Surface modification of fabrics is an effective way to endow them with antifouling properties while still maintaining their key advantages such as comfort,softness and stretchability.Herein,an atmospheric pressure die...Surface modification of fabrics is an effective way to endow them with antifouling properties while still maintaining their key advantages such as comfort,softness and stretchability.Herein,an atmospheric pressure dielectric barrier discharge(DBD)plasma method is demonstrated for the processing of silk fabrics using 1H,1H,2H,2H-perfluorodecyltriethoxysilane(PFDS)as the precursor.The results showed the successful grafting of PFDS groups onto the surface of silk fabrics without causing damage.Meanwhile,the gas temperature is rather low during the whole processing procedure,suggesting the non-equilibrium characteristics of DBD plasma.The influence on fabrics of the processing parameters(PFDS concentration,plasma treatment time and plasma discharge power)was systematically investigated.An optimum processing condition was determined to be a PFDS concentration of 8wt%,a plasma processing time of 40 s and a plasma power of 11.87 W.However,with prolonged plasma processing time or enhanced plasma power,the plasma-grafted PFDS films could be degraded.Further study revealed that plasma processing of silk fabrics with PFDS would lead to a change in their chemical composition and surface roughness.As a result,the surface energy of the fabrics was reduced,accompanied by improved water and oil repellency as well as enhanced antifouling performance.Besides,the plasma-grafted PFDS films also had good durability and stability.By extending the method to polyester and wool against different oil-/water-based stains,the DBD plasma surface modification technique demonstrated good versatility in improving the antifouling properties of fabrics.This work provides guidance for the surface modification of fabrics using DBD plasma to confer them with desirable functionalities.展开更多
The aging effects of the contact angle and surface energy on polyethylene terephthalate (PET) have been investigated with surface modification by water vapor plasma. The experimental results show that the contact ang...The aging effects of the contact angle and surface energy on polyethylene terephthalate (PET) have been investigated with surface modification by water vapor plasma. The experimental results show that the contact angle of water and PET decreases obviously and surface energy increases. However, with the increase of the aging time, the contact angle and surface energy change back gradually to original state.展开更多
The inner surface modification process by plasma-based low-energy ion implantation（PBLEII）with an electron cyclotron resonance（ECR）microwave plasma source located at the central axis of a cylindrical tube is model...The inner surface modification process by plasma-based low-energy ion implantation（PBLEII）with an electron cyclotron resonance（ECR）microwave plasma source located at the central axis of a cylindrical tube is modeled to optimize the low-energy ion implantation parameters for industrial applications.In this paper,a magnetized plasma diffusion fluid model has been established to describe the plasma nonuniformity caused by plasma diffusion under an axial magnetic field during the pulse-off time of low pulsed negative bias.Using this plasma density distribution as the initial condition,a sheath collisional fluid model is built up to describe the sheath evolution and ion implantation during the pulse-on time.The plasma nonuniformity at the end of the pulse-off time is more apparent along the radial direction compared with that in the axial direction due to the geometry of the linear plasma source in the center and the difference between perpendicular and parallel plasma diffusion coefficients with respect to the magnetic field.The normalized nitrogen plasma densities on the inner and outer surfaces of the tube are observed to be about 0.39 and 0.24,respectively,of which the value is 1 at the central plasma source.After a 5μs pulse-on time,in the area less than 2 cm from the end of the tube,the nitrogen ion implantation energy decreases from 1.5 keV to 1.3 keV and the ion implantation angle increases from several degrees to more than 40°;both variations reduce the nitrogen ion implantation depth.However,the nitrogen ion implantation dose peaks of about 2×10^（10）-7×10^（10）ions/cm^2 in this area are 2-4 times higher than that of 1.18×10^（10）ions/cm^2 and 1.63×10^（10）ions/cm^2 on the inner and outer surfaces of the tube.The sufficient ion implantation dose ensures an acceptable modification effect near the end of the tube under the low energy and large angle conditions for nitrogen ion implantation,because the modification effect is mainly determined by the ion implantation dose,just as the mass transfer process in PBLEII is dominated by low-energy ion implantation and thermal diffusion.Therefore,a comparatively uniform surface modification by the low-energy nitrogen ion implantation is achieved along the cylindrical tube on both the inner and outer surfaces.展开更多
