Non-aqueous System Research Articles

Efficient directional biosynthesis of isoquercitrin from quercetin by Bacillus subtilis CD-2 and its anti-inflammatory activity

Isoquercetin, as the sole product, was directionally biosynthesized from quercetin in a non-aqueous system using Bacillus subtilis CD-2 (1 g/L quercetin), and its structure was identified by LC-MS and NMR analysis. CCK8 assays showed no cytotoxicity and good cell proliferation. The anti-inflammatory experiments demonstrated strong inhibition of NO release, transcriptional downregulation of classical effective cellular factors tumour necrosis factor-α, interleukin-6, interleukin-1β, and transcriptional upregulation of interleukin-10 in LPS-induced RAW264.7 cells. Its stronger anti-inflammatory activity than quercetin provided a reference for modifying the structure of quercetin to obtain more compounds with better pharmacological activities for medical industry.

Study of substituents-regulated dyeing properties in non-aqueous media systems based on MD simulation and DFT

To investigate the relationship between N-acetoxyethyl group and dyeing properties of disperse dyes in D5 non-aqueous medium dyeing system, the adsorption and diffusion behaviors of three disperse dyes with different structures were studied by molecular dynamics (MD). The diffusion coefficients, the planar distribution densities of dyes in different directions, and the intermolecular interaction energies were calculated. Molecular dynamics simulation (MD) was used to calculate molecules polarity index (MPI). Meanwhile, the practical dyeing experiments also were investigated to compare with simulated results. The results showed that the adsorption and diffusion behavior of disperse dyes with different structures were significantly different. Compared with dye B257, D-1 and D-2 are more easily adsorbed and diffused into the interior of the fiber because of the introduction of polar acetoxyethyl group. Moreover, the diffusion coefficient of D-2 in the fiber was relatively low, indicating that the combination between dye and polyester fiber was stable. XY plane distribution density and MPI revealed that the introduction of acetoxyethyl was beneficial to increase the adsorption amount of dye on the fiber, which was mainly related to the high binding energy between dye molecule and polyester fiber. The results of dyeing experiments showed that the decreased solubility of disperse dyes in the D5 medium was conducive to improving the dyeing rate of disperse dyes. This was consistent with the simulated interaction between dyes and D5. This study will provide a basis for further rapid and accurate development and selection of disperse dyes with high dyeing rate in non-aqueous medium systems.

Electrochemical Reactivity of Hydrogen Storage Materials: Exploring Borohydride and Hydrazinium Salt Mixtures

Electrochemical characterization of hydrogen storage materials was conducted in a non-aqueous environment to investigate the direct electrochemical release and consumption of hydrogen and the potential for regeneration. We first address the challenge of minimal solubility of the synthetic precursors, sodium borohydride (NaBH4) and hydrazinium bromide (N2H5Br), in both organic and inorganic solvents. We next determine and calibrate a reference electrode formulation compatible with our non-aqueous media and analytes that demonstrates a stable reference potential. We employ cyclic voltammetry (CV) to characterize the precursors and mixtures thereof. Each CV peak is assigned to a corresponding electrochemical reaction. Using the rate-dependent CV method and Randles–Ševčík equation, we calculate the diffusion coefficient of each chemical (NaBH4 and N2H5Br). Analysis of the CVs, coupled with 11B NMR analysis, reveals a room temperature chemical transformation of NaBH4 and N2H5Br mixtures into hydrazine borane (N2H4BH3). These results are particularly significant, considering the limited information available on the electrochemical characterization of metal borohydride and hydrazinium salt in non-aqueous media. This work establishes a foundation for adapting a non-aqueous electrochemical system to further study the borohydride family of chemistries and to design and develop electrochemical devices for direct electrical and chemical energy interconversion with hydrogen storage materials.

Design Glutamate Dehydrogenase for Nonaqueous System by Motifs Reassembly and Interaction Network Analysis.

