Ocean wave energy is a significant and promising source of renewable energy.However,the energy harvesting is challenging due to the multi-directional nature of waves.This paper proposes a magnetic-field-assisted tribo...Ocean wave energy is a significant and promising source of renewable energy.However,the energy harvesting is challenging due to the multi-directional nature of waves.This paper proposes a magnetic-field-assisted triboelectric nanogenerator(MFATENG)for harvesting multi-directional wave energy.By incorporating a magnetic field,the planar motion of the pendulum is converted into spatial motion,increasing the triggering of multilayered TENG(M-TENG)and enhancing the output energy of the MFA-TENG.Experimental results demonstrate that the output energy of the MFA-TENG is increased by 73%by utilizing the magnetic field.Moreover,a spring model based on the origami-structured M-TENG is established to analyze the effect of different equivalent stiffnesses on the performance of the M-TENG,aiming to obtain optimal output performance.The results showcase the impressive output performance of the M-TENG,generating outputs of 250 V,18μA,and 255 nC.Furthermore,the proposed MFA-TENG effectively harvests multi-directional wave energy under water-wave driven conditions.This study significantly enhances the ability of the MFA-TENG to harvest multi-directional wave energy and presents a promising approach for self-powered marine monitoring in the future.展开更多
Polyvinylpyrrolidone （PVP） nanofibers were processed by magnetic-field-assisted electrospinning （MFAES） technique. Since electric field intensity was one of the most important parameters influencing fiber morpholo...Polyvinylpyrrolidone （PVP） nanofibers were processed by magnetic-field-assisted electrospinning （MFAES） technique. Since electric field intensity was one of the most important parameters influencing fiber morphology, the research aimed to study how electric field intensity affects fiber morphology in MFAES technique. The experimental results revealed that the distribution of diameter widened while the average diameter of PVP fibers decreased and the degree of the alignment reduced with the increase of electric field intensity. However, the fibers would be conglutinated together when the electric field intensity was too low. Also, the increase of working distance made the average diameter and the degree of the alignment increase slightly under the same electric field intensity, but the fibers could be partially curved instead of being fully straight if the working distance was too long. It was also indicated that maintaining the electric field intensity at 1 kV/cm With the voltage-distance combinations of 12 kV-12 cm （for 12wt% PVP） and 15 kV-15 cm （for 14wt% PVP） among all other combinations would result in the optimal alignment as well as a narrow size distribution of the fibers.展开更多
采用磁场辅助静电纺丝法制备了有序聚丙烯腈(PAN)纳米纤维,分析了PAN/二甲基甲酰胺(DMF)溶液浓度、纺丝电压、注射速度、磁铁间距和溶剂DMF及DMF与二甲基亚砜(DMSO)混合溶剂等因素对PAN纤维有序度的影响。结果表明:随着PAN/DMF溶液中PA...采用磁场辅助静电纺丝法制备了有序聚丙烯腈(PAN)纳米纤维,分析了PAN/二甲基甲酰胺(DMF)溶液浓度、纺丝电压、注射速度、磁铁间距和溶剂DMF及DMF与二甲基亚砜(DMSO)混合溶剂等因素对PAN纤维有序度的影响。结果表明:随着PAN/DMF溶液中PAN浓度增大,PAN纤维有序度逐渐增大;注射速度对纤维有序度影响不明显;随着纺丝电压和磁铁间距增大,PAN纤维有序度先增大后减小;DMSO的加入,使溶液可纺性降低,不利于纤维有序排列;对于PAN/DMF溶液体系,适宜的磁场辅助静电纺丝的工艺参数为PAN质量分数12%,纺丝距离12 cm,电压14 k V,注射速度0.5 m L/h,磁铁间距2.5 cm,纺丝得到的PAN纳米纤维的有序度为92%。展开更多
Nickel nanowires with large aspect ratio of up to 300 have been prepared by a hydrazine hydrate reduction method under applied magnetic field. The diameter of nickel nanowires is about 200 nm and length up to 60 μm. ...Nickel nanowires with large aspect ratio of up to 300 have been prepared by a hydrazine hydrate reduction method under applied magnetic field. The diameter of nickel nanowires is about 200 nm and length up to 60 μm. The role of magnetic field on the growth of magnetic nanowires is discussed and a magnetic nanowire growth mechanism has been proposed. Nickel ions are firstly reduced to nickel atoms by hydrazine hydrates in a strong alkaline solution and grow into tiny spherical nanoparticles. Then, these magnetic particles will align under a magnetic force and form linear chains. Furthermore, the as-formed chains can enhance the local magnetic field and attract other magnetic particles nearby, resulting finally as linear nanowires. The formation and the size of nanowires depend strongly on the magnitude of applied magnetic field.展开更多
基金supported by the National Key Research and Development Project from Minister of Science and Technology of China(Nos.2021YFA1201604 and 2021YFA1201601).
