Journal of Molecular Liquids最新文献_第5页

Effect of pH, NaCl, and sucrose on structural and rheological properties of fish gelatin/ι-carrageenan complexes pH、NaCl和蔗糖对鱼明胶/ι-卡拉胶配合物结构和流变性能的影响

IF 5.2 2区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Molecular Liquids

Pub Date : 2025-12-02 DOI: 10.1016/j.molliq.2025.129076

Bum Ju Kil, Yoon Hyuk Chang

The objective of this study was to investigate the effects of pH, NaCl, and sucrose on the structural and rheological properties of fish gelatin (FG)/ι-carrageenan (ι-CG) complexes. FG/ι-CG (pH 7) was prepared at pH 7. FG/ι-CG (pH 7) was subjected to different pH conditions (pH 5 and 3) and varying concentrations of NaCl (0.001–0.3 %) and sucrose (1–30 %). FT-IR and XRD analyses revealed that decreasing pH from 7 to 5 and 3 reduced hydrogen bonding and partially disrupted crystalline structures, weakening the molecular network. Low NaCl (0.001–0.01 %) slightly enhanced network cohesion via ionic screening, whereas high NaCl (0.1–0.3 %) disrupted electrostatic interactions and reduced structural stability. Low sucrose (1–10 %) strengthened hydrogen bonding and network rigidity, while high sucrose (20–30 %) induced partial crystallinity, plasticization, and structural disorder. Steady shear measurements showed non-Newtonian shear-thinning behavior. Apparent viscosity and consistency index increased at 0.001–0.01 % NaCl and 1–10 % sucrose, but decreased under acidic pH, at 0.1–0.3 % NaCl, or with 20–30 % sucrose, compared with FG/ι-CG at pH 7. Dynamic shear measurements indicated that G′ and G″ were moderately enhanced at 0.001 %–0.01 % NaCl and 1–10 % sucrose, whereas higher NaCl (0.1–0.3 %), sucrose (20–30 %), or acidic pH (5 and 3) progressively reduced both moduli. The largest decrease in G′ and G″ occurred at pH 3, reflecting weakened electrostatic and hydrogen-bonding interactions. Overall, pH, NaCl, and sucrose collectively influenced molecular interactions, network architecture, and viscoelastic behavior, providing a framework for the rational design of protein–polysaccharide complexes with tailored mechanical and thermal properties for food and biopolymer applications.

本研究的目的是研究pH、NaCl和蔗糖对鱼明胶(FG)/ι-卡拉胶（ι-CG）配合物结构和流变性能的影响。在pH为7的条件下制备FG/ι-CG （ph7）。FG/ι-CG （pH 7）在不同的pH条件下（pH 5和pH 3）， NaCl（0.001 ~ 0.3%）和蔗糖（1 ~ 30%）的浓度变化。FT-IR和XRD分析表明，当pH从7降低到5和3时，氢键减少，晶体结构部分破坏，分子网络减弱。低NaCl（0.001 - 0.01%）通过离子筛选略微增强了网络的内聚性，而高NaCl（0.1 - 0.3%）破坏了静电相互作用，降低了结构稳定性。低蔗糖（1 - 10%）增强了氢键和网络刚性，而高蔗糖（20 - 30%）诱导了部分结晶度、塑化和结构紊乱。稳定剪切测量显示非牛顿剪切减薄行为。与FG/ι-CG在pH 7下相比，在0.001 ~ 0.01% NaCl和1 ~ 10%蔗糖处理下，表观粘度和稠度指数升高，但在酸性pH、0.1 ~ 0.3% NaCl和20 ~ 30%蔗糖处理下，表观粘度和稠度指数降低。动态剪切测量表明，在0.001 % - 0.01% NaCl和1 - 10%蔗糖条件下，G′和G″适度增强，而较高的NaCl（0.1 - 0.3%）、蔗糖（20 - 30%）或酸性pH（5和3）逐渐降低这两个模量。G′和G″在pH为3时下降幅度最大，反映出静电和氢键相互作用减弱。总的来说，pH、NaCl和蔗糖共同影响分子相互作用、网络结构和粘弹性行为，为合理设计具有定制机械和热性能的蛋白质-多糖复合物提供了框架，用于食品和生物聚合物的应用。

