Pub Date : 2024-11-10DOI: 10.1016/j.molliq.2024.126423
Yuchen Hu , Ziyu Gao , Huidong Wang , Li Yang , Jiaxu Zhang , Jianmin Sun
A novel protic ionic liquid di-tertiary ammonium bromide ionic liquid (DTAB-IL) was synthesized by one-step condensation at 0 ℃ with 85 % yield. DTAB-IL also exhibited effective catalytic activity for CO2 cycloaddition without cocatalyst and solvent. The catalytic reaction conditions were optimized to 90 ℃, 4 h, 1 MPa, and the yield of propylene carbonate was obtained 96 % with high selectivity 99 %. Under the optimal conditions, DTAB-IL catalyst exhibited good recyclability and universality to various epoxides. Furthermore, temperature influence and kinetic investigation for propylene carbonate synthesis were studied. The activation energy for DTAB-IL catalyzing CO2 cycloaddition reaction was 43.93 kJ/mol, and the reaction was found to follow first-order for propylene oxide. Efficient cycloaddition reaction of CO2 and epoxide was attributed to the activation of epoxide and CO2 by di-tertiary ammonium and epoxide ring-opening by bromide anion in DTAB-IL.
{"title":"One-step condensation synthesis of di-tertiary ammonium salt protic ionic liquid for efficiently catalytic CO2 cycloaddition reaction under cocatalyst- and solvent-free conditions","authors":"Yuchen Hu , Ziyu Gao , Huidong Wang , Li Yang , Jiaxu Zhang , Jianmin Sun","doi":"10.1016/j.molliq.2024.126423","DOIUrl":"10.1016/j.molliq.2024.126423","url":null,"abstract":"<div><div>A novel protic ionic liquid di-tertiary ammonium bromide ionic liquid (DTAB-IL) was synthesized by one-step condensation at 0 ℃ with 85 % yield. DTAB-IL also exhibited effective catalytic activity for CO<sub>2</sub> cycloaddition without cocatalyst and solvent. The catalytic reaction conditions were optimized to 90 ℃, 4 h, 1 MPa, and the yield of propylene carbonate was obtained 96 % with high selectivity 99 %. Under the optimal conditions, DTAB-IL catalyst exhibited good recyclability and universality to various epoxides. Furthermore, temperature influence and kinetic investigation for propylene carbonate synthesis were studied. The activation energy for DTAB-IL catalyzing CO<sub>2</sub> cycloaddition reaction was 43.93 kJ/mol, and the reaction was found to follow first-order for propylene oxide. Efficient cycloaddition reaction of CO<sub>2</sub> and epoxide was attributed to the activation of epoxide and CO<sub>2</sub> by di-tertiary ammonium and epoxide ring-opening by bromide anion in DTAB-IL.</div></div>","PeriodicalId":371,"journal":{"name":"Journal of Molecular Liquids","volume":"416 ","pages":"Article 126423"},"PeriodicalIF":5.3,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The discharge of dyes in industrial wastewater poses significant environmental and health risks when released into natural water resources. In this study, we report the development of an EDTA-crosslinked cyclodextrin polymer (ECDP)-based sensor for the real-time, naked-eye detection of hazardous methylene blue (MB) dye in aqueous solutions and natural water samples. The sensor functions via a competitive host–guest inclusion mechanism involving sodium dodecyl sulphate (SDS) and ECDP, which modulates the alignment of liquid crystals (LCs). Initially, SDS induces homeotropic ordering at the fluid interface, but when complexed with ECDP, it causes a tilted LC alignment. Upon the introduction of MB, SDS is displaced from the ECDP cavity and re-adsorbs at the LC/aqueous interface, triggering an orientational transition from tilted to homeotropic. This transition is clearly observed as a distinct bright-to-dark shift under crossed polarizers. The host–guest (ECDP/MB) inclusion complexation mechanism was further confirmed by FT-IR, XRPD, and DSC analyses. The developed sensor exhibits high selectivity for MB in dye-contaminated natural water samples and sensitivity to MB concentrations upto 0.10 mM. This study demonstrates the potential of cyclodextrin-based polymers for liquid crystal sensing applications, offering promising pathways for future developments in environmental monitoring.
