TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
·
2024
·
IF 4.7
Xiao-qing LU,Ai-min LIU,Feng-guo LIU,Xian-wei HU,Zhong-ning SHI
The feasibility and reaction mechanism of NdFeB film electrodeposition in 1,3-dimethyl-2-imidazolidinone (DMI)−LiNO 3 ionic liquid analogs at room temperature were investigated. Cyclic voltammetry indicated that the reduction peak at −1.83 V (vs Ag) was related to the reduction of Fe(II) to Fe, while the reduction peak at −2.01 V (vs Ag) was related to the reduction of B(III) to B. The electrochemical reduction reaction of Fe(II) and B(III) were irreversible processes controlled by diffusion, and the diffusion coefficients of Fe(II) and B(III) at 313 K were 3.03×10 −6 and 6.74×10 −7 cm 2 /s, respectively. In addition, XRD analysis suggested that the product obtained by the electrodeposition in DMI−LiNO 3 −Nd(CF 3 SO 3 ) 3 −FeCl 2 −H 3 BO 3 ionic liquid analogs for 2 h on the Al substrate contained NdFe 3 B 3 . SEM and EDS analysis showed that Nd, Fe, and B in the cathode product were uniformly distributed. XPS analysis revealed that the mass fractions of Nd, Fe, and B on the W substrate were 27.44%, 27.90%, and 7.51%, respectively.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Coatings Technology and Research
·
2024
·
IF 2.3
Shen Zihan,Yang Hongyi,Zhang Pengjie,Cui Jiewu,Wang Dongmei,Shen Wangqiang,Xu Guangqing,Lv Jun
Solving the problems of interfacial compatibility and dispersibility between filler and epoxy resin (EP) can greatly improve the anticorrosion performances of epoxy coatings and expand their application field. In this work, carbon nanotubes (CNTs) were modified by poly(sodium 4-styrene sulfonate) and poly(3,4-ethylenedioxythiophene) to form PCNTs hybrids, and the cathodic electrophoretic deposition method was used to form composite epoxy coatings on the surface of sintered NdFeB magnets for enhancing the anticorrosion performance. The corrosion resistance of PCNTs was evaluated by electrochemical and static immersion corrosion tests. Results indicate that PCNTs hybrids possess better distribution and compatibility in epoxy resin than CNTs hybrids, resulting in the anticorrosion performances of higher density of composite epoxy coatings on NdFeB magnets. Optimized EP/PCNTs possess a much higher \(\left| Z \right|\) 0.01 Hz of 4.41 × 10 7 Ω·cm 2 and a much lower J corr of 9.648 × 10 − 10 A·cm − 2 than that of EP (1.34 × 10 4 Ω·cm 2 and J corr 4.436 × 10 − 6 A·cm − 2 ), demonstrating superior corrosion resistance.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Rui Qin,Ji Chen,Yan Bai
NdFeB waste serves not only as a crucial resource for the recovery of rare earth elements (REEs) but also as an underutilized source of gallium (Ga). In this work, to simultaneously extract REEs and Ga from NdFeB waste, an efficient and novel method was developed, which involved the process of leaching, reduction, solvent extraction, precipitation, and calcination. Initially, the Pr, Nd, and Ga were co-leached with 5 mol/L HCl and liquid-solid ratio (mL/g) of 5:1 at 90 °C for 150 min, resulting in the leaching rate of Pr, Nd, and Ga were 98 %, 99 %, and 98 %, respectively. Secondly, to mitigate the interference of Fe (III) on the extraction process, Fe (III) was reduced to Fe (II) completely using Fe powder for 10 min, given that the excess iron powder factor was 1.2. Then, the tributyl phosphate (TBP) was chosen as the extractant for Ga due to its high selectivity. Under the optimal conditions, three-stage counter-current extraction achieved an extraction efficiency of 99 % for Ga, with the addition of 10 % isodecanol to eliminate the third phase. The gallium was completely stripped by water at a phase ratio (O/A) of 2:1. Subsequently, di-2-ethylhexylphosphoric acid was selected as the Pr and Nd extractant because of its high separation ability between REEs and Fe (II). The extraction efficiency of Pr and Nd achieved more than 99 % through three-stage counter-current extraction and the entire stripping of Pr and Nd was realized by 1.8 mol/L HCl. Additionally, a significant amount of Fe (II) in the raffinate was treated via adding oxalic acid to obtain FeC 2 O 4 ⋅ 2H 2 O. Finally, the Ga 2 O 3 and Nd 2 O 3 (PrO 2 ) were prepared from the stripping solution. According to the whole process, the yield of Ga, Pr, and Nd was 93.4 %, 97 %, and 98 %, with the purity of Ga 2 O 3 and Nd 2 O 3 (PrO 2 ) being 98.6 % and 98.4 %, respectively. The results suggested that the stepwise recovery of REEs and Ga from NdFeB waste can be achieved.