Glutamate dehydrogenases (GDH) serve as the key regulated enzyme that links protein and carbohydrate metabolism. Combined with motif reassembly and mutation, novel GDHs were designed. Motif reassembly of thermophilic GDH and malate dehydrogenase aims to overcome stability and activity tradeoff in nonaqueous systems. Structural compatibility and dynamic cooperation of the designed AaDHs were studied by molecular dynamics simulation. Furthermore, multipoint mutations improved its catalytic activity for unnatural substrates. Amino acid interaction network analysis indicated that the high density of hydrogen-bonded salt bridges is beneficial to the stability. Finally, the experimental verification determines the kinetics of AaDHs in a nonaqueous system. The activity of Aa05 was increased by 1.78-fold with ionic liquid [EMIM]BF4. This study presents the strategy of a combination of rigid motif assembly and mutations of active sites for robust dehydrogenases with high activity in the nonaqueous system, which overcomes the activity-stability tradeoff effect.

A novel non-aqueous tertiary amine system for low energy CO2 capture developed via molecular dynamics simulation

The current technology for capturing CO2 using alkanolamine aqueous solutions is known for its high energy and capital costs. As a result, developing new absorbents for low-energy CO2 removal remains a challenge. An additional activator can promote CO2 absorption performance. However, it is based on experimental screening. In this study, based on molecular dynamic simulation, we have successfully developed a novel and energy-efficient CO2 absorbent by combining N, N-Dimethylethanolamine (DMEA), and ethylene glycol (EG), with different activators, including ethanolamine (MEA), ethylenediamine (EDA), and piperazine (PZ). The addition of these activators significantly enhances the CO2 absorption performance of DMEA-based absorbents. Among them, DMEA-PZ-EG exhibits the maximum CO2 absorption rate and capacity, achieving 6.35 (g-CO2/(kg-soln.·min.)) and 96.5 (g-CO2/kg-soln.), respectively, representing a 230.1 % and 206.35 % improvement over 2M DMEA-EG absorbent. Moreover, compared to a 30 wt% MEA solution, the energy consumption of DMEA-based absorbents is reduced by 33.93–51.56 %. The reaction products were characterized using various spectroscopic techniques, including Attenuated Total Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR), and 1D and 2D Nuclear Magnetic Resonance spectroscopy (1H and 13C NMR). The NMR results confirmed that DMEA becomes protonated after CO2 absorption in the DMEA-EG mixture. The deprotonation of EG promote its reaction with CO2, resulting in the forming of EG carbonates. This assumption has been confirmed by the IR spectrum. Furthermore, the effect of activators on CO2 absorption has been analysed at the molecular level through molecular dynamics simulation and a new method is proposed to predict the CO2 absorption performance of non-aqueous solvents. Using non-aqueous DMEA absorbents presents a promising approach for improving CO2 capture efficiency, reducing energy consumption, and facilitating regeneration.

Efficient glycosylation and in vitro neuroprotective evaluation of abundant prenylflavonoid in hops

Structurally unique isopentenyl flavonoids are extremely low in natural plant species, and their cumbersome chemical pathways, scarcity of donors, and poor stability have severely hindered their application scenarios. Xanthohumol (XN), an isopentenyl chalcone, is a unique and abundant herbal efficacy substance in hops (Humulus upulus L.), which is an herb with a variety of clinical benefits. However, 90% of XN is left behind in the production of hop residue, resulting in a waste of natural resources. The poor water solubility and low bioavailability of XN also limit its wide application. Combined biotransformation strategies can greatly enhance the added value of resource materials and become one of the important means for the sustainable utilization of traditional Chinese medicine resources. In this study, an extreme microbial screening strategy for efficient bioconversion of phrenylflavonids is established to achieve Bacillus zanthoxyli GQ8 obtained from brewer's dregs and a non-aqueous biosynthesis system of xanthohumol glycosides (XNG, substrate concentration of 0.5 g/L, conversion rate of 73.2%) is constructed by GQ8. With HT22 cell model of H2O2-induced oxidative damage and BV2 cell model of LPS-induced neuroinflammation, XNG showed little cytotoxicity and exhibited better anti-inflammatory and antioxidant effects compared with the original compound. Our experimental results firstly provide a high-efficiency biotransformation strategy for glycosylation of XN with bacteria and provide a support that prenylflavonoid glycoside derivatives have remarkable biological activity and show better development potential.