{"title":"Development of a liquid crystal-based sensor utilizing EDTA-cyclodextrin polymer for real-time optical detection of methylene blue in natural water samples","authors":"Madeeha Rashid , Satyabratt Pandey , Aradhana Chaudhary , Vishal Singh , Garima Singh , Rohit Verma , Krishna Kumar , Sachin Kumar Singh","doi":"10.1016/j.molliq.2024.126479","DOIUrl":"10.1016/j.molliq.2024.126479","url":null,"abstract":"<div><div>The discharge of dyes in industrial wastewater poses significant environmental and health risks when released into natural water resources. In this study, we report the development of an EDTA-crosslinked cyclodextrin polymer (ECDP)-based sensor for the real-time, naked-eye detection of hazardous methylene blue (MB) dye in aqueous solutions and natural water samples. The sensor functions via a competitive host–guest inclusion mechanism involving sodium dodecyl sulphate (SDS) and ECDP, which modulates the alignment of liquid crystals (LCs). Initially, SDS induces homeotropic ordering at the fluid interface, but when complexed with ECDP, it causes a tilted LC alignment. Upon the introduction of MB, SDS is displaced from the ECDP cavity and re-adsorbs at the LC/aqueous interface, triggering an orientational transition from tilted to homeotropic. This transition is clearly observed as a distinct bright-to-dark shift under crossed polarizers. The host–guest (ECDP/MB) inclusion complexation mechanism was further confirmed by FT-IR, XRPD, and DSC analyses. The developed sensor exhibits high selectivity for MB in dye-contaminated natural water samples and sensitivity to MB concentrations upto 0.10 mM. This study demonstrates the potential of cyclodextrin-based polymers for liquid crystal sensing applications, offering promising pathways for future developments in environmental monitoring.</div></div>","PeriodicalId":371,"journal":{"name":"Journal of Molecular Liquids","volume":"416 ","pages":"Article 126479"},"PeriodicalIF":5.3,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-10DOI: 10.1016/j.molliq.2024.126465
Mihály Purgel , A. Jalila Simaan , Yongxing Wang , Marius Réglier , Michel Giorgi , József Kaizer
The reaction of cyclohexylidene-2-carbamylcyclohex-1-enylamines with molecular oxygen does not undergo a [4+2] cycloaddition reactions but leads mainly to a dimer via single electron transfer (SET) from the enamine to 3O2, proton transfer (PT) and consecutive radical C–C coupling, an addition to the formation of hydroperoxide byproduct.
{"title":"Reinvestigation of the mechanism of the enamine-mediated dioxygen activation","authors":"Mihály Purgel , A. Jalila Simaan , Yongxing Wang , Marius Réglier , Michel Giorgi , József Kaizer","doi":"10.1016/j.molliq.2024.126465","DOIUrl":"10.1016/j.molliq.2024.126465","url":null,"abstract":"<div><div>The reaction of cyclohexylidene-2-carbamylcyclohex-1-enylamines with molecular oxygen does not undergo a [4+2] cycloaddition reactions but leads mainly to a dimer via single electron transfer (SET) from the enamine to <sup>3</sup>O<sub>2</sub>, proton transfer (PT) and consecutive radical C–C coupling, an addition to the formation of hydroperoxide byproduct.</div></div>","PeriodicalId":371,"journal":{"name":"Journal of Molecular Liquids","volume":"416 ","pages":"Article 126465"},"PeriodicalIF":5.3,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present the results of a systematic study of the influence of isomerism of selected primary and secondary alcohols on their processes of solvation in dimethylimidazolium (dmim+) chloride ionic liquids. The properties of this system are investigated near the melting temperature by means of the molecular dynamics method. The study of single particle tracking (SPT) trajectories plays a significant role in the present analysis of the features of the microscopic movement of molecules of the dissolved substance in the solution. We demonstrate that the isomerism of alcohol molecules in case of isobutanol and isopentanol leads to the increase of their self-diffusion coefficients due to the growth of the IL’s local structure near the solute as we move from the alcohol to its isomer. The motion of butanol/isobutanol and pentanol/isopentanol alcohols molecules in this process is determined both by the mass, and the hydrophobic properties of the solute. Conversely, we demonstrate that the motion of systems with propanol/isopropanol are determined by the structure of the solute.
