ACS Applied Polymer Materials
·
2025
·
IF 4.7
Jiahong Xiang,Li GuangMing,Zhenbang Zhang,Tao Chen
This study introduces the fabrication of dual-layer composite nanofiber membranes incorporating AG80 (tetrafunctional epoxy resin), BN (boron nitride), and PI (polyimide) through electrospinning, with the aim of overcoming the limitations of conventional polyimide (PI) materials in thermal management and electrical insulation for flexible circuit boards. Although PI is recognized for its mechanical strength, chemical stability, and insulating properties, its low thermal conductivity, brittleness, and complex processing challenges limit its broader application. By precisely controlling the composition of AG80, BN, and PI, and optimizing electrospinning parameters, we successfully developed a nanofiber membrane that exhibits enhanced thermal stability and insulation properties. The resultant membrane demonstrates remarkable flexibility, retaining mechanical integrity after 10,000 bending cycles, and achieves a high thermal conductivity of 1.42 W/m·K. Optimized porosity further enhances surface adhesion, rendering it ideal for high-performance flexible circuit boards. These findings provide valuable theoretical and practical insights for the design and development of advanced flexible electronic devices.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Liangzhu Pan,Xiaoping Zhang,Songwen He,Guichang Zhang,Wei Xu
Gold is one of the most fascinating resources in the waste mobile phones’ printed circuit boards (WMPPCBs). In this study, a new process for recovering Au from WMPPCBs by the Na 2 S 2 O 8 -KI system was developed. This process comprises a two-stage leaching process to provide a separation of copper and gold from WMPPCBs. 98% Cu and 78% Fe were dissolved by the 1st base metals' leaching (H 2 SO 4 -H 2 O 2 leaching) step. The leaching of gold from the solid reside of 2nd leaching step was performed to study the effect of Na 2 S 2 O 8 concentration, KI concentration, temperature, and solid-liquid ratio in Na 2 S 2 O 8 -KI leaching system. The results showed that removing most of Cu greatly promoted the leaching efficiency of gold in Na 2 S 2 O 8 -KI leaching system. The mechanism of gold leaching was studied by the thermodynamic analysis. Leaching kinetics data showed that gold leaching followed an intermediate-controlled mechanism with E a , 30.3 kJ mol −1 . The best conditions for leaching of gold in Na 2 S 2 O 8 -KI system were determined to be 0.02 M Na 2 S 2 O 8 , 0.15 M KI, 40 ℃, a solid-liquid ratio of 1: 20 (g/mL), and a stirring speed of 200 rpm. Under the optimal leaching parameters, the efficiency of gold leaching from WMPPCBs attained 96% after 120 min. Due to the non-toxic and low-cost properties of Na 2 S 2 O 8 , the Na 2 S 2 O 8 -KI leaching process is more sustainable than conventional processes (cyanide leaching et al.).
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
高影响因子
Journal of Cleaner Production
·
2024
·
IF 9.7
Tao Chen,Chuan Ma,Ben Wang,Linlin Xu,Wu Yang,Lushi Sun
Pyrolysis has proven an effective method of recycling waste printed circuit boards (WPCBs) for high-value product generation. The kinetics and debromination studies on the pyrolysis of WPCBs with copper species was performed using a thermogravimetric-mass spectroscopy analyzer and a vertical quartz-tube reactor. A multiple distributed activation energy model (M-DAEM) was applied to illustrate the potential multiple reactions over the thermal decomposition process. The introduction of copper species into WPCBs reduced the initial activation energies, resulting in lower decomposition temperatures. Meanwhile, several distinct subprocesses were observed and resolved by three-reaction models. The addition of CuO obtained the lowest liquid yield (53.9 wt %) and the maximum gas yield (8.9 wt %), and the introduction of Cu 2 O resulted in the highest solid yield (40.4 wt %). Copper particles preserved 57 % of bromine in residual solid, while CuO and Cu 2 O particles resulted in approximately 65 % and 74 % retention of bromine in the residues, respectively. Particularly, less than 3.7 % of bromine was transferred into the liquid when Cu 2 O was added. The optimal debromination performance of Cu 2 O was attributed to its effective capture capacity of HBr/Br 2 , fairly high catalytic efficiency on dissociating C–Br bond, and multipath conversion of organobromine to cross-linked carbonaceous compounds.