Ball type (4-(tert-butyl)-1,2-phenylene)dimethanolate bridged dinuclear metallo phthalocyanines: Synthesis, characterization, electrochemistry, and in situ spectroelectrochemistry

In this research, cofacial ball type metallo phthalocyanines (MPcs) with a longer bridge, which by adding a –CH2 group to the oxo bridge, were obtained by working the 4,4′-(((4-(tert-butyl)-1,2-phenylene)bis(methylene))bis(oxy))diphthalonitrile beginning complex. Molecular characterizations of the starting compound and dinuclear ball-type MPcs (Co, Fe, Mn, Zn, Ni) obtained from it were made using elemental analysis, 1H-NMR, 13C-NMR, FT-IR, UV–Vis, and MALDI-TOF mass spectroscopy. In addition, how the macromolecule’s spectral, electrochemical, in situ spectroelectrochemical, and electrochromic properties changed was investigated when the phthalocyanine (Pc) rings moved away from each other due to the increasing linking bridge length. The electrochemical properties of ball-type Pcs were investigated via Cyclic Voltammetry (CV) and Square Wave Voltammetry (SWV) in the non-aqueous solvent system on a Pt working electrode (WE). In situ spectroelectrochemical measurements also were carried out to support the electrochemical measurements. In situ electrocolorimetric techniques revealed color changes relevant to the redox processes. Electrochemical and spectroelectrochemical measurements showed that ball type metallo-Pcs form steadfast mixed-valence species based on metal and/or Pc ring on account of the fact that there are forceful and striking intramolecular interactions between the two Pc segments. As a result of the cofacial molecular structure of ball type metallo-Pcs and the split molecular orbitals, the complexes have rich redox properties. They can be utilized as a material in electrochemical technologies since they have plentiful redox behaviors. In situ spectroelectrochemical and in situ electrocolorimetric measurements demonstrated that they also have rich spectral and chromatic features. Due to the apparent color and spectral variations, they are appropriate for electrochromic appliances.

Energy optimization of a non-aqueous solvent CO2 absorption system with pressure swing regeneration

This study focuses on optimizing the energy requirement in the post-combustion CO2 capture system using pressure swing regeneration through a model-based design (MBD). The simulation results highlight the significant impact of CO2 recovery, inlet gas and liquid flow rate, and CO2 concentration in the flue gas on the overall energy demand of the system. Moreover, an investigation into the de-sublimation chamber was undertaken, revealing a relationship between dry ice formation and the heat transfer between the LNG stream and CO2 in the heat exchanger. The parametric analysis study reveals that the sensible heat of the lean solvent is significantly influenced by the CO2 concentration in the liquid, consequently affecting the overall system energy. According to the results, the utilization of cold energy from LNG could save 80 % of the total energy requirement. The optimization results found the best working condition, which consumes energy of 0.190 GJ/ton CO2, 31 % lower than the basic scenario.

Rationally Designed Spherical V2O5 Encapsulated by 2d-VS2 as High Capacity Insertion Cathode for Mg-Ion Battery