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引用次数: 0

Effect of freeze-thawing on polyvinyl alcohol hydrogel: Films before and after solvent evaporation casting 冻融对聚乙烯醇水凝胶的影响：溶剂蒸发铸造前后的膜

IF 5.2 2区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Molecular Liquids

Pub Date : 2025-12-02 DOI: 10.1016/j.molliq.2025.129040

Gabriel Goetten de Lima , Mirela Angelita Artne , Izabelli Cristiani Barcelar Zakaluk , Bruno Bernardi Aggio , Tielidy Angelina de Morais de Lima , Washington Luiz Esteves Magalhães

Freeze-thawing (F/T), a process widely reported in literature for crosslinking Polyvinyl alcohol (PVA), is widely known in the science community to develop toxic-free hydrogels. Despite extensive characterization, optimizing both the viscous and elastic properties of hydrogels remains challenging. To address this issue, we studied the F/T mechanisms. The common understanding is due to the hydrogel transition that occurs within the solid-liquid interface upon freezing and subsequent thawing. However, in this study, we demonstrate that it is possible to crosslink PVA films prior F/T, i.e. after solvent-evaporation casting. This observation translates to crystallinity, swelling, and mechanical properties. When F/T was applied to cast films, the PVA exhibited an increase in melting enthalpy from 47.3 to 53.7 J/g and a rise in melting temperature from 207.5 to 223.0 °C. Moreover, post-casting F/T increased the storage modulus (G′) from 0.19 KPa (control) to 2.11 KPa. Swelling experiments further showed that films treated after casting absorbed less water than untreated PVA films, which reached values above 800 %, indicating a denser physically crosslinked. Network. These observations can also be translated into more complex systems, known to crosslink with PVA, such as nanocellulose and chitosan.

冻融（F/T）是文献中广泛报道的一种用于交联聚乙烯醇（PVA）的工艺，在科学界被广泛认为是开发无毒水凝胶的方法。尽管进行了广泛的表征，但优化水凝胶的粘性和弹性特性仍然具有挑战性。为了解决这个问题，我们研究了F/T机制。通常的理解是由于在冻结和随后的解冻时固液界面内发生的水凝胶转变。然而，在本研究中，我们证明了在F/T之前，即在溶剂蒸发铸造之后，交联PVA薄膜是可能的。这一观察结果转化为结晶度、膨胀和机械性能。当F/T作用于铸膜时，PVA的熔化焓从47.3增加到53.7 J/g，熔化温度从207.5增加到223.0℃。此外，后浇铸F/T使存储模量（G′）从0.19 KPa（对照）增加到2.11 KPa。溶胀实验进一步表明，浇铸后处理的膜比未处理的PVA膜吸水性更低，吸水性达到800%以上，表明物理交联更致密。网络。这些观察结果也可以转化为更复杂的系统，已知与聚乙烯醇交联，如纳米纤维素和壳聚糖。

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引用次数: 0

Electrochemical performance and microstructure of microemulsion electrolytes for supercapacitors 超级电容器用微乳液电解质的电化学性能和微观结构

IF 5.2 2区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Molecular Liquids

Pub Date : 2025-12-02 DOI: 10.1016/j.molliq.2025.129069

Aliyu Salisu , Fraser Hughson , Rohan Borah , Xianjue Chen , Stephen Holt , Vanessa K. Peterson , Thomas Nann , Jitendra Mata , Renee V. Goreham

In this study, the structural and electrochemical properties of microemulsions (MEs) with varying hydrophobicity and water content, controlled through the amount of surfactant (