研究领域:
环境科学
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化学工程
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产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Gan Wan,Tao Chen,Linlin Xu,Lushi Sun
Waste printed circuit boards (WPCBs) containing brominated flame retardants (BFRs) would result in serious environmental pollution without pertinent treatments. However, bromine-containing materials have been proven highly efficient for elemental mercury removal (Hg 0 ). This work proposes a win–win strategy of a cost-effective Hg 0 removal method and a highly efficient utilization of WPCB-derived chars. Diverse copper-containing brominated pyrolytic chars of WPCBs were prepared in a fixed bed reactor at 500–700 °C tailored for Hg 0 removal from coal-fired flue gas. The resulting copper-containing pyrolytic chars were proven to have a high Hg 0 removal efficiency. Various characterizations and adsorption curves insights into the impacts of copper, sorbent weights, pyrolysis and adsorption temperatures, on Hg 0 removal efficiency of WPCB-derived chars. The results indicate that copper in WPCBs enhances the fixation of the bromine elements in pyrolytic chars, resulting in improved Hg 0 removal performance. The optimal pyrolysis and adsorption temperatures for pyrolytic chars are 600 °C and 140 °C, respectively. Under optimized conditions, a Hg 0 removal efficiency exceeding 90 % is realized after 30 min of adsorption. Notably, the results indicating the Hg 0 adsorption capacity of WPCB-derived chars rivals that of commercial activated carbons and significantly surpasses that of biochar. Both adsorption kinetics and characterizations affirm that chemisorption is the predominant adsorption method. The C-Br bond and CuO emerge as crucial active sites facilitating the oxidation of Hg 0 .
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2017
·
IF 2.714
Shan Wan,Yun Cong,Dan Jiang,Ze-Hua Dong
Superhydrophobic coating was firstly applied on printed circuit board (PCB) based on fluoroalkylsilane modified silica colloid suspension in methyl triethoxysilane solution. Through a feasible sol-gel method and subsequent curing process, we prepared a superhydrophobic coating on PCB that exhibits high water contact angle (CA) of 158° and low sliding angle (SA) of 3°. Weathering test results verify that the superhydrophobic coating not only has good waterproof and self-cleaning capability, but also performs well in protecting against UV irradiation or strong acid or base solution to some extent. Further electrochemical tests indicate that the superhydrophobic coating on the PCB-Cu and PCB-Sn electrodes shows excellent corrosion resistance in 1 wt.% NaCl aqueous solution with 99.6% and 98.7% inhibition efficiency respectively. In addition, the thin superhydrophobic coating (∼2 μm) may endow the underlying PCB with promising heat dissipation ability. Therefore, it can be concluded that the superhydrophobic coating could dramatically increase the weathering resistance of PCB.
研究领域:
材料科学
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电子工程
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2022
·
IF 7.336
Zhao-Yun Wang,Lei Jin,Guang Li,Jia-Qiang Yang,Wei-Qing Li,DongPing Zhan,Yan-Xia Jiang,Fang-Zu Yang,Shi-Gang Sun
An organic additive, gentian violet (GVT), is explored for the first time as a novel leveler with excellent property in through-holes (THs) metallization of Cu electronic plating in acidic medium for printed circuit board (PCB) applications. Studies of galvanostatic measurements with a platinum rotation disk electrode and density functional theory calculations demonstrate that the GVT behaves the fundamental leveler's characteristics of mass transfer adsorption, and displays a strong inhibition effect on electro-reduction of cupric ions at high rotating rate. Although the adsorption ability of GVT on Cu surface is weaker than that of commercial leveler Janus Green B (JGB), the potential difference of cupric ion reduction between low and high rotating rates is larger in case of GVT than that of JGB at same current density. Cyclic voltammetry measurements indicate that the Cu amounts of cathodic deposition and that of anodic stripping tend to the same at both low and high rotating rates when GVT, Cl − , polyethylene glycol (PEG) and bis-(sodium sulfopropyl)-disulfide (SPS) coexist in the solution, demonstrating excellent synergistic action of these additives and super leveling effect. In situ FTIR spectroscopic analysis combined with cyclic voltammetry measurements illustrate that the GVT adsorbs on Cu surface and thus affects the electro-reduction of cupric ions, which reveals the very complicated synergistic actions of these additives, i.e., the adsorption ability of GVT can be slightly enhanced by Cl − , while it has been greatly enhanced in the presence of PEG which nevertheless decreases slightly the inhibition effect of PEG on electro-reduction of cupric ions; the SPS plays an antagonistic effect with GVT due to their competitive adsorption. Based on the characterization of GVT as a novel leveler, we developed a GVT-based formula of THs metallization of Cu electronic plating, and demonstrated an excellent efficiency of a throwing power of 97.6% at 10 mA·cm −2 in a real PCB THs metallization of Cu electronic plating.