我们系统研究了某些伯醇和仲醇的异构现象对其在二甲基咪唑（dmim+）氯离子液体中溶解过程的影响。通过分子动力学方法研究了该体系在熔化温度附近的特性。单粒子跟踪（SPT）轨迹研究在分析溶液中溶解物质分子的微观运动特征方面发挥了重要作用。我们证明，在异丁醇和异戊醇的情况下，醇分子的异构性导致其自扩散系数增加，这是因为当我们从醇移动到其异构体时，溶质附近的 IL 局部结构会增长。在此过程中，丁醇/异丁醇和戊醇/异戊醇分子的运动是由溶质的质量和疏水特性决定的。相反，我们证明丙醇/异丙醇体系的运动是由溶质的结构决定的。
{"title":"Local structure and mobility in melts of ionic liquids-selected primary and secondary alcohols","authors":"N.O. Atamas, K.S. Yablochkova, V.Yu. Malyshev, I.P. Matushko, M.M. Lazarenko","doi":"10.1016/j.molliq.2024.126481","DOIUrl":"10.1016/j.molliq.2024.126481","url":null,"abstract":"<div><div>We present the results of a systematic study of the influence of isomerism of selected primary and secondary alcohols on their processes of solvation in dimethylimidazolium (dmim<sup>+</sup>) chloride ionic liquids. The properties of this system are investigated near the melting temperature by means of the molecular dynamics method. The study of single particle tracking (SPT) trajectories plays a significant role in the present analysis of the features of the microscopic movement of molecules of the dissolved substance in the solution. We demonstrate that the isomerism of alcohol molecules in case of isobutanol and isopentanol leads to the increase of their self-diffusion coefficients due to the growth of the IL’s local structure near the solute as we move from the alcohol to its isomer. The motion of butanol/isobutanol and pentanol/isopentanol alcohols molecules in this process is determined both by the mass, and the hydrophobic properties of the solute. Conversely, we demonstrate that the motion of systems with propanol/isopropanol are determined by the structure of the solute.</div></div>","PeriodicalId":371,"journal":{"name":"Journal of Molecular Liquids","volume":"416 ","pages":"Article 126481"},"PeriodicalIF":5.3,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-10DOI: 10.1016/j.molliq.2024.126483
Chandra Sekhar Espenti , T.V. Surendra , K.S.V. Krishna Rao , Mushtaq Ahmad Ansari , Kummara Madhusudana Rao , Sung Soo Han
Growing concern regarding microbial infections has prompted significant research into antimicrobial textiles. This study presents a green, eco-friendly approach to imparting antimicrobial properties to cellulose cotton fabric (CCF) by depositing silver nanoparticles (AgNPs) synthesized using Bryophyllum pinnatum (BP) leaf extract as a natural reducing agent. To improve the durability of AgNPs on CCF, an environmentally friendly method was used to synthesize AgNPs, which were subsequently applied to biocompatible CCF using BP leaf extract as a natural reducing agent. Owing to the presence of phytochemicals, the AgNPs were rapidly produced with a uniform size and shape under ambient conditions. The synthesized nanoparticles were characterized using techniques such as ultraviolet–visible spectroscopy, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX) spectrophotometry, and X-ray diffraction (XRD) analysis to confirm their size (average size 60.4 ± 8.5 nm), morphology, and crystalline structure. Subsequently, the CCF was coated with these AgNPs using an eco-friendly deposition method. The mechanical properties of the treated fabric were assessed to ensure that the coating process did not compromise the fabric’s integrity or safety for human use. The results indicated that the CCF–BP–AgNPs retained its mechanical strength and exhibited no cytotoxic effects, regarding it suitable for various applications in healthcare, apparel, and household textiles. The antibacterial activity of the CCF–BP–AgNPs was evaluated by measuring zone inhibition against Escherichia coli, Bacillus subtilis, and Staphylococcus aureus. The photocatalytic activity of the coated cloth was assessed by observing the breakdown of organic dye Congo Red (CR) in simulated sunlight. Interestingly, the CCF–BP–AgNPs demonstrated effective photocatalytic degradation of CR, revealing its potential for wastewater treatment and environmental remediation applications. The fabric’s antimicrobial properties remained intact throughout the photocatalytic process, enabling disinfection and pollutant breakdown to occur simultaneously.
人们对微生物感染的关注与日俱增，促使人们对抗菌纺织品进行了大量研究。本研究提出了一种绿色、环保的方法，即通过沉积以银莲花（Bryophyllum pinnatum，BP）叶提取物为天然还原剂合成的银纳米粒子（AgNPs），为纤维素棉织物（CCF）赋予抗菌特性。为了提高 AgNPs 在 CCF 上的耐久性，采用了一种环境友好型方法来合成 AgNPs，然后用 BP 叶提取物作为天然还原剂将其应用到生物相容性 CCF 上。由于植物化学物质的存在，AgNPs 在环境条件下迅速生成，且大小和形状均一。利用紫外可见光谱、傅立叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）和能量色散 X 射线（EDX）分光光度法以及 X 射线衍射（XRD）分析等技术对合成的纳米粒子进行了表征，以确定其尺寸（平均尺寸为 60.4 ± 8.5 nm）、形态和晶体结构。随后，采用环保沉积法在 CCF 上涂覆了这些 AgNPs。对处理后织物的机械性能进行了评估，以确保涂层过程不会损害织物的完整性或人体使用的安全性。结果表明，CCF-BP-AgNPs 保持了其机械强度，并且没有表现出细胞毒性效应，因此适用于医疗保健、服装和家用纺织品的各种应用。通过测量对大肠杆菌、枯草杆菌和金黄色葡萄球菌的抑菌区，评估了 CCF-BP-AgNPs 的抗菌活性。通过观察有机染料刚果红（CR）在模拟阳光下的分解情况，评估了涂层布的光催化活性。有趣的是，CCF-BP-AgNPs 能有效光催化降解刚果红，揭示了其在废水处理和环境修复方面的应用潜力。在整个光催化过程中，织物的抗菌特性保持不变，使消毒和污染物分解同时进行。
