Ni–Cr enrichment on stainless steel SS316 L resulting from chemical activation enabled the deposition of carbon by spraying a stable suspension of carbon nanoparticles; trace Ag was deposited in situ to prepare a thi...Ni–Cr enrichment on stainless steel SS316 L resulting from chemical activation enabled the deposition of carbon by spraying a stable suspension of carbon nanoparticles; trace Ag was deposited in situ to prepare a thin continuous Ag-doped carbon film on a porous carbon-coated SS316 L substrate. The corrosion resistance of this film in 0.5 mol·L^（-1） H_2SO_4 solution containing 5 ppm F- at 80°C was investigated using polarization tests. The results showed that the surface treatment of the SS316 L strongly affected the adhesion of the carbon coating to the stainless steel. Compared to the bare SS316 L, the Ag-doped carbon-coated SS316 L bipolar plate was remarkably more stable in both the anode and cathode environments of proton exchange membrane fuel cell（PEMFC） and the interface contact resistance between the specimen and Toray 060 carbon paper was reduced from 333.0 m？·cm^2 to 21.6 m？·cm^2 at a compaction pressure of 1.2 MPa.展开更多
A simple electroless plating process was employed to prepare silver-coated glass frits for solar cells. The surface of the glass frits was modified with polyvinyl-pyrrolidone（PVP） before the electroless plating proc...A simple electroless plating process was employed to prepare silver-coated glass frits for solar cells. The surface of the glass frits was modified with polyvinyl-pyrrolidone（PVP） before the electroless plating process. Infrared（IR） spectroscopy,field emission scanning electron microscopy（FESEM）, and x-ray diffraction（XRD） were used to characterize the PVP modified glass frits and investigate the mechanism of the modification process. It was found that the PVP molecules adsorbed on the glass frit surface and reduced the silver ions to the silver nanoparticles. Through epitaxial growth, these nanoparticles were uniformly deposited onto the surface of the glass frit. Silicon solar cells with this novel silver coating exhibited a photoelectric conversion efficiency increase of 0.33%. Compared with the electroless plating processes, this method provides a simple route to prepare silver-coated glass frits without introducing impurity ions.展开更多
The proliferation of electromagnetic spectrum applications and increasing integration density of electronic devices have intensified electromagnetic pollution,driving demand for advanced electromagnetic interference(E...The proliferation of electromagnetic spectrum applications and increasing integration density of electronic devices have intensified electromagnetic pollution,driving demand for advanced electromagnetic interference(EMI)shielding materials.While conductive polymer composites present promising alternatives to traditional metals,attaining both exceptional EMI shielding performance and environmental sustainability remains challenging.Here,we adopt controlled mild alkaline hydrolysis to precisely engineer the surface roughness and hydrophilicity of polylactic acid(PLA)fibers,generating optimal substrates for subsequent electroless silver(Ag)deposition.The resulting Ag/PLA conductive fibers are structured into flexible films through vacuum filtration and hot-pressing.These films demonstrate remarkable electrical conductivity of 102,270 S/m,attributed to the continuous Ag coating and three-dimensional fibrous conductive network.Despite a thickness of merely 66μm,the Ag/PLA films exhibit an ultra-high EMI shielding effectiveness(EMI SE)of 101.0 dB and a specific shielding effectiveness of 9749.4 dB·cm^(2)/g.Notably,the films maintain military-grade EMI shielding performance(>90 dB)after thermal cycling across a~300 oC temperature range and 5000 bending cycles,confirming superior durability and mechanical flexibility.By synergistically coupling biodegradable PLA with recoverable Ag,this work simultaneously achieves outstanding EMI shielding performance and environmental sustainability,providing valuable insights for developing next-generation green EMI protection materials.展开更多
Polystyrene(PS)microspheres have the advantages of good stability,corrosion resistance and low density,which have a broad application prospect.In this paper,PS composite microspheres with 20%silver plating content wer...Polystyrene(PS)microspheres have the advantages of good stability,corrosion resistance and low density,which have a broad application prospect.In this paper,PS composite microspheres with 20%silver plating content were prepared by chemical plating method and incorporated into polydimethylsiloxane(PDMS)flexible matrix to prepare Ag@PS/PDMS flexible wave-absorbing materials.The electromagnetic parameters were adjusted to optimize the dielectric and wave-absorbing properties by varying the additional amount of Ag@PS composite microspheres in Ag@PS/PDMS composites.The X-ray diffraction(XRD)results proved the successful preparation of Ag@PS composite microspheres.The SEM and EDS images indicated that the Ag particles were attached to the external surface of PS.The presence of Ag particles in the Ag@PS composite microspheres enhances their electrical conductivity and enables the formation of a conductive network.This,in turn,improves the composites’dielectric constant.The optimal wave-absorbing capability of the composites was achieved when the Ag@PS composite microspheres were added at a weight percentage of 50%.When the sample attains a thickness of 1.8 mm,a reflection loss of at least-39.8 dB is attained at 10.4 GHz,along with a bandwidth of 1.6 GHz(9.1–10.7 GHz)for the effective absorption bandwidth(EAB).The pressure-sensitive properties of the pliable composites were investigated as well.The optimal pressure-sensitive performance of Ag@PS/PDMS composites was achieved with a 60 wt.% addition of Ag@PS composite microspheres.The resistance undergoes significant changes when subjected to pressure with a sensitivity of 9.7.The results indicate that the flexible composites’wave-absorption and pressuresensitivity properties can be modulated by adjusting the amount of Ag@PS composite microspheres added.展开更多
基金financially supported by the National Natural Science Foundation of China(No.21106012)the Educational Department Foundation of Liaoning Province of China(NO.L2014180)
文摘Ni–Cr enrichment on stainless steel SS316 L resulting from chemical activation enabled the deposition of carbon by spraying a stable suspension of carbon nanoparticles; trace Ag was deposited in situ to prepare a thin continuous Ag-doped carbon film on a porous carbon-coated SS316 L substrate. The corrosion resistance of this film in 0.5 mol·L^（-1） H_2SO_4 solution containing 5 ppm F- at 80°C was investigated using polarization tests. The results showed that the surface treatment of the SS316 L strongly affected the adhesion of the carbon coating to the stainless steel. Compared to the bare SS316 L, the Ag-doped carbon-coated SS316 L bipolar plate was remarkably more stable in both the anode and cathode environments of proton exchange membrane fuel cell（PEMFC） and the interface contact resistance between the specimen and Toray 060 carbon paper was reduced from 333.0 m？·cm^2 to 21.6 m？·cm^2 at a compaction pressure of 1.2 MPa.