S

) and oil (

O

) relative to water (

W

),

x = (S + O) / W

, were investigated to understand their potential as electrolytes for energy storage applications. The ellipsoidal and Teubner-Strey (T–S) structural models were applied to the MEs’ small-angle neutron scattering (SANS) data, revealing a morphological transition from droplets to bicontinuous-like structures with increasing

x

. Cryo-TEM imaging and SANS data analysis via Porod analysis confirmed this structural evolution and highlighted the associated changes in flexibility, compactness, and nanoscale organisation. Electrochemical studies using ferrocene (Fc) as a probe demonstrated that the Fc diffusion increased with

x

, reflecting the enhanced structural heterogeneity and diffusional pathways of the bicontinuous MEs. Higher conductivity and lower resistance at the lower

x = 0.2

suggested superior supercapacitor performance. In contrast, higher

x = 1.0

and

1.5

MEs showed promise for application in redox flow batteries with differently polar charged states due to their well-defined biphasicity, which facilitates fast diffusion and electron transfer. Capacitance measurements and Ragone plots further corroborated the correlation between structure and performance, with the

x = 0.2

ME outperforming its counterparts in energy and power density. These findings highlight the critical influence of morphology on ME functionality, with future studies using neutron reflectometry (NR) planned to probe the lamellar interfacial structures believed to be responsible for high-voltage activity.

在这项研究中，通过表面活性剂(S)和油(O)相对于水(W)的量（x=(S+O)/W）来控制具有不同疏水性和含水量的微乳（MEs）的结构和电化学性能，以了解它们作为储能电解质的潜力。椭球和Teubner-Strey （T-S）结构模型应用于MEs的小角中子散射（SANS）数据，揭示了随着x的增加，从液滴到双连续结构的形态转变。低温透射电镜成像和通过Porod分析的SANS数据分析证实了这一结构演变，并强调了柔性、致密性和纳米级组织的相关变化。以二茂铁（Fc）为探针的电化学研究表明，Fc的扩散随x的增加而增加，反映了双连续MEs的结构非均质性和扩散途径的增强。当x=0.2时，较高的电导率和较低的电阻表明超级电容器性能优越。相比之下，更高的x=1.0和1.5 MEs由于具有明确的双相性，有利于快速扩散和电子转移，因此有望应用于具有不同极性带电状态的氧化还原液流电池。电容测量和Ragone图进一步证实了结构与性能之间的相关性，其中x=0.2 ME在能量和功率密度方面优于同类产品。这些发现强调了形态对ME功能的关键影响，未来的研究计划使用中子反射（NR）来探测被认为是导致高压活性的层状界面结构。

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引用次数: 0

Molecular mechanisms of methane hydrate dissociation under static and oscillating electric fields 静态和振荡电场作用下甲烷水合物解离的分子机制

IF 5.2 2区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Molecular Liquids

Pub Date : 2025-12-01 DOI: 10.1016/j.molliq.2025.129070

Tairan Zhou , Jinxiang Liu , Yalin Zhang, Tiantian Jia, Shengli Liu

This study employs molecular dynamics simulations to investigate electric field-induced methane hydrate dissociation. Our results indicate that static fields exceeding a critical threshold (2.78 V/nm) induce dissociation via hydrogen-bond network disruption and water dipole alignment, leading to either methane nanobubbles or supersaturated solutions. Dissociation kinetics show strong field-strength dependence, with complete dissociation at higher strengths. In contrast, oscillating fields produce markedly different behavior: sustained exposure triggers abrupt dissociation, showing distinct frequency- and intensity-dependent kinetics that consistently yield methane nanobubbles. These mechanistic insights establish a theoretical framework for electric field-based hydrate extraction, while highlighting the need for optimized field parameters and energy efficiency.