{"title":"Harnessing durable antimicrobial cellulose cotton fabric coated with silver nanoparticles via a green approach for photocatalytic applications","authors":"Chandra Sekhar Espenti , T.V. Surendra , K.S.V. Krishna Rao , Mushtaq Ahmad Ansari , Kummara Madhusudana Rao , Sung Soo Han","doi":"10.1016/j.molliq.2024.126483","DOIUrl":"10.1016/j.molliq.2024.126483","url":null,"abstract":"<div><div>Growing concern regarding microbial infections has prompted significant research into antimicrobial textiles. This study presents a green, eco-friendly approach to imparting antimicrobial properties to cellulose cotton fabric (CCF) by depositing silver nanoparticles (AgNPs) synthesized using <em>Bryophyllum pinnatum</em> (BP) leaf extract as a natural reducing agent. To improve the durability of AgNPs on CCF, an environmentally friendly method was used to synthesize AgNPs, which were subsequently applied to biocompatible CCF using BP leaf extract as a natural reducing agent. Owing to the presence of phytochemicals, the AgNPs were rapidly produced with a uniform size and shape under ambient conditions. The synthesized nanoparticles were characterized using techniques such as ultraviolet–visible spectroscopy, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX) spectrophotometry, and X-ray diffraction (XRD) analysis to confirm their size (average size 60.4 ± 8.5 nm), morphology, and crystalline structure. Subsequently, the CCF was coated with these AgNPs using an eco-friendly deposition method. The mechanical properties of the treated fabric were assessed to ensure that the coating process did not compromise the fabric’s integrity or safety for human use. The results indicated that the CCF–BP–AgNPs retained its mechanical strength and exhibited no cytotoxic effects, regarding it suitable for various applications in healthcare, apparel, and household textiles. The antibacterial activity of the CCF–BP–AgNPs was evaluated by measuring zone inhibition against <em>Escherichia coli</em>, <em>Bacillus subtilis</em>, and <em>Staphylococcus aureus</em>. The photocatalytic activity of the coated cloth was assessed by observing the breakdown of organic dye Congo Red (CR) in simulated sunlight. Interestingly, the CCF–BP–AgNPs demonstrated effective photocatalytic degradation of CR, revealing its potential for wastewater treatment and environmental remediation applications. The fabric’s antimicrobial properties remained intact throughout the photocatalytic process, enabling disinfection and pollutant breakdown to occur simultaneously.</div></div>","PeriodicalId":371,"journal":{"name":"Journal of Molecular Liquids","volume":"416 ","pages":"Article 126483"},"PeriodicalIF":5.3,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-10DOI: 10.1016/j.molliq.2024.126475
Mohammad Amin Moradkhani , Seyyed Hossein Hosseini
Deep eutectic solvents (DESs) have recently gained significant attention due to their sustainable and environmentally friendly properties. Acquiring exact knowledge regarding the isobaric heat capacity (Cp) of DESs is essential for energy-related processes, in which these green solvents are utilized. Hence, this study deals with the development of comprehensive models for estimating the Cp of DESs. To reach this target, 682 experimental data, encompassing the Cp of 36 different DESs over widespread ranges of pressure and temperature, were assembled from the literature. The foregoing data were employed to establish new models based on four machine learning techniques, including Gaussian process method (GPM), Adaptive neuro-fuzzy inference system (ANFIS), Radial basis function neural network (RBF-NN) and Multilayer perceptron neural network (MLP-NN). The evaluations performed based on the statistical indices and graphical tools demonstrated that although all suggested models present excellent estimations, that designed based on the MLP-NN method yields the highest accuracy with Mean absolute percentage error (MAPE) and coefficient of determination (R2) values being 0.4% and 99.93, respectively, for the validation data. A comparison between the results of the literature correlations and those of novel models confirmed the obvious superiority of the latter. Moreover, the proposed models properly described the Cp variations of different DESs versus pressure and temperature. The order of importance of various factors in controlling the Cp of DESs was also determined based on the sensitivity analysis. Eventually, the intelligent models showed excellent performance in estimating the Cp of unseen DESs.
