MINERALS ENGINEERING
·
2024
·
IF 4.9
Weilun Qian,Huibin Zhang,Jiankang Tan,Wenyu Feng,Huazhen Cao,Guoqu Zheng
The transformation of pyrite into ferrous sulfide (FeS) has a substantial significance in gold extraction from gold-bearing pyrite. This work proposed to treat pyrite by reactive diffusion with added elemental Fe for generating FeS. The diffusion kinetics and transformation mechanism during reactive synthesis were investigated via constructing Fe-FeS 2 powder diffusion couples. The results indicated that the formation of the pyrrhotite phase (Fe 1-x S, x = 0–0.5) firstly occurred at the interface of the diffusion couple. The interdiffusion coefficient ranged from 10 −16 m 2 s −1 ∼ 10 −12 m 2 s −1 at 723–873 K and the apparent activation energy of the product layer was about 147.59 kJ mol −1 . XRD and HRTEM results demonstrated that with the increase of sintering temperature, the diffusion of Fe played the pivotal role in the phase transformation of Fe 1-x S to FeS. Furthermore, the conversion rate of FeS can reach 95.82 % by optimizing sintering process. The synthesized FeS can be readily dissolved by sulfuric acid and the mass ratio of leaching residue is only 2.3 %, indicating that the precious metals in pyrite such as gold can be concentrated by nearly 43.5 times. This proposed method with the green economy characteristic would be a promising candidate for the pretreatment of gold-bearing pyrite.
研究领域:
化学工程
·
材料科学
·
冶金工程
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产品关联
DOI
高影响因子
Cell Reports Physical Science
·
2021
·
IF 0
Lin Qiao,Qing Dai,Huamin Zhang,Xianfeng Li
Summary Turing patterns and reaction-diffusion models are of great significance in biological and chemical fields. However, Turing-shape materials together with their application are rarely investigated, since at present Turing patterns are typically formed by the reaction of small molecules in a viscous system. Herein, a facile route to fabricate membrane materials with macro-scale Turing patterns is proposed. Macromolecules, rather than small molecules, are chosen as reactants to generate chemical Turing patterns, which makes it easy to freeze and construct Turing-shape materials. The formation mechanism and influence factors of Turing patterns are discussed in detail via experimental investigation and numerical simulation. Turing-shape membranes are successfully applied to electrochemical energy storage and exhibit good performance benefiting from the rich surface area.
研究领域:
材料科学
·
化学
·
生物学
✓ 已验证
DOI
Progress in Natural Science-Materials International
·
2023
·
IF 4.7
Shuting Shen,Na Pan,Chengfei Liu,Wenxin Fan,Kunyan Sui
Under external stimuli, the bilayer hydrogels can change their shapes or move mechanically with fast, sensitive and adjustable motion characteristics. However, the main methods for preparing bilayer hydrogels have many limitations, such as they involve complicated synthesis processes, lead to fragile bilayer interface and structure, and result in single responsiveness and deformation, which hinders the practical applications of bilayer hydrogel in intelligent bionics. Here, we used the reaction-diffusion of sodium alginate (SA) and chitosan (CS) combined with the photopolymerization of N-isopropylacrylamide (NIPAM) to prepare (PNIPAM/SA)/(SA/CS) bilayer hydrogel film. The bilayer hydrogel film can well respond to the alteration of temperature, pH, salt concentration and thickness ratio with good interlayer bonding. This strategy can be applied to intelligent drive device to promote its practical application.
研究领域:
材料科学
·
生物医学工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Zhiheng Wang,Jiali Huang,Guancong Jiang,Tuo Ji,Han Lin,Liwen Mu,Xiaohua Lu,Jiahua Zhu
In heterogeneous reactions, catalyst support plays an important role in tuning catalytic activity of metallic structures and regulating fluid transport during reaction, while it needs to be engineered to balance reaction and diffusion for optimized outcome. In this work, a combined delignification and activation strategy was used to prepare a series of carbon supports with varied porous structures and surface properties. Pd was then loaded on the carbon supports for direct synthesis of H 2 O 2 (DSHP) reaction. Results indicated that highly developed meso-macropore structures significantly promoted the dispersion of Pd and exposed more active sites for H 2 dissociation. However, the enrichment of pore structure brought excessive surface oxygen groups, leading to the transition of Pd from Pd 0 to PdO and thus inhibiting the hydrogenation activity. The optimized catalyst, with desirable porous structure and appropriate Pd 0 /PdO ratio, exhibited an extraordinarily high H 2 O 2 productivity of 37346.42 mmol g Pd −1 h −1 under atmospheric conditions. This work provided a case study on the regulation of reactivity and diffusion through catalyst support engineering, demonstrating the essential role of matched reaction–diffusion in heterogeneous DSHP reactions.