研究领域:
材料科学
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电化学
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表面工程
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产品关联
DOI
高影响因子
Waste and Biomass Valorization
·
2023
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IF 3.2
Li Zhi-jian,Wang Wei,Jiang Long-jin,Chang Zhi-dong,Ma Xi-ping,Luo Xin
In order to extend the duration of the electrolyte solution in which copper granules recovered from waste printed circuit board are refined through electrolysis to obtain copper foil with high purity and which is contaminated by the accumulation of metallic impurities along with the refinery of waste printed circuit board, the leaching and electrowinning processes are used to pretreat the copper granules. The effects of impurities of copper granules as well as H 2 SO 4 mole ratio, leaching temperature, liquid-solid ratio, and operation time on the removing efficiencies of Zn, Sn, Fe and Al, were studied. The results showed that more than 95% of impurities can be removed when the mole ratio of impurities to H 2 SO 4 was 1:4, the temperature was 70 °C, the liquid-solid ratio was 20 mL/g, along with the leaching time of 180 min. After 1440 min electrolysis of the pretreated granules with the electric current density of 40 mA/cm 2 , the purity of refined copper foil maintained at 99% in contrast with 95% which copper granules are without pretreatment. The maximal concentration of the accumulated ions of impurities is less than 60 mg/L, which suggests that sulfuric acidic pretreatment is a promising approach to increase the duration of the electrolyte solution.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2024
·Vol. 34
·期 34
·2401822
·
IF 18.5
Wenjie Wang,Xingyuan Lu,Yixuan Li,Xiang Li,Haoxiang Sun,Junqi Sun
It remains a huge challenge to efficiently recycle the printed circuit boards (PCBs) because of the diversity and complexity of the PCBs in terms of material composition. The recycling of PCBs highly depends on the design of the polymers that make up the polymer substrates and conductive pastes. Herein, closed-loop recyclable plastics for use as the polymer substrates and for the preparation of the conductive pastes are fabricated by dynamically cross-linking phenylboronic acid-functionalized poly(methylmethacrylate) (PMMA-B) and poly(urea-urethane) (PUU-B) with boroxines. The closed-loop recyclable plastic, which is denoted as PMMA-PUU exhibits a breaking strength of 71.0 MPa and Young's modulus of 1.8 GPa. Because of the dynamic nature of boroxines, the PMMA-PUU 0.6 plastic can be depolymerized in the N, N-dimethylacetamide/ethanol mixture solvent. The depolymerized PMMA and PUU can be efficiently recovered in high yields and purity through their solubility differences in selective solvents. Conductive pastes suitable for printing of electrical circuits are fabricated through complexation of Ag particles with PMMA-PUU. PCBs composed of PMMA-PUU substrates and PMMA-PUU-based conductive pastes are flexible, healable, and recyclable. The closed-loop recycling of the PCBs enables the collection of highly purified Ag particles, PMMA-B, and PUU-B monomers even when the PCBs are mixed with polymer wastes.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
LAB ON A CHIP
·
2022
·Vol. 22
·期 4
·709-716
·
IF 7.517
Donghao Li,Xinyu Liu,Yujuan Chai,Jieying Shan,Yihan Xie,Yong Liang,Susu Huang,Weidong Zheng,Zida Li
The monitoring of coagulation function has great implications in many clinical settings. However, existing coagulation assays are simplex, sample-consuming, and slow in turnaround, making them less suitable for point-of-care testing. In this work, we developed a novel blood coagulation assay that simultaneously assesses both the tendency of clotting and the stiffness of the resultant clot using printed circuit board (PCB)-based digital microfluidics. A drop of blood was actuated to move back and forth on the PCB electrode array, until the motion winded down as the blood coagulated and became thicker. The velocity tracing and the deformation of the clot were calculated via image analysis to reflect the coagulation progression and the clot stiffness, respectively. We investigated the effect of different hardware and biochemical settings on the assay results. To validate the assay, we performed assays on blood samples with hypo- and hyper-coagulability, and the results confirmed the assay's capability in distinguishing different blood samples. We then examined the correlation between the measured metrics in our assays and standard coagulation assays, namely prothrombin time and fibrinogen level, and the high correlation supported the clinical relevance of our assay. We envision that this method would serve as a powerful point-of-care coagulation testing method.