深共晶溶剂（DES）因其可持续和环境友好的特性，最近受到了广泛关注。获得有关 DESs 等压热容 (Cp) 的准确知识对于使用这些绿色溶剂的能源相关过程至关重要。因此，本研究涉及开发用于估算 DESs Cp 的综合模型。为了实现这一目标，我们从文献中收集了 682 个实验数据，其中包括 36 种不同 DES 在不同压力和温度范围内的 Cp。利用上述数据建立了基于四种机器学习技术的新模型，包括高斯过程法（GPM）、自适应神经模糊推理系统（ANFIS）、径向基函数神经网络（RBF-NN）和多层感知器神经网络（MLP-NN）。根据统计指数和图形工具进行的评估表明，尽管所有建议的模型都能提供出色的估算结果，但基于 MLP-NN 方法设计的模型准确度最高，验证数据的平均绝对百分比误差（MAPE）和判定系数（R2）值分别为 0.4% 和 99.93。通过比较文献相关性和新模型的结果，证实了后者的明显优越性。此外，所提出的模型恰当地描述了不同 DES 的 Cp 随压力和温度的变化。根据敏感性分析，还确定了控制 DES Cp 的各种因素的重要性顺序。最终，智能模型在估算未见过的 DES 的 Cp 方面表现出色。
{"title":"Comprehensive models to estimate the Isobaric heat capacity of deep eutectic solvents based on Machine learning algorithms","authors":"Mohammad Amin Moradkhani , Seyyed Hossein Hosseini","doi":"10.1016/j.molliq.2024.126475","DOIUrl":"10.1016/j.molliq.2024.126475","url":null,"abstract":"<div><div>Deep eutectic solvents (DESs) have recently gained significant attention due to their sustainable and environmentally friendly properties. Acquiring exact knowledge regarding the isobaric heat capacity (<em>C<sub>p</sub></em>) of DESs is essential for energy-related processes, in which these green solvents are utilized. Hence, this study deals with the development of comprehensive models for estimating the <em>C<sub>p</sub></em> of DESs. To reach this target, 682 experimental data, encompassing the <em>C<sub>p</sub></em> of 36 different DESs over widespread ranges of pressure and temperature, were assembled from the literature. The foregoing data were employed to establish new models based on four machine learning techniques, including Gaussian process method (GPM), Adaptive neuro-fuzzy inference system (ANFIS), Radial basis function neural network (RBF-NN) and Multilayer perceptron neural network (MLP-NN). The evaluations performed based on the statistical indices and graphical tools demonstrated that although all suggested models present excellent estimations, that designed based on the MLP-NN method yields the highest accuracy with Mean absolute percentage error (MAPE) and coefficient of determination (<em>R<sup>2</sup></em>) values being 0.4% and 99.93, respectively, for the validation data. A comparison between the results of the literature correlations and those of novel models confirmed the obvious superiority of the latter. Moreover, the proposed models properly described the <em>C<sub>p</sub></em> variations of different DESs versus pressure and temperature. The order of importance of various factors in controlling the <em>C<sub>p</sub></em> of DESs was also determined based on the sensitivity analysis. Eventually, the intelligent models showed excellent performance in estimating the <em>C<sub>p</sub></em> of unseen DESs.</div></div>","PeriodicalId":371,"journal":{"name":"Journal of Molecular Liquids","volume":"416 ","pages":"Article 126475"},"PeriodicalIF":5.3,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The development of advanced photocatalysts is critical for addressing environmental pollution and enhancing water purification processes. Our study has effectively developed a novel MnO2/g-C3N4 (MGC) heterojunction composite photocatalyst exhibiting superior photo-degradation under visible-light (VL) conditions and also established antibacterial activities. Comprehensive characterization was acquired using XRD, FT-IR, FE-SEM with EDX-associated mapping images, TEM, UV–Vis DRS and PL investigations, indicating the successful formation of well-dispersed MnO2 nanoparticles (NPs) over the g-C3N4 catalyst. The MGC composite heterojunction photocatalyst demonstrated increased photocatalytic degradation activity of 77.2 % in aqueous crystal violet (CV) under VL within 120 min, significantly outperforming pure g-C3N4 and MnO2 by 3.02 and 2.37 times, respectively. The MGC composite demonstrates remarkable stability and reusability, retaining 73.7 % of its efficiency after five consecutive cycles. Additionally, the as-synthesised composite endows potent antibacterial action against various pathogenic bacteria including K. pneumonia, S. aureus, E. coli and B. cereus. The active species analysis indicates that the composite photocatalyst facilitates charge transfer, while effectively preventing the recombination of photo-produced carriers via an effective Z-scheme mechanism, and the synergistic things among MnO2 and g-C3N4 are accredited to the boosted photocatalytic and antibacterial activities. This research describes a photocatalytic approach for efficiently eliminating various contaminants from water bodies, which has significant implications for the future development of photocatalytic technology for wastewater handling.