本研究采用分子动力学模拟研究电场诱导的甲烷水合物解离。我们的研究结果表明，超过临界阈值（2.78 V/nm）的静电场通过氢键网络破坏和水偶极子排列诱导解离，导致甲烷纳米气泡或过饱和溶液。解离动力学表现出较强的场强依赖性，在较高场强下解离完全。相比之下，振荡场产生明显不同的行为：持续暴露引发突然解离，表现出明显的频率和强度相关的动力学，始终产生甲烷纳米气泡。这些机理见解为基于电场的水合物提取建立了理论框架，同时强调了优化油田参数和能源效率的必要性。

引用次数: 0

Water selectively solvates a solute in ionic liquid and water mixtures: dependence on ionic liquid type 水选择性溶剂化离子液体和水混合物中的溶质：依赖于离子液体类型

IF 5.2 2区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Molecular Liquids

Pub Date : 2025-12-01 DOI: 10.1016/j.molliq.2025.129065

Ayaka Kawano , Yuji Higuchi , Kyoko Fujita , Mafumi Hishida

Ionic liquids (ILs), which differ from conventional salts in terms of weaker electrostatic interactions, possess lower melting points and are gaining traction as “third solvents” alongside water and organic solvents. Recently, some ILs have been reported to have a pronounced ability to preserve the structure and function of proteins upon the addition of a small amount of water. To clarify the underlying mechanism of protein preservation in IL/water mixtures, in this study, we investigated the solvation structure around a solute in aqueous solutions of three ILs with different protein-stabilizing abilities, viz., choline dihydrogen phosphate ([ch][dhp]), choline bromide ([ch][Br]), and 1-butyl-3-methylimidazolium chloride [C₄mim][Cl]. Small-angle X-ray scattering studies revealed that these ILs formed water-rich solvation layers around a silica particle used as a model solute. The [ch][dhp]/water system, which has the most effective protein-stabilizing ability, was found to have the thickest solvation layer with a water content of 97–87 %. The thickness of the solvation layer increased as the water content was decreased, reaching approximately three layers of water molecules. Infrared spectral studies revealed that the hydrogen bonds between the water molecules in the solvation layer were broken to some extent. Molecular dynamics simulations indicated that water molecules aggregated in the binary mixture of [ch][dhp] and water. This result suggests that the aggregated water selectively approached the solute surface to form a water-rich solvation layer in the [ch][dhp]/water system. In contrast, the [ch][Br]/water and [C₄mim][Cl]/water systems had less pronounced water-rich layers. The strong correlation between solvation layer formation and protein stabilization suggests that the protein-stabilizing effect of IL/water systems is achieved through the formation of water-rich solvation layers, which is supported by the observed IL concentration dependence of the solvation layer thickness.

离子液体（ILs）与传统盐的不同之处在于静电相互作用较弱，熔点较低，与水和有机溶剂一起成为“第三溶剂”。最近，一些il被报道在加入少量水的情况下具有明显的保持蛋白质结构和功能的能力。为了阐明IL/水混合物中蛋白质保存的潜在机制，本研究研究了三种具有不同蛋白质稳定能力的IL，即胆碱磷酸二氢酯（[ch][dhp]）、溴化胆碱（[ch][Br]）和1-丁基-3-甲基咪唑氯[C4mim][Cl]，在水溶液中围绕溶质的溶剂化结构。小角度x射线散射研究表明，这些il在作为模型溶质的二氧化硅颗粒周围形成了富水的溶剂化层。[ch][dhp]/水体系具有最有效的蛋白质稳定能力，其溶剂化层最厚，含水量为97 ~ 87%。随着水含量的减少，溶剂化层的厚度增加，达到大约三层水分子。红外光谱研究表明，溶剂化层中水分子之间的氢键发生了一定程度的断裂。分子动力学模拟表明，水分子在[ch][dhp]和水的二元混合物中聚集。这一结果表明，在[ch][dhp]/水体系中，聚集的水选择性地接近溶质表面，形成富水的溶剂化层。相比之下，[ch][Br]/water和[C4mim][Cl]/water体系的富水层不那么明显。溶剂化层的形成与蛋白质稳定之间的强相关性表明，IL/水系统的蛋白质稳定作用是通过形成富水的溶剂化层来实现的，这得到了观察到的IL浓度对溶剂化层厚度的依赖性的支持。