研究领域:
材料科学
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冶金工程
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资源回收
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2021
·Vol. 21
·期 1
·715-719
·
IF 0
Zhao Dong,Pei Wenli,Wang Xiaoyang,Zheng Jian,Liu Chunhong,Wang Jianjun
NdFeB magnetic nanoparticles with a main phase of Nd2Fe14B have successfully been synthesized. The preparation includes the following processes. First, the NdFeB intermediate was synthesized by a wet-chemical method. The NdFeB intermediate was annealed at 800 °C,
which resulted in the formation of an NdFeB oxide. Then, the NdFeB oxide was reduced into NdFeB nanoparticles by a second-step reduction annealing with a CaH2 reductant. The second-step reduction annealing temperature was a key factor in preparing the NdFeB nanoparticles. A lower
reduction temperature of 900 °C could not completely reduce the NdFeB oxide into Nd2Fe14B. There were some residual unreduced nonmagnetic phases in the prepared materials, which resulted in obvious decreases of coercivity. A sufficiently high second-stage reduction
temperature resulted in an increased reduction, and more of the Nd2Fe14B phase could be obtained. In this work, nanoparticles with a uniform morphology and an increased Nd2Fe14B phase could be obtained at an optimum reduction temperature of 940 °C,
achieving a high coercivity of 5.4 kOe.
研究领域:
材料科学
·
磁学
✓ 已验证
DOI
PubMed
Surfaces and Interfaces
·
2020
·
IF 3.724
Xunwen Su,Liqun Zhu,Weiping Li,Haining Chen,Rui Cao,Huicong Liu
Al 2 O 3 -contained zinc coatings with enhanced protective and mechanical performances were prepared on NdFeB magnets by in situ electro-deposition methods from the zinc plating baths containing alumina sol. The positively charged alumina sol particles migrate to the NdFeB cathode and then gel along with zinc on the cathode surface, which changes the electro-deposition process of zinc. As a result, the surface morphology and phase structure of the zinc coating is significantly changed. The incorporation of alumina particles achieves a denser zinc coating with a smaller grain size and the hardness is well improved. By increasing alumina sol concentration in the plating bath, the micro-hardness and wear resistance of the zinc coatings gradually increased. What's more, the alumina sol addition also improved the corrosion resistance of zinc coatings. When 20 wt. % alumina sol is added, the corrosion potential of the zinc coating is positively shifted for 168 mV and the corrosion current was more than one order magnitude lower than the blank one. Therefore, this approach shows great promise to obtain alumina-contained zinc coatings with enhanced anti-corrosion properties and mechanical properties.
研究领域:
材料科学
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电化学
·
表面工程
✓ 已验证
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2024
·
IF 5.8
Huangying Guo,Haonan Zhang,Wenyao Li,Rijia Jiang,Xiaolong Liang,Xing Zhou
With the rapid development of today’s society, magnetic self-healing materials are widely used in many fields due to their excellent magnetism and self-healing ability. This article presents a magnetic self-healing composite with good mechanical, self-healing and magnetic properties and magnetic drive performance. Tetraethyl orthosilicate (TEOS), silane coupling agent and succinic anhydride (SA) were used for surface modification of NdFeB magnetic particles (MPs) and NdFeB@SiO 2 -COOH MPs was synthesized. Iron(III) ions were added to the self-polymerization process of the natural small molecule thioctic acid (TA) to form the PTA-Fe prepolymer. PTA-Fe prepolymer, isophorone diisocyanate (IPDI) and polyether amine (PEA) reacted to synthesis PTA-Fe-PU matrix with good self-healing performance at room temperature. The prepared NdFeB@SiO 2 -COOH MPs was mixed with the self-healing matrix and cured to obtain the magnetic room-temperature self-healing composite MPTA-Fe-PU. The best tensile strength of the composite was 7.31 MPa and the ultimate elongation was 833 %. After the prepared MPTA-Fe-PU sample strip was completely cut, the incision on the surface almost disapeared and the tensile strength recovered to 6.35 MPa after 12 h self-healing at room temperature. The self-healing efficiency was up to 87 %. The highly efficient self-healing properties were mainly derived from the disulfide bonds exchange reaction and iron(III) ion coordination in the matrix.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Qingping Zhang,Yang Xu,Haiqing Hao,Zhongxiang Guan,Meng Wang,Zongyu Feng,Xiaowei Huang,Guang Yang,Chunmei Wang