文摘A simple electroless plating process was employed to prepare silver-coated glass frits for solar cells. The surface of the glass frits was modified with polyvinyl-pyrrolidone（PVP） before the electroless plating process. Infrared（IR） spectroscopy,field emission scanning electron microscopy（FESEM）, and x-ray diffraction（XRD） were used to characterize the PVP modified glass frits and investigate the mechanism of the modification process. It was found that the PVP molecules adsorbed on the glass frit surface and reduced the silver ions to the silver nanoparticles. Through epitaxial growth, these nanoparticles were uniformly deposited onto the surface of the glass frit. Silicon solar cells with this novel silver coating exhibited a photoelectric conversion efficiency increase of 0.33%. Compared with the electroless plating processes, this method provides a simple route to prepare silver-coated glass frits without introducing impurity ions.
基金support from the National Natural Science Foundation of China(Nos.U24A2074,52403045,52473044,and 52273270)the Postdoctoral Fellowship Program of CPSF(No.GZC20241106)+1 种基金the Opening Project of Robotic Satellite Key Laboratory of Sichuan Provincethe Sichuan University Postdoctoral Interdisciplinary Innovation Fund.
文摘The proliferation of electromagnetic spectrum applications and increasing integration density of electronic devices have intensified electromagnetic pollution,driving demand for advanced electromagnetic interference(EMI)shielding materials.While conductive polymer composites present promising alternatives to traditional metals,attaining both exceptional EMI shielding performance and environmental sustainability remains challenging.Here,we adopt controlled mild alkaline hydrolysis to precisely engineer the surface roughness and hydrophilicity of polylactic acid(PLA)fibers,generating optimal substrates for subsequent electroless silver(Ag)deposition.The resulting Ag/PLA conductive fibers are structured into flexible films through vacuum filtration and hot-pressing.These films demonstrate remarkable electrical conductivity of 102,270 S/m,attributed to the continuous Ag coating and three-dimensional fibrous conductive network.Despite a thickness of merely 66μm,the Ag/PLA films exhibit an ultra-high EMI shielding effectiveness(EMI SE)of 101.0 dB and a specific shielding effectiveness of 9749.4 dB·cm^(2)/g.Notably,the films maintain military-grade EMI shielding performance(>90 dB)after thermal cycling across a~300 oC temperature range and 5000 bending cycles,confirming superior durability and mechanical flexibility.By synergistically coupling biodegradable PLA with recoverable Ag,this work simultaneously achieves outstanding EMI shielding performance and environmental sustainability,providing valuable insights for developing next-generation green EMI protection materials.
基金funded and supported by the National Natural Science Foundation of China(No.52103361)Shaanxi University Youth Outstanding Talents Support Plan.Scientific and Technological Plan Project of Xi’an Science and Technology Bureau(23GXFW0018,23KGDW0031-2022)Scientific and Technological Guidance Project of Xi’an Key Laboratory of Textile Composites(xafzfc-zd08).
文摘Polystyrene(PS)microspheres have the advantages of good stability,corrosion resistance and low density,which have a broad application prospect.In this paper,PS composite microspheres with 20%silver plating content were prepared by chemical plating method and incorporated into polydimethylsiloxane(PDMS)flexible matrix to prepare Ag@PS/PDMS flexible wave-absorbing materials.The electromagnetic parameters were adjusted to optimize the dielectric and wave-absorbing properties by varying the additional amount of Ag@PS composite microspheres in Ag@PS/PDMS composites.The X-ray diffraction(XRD)results proved the successful preparation of Ag@PS composite microspheres.The SEM and EDS images indicated that the Ag particles were attached to the external surface of PS.The presence of Ag particles in the Ag@PS composite microspheres enhances their electrical conductivity and enables the formation of a conductive network.This,in turn,improves the composites’dielectric constant.The optimal wave-absorbing capability of the composites was achieved when the Ag@PS composite microspheres were added at a weight percentage of 50%.When the sample attains a thickness of 1.8 mm,a reflection loss of at least-39.8 dB is attained at 10.4 GHz,along with a bandwidth of 1.6 GHz(9.1–10.7 GHz)for the effective absorption bandwidth(EAB).The pressure-sensitive properties of the pliable composites were investigated as well.The optimal pressure-sensitive performance of Ag@PS/PDMS composites was achieved with a 60 wt.% addition of Ag@PS composite microspheres.The resistance undergoes significant changes when subjected to pressure with a sensitivity of 9.7.The results indicate that the flexible composites’wave-absorption and pressuresensitivity properties can be modulated by adjusting the amount of Ag@PS composite microspheres added.
