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A facile strategy for preparation of strong tough poly(lactic acid) foam with a unique microfibrillated bimodal micro/nano cellular structure. Int J Biol Macromol 2022; 199:264-274. [PMID: 34999040 DOI: 10.1016/j.ijbiomac.2021.12.187] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/12/2021] [Accepted: 12/29/2021] [Indexed: 12/13/2022]
Abstract
This work reports the design and fabrication of strong tough poly(lactic acid) (PLA) foam by combining pressure-induced-flow (PIF) processing with supercritical CO2 foaming. PIF processing widened the foaming window of PLA to 40-120 °C, while supercritical CO2 foaming released the undesired internal stress of PLA samples with PIF processing (P-PLA). The prepared PLA foams displayed a unique microfibrillated bimodal micro/nano cellular structure which is strongly affected by saturation temperature (Ts). Both micron and nano cells showed decreasing cells size and increasing cell density as Ts elevated. The orientation factor as well as internal stress of PLA foams decreased with increased Ts. Compared with P-PLA samples, PLA foam prepared at Ts of 40 °C showed negligible reduction of orientation from 0.45 to 0.41 and release of internal stress characterized by the rightward shift of Raman peak (stretching vibration of CO bond from 1763 to 1766 cm-1). Furthermore, PLA foam prepared at Ts of 40 °C presented excellent impact strength (32.3 kJ/m2), tensile strength (42.0 MPa), and ductility (14.2%). The combination of PIF processing and supercritical CO2 foaming provides a facile and effective method to prepare strong tough PLA foam that has immense potential in biomedical, aerospace, automotive, and other structural applications.
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Zhang F, Zuo J, Jin W, Xu F, Jiang L, Xi D, Wen Y, Li J, Yu Z, Li Z, Xu R, Zhang G, Zhou C, Duan N. Size effect of γ-MnO 2 precoated anode on lead-containing pollutant reduction and its controllable fabrication in industrial-scale for zinc electrowinning. CHEMOSPHERE 2022; 287:132457. [PMID: 34610373 DOI: 10.1016/j.chemosphere.2021.132457] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/30/2021] [Accepted: 10/01/2021] [Indexed: 06/13/2023]
Abstract
Lead (Pb) is the most widely used anode in zinc (Zn) electrowinning and other metallurgical industries. The resource loss and environmental pollution caused by Pb anode corrosion are urgent problems to be solved. A γ-MnO2 precoated anode was prepared successfully to reduce the Pb-containing pollutant. The size effects with its controllable preparation on an industrial scale were studied. Severe nonuniform distribution of γ-MnO2 film was observed with curbing the reduction of anode slime only 68%, when anode size increased from lab to industry. Nonuniform rate (R) and average thickness (d) were found to be the key indicators to determine the film structure distribution and their performance differences, which were random and difficult to be controlled in scale-up size. However, a controllable industrial γ-MnO2 precoated anodes (IMPA) fabricated through optimized current density (J0) and electrodeposition time (t) in our developed film-forming system. Then, the long-term performances of two IMPA with different indicators (IMPA-1: R = 34%, d = 108 μm, IMPA-2: R = 23%, d = 55 μm) were compared with the industrial typical Pb-based anode (ITPA). Of the three different anodes, the optimized IMPA-2 displayed the best performance. Within 24 d of electrowinning cycle, the corrosion inhibition effect and the anode slime reduction rate for IMPA-2 improved by 56% and 30% than IMPA-1, and improved by 100% and 91% than ITPA. Furthermore, the mechanism analysis of size effect change showed that R of IMPA was contributed to the local gas holdup distribution along the anode. Controlled size effect of uniform oxide film will have a future application prospect for the sustainability of industry, which provides an important cleaner production of Zn electrowinning and related hydrometallurgy industries.