Owing to high energy density and economic viability, rechargeable Mg-ion batteries (MIB) are considered as alternative to lithium-ion batteries. However, beside chevrel phase, none of conventional inorganic cathode materials demonstrate reversible intercalation/deintercalation of Mg+2 ions in anhydrous electrolyte system. The lack of high voltage and high-capacity cathode frustrates the realization of MIB. Previous studies indicated that vanadium pentoxide (V2O5) has potential to reversibly insert\\extract Mg ions. However, many attempts to utilize V2O5 demonstrated limited electrochemical response, due to hindered Mg ion mobility in solid. Herein, we demonstrated a tailored approach to synthesize uniformly dispersed spherical V2O5 homogeneously coated with 2D VS2 through a facile in-situ chemical method and study the electrochemical activity in 0.2 M Mg(TFSI)2 + MgCl2 in DME electrolyte system and Mg metal anode. The V2O5@VS2 cathode exhibit the highest reported 1st discharge capacity of ~ 260 mA.h.g-1, excellent stability, retention and restricted capacity fading after 100 cycles which witness the prominence of VS2 coating in rationally designed V2O5 as a cathode material in non-aqueous electrolyte system for next generation high capacity MIB. Most interestingly, exact phase and morphology is completely retained even after repeated Mg+2 ion intercalation/deintercalation at different current rates, demonstrating pronounced electrochemical activity in anhydrous magnesium electrolyte and realization of a practical MIB.

Low temperature non-aqueous dyeing of wool fiber with reactive dyes: A sustainable and eco-friendly method

Conventional wool dyeing usually performed at a boiling point, often destroys the wool structure, consumes plenty energy and water. Aiming at realizing the sustainable cleaning coloration of wool dyeing and keeping the excellent natural quality of wool fiber, a green dyeing technology, non-aqueous dyeing, has been successfully applied. The effect of acid-pretreatment on the reactive dye adsorption behaviors was explored and optimized the dyeing parameters by the design of experiments as well as a single factor screening way. The results demonstrate that acid-pretreatment improved the dye exhaustion rate to 99.79 % effectively by lowering the pH value of wool fiber and increased the dye fixation rate from 75.33 % to 86.93 % by enlarging the dyeing channel. Additionally, the factors that affected wool dyeing were analyzed, approving additional acetic acid had the most significant effect on the wool dyeing. The optimal wool dyeing condition included 1 % on the weight of fiber (o.w.f) acetic acid indicating low-temperature wool dyeing was achieved by this non-aqueous dyeing system at 85 °C for 60min. Furthermore, a higher color depth, constant mechanical properties, good rubbing fastness, and soaping fastness were obtained by this dyeing method. Compared with conventional dyeing, 24.28% energy consumption, 32.50% water usage, and 31.36% wastewater were reduced by this dyeing method. Therefore, sustainable non-aqueous dyeing technology is eco-friendly and has the potential to protect the wool structure from being damaged in the dyeing process.

Catalytic Decomposition of an Organic Electrolyte to Methane by a Cu Complex-Derived In Situ CO2 Reduction Catalyst.

Metal complexes are often transformed to metal complex-derived catalysts during electrochemical CO2 reduction, enhancing the catalytic performance of CO2 reduction or changing product selectivity. To date, it has not been investigated whether metal-complex derived catalysts also enhance the decomposition of the solvent/electrolyte components as compared to an uncoated electrode. Here, we tested the electrochemical stability of five organic solvent-based electrolytes with and without a Cu complex-derived catalyst on carbon paper in an inert atmosphere. The amount of methane and hydrogen produced was monitored using gas chromatography. Importantly, the onset potential for methane production was reduced by 300 mV in the presence of a Cu complex-derived catalyst leading to a significant amount of methane (417.7 ppm) produced at -2.17 V vs Fc/Fc+ in acetonitrile. This suggests that the Cu complex-derived catalyst accelerated not only CO2 reduction but also the reduction of the electrolyte components. This means that Faradaic efficiency (FE) measurements under CO2 in acetonitrile may significantly overestimate the amount of CH4. Only 28.8 ppm of methane was produced in dimethylformamide under an inert atmosphere, much lower than that produced under CO2 (506 ppm under CO2) at the same potential, suggesting that dimethylformamide is a more suitable solvent. Measurements in propylene carbonate produced mostly hydrogen gas while in dimethyl sulfoxide and 3-methoxypropionitrile neither methane nor hydrogen was detected. A strong linear correlation between the measured current and the amount of methane produced with and without the Cu complex-derived catalyst confirmed that the origin of methane production is solvent/electrolyte decomposition and not the decomposition of the catalyst itself. The study highlights that in a nonaqueous system, highly active catalyst in situ deposited during electrochemical testing can significantly influence background measurements as compared to uncoated electrodes, therefore the choice of solvent is paramount for reliable testing.