{"title":"Design of MnO2/g-C3N4 heterojunction composite photocatalysts for augmented charge separation and photocatalytic degradation performance with superior antibacterial activity","authors":"Shanmugam Vignesh , Renji Rajendran , P. Sivaprakash , Govindasami Periyasami , Ikhyun Kim , Kumar Manimaran , Sanjeevamuthu Suganthi , Tae Hwan Oh","doi":"10.1016/j.molliq.2024.126470","DOIUrl":"10.1016/j.molliq.2024.126470","url":null,"abstract":"<div><div>The development of advanced photocatalysts is critical for addressing environmental pollution and enhancing water purification processes. Our study has effectively developed a novel MnO<sub>2</sub>/g-C<sub>3</sub>N<sub>4</sub> (MGC) heterojunction composite photocatalyst exhibiting superior photo-degradation under visible-light (VL) conditions and also established antibacterial activities. Comprehensive characterization was acquired using XRD, FT-IR, FE-SEM with EDX-associated mapping images, TEM, UV–Vis DRS and PL investigations, indicating the successful formation of well-dispersed MnO<sub>2</sub> nanoparticles (NPs) over the g-C<sub>3</sub>N<sub>4</sub> catalyst. The MGC composite heterojunction photocatalyst demonstrated increased photocatalytic degradation activity of 77.2 % in aqueous crystal violet (CV) under VL within 120 min, significantly outperforming pure g-C<sub>3</sub>N<sub>4</sub> and MnO<sub>2</sub> by 3.02 and 2.37 times, respectively. The MGC composite demonstrates remarkable stability and reusability, retaining 73.7 % of its efficiency after five consecutive cycles. Additionally, the as-synthesised composite endows potent antibacterial action against various pathogenic bacteria including <em>K. pneumonia, S. aureus, E. coli and B. cereus</em>. The active species analysis indicates that the composite photocatalyst facilitates charge transfer, while effectively preventing the recombination of photo-produced carriers via an effective Z-scheme mechanism, and the synergistic things among MnO<sub>2</sub> and g-C<sub>3</sub>N<sub>4</sub> are accredited to the boosted photocatalytic and antibacterial activities. This research describes a photocatalytic approach for efficiently eliminating various contaminants from water bodies, which has significant implications for the future development of photocatalytic technology for wastewater handling.</div></div>","PeriodicalId":371,"journal":{"name":"Journal of Molecular Liquids","volume":"416 ","pages":"Article 126470"},"PeriodicalIF":5.3,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-10DOI: 10.1016/j.molliq.2024.126461
Bingyou Jiang , Leyun Cui , Chang-Fei Yu , Kunlun Lu , Yu Zhou , Mingqing Su , Yuqian Zhang
Spray dust reduction is a commonly used dust reduction method in coal mines and has been widely adopted. However, the thermal stability of coal dust after being wetted by dust suppressants remains unknown. The work aimed to investigate the potential environmental hazards posed by the secondary dust dispersion resulting from the cracking of lump coal dust after being wetted by surfactants and subsequently air-dried. Lignite and AES were used as experimental samples. Use thermodynamic equations to analyze, calculate, and compare the changes in the average apparent activation energy of lignite before and after AES solution wetting. Compared with lignite before AES solution wetting, the combustion characteristic index of lignite decreased by 1.93 % after wetting, and before and after AES solution wetting, the average apparent activation energy of lignite calculated by reaction kinetics methods decreased by 7.6 %, 6.7 %, and 17.1 % respectively. FTIR analysis shows the proportion of aliphatic hydrocarbons in lignite after AES solution wetting has decreased compared with before wetting, and the proportion of oxygen-containing functional groups has shown an upward trend. The work elucidated the complex microscopic mechanisms underlying hazards caused by secondary dust dispersion, providing new scientific evidence for preventing and controlling coal dust explosion accidents.
{"title":"Study on the thermal hazards of anionic surfactant AES on lignite via experiments and calculations","authors":"Bingyou Jiang , Leyun Cui , Chang-Fei Yu , Kunlun Lu , Yu Zhou , Mingqing Su , Yuqian Zhang","doi":"10.1016/j.molliq.2024.126461","DOIUrl":"10.1016/j.molliq.2024.126461","url":null,"abstract":"<div><div>Spray dust reduction is a commonly used dust reduction method in coal mines and has been widely adopted. However, the thermal stability of coal dust after being wetted by dust suppressants remains unknown. The work aimed to investigate the potential environmental hazards posed by the secondary dust dispersion resulting from the cracking of lump coal dust after being wetted by surfactants and subsequently air-dried. Lignite and AES were used as experimental samples. Use thermodynamic equations to analyze, calculate, and compare the changes in the average apparent