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Affiliation(s)
- Feilong Zhang
- School of Environment, Tsinghua University, Beijing, 100084, China; State Environmental Protection Key Laboratory of Eco-Industry, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Jiane Zuo
- School of Environment, Tsinghua University, Beijing, 100084, China
| | - Wei Jin
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Fuyuan Xu
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China; State Environmental Protection Key Laboratory of Eco-Industry, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
| | - Linhua Jiang
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China; State Environmental Protection Key Laboratory of Eco-Industry, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
| | - Duoxiang Xi
- Northwest Lead and Zinc Smelter, Baiyin Nonferrous Metals Group Co., Ltd, Gansu, 730900, China
| | - Yucheng Wen
- State Environmental Protection Key Laboratory of Eco-Industry, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Jianhui Li
- State Environmental Protection Key Laboratory of Eco-Industry, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Zhaosheng Yu
- Tianjin Xinke Environmental Protection Technology Co., Ltd., Tianjin, 300000, China
| | - Zhiqiang Li
- State Environmental Protection Key Laboratory of Eco-Industry, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Ruichao Xu
- School of Materials Science and Engineering, Anhui University of Science and Technology, Huainan, Anhui, 232001, China
| | - Ge Zhang
- State Environmental Protection Key Laboratory of Eco-Industry, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Chao Zhou
- State Environmental Protection Key Laboratory of Eco-Industry, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Ning Duan
- School of Environment, Tsinghua University, Beijing, 100084, China; State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China; State Environmental Protection Key Laboratory of Eco-Industry, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
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Ye W, Xu F, Jiang L, Duan N, Li J, Ma Z, Zhang F, Chen L. Lead release kinetics and film transformation of Pb-MnO 2 pre-coated anode in long-term zinc electrowinning. JOURNAL OF HAZARDOUS MATERIALS 2021; 408:124931. [PMID: 33373954 DOI: 10.1016/j.jhazmat.2020.124931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 11/28/2020] [Accepted: 12/20/2020] [Indexed: 06/12/2023]
Abstract
Lead pollution precaution caused by lead-based anode corrosion is a hot and challenging issue for zinc electrowinning. A novel functional lead-based anode (MnO2 pre-coated anode-MPA) was precisely fabricated and its long-term performances were studied compared with typical Pb-1%Ag anode (TPA). Results indicated that MPA posed excellent effects on synergistic inhibiting lead dissolution and reducing hazardous pollutants generation, and decreasing the lead content of zinc products by 81%. Further, the underlying mechanism of film growth and transformation in structure, composition and crystal phase, the migration and distribution of lead and anode slime during electrolytic, were clarified in-depth. Dynamic material flow analysis confirmed that MPA reduced the entire lead migration amount by over 92% compared with TPA. The compact multilayer structure of the MPA film and self-reparation effects of local structure provided better and persistent protection for the lead matrix, which greatly retarded the high-speed corrosion of lead anode. Compared with α-MnO2 in TPA, the formation and maintenance of γ-MnO2 in MPA accelerated the oxygen evolution reaction and inhibited the anode slime generation. This finding provides new insights in pollution precaution and control by designing and tuning new functional anode in hydrometallurgy process.
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Affiliation(s)
- Wanqi Ye
- State Environmental Protection Key Laboratory of Eco-Industry, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; School of Environment, Tsinghua University, Beijing 100084, China
| | - Fuyuan Xu
- State Environmental Protection Key Laboratory of Eco-Industry, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| | - Linhua Jiang
- State Environmental Protection Key Laboratory of Eco-Industry, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| | - Ning Duan
- State Environmental Protection Key Laboratory of Eco-Industry, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; School of Environment, Tsinghua University, Beijing 100084, China
| | - Jianhui Li
- State Environmental Protection Key Laboratory of Eco-Industry, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Zizhen Ma
- State Environmental Protection Key Laboratory of Eco-Industry, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; School of Environment, Tsinghua University, Beijing 100084, China
| | - Feilong Zhang
- State Environmental Protection Key Laboratory of Eco-Industry, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; School of Environment, Tsinghua University, Beijing 100084, China
| | - Lujun Chen
- School of Environment, Tsinghua University, Beijing 100084, China
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Li B, Wang J, Tu H, Yang Z, Zhao D, Feng H, Yang J. A self-designed versatile and portable sensing device based on smart phone for colorimetric detection. Anal Bioanal Chem 2020; 413:533-541. [PMID: 33164153 DOI: 10.1007/s00216-020-03024-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Accepted: 10/22/2020] [Indexed: 01/12/2023]
Abstract
A UV-vis spectrometer, as a sort of important analytical instrument, has been widely used to analyze various substances. However, expensive equipment and skilled operators are required, which limits its broad applications for out-of-lab and daily measurements. In this work, a self-designed sensing device based on smart phone was developed as a sensitive, cost-effective, facile, and portable testing tool. The sensing device fabricated by 3D printing was used to lodge a sample solution and produce a light signal, and the optical sensor on a smart phone worked as a transducer. The light source in the device generated wide-wavelength radiation, which passed through an inner filter and only light of a designated wavelength reached the testing solution. The intensity of transmitted light was then measured by an optical sensor internally installed in most smart phones, where the signals were processed as well. The feasibility of our device was verified by detecting four kinds of common heavy metal ions in actual water samples, and the testing results showed good agreement with those obtained from the UV-vis spectrometer. This work is expected to shed some light on the construction of smart phone-based sensors, featuring decent portability, simple operation, low cost, high sensitivity, and good accuracy.
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Affiliation(s)
- Binghan Li
- College of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen, 518055, Guangdong, China
| | - Jihong Wang
- College of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen, 518055, Guangdong, China
| | - Honghua Tu
- College of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen, 518055, Guangdong, China
| | - Zhijie Yang
- College of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen, 518055, Guangdong, China
| | - Dongfang Zhao
- College of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen, 518055, Guangdong, China
| | - Huanhuan Feng
- College of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen, 518055, Guangdong, China. .,Flexible Printed Electronics Technology Center, Harbin Institute of Technology, Shenzhen, 518055, Guangdong, China.
| | - Jiao Yang
- Flexible Printed Electronics Technology Center, Harbin Institute of Technology, Shenzhen, 518055, Guangdong, China. .,College of Science, Harbin Institute of Technology, Shenzhen, 518055, Guangdong, China.
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