Conventional advanced oxidation processes (AOPs) face technological bottlenecks in the stepwise treatment of heavy metal complexes (HMCs), and single-step removal strategies have attracted increasing attention. Herein, we pioneered a waste-derived strategy using NdFeB waste (NFBW) to activate H 2 O 2 for establishing a heterogeneous Fenton-like system, achieving concurrent Cu-EDTA decomplexation and Cu capture. Remarkably, 99.10 % Cu-EDTA decomplexation and 96.84 % total Cu capture were synchronously achieved within 30 min. This one-step technology is effective over a wide pH range (2.0–9.5). Notably, this system demonstrated practical efficacy in treating rare-earth purification wastewater, achieving synchronous removal of heavy metals (Cu, Zn) and rare-earth elements (Yb, Ce) as mixed organic complexes with effluent meeting industrial discharge standards. Mechanistic investigations revealed that Cu-EDTA decomplexation originated from Fe(Ⅲ)-induced ligand substitution coupled with reactive oxygen species (·OH and ·O 2 - ) attack. The ≡Fe(Ⅱ)/≡Fe(Ⅲ)-mediated heterogeneous Fenton reaction synergized with homogeneous Fe(Ⅱ)/Fe(Ⅲ) cycling to generate ROSs, where the B-B bonds and Fe 0 in NFBW facilitated electron transfer for enhanced redox cycling. Possible pathways for the decomplexation of Cu-EDTA in this system are proposed. The 90.10 % TOC removal verified EDTA mineralization through stepwise degradation pathways. Liberated Cu(Ⅱ) was captured via multiple routes: surface reduction (Cu 0 ), precipitation (Cu(OH) 2 , Cu 2 (OH) 2 CO 3 ), and Fe(OH) 3 adsorption-flocculation. This work not only opens new avenues for Fenton-like treatment of HMC wastewater through a “waste-treats-waste” strategy but also provides new ideas for synergistic activation of H 2 O 2 by multivalent iron materials.
研究领域:
环境科学
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废水处理
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Coatings Technology and Research
·
2022
·Vol. 19
·期 5
·1317-1329
·
IF 2.339
Yang Hongyi,Duan Liangsong,Zhang Pengjie,Xu Guangqing,Cui Jiewu,Lv Jun,Sun Wei,Li Bingshan,Wang Dongmei,Wu Yucheng
In this work, tannic acid (TA) was employed to modify the surface of multiwall carbon nanotubes (CNTs) to form TCNTs hybrids via noncovalent functionalization to enhance its dispersibility in water. Then, the TCNTs enhanced epoxy coatings were applied on sintered NdFeB magnets by cathodic electrophoretic deposition method for corrosion test. The corrosion resistance of prepared specimens was assessed by electrochemical experiments. The results show that TCNTs hybrids present a more homogeneous distribution in epoxy resin than pristine CNTs and could obviously promote anticorrosion properties of prepared specimens. Within 36-day soaking in 3.5 wt.% NaCl solution, the specimens maintain a high value of | Z | 0.01Hz (10 8 Ω cm 2 ) when the concentration of TCNTs is 2 g/L. When immersed in 3.5 wt.% NaCl solution for 40 days, the E corr of specimens shifts to − 0.207 V and J corr is about 5.281 × 10 −11 A cm −2 , which demonstrates superior corrosion resistance.
研究领域:
材料科学
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电化学
·
涂层与表面工程
✓ 已验证
产品关联
DOI
高影响因子
Nano Energy
·
2024
·
IF 16.8
Tong Wu,Xueqing Wang,Xia Cao,Ning Wang
High performance and versatility may be the key for the development of flexible electronic skins that are based on triboelectric nanogenerators (TENGs), and multifunctional components at the triboelectric interface is essential for empowering these devices to mimic or even surpass the sensing properties of human skin, and enabling their response to both environmental and intrinsic conditions. In this context, we present an efficient, low-cost strategy for constructing magnetically responsive TENGs by introducing NdFeB powders into a polydimethylsiloxane film. Besides superior stability, resiliency, and flexibility, the as-designed TENG presents an enhanced output of open circuit voltage of 150 V, short circuit current of 16.7 mA/m 2 , and Q sc of 35 nC, which is almost 3.5 times of the pristine one. Interestingly, the output performance of MR-TENG shows dependence on both the concentration of NdFeB and the direction and intensity of magnetization. Such a correlation in turn provides the linear relationship of the output with the magnetic field (∼80 V/T) and the applied dynamic force (∼0.64 V/N), which helps seamlessly integrating energy harvesting with tactile sensing for self-powered human activity monitoring and other intelligent sensing applications.