Performance of a non-aqueous nanofluid thermally regenerative flow battery for electrical energy recovery from low-grade waste heat

Non-aqueous thermally regenerative battery (non-aqueous TRB) operating at voltages above 1 V is a promising technology for converting low-grade waste heat into electrical energy. To improve the power generation of non-aqueous TRB, the operating parameters that affect the performance of non-aqueous TRB, including the membrane type, electrode materials, acetonitrile volume fraction and electrolyte flow rate were investigated through experimental research. In addition, the thermal-to-electric efficiency of non-aqueous TRB system with different acetonitrile volume fraction and active species concentration was investigated by theoretical calculation. Because of the enhanced active species transport, the optimized maximum power density value of 235 W m−2 was achieved with the use of an anion exchange membrane, reticulated vitreous carbon as the anode electrode, etched carbon felt as the cathode electrode, acetonitrile fraction of 70 %, and electrolyte flow rate of 35 mL min−1. Moreover, theoretical thermal efficiency of 6.6 % was calculated with consisting of 10 % acetonitrile and 0.5 M active species. The above optimized performance in this study is competitive and promotes the development and application of TRBs.

Gas-liquid surface characterization and liquid film thinning of Non-Aqueous foam

Foam flooding is a crucial enhanced oil recovery technique for profile control during the oil displacement process. The stability of the foam is the key factor for the success of foam flooding, but typical aqueous foams generally lose their stability in the presence of hydrocarbons because of their low oil tolerance. Non-aqueous foams could possess outstanding stability in the presence of hydrocarbons as a result of their unique properties. However, few studies have been conducted on the stabilization mechanisms of non-aqueous foams in the presence of hydrocarbons. In this study, comparative experiments are performed to investigate differences in the stabilization mechanism between aqueous and non-aqueous foams. The results show that a non-aqueous foam had excellent oil tolerance in a bulk foaming test. Then, the stabilization mechanisms of foams are investigated in terms of surface dilatational viscoelasticity and liquid film thinning. For a non-aqueous foam system, the maximum viscoelastic modulus of 55 mN/m occurs at the maximum surfactant concentration used which was 5.0 wt% for this set of tests, which indicates that the liquid film of FS22 non-aqueous foam was more stable. In a foam film thinning experiment, the thinning time of an aqueous foam system is shortened but the liquid film thickness is increased by crude oil, whereas crude oil increased the thinning time of a non-aqueous foam system but decreased its liquid film thickness. In a non-aqueous foam system, the film could remain stable for hours before rupturing, which indicates that its stability in the presence of an oil phase is excellent. These results are meaningful for the understanding of the stabilization mechanisms of oil-based foams and the employment of non-aqueous foams for enhanced oil recovery.

Fundamental investigations on the ionic transport and thermodynamic properties of non-aqueous potassium-ion electrolytes

Non-aqueous potassium-ion batteries (KIBs) represent a promising complementary technology to lithium-ion batteries due to the availability and low cost of potassium. Moreover, the lower charge density of K+ compared to Li+ favours the ion-transport properties in liquid electrolyte solutions, thus, making KIBs potentially capable of improved rate capability and low-temperature performance. However, a comprehensive study of the ionic transport and thermodynamic properties of non-aqueous K-ion electrolyte solutions is not available. Here we report the full characterisation of the ionic transport and thermodynamic properties of a model non-aqueous K-ion electrolyte solution system comprising potassium bis(fluorosulfonyl)imide (KFSI) salt and 1,2-dimethoxyethane (DME) solvent and compare it with its Li-ion equivalent (i.e., LiFSI:DME), over the concentration range 0.25–2 molal. Using tailored K metal electrodes, we demonstrate that KFSI:DME electrolyte solutions show higher salt diffusion coefficients and cation transference numbers than LiFSI:DME solutions. Finally, via Doyle-Fuller-Newman (DFN) simulations, we investigate the K-ion and Li-ion storage properties for K∣∣graphite and Li∣∣graphite cells.