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引用次数: 0

Editorial of the special issue of 29th EUCHEMSIL EUCHEMSIL第29期特刊社论

IF 5.2 2区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Molecular Liquids

Pub Date : 2025-12-01 DOI: 10.1016/j.molliq.2025.128914

Luis M. Varela, Josefa Salgado, Trinidad Méndez-Morales, Hadrián Montes-Campos, Juan J. Parajó

引用次数: 0

Electrode geometry optimization in Thomson-Lampard biosensors: enhancing urea detection via ionic conductivity in biological liquids Thomson-Lampard生物传感器的电极几何优化：通过生物液体中的离子电导率增强尿素检测

IF 5.2 2区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Molecular Liquids

Pub Date : 2025-11-30 DOI: 10.1016/j.molliq.2025.129022

M. Ashoorirad , R. Baghbani , R. Fereydooni , R. Davoodi

Impedance spectroscopy provides a non-invasive method for monitoring biomarkers that are vital for health diagnostics, such as urea—a key indicator of kidney and liver function. This study introduces two novel biosensors based on the Thomson-Lampard (TL) theorem, namely cubic-TL and cylindrical-TL, designed for precise measurement of urea concentration in biological solutions. The sensor geometries were optimized via finite element modeling (FEM) in COMSOL, revealing that a height-to-side length ratio ≤ 1 for the cubic-TL and a height-to-radius ratio ≈1 for the cylindrical-TL yield the best agreement with reference biological tissue data (Gabriel dataset). The electrode surface area was identified as a critical factor, with full coverage minimizing measurement errors. Experimentally, both sensors exhibited high sensitivity over urea concentrations of 1–200 mg/mL, showing a strong inverse correlation between concentration and resistivity (R² > 0.98) due to increased ionic conductivity. The cylindrical-TL configuration marginally outperformed the cubic-TL (MSE: 1.29 % vs. 3.45 % for real resistivity), attributed to its more uniform electric field distribution and reduced edge effects. Statistical validation (p < 0.05) confirmed measurement reproducibility across five trials. These findings highlight the significance of geometric optimization and electrode design in enhancing biosensor performance and demonstrate the potential of TL-based architectures for developing cost-effective, portable, and non-invasive urea monitoring devices suitable for point-of-care diagnostic applications.

阻抗谱提供了一种非侵入性的方法来监测对健康诊断至关重要的生物标志物，如尿素——肾脏和肝脏功能的关键指标。本研究介绍了两种基于Thomson-Lampard （TL）定理的新型生物传感器，即立方TL和圆柱TL，用于精确测量生物溶液中的尿素浓度。通过COMSOL有限元建模（FEM）对传感器几何形状进行了优化，结果表明，立方体tl的高度与侧长比≤1，圆柱形tl的高度与半径比≈1与参考生物组织数据（Gabriel数据集）最吻合。电极表面积被确定为一个关键因素，具有全覆盖最小化测量误差。实验结果表明，两种传感器在尿素浓度为1-200 mg/mL时均表现出较高的灵敏度，由于离子电导率增加，浓度与电阻率之间存在很强的负相关关系（R2 > 0.98）。由于其更均匀的电场分布和更小的边缘效应，圆柱tl结构的性能略优于立方tl（实际电阻率的MSE: 1.29% vs. 3.45%）。统计验证（p < 0.05）证实了五项试验的测量可重复性。这些发现突出了几何优化和电极设计在提高生物传感器性能方面的重要性，并展示了基于tl的架构在开发适合于即时诊断应用的具有成本效益，便携式和非侵入性尿素监测设备方面的潜力。