研究领域:
催化化学
·
材料科学
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产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2020
·
IF 9.567
Na Pan,Min Lin,Huilin Cui,Wenxin Fan,Chunzhao Liu,Fu Chen,Changjiang Fan,Yanzhi Xia,Kunyan Sui
Hollow multishelled structures (HoMSs) enable material intriguing properties and diverse applications. However, constructing all-polymer HoMSs (p-HoMSs) remains a great challenge. Here, we first develop a one-step self-template strategy to synthesize p-HoMS spheres through controlled reaction–diffusion of a polyelectrolyte pair. Besides instant reaction, the high concentration and moderate molecular weight of one polyelectrolyte as the self-template are required to fulfill the key conditions (i.e., high cross-linking density and high diffusion difference of the two reactants) for the p-HoMS sphere fabrication. In consequence, scalable p-HoMSs are rationally designed with structural and composition control, including shell number, core size, and morphology. More importantly, this p-HoMS could facilely template the synthesis of hierarchical macroscopic HoMS metal oxide with a shell number up to 12. This self-template strategy provides a simple, general, controllable, and large-scale way for the fabrication of HoMS materials with various compositions, complex structures, and diverse functions, signifying for a new methodology in material science.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Ying Liu,Runxia Wang,Haiyan Wang,Xijuan Yu,Xien Liu,Peng He,Xilin She,Tianrong Zhan
It is established that ultrathin layered double hydroxide nanosheets (LDHNS) and zeolitic imidazole frameworks (ZIF) are desirable electrochemical sensing modifiers owing to their large surface area and abundant catalytic sites. Integration of them is thus an effective solution to maximize their electrocatalytic activity . Herein, a novel reaction–diffusion framework (RDF) technique is applied for the in situ growth of ZIF-67 on ultrathin CoAl-LDHNS (CoAl-LDHNS@ZIF-67). In a confined space of the agar gel matrix of RDF, the coordination reaction between organic ligands and CoAl-LDHNS without an additional Co 2+ source achieves the controllable growth of ZIF-67 crystals through a long vertical diffusion . The prepared composite comprises both CoAl-LDHNS and ZIF-67 components with a certain ratio and provides a large surface area and amply catalytic sites, thus realizing a rapid transfer of electron and mass. The CoAl-LDHNS@ZIF-67 modified electrode is employed for the simultaneous detection of naphthol isomers by differential pulse voltammetry . Naphthol isomers display anodic reactions with a wide peak potential difference, allowing their simultaneous detection feasible. Voltammetric responses of α-naphthol and β-naphthol follow good linearity against the concentration in a wide range from 0.3 to 150 μM with limits of detection of 54 and 82 nM, respectively. The proposed sensor also demonstrates excellent selectivity , stability, reproducibility, and practicability for the simultaneous detection of naphthol isomers.