Rational design of artificial Lewis pairs coupling with polyethylene glycol for efficient electrochemical ammonia synthesis

Ammonia (NH3) synthesis at mild conditions by electrocatalytic nitrogen reduction (eNRR) has received more attention and has been regarded as a promising alternative to the traditional Haber–Bosch process. Lewis acid-base pairs (LPs) can chemisorb and react with nitrogen by electronic interaction, while the tuning of the microenvironment near electrode can hinder hydrogen evolution reaction (HER) thus improving the selectivity of the eNRR. Herein, the FeOOH nanorod coupled with LPs on the surface (i.e., Fe, Fe–O) was synthesized, which could effectively drive eNRR. Meanwhile, polyethylene glycol (PEG) was introduced to serve as a local non-aqueous electrolyte system to inhibit HER. The prepared FeOOH-150 catalyst achieved outstanding eNRR performance with an NH3 yield rate of 118.07 μg h−1mgcat−1 and a Faradaic efficiency of 51.4 % at −0.6 V vs. RHE in 0.1 M LiClO4 + 20 % PEG. Both the experiment and DFT calculations revealed that the interaction of PEG with Lewis base sites could optimize nitrogen adsorption configuration and activation.

Study on reactive dyeing in a sustainable nonaqueous medium dyeing system by X-ray electron spectroscopy

In the nonaqueous medium dyeing system (decamethylcyclopenta siloxane; D5), the bonding between cotton fiber and reactive dye may be influenced by the dyeing medium. To evaluate the dyeing performance of reactive dye in the D5 dyeing system, the fixing of reactive dyes with different structures was studied. Before and after dyeing, the chemical environment of cotton fiber was investigated by X-ray electron spectroscopy, and compared with the spectroscopic method. Compared with traditional reactive dyeing, the color depth of the dyed cotton fabrics and the final fixation of dyes are much higher in the D5 dyeing system. The elements of the cellulose fiber surface are changed after dyeing. Especially for N element, its content is increased after dyeing. After 30 minutes, the final fixation of reactive dye is about 80% by analyzing the account of N. Compared with the undyed cellulose fiber, the peak area of C–C or C–H is gradually increased after dyeing, but the proportion of C–O is decreased with the fixing time. The proportion of O–C–O is not changed much with the fixation time. Therefore, the C–C or C–H chemical environment on the cellulose fiber surface will be changed after dyeing. Therefore, the bonding of dyes and fibers can be analyzed through the change of the C1s chemical environment or the amount of N element before and after dyeing. This investigation successfully developed a method which could evaluate the fixation process in the D5 dyeing system.

Controllable construction of non-hydrophilic Cu-PmPD nanoshells on Ni-rich cathode materials in non-aqueous system for lithium-ion batteries

Controllable construction of non-hydrophilic Cu-PmPD nanoshells on Ni-rich cathode materials in non-aqueous system for lithium-ion batteries

Exploring Oxidoreductases from Extremophiles for Biosynthesis in a Non-Aqueous System.

Organic solvent tolerant oxidoreductases are significant for both scientific research and biomanufacturing. However, it is really challenging to obtain oxidoreductases due to the shortages of natural resources and the difficulty to obtained it via protein modification. This review summarizes the recent advances in gene mining and structure-functional study of oxidoreductases from extremophiles for non-aqueous reaction systems. First, new strategies combining genome mining with bioinformatics provide new insights to the discovery and identification of novel extreme oxidoreductases. Second, analysis from the perspectives of amino acid interaction networks explain the organic solvent tolerant mechanism, which regulate the discrete structure-functional properties of extreme oxidoreductases. Third, further study by conservation and co-evolution analysis of extreme oxidoreductases provides new perspectives and strategies for designing robust enzymes for an organic media reaction system. Furthermore, the challenges and opportunities in designing biocatalysis non-aqueous systems are highlighted.

