomers showed distinguished hydrolytic stability under acidic aqueous solution. • Degree of conversions of (meth)acrylamides at 30 s were comparable to a reference methacrylate. [ABSTRACT FROM AUTHOR]

Polymerization shrinkage of composite resin during curing can form microcracks between the restoration and tooth tissue, facilitating bacterial colonization at the bonding interface and increasing the risk of secondary caries. Thus, developing antibacterial adhesives is crucial. This study synthesized a fluoride-containing dimethylaminohexadecyl methacrylate salt (DMAHDM-F) as a co-monomer to create a fluoride-rechargeable resin adhesive (FD-A) with long-term antibacterial properties. FD-A exhibits stable shear bonding strength, curing kinetics, high mechanical properties, and excellent biocompatibility. Its fluoride release can be sustained for over 1 year, achieving efficient antibacterial effect associated with the quaternary ammonium groups, being superior to those adhesives containing only NaF nanoparticles or quaternary ammonium groups. Of note, the FD-A adhesive is recharged with 10 ppm NaF solution after the one-year release test, and the re-fluorinated sample continues to release more fluoride ion, maintaining its antibacterial efficacy for extended period, which is a welcomed feature for dental applications. In summary, the photopolymerizable fluorinated quaternary ammonium salt provides a potential solution for making dental resin adhesives and composites with stable antibacterial effect to enhance the longevity of dental restorations. • Fluorinated monomer is synthesized for preparing dental resin adhesive. • The adhesive shows sustained fluoride release without cytotoxicity. • The fluorinated unit endows the adhesive with fluoride rechargeable ability. • The adhesive provides long-term antibacterial properties both in vitro and in vivo. [ABSTRACT FROM AUTHOR]