研究领域:
材料科学
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分析化学
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产品关联
DOI
PubMed
高影响因子
Polymers
·
2024
·Vol. 16
·期 7
·873
·
IF 4.7
Xiong Yi,Shengfang Li,Pin Wen,Shilin Yan
Traditional polymer curing techniques present challenges such as a slow processing speed, high energy consumption, and considerable initial investment. Frontal polymerization (FP), a novel approach, transforms monomers into fully cured polymers through a self-sustaining exothermic reaction, which enhances speed, efficiency, and safety. This study focuses on acrylamide hydrogels, synthesized via FP, which hold significant potential for biomedical applications and 3D printing. Heat conduction is critical in FP, particularly due to its influence on the temperature distribution and reaction rate mechanisms, which affect the final properties of polymers. Therefore, a comprehensive analysis of heat conduction and chemical reactions during FP is presented through the establishment of mathematical models and numerical methods. Existing research on FP hydrogel synthesis primarily explores chemical modifications, with limited studies on numerical modeling. By utilizing Differential Scanning Calorimetry (DSC) data on the curing kinetics of polymerizable deep eutectic solvents (DES), this paper employs Malek’s model selection method to establish an autocatalytic reaction model for FP synthesis. In addition, the finite element method is used to solve the reaction–diffusion model, examining the temperature evolution and curing degree during synthesis. The results affirm the nth-order autocatalytic model’s accuracy in studying acrylamide monomer curing kinetics. Additionally, factors such as trigger temperature and solution initial temperature were found to influence the FP reaction’s frontal propagation speed. The model’s predictions on acrylamide hydrogel synthesis align with experimental data, filling the gap in numerical modeling for hydrogel FP synthesis and offering insights for future research on numerical models and temperature control in the FP synthesis of high-performance hydrogels.
研究领域:
材料科学
·
生物医学工程
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Soft Matter
·
2021
·Vol. 17
·期 35
·8059-8067
·
IF 3.679
Jingda Tang,Liangsong Zeng,Zishun Liu
Magnetic hydrogels have found a myriad of applications in bioengineering and soft robotics. As the function of magnetic hydrogels is affected by the distribution of magnetic nanoparticles, it is imperative to propose a strategy for fabricating patterned magnetic hydrogels. However, previous strategies can only achieve very simple distribution by using external magnetic fields to guide the chain-like assembly of nanoparticles. It remains challenging to realize the complex distribution of magnetic nanoparticles in a hydrogel. Here we propose an ion transfer printing strategy to prepare patterned magnetic hydrogels, taking advantage of the ion permeation and nanoparticle precipitation in the hydrogel. The polyacrylamide (PAAm) hydrogel is loaded with Fe2+/Fe3+ ions and covered with a patterned filter paper with OH− ions to generate Fe3O4 nanoparticles locally. The effect of the ion concentration and covering time on the generation of nanoparticles is investigated by using a reaction–diffusion model. Furthermore, the magnetothermal response of the patterned magnetic hydrogels has been characterized to reveal the distribution and thermogenesis of magnetic nanoparticles. We hope that the fabricated magnetic hydrogels with complex patterns can open up new opportunities for applications.
研究领域:
生物工程
·
软体机器人
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CRYSTENGCOMM
·
2016
·Vol. 19
·期 1
·72-79
·
IF 3.849
Tao Yang,Jianmei Liu,Jinhui Dai,Yongsheng Han
Here, we report a general role of chemical diffusion and reaction in shaping particles. It is supposed that chemical diffusion and reaction play a role in shaping particles by changing the chemical distribution around the growth front of particles. Based on this understanding, three growth modes of particles are proposed in this paper, namely, reaction-limited mode, diffusion-limited mode, and reaction–diffusion balance mode. Silver particles are synthesized in different growth modes by various methods. No matter which method is employed, silver particles synthesized in the same mode have similar morphologies. To further generalize diffusion and reaction effects, copper and gold particles are synthesized. The morphological evolution of these two types of particles is similar to that of silver. These results indicate the general role of chemical diffusion and reaction in shaping particles, promising that a regulation on these two kinetic factors is a green and powerful technique for rational synthesis of materials.