activation energy of lignite before and after AES solution wetting. Compared with lignite before AES solution wetting, the combustion characteristic index of lignite decreased by 1.93 % after wetting, and before and after AES solution wetting, the average apparent activation energy of lignite calculated by reaction kinetics methods decreased by 7.6 %, 6.7 %, and 17.1 % respectively. FTIR analysis shows the proportion of aliphatic hydrocarbons in lignite after AES solution wetting has decreased compared with before wetting, and the proportion of oxygen-containing functional groups has shown an upward trend. The work elucidated the complex microscopic mechanisms underlying hazards caused by secondary dust dispersion, providing new scientific evidence for preventing and controlling coal dust explosion accidents.</div></div>","PeriodicalId":371,"journal":{"name":"Journal of Molecular Liquids","volume":"416 ","pages":"Article 126461"},"PeriodicalIF":5.3,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-09DOI: 10.1016/j.molliq.2024.126460
Yong Zeng , Yingdi Dong , Xiongxing Zhang , Zhongbao Hua , Xiqing Wu , Wei Sun , Haisheng Han , Li Wang , Honghu Tang
In the flotation separation of Mo-Pb bulk concentrate and the purification process of Pb-containing molybdenite concentrate, depressants are typically added to depress galena or molybdenite, aiming to obtain high-quality flotation products. Previous studies have focused on the depression of galena. In this study, gallic acid (GA) was utilized as a molybdenite depressant during Mo-Pb flotation separation. Single mineral flotation experiments showed that pH notably influenced galena and molybdenite flotation with GA, particularly at pH 10, displaying the most substantial recovery difference. Mixed mineral flotation experiments revealed GA’s selective depression on molybdenite. At the optimal dosage of GA, the Mo recovery was reduced by 76.62 percentage points, while the Pb recovery remained unaffected. The depression and separation mechanisms of GA were investigated using contact angle, infrared spectroscopy, Zeta potential, inductively coupled plasma optical emission spectrometer (ICP-OES), X-ray photoelectron spectroscopy (XPS) analysis, first-principles calculations analysis, and interface interaction free energy calculations. The results indicate that GA treatment significantly reduces the hydrophobicity of molybdenite surfaces; however, it slightly enhances the hydrophobicity of galena surfaces. At pH 10, the primary species in GA solution is HGA3-. It adsorbs on PbO species of the galena surface as Pb-GA complexes and tends to detach from the surface at high adsorption capacity, resulting in galena not being depressed by GA. Differently, GA adsorbs on the molybdenite surface through hydrophobic attraction force, rendering it hydrophilic. Additionally, after treatment with potassium butyl xanthate (PBX), the hydrophobicity of GA-treated galena is significantly enhanced, while the hydrophobicity of GA-treated molybdenite is not restored. This is because PBX can adsorb stably on GA-treated galena, but its adsorption on GA-treated molybdenite is hindered by the pre-adsorbed GA.
在钼铅大块精矿的浮选分离和含铅辉钼矿精矿的提纯过程中，通常会添加抑制剂来抑制方铅矿或辉钼矿，以获得高质量的浮选产品。以往的研究主要集中在方铅矿的抑制方面。在本研究中，没食子酸（GA）被用作钼铅浮选分离过程中的辉钼矿抑制剂。单矿物浮选实验表明，pH 值对方铅矿和辉钼矿的浮选有显著影响，尤其是在 pH 值为 10 时，GA 的回收率差异最大。混合矿物浮选实验显示了 GA 对辉钼矿的选择性抑制作用。在 GA 的最佳用量下，钼的回收率降低了 76.62 个百分点，而铅的回收率则未受影响。采用接触角、红外光谱、Zeta 电位、电感耦合等离子体光发射光谱（ICP-OES）、X 射线光电子能谱（XPS）分析、第一原理计算分析和界面相互作用自由能计算等方法研究了 GA 的抑制和分离机理。结果表明，GA 处理能明显降低辉钼矿表面的疏水性，但会轻微增强方铅矿表面的疏水性。在 pH 值为 10 时，GA 溶液中的主要物种是 HGA3-。它以 Pb-GA 复合物的形式吸附在方铅矿表面的 PbO 物种上，在高吸附容量时往往会从表面脱离，导致方铅矿不受 GA 的影响。不同的是，GA 通过疏水吸引力吸附在辉钼矿表面，使其具有亲水性。此外，用黄原酸丁酯钾（PBX）处理后，GA 处理过的方铅矿的疏水性显著增强，而 GA 处理过的辉钼矿的疏水性却没有恢复。这是因为PBX可以稳定地吸附在GA处理过的方铅矿上，但它在GA处理过的辉钼矿上的吸附却受到了预先吸附的GA的阻碍。
{"title":"Enhancement of Mo-Pb flotation separation using gallic acid as a molybdenite depressant: Investigating flotation behavior and mechanism","authors":"Yong Zeng , Yingdi Dong , Xiongxing Zhang , Zhongbao Hua , Xiqing Wu , Wei Sun , Haisheng Han , Li Wang , Honghu Tang","doi":"10.1016/j.molliq.2024.126460","DOIUrl":"10.1016/j.molliq.2024.126460","url":null,"abstract":"<div><div>In the flotation separation of Mo-Pb bulk concentrate and the purification process of Pb-containing molybdenite concentrate, depressants are typically added to depress galena or molybdenite, aiming to obtain high-quality flotation products. Previous studies have focused on the depression of galena. In this study, gallic acid (GA) was utilized as a molybdenite depressant during Mo-Pb flotation separation. Single mineral flotation experiments showed that pH notably influenced galena and molybdenite flotation with GA, particularly at pH 10, displaying the most substantial recovery difference. Mixed mineral flotation experiments revealed GA’s selective depression on molybdenite. At the optimal dosage of GA, the Mo recovery was reduced by 76.62 