研究领域:
医学工程
·
临床检验
✓ 已验证
DOI
PubMed
高影响因子
BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING
·
2024
·
IF 1.5
Li Yufang,Chen Yunlong,Zi Futing,Hu Xianzhi
Eco-friendly gold extraction from printed circuit boards (PCBs) is highly attractive due to the increasing demand for gold in various fields. The conventional Cu 2+ -NH 3 - S 2 O 3 2− method for PCBs involves polluting NH3 gas and requires additional copper. This study explored a new eco-friendly alternative using ethylenediamine (en) and thiosulfate to extract gold from CPU (the PCB material used in this study). The results showed that 81% of gold in CPUs could be successfully leached out after 48 h, using 10 mM ethylenediamine and 0.2 M thiosulfate. Various analyses, including SEM, ICP, XPS, were conducted to further investigate the process. It was found that the metal in CPU was Au(0) → Ni(II) → Cu(0) from the outside to the inside, and possible gold leaching mechanism was related to the oxidation of Cu(en) 2 2+ produced from CPU’s defective position and the presence of S 2 O 3 2− . As for Au(S 2 O 3 ) 2 3− recovery, different from our previous study, it is necessary to add a small amount of ethylenediamine (en) except for carbon and thiosemicarbazone (TSC); consequently, a gold adsorption efficiency of 99% was achieved. In summary, the leaching method proposed in this work solved the problem of NH 3 pollution of traditional one and achieves green, efficient, and selective gold adsorption from CPU leaching solution through a simple method, which is hopeful to replace the traditional unfriendly Cu-NH 3 - S 2 O 3 2− .
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Wanying Zhou,Huiting Liang,He Xu
In recent years, waste mobile phones have become popular as electronic waste due to the huge amount, serious pollution with improper disposal and high resource value. It is imperative to realize the recycling of resources in waste mobile phones. The application of emulsion liquid membrane in the recovery of gold and synthesis of nanomaterials from waste mobile phone printed circuit boards (WMPCBs) was studied. The components of the emulsion liquid membrane, effects of 7 factors on the extraction rate and the morphology of the synthesized nanomaterials were explored. The results show that it is possible to extract 99.79% of Au(III) from WMPCBs leachate with kerosene as diluent, Span80 as surfactant, methyl isobutyl ketone(MIBK) as carrier, ascorbic acid solution as stripping agent and liquid paraffin as membrane stabilizer. The external phase pH and the internal phase concentration had a greater influence on the extraction efficiency of Au(III) among 7 factors. The morphology of the synthesized product was affected by the concentration and type of the surfactant. It provides a new idea to connect recovery from waste with deep processing, extending the waste mobile phone recycling process chain and achieving high-value utilization of waste mobile phone secondary metal resource products.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Xinrong Li,Shuliang Chen,Peng Yang,Yue Lin,Chen Chen,Xianzhi Hu,Futing Zi
With the gradual depletion of natural gold ore , waste printed circuit boards (WPCBs) have become one of the most attractive alternatives to gold ore. Here, a series of quaternary phosphonium adsorbents with a large size were successfully synthesized by adjusting the number of functional groups and carbon chain length of functional monomers , which can be used for selective recovery of gold(III) from WPCBs leaching solution . The quaternary phosphonium adsorbent (PS-TEP) prepared by the nucleophilic substitution reaction between triethyl phosphine with the smallest volume and chloromethylated polystyrene (PS-Cl) exhibited the best gold loading capacity (617.90 mg g −1 ). The adsorption mechanism of gold(III) on PS-TEP surface mainly involves anion exchange between AuCl 4 − and Cl − in the adsorbent. The charge level of the H atom closest to –CH 2 –P + group directly determines the strength of the interaction between the adsorbent and the gold ion . Multiwfn and VMD programs visually confirm the weak interaction between PS-TEP + and AuCl 4 − . After 5 adsorption-stripping cycles, the adsorption rate of gold(III) in solution remained at about 99 %. In addition, PS-TEP exhibited good gold(III) selectivity in both simulated and actual WPCBs gold leaching solutions. These results indicate that the large-particle PS-TEP with high capacity is suitable for selective gold recovery from WPCBs leaching solution.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）