研究领域:
材料科学
·
化学
·
纳米技术
✓ 已验证
DOI
高影响因子
MATERIALS CHARACTERIZATION
·
2025
·
IF 5.5
Dang Xu,Pengqi Chen,Kaichao Fu,Changcheng Sang,Ruizhi Chen,Tao Hong,Jigui Cheng,Kai Xu
The inherent metallurgical incompatibility between dissimilar metals such as tungsten (W) and copper (Cu) engenders weak chemical bonding, substantially constraining the attainment of high strength. This constitutes a critical limitation for nuclear fusion applications demanding robust interfacial integrity. To address these limitations, this study introduces a dual interface reinforcement strategy employing a CrCoNi medium entropy alloy (MEA) interlayer and achieving diffusion bonding of oxide diffusion-strengthened tungsten (ODS-W) and Cu through spark plasma sintering (SPS) technology. At the optimized bonding temperature of 1000 °C, the joint achieves a maximum tensile strength of 256.7 ± 8.2 MPa, corresponding to a 171 % enhancement over direct bonding (DB) joint (94.6 ± 5.1 MPa), accompanied by a fracture mode transition from brittle to ductile failure. Multi-scaled microstructure and interface element diffusion behavior analyses reveal that reactive diffusion at the W/MEA interface facilitates the formation of a solution-strengthened matrix associated with an amorphous diffusion layer. Whereas mutual diffusion at the Cu/MEA interface induces multiple phase structures, resulting concurrently in solid solution strengthening and precipitation strengthening, thereby reinforcing the interface bonding. This dual interface reinforcement methodology establishes an effective design strategy for enhancing mechanical properties in immiscible metal systems.
研究领域:
材料科学
·
冶金学
·
核工程
·
机械工程
·
连接技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2023
·
IF 9.2
Shaohui Zhang,Haikun Zhou,Xuanzhi Liu,Pengfei Tan,Hongwei Liu,Jun Pan
Developing platinum-based catalyst with low-platinum content and efficient oxygen reduction reaction (ORR) is critical to expediting the industrialization of fuel cells. Platinum-based alloy nanowires are widely applied as ORR catalyst but limited by poor stability and high platinum consumption. Herein, platinum-copper 3 -gold y nanowires-nanoparticles composite (PtCu 3 Au y NWP, y = 0.2, 0.5 and 0.8) is smoothly synthesized by solvothermal and in-situ reaction diffusion . The mass activity (MA) of PtCu 3 Au 0.5 NWP/C reaches 1.422 A mg Pt&Au −1 (with an ultralow Pt&Au loading of around 6.43 wt%) which is 13.16 times higher than commercial Pt/C. The excellent ORR catalytic activity of PtCu 3 Au 0.5 NWP is attributable to its structure of nanowires-nanoparticles, strong ligand effect and proper lattice strain. The MA of PtCu 3 Au 0.5 NWP only decreases by 13.2% while Pt/C decreases by 52.8% after 10,000 cycles of the accelerated durability testing (ADT). Moreover, the PtCu 3 Au 0.5 NWP catalyst exhibits only 7.88% loss of maximum power density after 10,000 ADTs in single-cell test. Such an excellent stability for PtCu 3 Au 0.5 NWP can be ascribed to the structure of nanowires-nanoparticles composite and Au-rich layer on the surface. This research uncovers a practical method for improving the stability and activity of nanowires made from platinum-based alloy.
研究领域:
材料科学
·
电化学
·
纳米技术
·
催化
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2019
·
IF 12.221
Zhongzhe Wei,Zihao Yao,Qiang Zhou,Guilin Zhuang,Xing Zhong,Shengwei Deng,Xiaonian Li,Jianguo Wang
The reaction/diffusion kinetics are fundamentally determined by the electronic properties of supported Pd catalysts and further govern the catalytic activity and selectivity in the partial hydrogenation of alkynes. However, how the electronic metal–support interactions and the tradeoff between reaction and diffusion affect the catalytic performance still remain elusive. Here, the optimized catalyst Pd supported on carbon decorated with oxygen-deficient TiO2(Pd/TiO2-VO@C) features a remarkable enhancement in performance for semihydrogenation of 2-methyl-3-butyn-2-ol with a TOF 31-fold higher than that of Lindlar catalyst. The improved performance of Pd/TiO2-VO@C benefits from the fact that TiO2-VO@C subtly modulates the electronic properties of Pd, and an appropriate amount of TiO2-VO allows a decrease in the reaction barrier and C promotes the diffusion ability of the catalyst, achieving the balance between reaction and diffusion. By using microkinetic modeling, the reactivity difference of various catalysts is quantitatively predicted and the calculated turnover frequency volcano curve is rationalized as a function of reaction barrier and diffusion ability, which agrees well with the experimental results. The quantitative regulation of catalytic performance by tuning the support properties is a general strategy, which provides a basis to design robust catalysts for diverse reactions.
研究领域:
催化
·
化学工程
·
材料科学
·
物理化学
✓ 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）