Adsorption of Reactive Red 120 in Decamethyl-Cyclopentasiloxane Non-Aqueous Dyeing System

Traditional dyeing usually consumes a significant amount of water and salts, thus causing environmental pollution. Salt-free and low-water dyeing has become an important research direction in the cotton fabric dyeing industry. The non-aqueous media dyeing technology, using decamethylcyclopentasiloxane (D5) as the dyeing medium, has achieved energy saving and emission reduction in this industry. To investigate the influence of inorganic salts on the dyeing properties of reactive dyes in a non-aqueous medium dyeing system, the adsorption kinetics and level dyeing property of C.I. Reactive Red 120 were investigated at various concentrations of sodium sulfate. When no salts were included in the siloxane non-aqueous dyeing system, 80% of the reactive dye could diffuse onto the cotton fabric surface after 10 min. However, if 13% salts were added during dyeing, 87% of the reactive dye could diffuse to cotton fabric surface over the same amount of time. Moreover, the adsorption rate of dye was increased from 3.85 mg/g·min to 5.04 mg/g·min when the quantity of salts was increased from 0% to 13%. However, the concentration of sodium sulfate had minimal effect on the color depth of the dyed fabric and the final uptake of dye. But, when the concentration of sodium sulfate was significant, the level dyeing property of the dye became poor as the Sγ(λ) value was increased from 0.020 to 0.042. The adsorption kinetic of C.I. Reactive Red 120 in D5 dyeing solution may be best described by the pseudo-second-order kinetic model. As the sodium sulfate concentration increases, the half-dyeing time gradually decreases and the adsorption rate of dye increases. The repulsive force between the dye and the cotton fiber was lowered by the addition of sodium sulfate. Consequently, in the D5 dyeing system, the level dyeing property of reactive dye may be affected by the adsorption rate. Therefore, the formula of reactive dyes that do not contain salts can be applied successfully in non-aqueous dyeing systems.

Anti-corrosive non-aqueous DBSA/MEA lamellar liquid crystal lubrication system

HypothesisSince lamellar liquid crystals (LLCS) could be used for lubrication, many LLCS systems have been constructed to improve lubrication performance. However, most studies focused on the LLCS of the water system, and its corrosiveness brought some limitations to its application. Therefore, it is necessary to construct a non-aqueous LLCS system with good lubrication and anti-corrosion properties to improve its applicability. ExperimentsAnionic surfactant dodecyl benzene sulfonic acid (DBSA) was used to construct non-aqueous LLCS in different solvents, including monoethanolamine (MEA) and diethanolamine (DEA). DBSA/H2O LLCS system was constructed for comparison. The LLCS was characterized by polarizing microscope (POM), small-angle X-ray scattering (SAXS), and rheology. Its microstructure was discussed. Meanwhile, we evaluated the lubrication and anti-corrosion performance of LLCS. Its lubrication mechanism was explained through tribology tests and X-ray photoelectron spectrometer (XPS) analysis of the wear scar surface. Its anti-corrosion mechanism was investigated by using the weightlessness method, electrochemical test method, and quantum chemical theoretical calculations. FindingsThe DBSA/MEA non-aqueous LLCS system showed better lubrication performance than DBSA/DEA and DBSA/H2O LLCS. It can adsorb on the surface of the friction pair to form a lubrication friction film, which plays a better role in reducing friction and wear. The DBSA/MEA LLCS is less corrosive to metals because it can effectively isolate oxygen and water in the air between friction pairs. Furthermore, the lone pair electrons in the 2p orbital of the N atom in the MEA molecule could coordinate with the 3d empty orbital of the Fe atom, forming a protective film on the metal surface, which plays a good anti-corrosion effect. This work not only enriched the study of non-aqueous LLCS but also expanded its potential applications in the field of lubrication.