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引用次数: 0

Study on the multi interface synergistic mechanism of simultaneous fixation of cadmium and degradation of imidacloprid in biochar system mediated by oxygen vacancy free radicals 氧空位自由基介导的生物炭系统中镉同时固定与吡虫啉降解的多界面协同机制研究

IF 5.2 2区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Molecular Liquids

Pub Date : 2025-11-30 DOI: 10.1016/j.molliq.2025.129068

Xuan Xiao , Fenghui Wu , Yuanchuan Ren

This study successfully constructed humic acid activated microporous biochar (BSSB-HA₅) using bamboo shoot shell biochar (BSSB) and humic acid (HA) as precursors through etching method, aiming to achieve efficient synchronous treatment of cadmium (Cd(II)) and imidacloprid (IMI) composite pollution in the rhizosphere environment of paddy fields. System characterization (SEM, XRD, FTIR, XPS) confirmed that HA activation effectively increased the specific surface area of the material (171.85 m²/g) and introduced abundant oxygen-containing functional groups, providing sufficient active sites for pollutant removal. Batch experiments showed that BSSB-HA₅ achieved removal rates of 95.69 % and 97.40 % for Cd (II) (50 mg/L) and IMI (20 μM) within 45 and 20 min, respectively, with reaction rate constants of 0.0593 min⁻¹ and 0.1445 min⁻¹, respectively. Mechanism studies reveal that the fixation of Cd(II) is mainly achieved through multiple synergistic pathways such as surface complexation, electrostatic attraction, cation-π interactions, and (surface) precipitation; The degradation of IMI is mainly driven by advanced oxidation processes mediated by free radicals. Quenching experiments and EPR analysis confirm that ·OH, ¹O₂, and ·O₂⁻ are the main active species, with contribution rates of 71.08 %, 18.43 % and 2.69 %, respectively. LC-MS identified 28 intermediate products and derived three possible degradation pathways based on them: hydroxylation, oxidative denitrification, and ring opening mineralization. In addition, the material maintained excellent removal performance (Cd(II) > 94.60 %, IMI > 97.40 %) and structural stability after six cycles, and showed significant buffering ability towards the pH of the rhizosphere microenvironment. This work provides new strategies and theoretical basis for the development of multifunctional carbon based materials suitable for agricultural non-point source pollution, especially for the remediation of rice rhizosphere microenvironment.

本研究以竹笋壳生物炭（BSSB）和腐植酸（HA）为前体，通过刻蚀法成功构建了腐植酸活化的微孔生物炭（BSSB- ha5），旨在实现水稻根际环境中镉（Cd(II)）和吡虫啉（IMI）复合污染的高效同步治理。系统表征（SEM， XRD， FTIR， XPS）证实，HA活化有效地增加了材料的比表面积（171.85 m2/g），并引入了丰富的含氧官能团，为污染物的去除提供了足够的活性位点。批量实验表明，BSSB-HA5对Cd (II) （50 mg/L）和IMI （20 μM）的去除率分别在45 min和20 min内达到95.69%和97.40%，反应速率常数分别为0.0593 min−1和0.1445 min−1。机理研究表明，Cd（II）的固定主要通过表面络合、静电吸引、阳离子-π相互作用和（表面）沉淀等多种协同途径实现；IMI的降解主要是由自由基介导的高级氧化过程驱动的。猝灭实验和EPR分析证实，·OH、1O2和·O2−是主要的活性物质，贡献率分别为71.08%、18.43%和2.69%。LC-MS鉴定了28个中间产物，并基于它们推导出3种可能的降解途径：羟基化、氧化反硝化和开环矿化。此外，经过6次循环后，材料保持了优异的去除率（Cd(II) > 94.60%, IMI > 97.40%）和结构稳定性，并对根际微环境的pH值表现出显著的缓冲能力。本研究为开发适用于农业面源污染特别是水稻根际微环境修复的多功能碳基材料提供了新的策略和理论依据。