研究领域:
材料科学
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纳米技术
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生物医学工程
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能量收集
·
传感器与执行器
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Wenfeng Xue,Ronghao Liu,Xiaoxia Liu,Yangyang Wang,Ping Lv,Yanzhao Yang
The development of an environmentally friendly extractant for selective recovery of rare earth elements is critical but still faces significant challenges. Two low viscosity carboxylic acid based ionic liquids [A336][BTA] and [A336][OTA] were synthesized for selective extraction of Nd(III) from waste NdFeB magnets. First, the extraction behaviors of two kinds of ionic liquids were compared under different conditions, such as time, pH value of aqueous phase, dosage of ionic liquids, and concentration of salting-out agent. The optimal extraction condition of [A336][OTA] was optimized by response surface methodology, and the extraction efficiency reached 99.1%. The extraction mechanism was proposed as ion association by UV–Vis spectrum, IR spectrum and 1 H NMR, and was supported from that perspective of quantum chemical calculation. The extraction thermodynamics, kinetics and isothermal model were studied in detail. [A336][OTA] maintained an extraction efficiency of 95.6% even after seven cycles. The extractant shows good selective separation performance in waste NdFeB magnets, and is an extractant with good application prospect. This work has provided an environmentally friendly extractant for the recovery of Nd(III) from waste NdFeB magnets.
研究领域:
化学工程
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材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Ruihui Wu,Ronghao Liu,Xiaoxia Liu,Jianwei Zhang,Wenfeng Xue,Yanzhao Yang
The recovery of Nd(III) from NdFeB permanent magnets is gaining increasing attention. In the rare earth elements separation industry, wastewater produced through saponification has become a serious environmental problem. In this work, a novel non-saponification P350-N235 synergistic extraction system was established for the extraction of Nd(III) from nitric acid medium. Almost 100% of Nd(III) was extracted by using a P350-N235 system when the molar fraction (X) of P350 was 0.3. And the synergistic enhancement factor R max reached 60.03. Firstly, the effects of time, pH, volume ratio and other variables were investigated to determine the extraction behaviors. Response surface methodology (RSM) was used to optimize the extraction conditions. The mechanism of synergistic extraction was investigated by FT-IR, UV–vis, NMR methods and ESP maps, indicating that the composition of the extracted complex was Nd(NO 3 ) 3 ·(P350) 2.5 (N235) 2.5 . Then, the extraction thermodynamics and kinetics were also thoroughly investigated, the extraction process is demonstrated to be a spontaneously exothermic reaction. In the NdFeB leaching solution, the synergistic system showed excellent separation factor (β) for Nd/Sm (1.43), Nd/Gd (7.33), and Nd/Dy (9.81). Finally, after 5 cycles, the P350-N235 synergistic system maintained high extraction efficiency. In conclusion, this study overcame the saponification problem in traditional extraction techniques and proposed an environmentally friendly green extraction system.
研究领域:
环境科学
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化学工程
·
材料科学
·
稀土元素分离
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2022
·Vol. 33
·期 6
·2207209
·
IF 19.924
Lianzhen Li,Ziqiang Shang,Jianfu Tang,Jiameng Li,Zefang Xiao,Yanjun Xie,Jiuqing Liu,Zhenjie Li,Shilong Yang,Yiqi Liu,Wentao Gan
The development of environmentally-friendly stimuli-responsive materials is vital to green electronics, sensors, and biomedicine. However, fast responsiveness and precise locomotion control of biomass materials have not been accomplished. Herein, a magnetically responsive wood is reported that can achieve programmable locomotion in the rotating magnetic field. The magnetized wood is fabricated by removing lignin from the cell walls, which produces a porous microstructure, enabling facile and stable combination between NdFeB and wood. With the directional arrangement of magnetic moments after magnetization, the magnetized wood with obviously positive and negative magnetic poles is magnetic stability, and can complete various movements including spatial flipping, bypass obstacles, climb up, and down under the driven by magnetic torques. Meanwhile, the magnetized wood is lightweight (0.26 g cm −3 ), showing a fast walking speed of up to 11.3 mm s −1 under magnetic actuation (10 mT and 0.6 Hz), which is greater than those of petroleum-based polymeric materials. Benefitting from the unique porous structure, the magnetized wood can be used as the drug-carrier to deliver and release nano-cargoes effectively. This approach expands the range of stimuli-responsive materials beyond hydrogel, elastomers, and synthetic polymer, inspiring the creation of next-generation intelligent robots based on biocompatible and sustainable biomass materials.
研究领域:
材料科学
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生物医学工程
·
绿色电子学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）