文摘Ocean wave energy is a significant and promising source of renewable energy.However,the energy harvesting is challenging due to the multi-directional nature of waves.This paper proposes a magnetic-field-assisted triboelectric nanogenerator(MFATENG)for harvesting multi-directional wave energy.By incorporating a magnetic field,the planar motion of the pendulum is converted into spatial motion,increasing the triggering of multilayered TENG(M-TENG)and enhancing the output energy of the MFA-TENG.Experimental results demonstrate that the output energy of the MFA-TENG is increased by 73%by utilizing the magnetic field.Moreover,a spring model based on the origami-structured M-TENG is established to analyze the effect of different equivalent stiffnesses on the performance of the M-TENG,aiming to obtain optimal output performance.The results showcase the impressive output performance of the M-TENG,generating outputs of 250 V,18μA,and 255 nC.Furthermore,the proposed MFA-TENG effectively harvests multi-directional wave energy under water-wave driven conditions.This study significantly enhances the ability of the MFA-TENG to harvest multi-directional wave energy and presents a promising approach for self-powered marine monitoring in the future.
基金Fund by the Youth Foundation of the North University of China(2012)the Project of Graduate Innovation of Shanxi Province(20133102)
文摘Polyvinylpyrrolidone （PVP） nanofibers were processed by magnetic-field-assisted electrospinning （MFAES） technique. Since electric field intensity was one of the most important parameters influencing fiber morphology, the research aimed to study how electric field intensity affects fiber morphology in MFAES technique. The experimental results revealed that the distribution of diameter widened while the average diameter of PVP fibers decreased and the degree of the alignment reduced with the increase of electric field intensity. However, the fibers would be conglutinated together when the electric field intensity was too low. Also, the increase of working distance made the average diameter and the degree of the alignment increase slightly under the same electric field intensity, but the fibers could be partially curved instead of being fully straight if the working distance was too long. It was also indicated that maintaining the electric field intensity at 1 kV/cm With the voltage-distance combinations of 12 kV-12 cm （for 12wt% PVP） and 15 kV-15 cm （for 14wt% PVP） among all other combinations would result in the optimal alignment as well as a narrow size distribution of the fibers.
文摘采用磁场辅助静电纺丝法制备了有序聚丙烯腈(PAN)纳米纤维,分析了PAN/二甲基甲酰胺(DMF)溶液浓度、纺丝电压、注射速度、磁铁间距和溶剂DMF及DMF与二甲基亚砜(DMSO)混合溶剂等因素对PAN纤维有序度的影响。结果表明:随着PAN/DMF溶液中PAN浓度增大,PAN纤维有序度逐渐增大;注射速度对纤维有序度影响不明显;随着纺丝电压和磁铁间距增大,PAN纤维有序度先增大后减小;DMSO的加入,使溶液可纺性降低,不利于纤维有序排列;对于PAN/DMF溶液体系,适宜的磁场辅助静电纺丝的工艺参数为PAN质量分数12%,纺丝距离12 cm,电压14 k V,注射速度0.5 m L/h,磁铁间距2.5 cm,纺丝得到的PAN纳米纤维的有序度为92%。
基金supported by the Hi-Tech Research and Development Program of China(No.2007AA03Z300)Shanghai-Applied Materials Research and Development fund(No.07SA10)+3 种基金National Natural Science Foundation of China(No.50730008)Shanghai Science and Technology Grant(No:0752nm015,09ZR1414800,1052nm05500)National Basic Research Program of China(No.2006CB300406)the fund of Defence Key Laboratory of Nano/Micro Fabrication Technology
文摘Nickel nanowires with large aspect ratio of up to 300 have been prepared by a hydrazine hydrate reduction method under applied magnetic field. The diameter of nickel nanowires is about 200 nm and length up to 60 μm. The role of magnetic field on the growth of magnetic nanowires is discussed and a magnetic nanowire growth mechanism has been proposed. Nickel ions are firstly reduced to nickel atoms by hydrazine hydrates in a strong alkaline solution and grow into tiny spherical nanoparticles. Then, these magnetic particles will align under a magnetic force and form linear chains. Furthermore, the as-formed chains can enhance the local magnetic field and attract other magnetic particles nearby, resulting finally as linear nanowires. The formation and the size of nanowires depend strongly on the magnitude of applied magnetic field.