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引用次数: 0

Mechanistic insights into toxic metal adsorption in multicomponent systems using graphene oxide membranes: kinetic, equilibrium, and reuse studies 使用氧化石墨烯膜的多组分系统中有毒金属吸附的机理：动力学、平衡和再利用研究

IF 5.2 2区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Molecular Liquids

Pub Date : 2025-11-30 DOI: 10.1016/j.molliq.2025.129055

Tauany de Figueiredo Neves , Cláudia Batista Lopes , Valmor Roberto Mastelaro , Renato Falcão Dantas , Carlos Manuel Silva , Patrícia Prediger

In this study, a composite membrane based on hydrolyzed polyacrylonitrile (hPAN) coated with graphene oxide (GO) and poly(4-vinylpyridinium iodide) (PVPI), referred to as hPAN/PVPI₃/GO₃, was evaluated for the removal of Cr³⁺, Cu²⁺, and Pb²⁺ ions from multicomponent aqueous systems. Adsorption performance was assessed through kinetic and equilibrium studies, while post-adsorption characterization elucidated the underlying adsorption mechanisms. Batch adsorption experiments, conducted over 24 h at 298 K and pH 5.5 with initial concentrations of 10 mg L ^{̶ 1} for Cr³⁺ and Pb²⁺ and 20 mg L ^{̶ 1} for Cu²⁺, yielded maximum adsorption loadings of 6.42 mg g ^{̶ 1}, 23.2 mg g ^{̶ 1}, and 29.6 mg g ^{̶ 1} for Cr³⁺, Cu²⁺, and Pb²⁺, respectively. The experimental assays revealed selective adsorption behavior. Spectroscopic and microscopic analyses confirmed interactions between metal cations and electron-rich functional groups on the membrane surface, as well as the reduction of Cu²⁺ to Cu⁺. The hPAN/PVPI₃/GO₃ membrane maintained high adsorption efficiency for Cr³⁺ and Pb²⁺ over five consecutive cycles, demonstrating strong reusability. These results underscore the potential of hPAN/PVPI₃/GO₃ as a promising material for the remediation of toxic metals from contaminated water, with performance comparable to, or even exceeding, that of other reported adsorbents.

在这项研究中，以氧化石墨烯（GO）和聚（4-乙烯基碘化吡啶）（PVPI）为涂层的水解聚丙烯腈（hPAN）为基础的复合膜（hPAN /PVPI3/GO3），对多组分水体系中Cr3+、Cu2+和Pb2+离子的去除效果进行了评估。通过动力学和平衡研究评估了吸附性能，而吸附后表征阐明了潜在的吸附机理。在298 K和pH 5.5条件下，Cr3+和Pb2+的初始浓度为10 mg L * 1， Cu2+的初始浓度为20 mg L * 1，进行了24小时的批量吸附实验，Cr3+、Cu2+和Pb2+的最大吸附量分别为6.42 mg g * 1、23.2 mg g * 1和29.6 mg g * 1。实验分析显示了选择性吸附行为。光谱和微观分析证实了金属阳离子与膜表面富电子官能团之间的相互作用，以及Cu2+还原为Cu+。hPAN/PVPI3/GO3膜在连续5个循环中对Cr3+和Pb2+保持了较高的吸附效率，具有较强的可重复使用性。这些结果强调了hPAN/PVPI3/GO3作为一种有前途的材料修复污染水中有毒金属的潜力，其性能与其他报道的吸附剂相当，甚至超过。

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引用次数: 0

Study on the forms and volatilization behavior of hydrogen fluoride in phosphoric acid with deep potential molecular dynamics (DPMD) 深势分子动力学（DPMD）研究磷酸中氟化氢的形态及挥发行为