percentage points, while the Pb recovery remained unaffected. The depression and separation mechanisms of GA were investigated using contact angle, infrared spectroscopy, Zeta potential, inductively coupled plasma optical emission spectrometer (ICP-OES), X-ray photoelectron spectroscopy (XPS) analysis, first-principles calculations analysis, and interface interaction free energy calculations. The results indicate that GA treatment significantly reduces the hydrophobicity of molybdenite surfaces; however, it slightly enhances the hydrophobicity of galena surfaces. At pH 10, the primary species in GA solution is HGA<sup>3-</sup>. It adsorbs on PbO species of the galena surface as Pb-GA complexes and tends to detach from the surface at high adsorption capacity, resulting in galena not being depressed by GA. Differently, GA adsorbs on the molybdenite surface through hydrophobic attraction force, rendering it hydrophilic. Additionally, after treatment with potassium butyl xanthate (PBX), the hydrophobicity of GA-treated galena is significantly enhanced, while the hydrophobicity of GA-treated molybdenite is not restored. This is because PBX can adsorb stably on GA-treated galena, but its adsorption on GA-treated molybdenite is hindered by the pre-adsorbed GA.</div></div>","PeriodicalId":371,"journal":{"name":"Journal of Molecular Liquids","volume":"416 ","pages":"Article 126460"},"PeriodicalIF":5.3,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-09DOI: 10.1016/j.molliq.2024.126459
M. Azogagh , A. El Magri , R. Hsissou , R. Lachhab , Konstantin P. Katin , Elyor Berdimurodov , M. Galai , S.E. Hegazi , M. Rafik
This work reports the synthesis of new epoxy resin namely tetraglycidyl bisurea bisphenyl S (TGBUBS). TGBUBS was characterized through using nuclear magnetic resonance (1H NMR and 13C NMR) and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). TGBUBS was investigated as an excellent organic inhibitor for protecting the mild steel from corrosion in 1M HCl solution at different concentrations. Anticorrosion protection behaviors were evaluated and more discussed including different techniques such as potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and contact angle (CA) measurements. The obtained results showed that the TGBUBS exhibited inhibition efficiencies at lower concentration are 93.19 % (PDP) and 91.21 % (EIS), respectively. Further, PDP measurements indicated that the TGBUBS acted as a mixed-type inhibitor in 1M HCl solution. Furthermore, SEM and EDS analysis showed a significant reduction in the corrosion on the mild steel surface when the inhibitory epoxy resin was present compared to the blank solution (1M HCl). The effectiveness and interactions of the new epoxy resin on the mild steel surface were also predicted using DFT calculations and molecular dynamics (MD) simulations. The theoretical approaches are in agreement with the experiment results.
{"title":"Synthesis investigation and exploring of new tetraglycidyl bisurea bisphenyl S polyepoxide as an excellent corrosion inhibitory resin for mild steel in 1M HCl environment: Comprehensive approaches","authors":"M. Azogagh , A. El Magri , R. Hsissou , R. Lachhab , Konstantin P. Katin , Elyor Berdimurodov , M. Galai , S.E. Hegazi , M. Rafik","doi":"10.1016/j.molliq.2024.126459","DOIUrl":"10.1016/j.molliq.2024.126459","url":null,"abstract":"<div><div>This work reports the synthesis of new epoxy resin namely tetraglycidyl bisurea bisphenyl S (TGBUBS). TGBUBS was characterized through using nuclear magnetic resonance (<sup>1</sup>H NMR and <sup>13</sup>C NMR) and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). TGBUBS was investigated as an excellent organic inhibitor for protecting the mild steel from corrosion in 1M HCl solution at different concentrations. Anticorrosion protection behaviors were evaluated and more discussed including different techniques such as potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and contact angle (CA) measurements. The obtained results showed that the TGBUBS exhibited inhibition efficiencies at lower concentration are 93.19 % (PDP) and 91.21 % (EIS), respectively. Further, PDP measurements indicated that the TGBUBS acted as a mixed-type inhibitor in 1M HCl solution. Furthermore, SEM and EDS analysis showed a significant reduction in the corrosion on the mild steel surface when the inhibitory epoxy resin was present compared to the blank solution (1M HCl). The effectiveness and interactions of the new epoxy resin on the mild steel surface were also predicted using DFT calculations and molecular dynamics (MD) simulations. The theoretical approaches are in agreement with the experiment results.</div></div>","PeriodicalId":371,"journal":{"name":"Journal of Molecular Liquids","volume":"416 ","pages":"Article 126459"},"PeriodicalIF":5.3,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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