IF 5.2 2区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Molecular Liquids

Pub Date : 2025-11-30 DOI: 10.1016/j.molliq.2025.129066

Linfei Li , Jie Zhou , Rong Yu , Xiumin Chen , Yunmin Chen , Kangming Wu , Zhicheng Gao , Guihua Zhu , Wei Jiang

The forms and volatilization behavior of HF in phosphoric acid are crucial for the defluorination of wet-process phosphoric acid. However, due to the toxicity, strong corrosivity, and high volatility of hydrogen fluoride, experimental research is challenging. Therefore, this study employs first principle molecular dynamics (FPMD) to investigate the structural characteristics of hydrogen fluoride, water, phosphoric acid, and fluorinated phosphoric acid solutions. Based on the calculated FPMD data, a Deep Potential Molecular Dynamics (DPMD) is trained to simulate the evaporation behavior of fluorinated phosphoric acid at 353 K on the nanosecond scale. FPMD results show that the hydrogen bond network structure of pure hydrogen fluoride is long-chain, pure water has a mixed chain and network structure, and phosphoric acid has a three-dimensional network structure. Hydrogen fluoride can partially dissociate and form stable HF₂ molecules in water and phosphoric acid. The differences in F-H···X (X = F, O) and H-O···X (X = F, O) hydrogen bonds in different systems, as well as the electronic structure characteristics of hydrogen fluoride, lead to large diffusion coefficients for fluorinated species in phosphoric acid. Simulation results from deep neural network model potential molecular dynamics (DPMD) for phosphoric acid and fluorinated phosphoric acid systems show that due to the dissociation of hydrogen fluoride and the formation of HF₂ in phosphoric acid aqueous solutions, coupled with the strong F-H···F and F-H···O (P) hydrogen bonds in fluorinated phosphoric acid systems, hydrogen fluoride on the surface of fluorinated phosphoric acid can rapidly escape in the forms of HF₂ and H₃PO4·HF. The fluorinated species inside the phosphoric acid are aggregated and their migration is limited by the hydrogen bond network of the phosphoric acid aqueous solution. The calculated diffusion coefficient of fluorine in fluorinated phosphoric acid at 353 K is 1.7635 × 10⁻⁸ m²·s⁻¹, and the diffusion coefficient of phosphorus is 0.7182 × 10⁻⁸ m²·s⁻¹. The research results provide a theoretical basis for the defluorination of wet-process phosphoric acid.

HF在磷酸中的形态和挥发行为对湿法磷酸的脱氟至关重要。然而，由于氟化氢的毒性、强腐蚀性和高挥发性，实验研究具有挑战性。因此，本研究采用第一性原理分子动力学（first principle molecular dynamics， FPMD）研究氟化氢、水、磷酸和氟化磷酸溶液的结构特征。基于计算得到的FPMD数据，训练了一个深势分子动力学（DPMD）来模拟353 K下氟化磷酸在纳秒尺度上的蒸发行为。FPMD结果表明，纯氟化氢的氢键网络结构为长链，纯水为链网混合结构，磷酸为三维网络结构。氟化氢可以在水和磷酸中部分解离并形成稳定的HF2分子。不同体系中F- h··X （X = F， O）和H-O··X （X = F， O）氢键的差异，以及氟化氢的电子结构特征，导致氟化物质在磷酸中的扩散系数较大。磷酸和氟化磷酸体系的深度神经网络模型电位分子动力学（DPMD）模拟结果表明，由于磷酸水溶液中氟化氢解离形成HF2，再加上氟化磷酸体系中F- h··F和F- h···O (P)氢键较强，氟化磷酸表面的氟化氢能以HF2和H3PO4·HF的形式快速逸出。磷酸中的氟化物质聚集在一起，它们的迁移受到磷酸水溶液氢键网络的限制。计算得到氟在353 K氟化磷酸中的扩散系数为1.7635 × 10−8 m2·s−1，磷的扩散系数为0.7182 × 10−8 m2·s−1。研究结果为湿法磷酸的脱氟工艺提供了理论依据。

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