Three different low-temperature plasma-based methods were used to improve the surface hydrophilicity of polyethy- lene （PE） films, and all the modification processes were carried out by employing an atmospheric pres...Three different low-temperature plasma-based methods were used to improve the surface hydrophilicity of polyethy- lene （PE） films, and all the modification processes were carried out by employing an atmospheric pressure plasma jet （APPJ） system. （a） PE films were directly modified by APPJ using a gas mixture of He and 02. （b） Acrylic acid （AA） was introduced into the system and a polymer acrylic acid （PAA） coating was deposited onto the PE films. （c） AA was grafted onto the PE surface activated by plasma pre-treatment. It was found that the hydrophilicity of the PE films was significantly improved for all the three methods. However, the samples modified by Process （a） showed hydrophobicity recovery after a storage time of 20 days while no significant change was found in samples modified by Process （b） and Process （c）. The Fourier transform infrared spectroscopy （FTIR） results indicated that the most intensive C=O peak was detected on the PE surface modified by Process （c）. According to the X-ray photoelectron spectroscopy （XPS） analysis, the ratios of oxygen-containing polar groups for samples modified by Process （b） and Process （c） were higher than that modified by Process （a）.展开更多
To understand the characteristics of the plasma sheath within small tubes,a 2D numerical model of He discharge within dielectric tubes is developed.During plasma propagation for a tube diameter of 0.05 mm,the sheath t...To understand the characteristics of the plasma sheath within small tubes,a 2D numerical model of He discharge within dielectric tubes is developed.During plasma propagation for a tube diameter of 0.05 mm,the sheath thickness in the plasma head is almost equal to the tube radius.It decreases rapidly to several micrometers at an axial distance of 0.05 mm behind the plasma head,and then slightly increases and saturates at the axial position far behind the plasma head.A plasma-gas sheath surrounding the central plasma column is observed for a tube diameter equal to or greater than 0.8 mm.It is replaced by a plasma-wall sheath for smaller tubes.With the decrease in the tube diameter,the sheath thickness far behind the plasma head decreases while the ion flux increases significantly.However,when O_(2)gas with a proportion of 2%is added,both the sheath thickness and ion flux decrease.展开更多
With consideration of the effects of the atomic process and the sight line direction on the charge exchange re-combination spectroscopy （CXRS）, a code used to modify the poloidal CXRS measurement on Tokamak-60 Upgra...With consideration of the effects of the atomic process and the sight line direction on the charge exchange re-combination spectroscopy （CXRS）, a code used to modify the poloidal CXRS measurement on Tokamak-60 Upgrade （JT-60U） in Japan Atomic Energy Research Institute is developed, offering an effective tool to modify the measurement and analyse experimental results further. The results show that the poloidal velocity of ion is overestimated but the ion temperature is underestimated by the poloidal CXRS measurement, and they also indicate that the effect of observation angle on rotation velocity is a dominant one in a core region （r/a 〈 0.65）, whereas in an edge region where the sight line is nearly normal to the neutral beam, the observation angle effect is very small. The difference between the modified velocity and the neoclassical velocity is not larger than the error in measurement. The difference inside the internal transport barrier （ITB） region is 2-3 times larger than that outside the ITB region, and it increases when the effect of excited components in neutral beam is taken into account. The radial electric field profile is affected greatly by the poloidal rotation term, which possibly indicates the correlation between the poloidal rotation and the transport barrier formation.展开更多
基金the financial support from National Natural Science Foundation of China(Nos.22078125 and 52004102)Postdoctoral Science Foundation of China(No.2023M741472)。
文摘Surface modification of fabrics is an effective way to endow them with antifouling properties while still maintaining their key advantages such as comfort,softness and stretchability.Herein,an atmospheric pressure dielectric barrier discharge(DBD)plasma method is demonstrated for the processing of silk fabrics using 1H,1H,2H,2H-perfluorodecyltriethoxysilane(PFDS)as the precursor.The results showed the successful grafting of PFDS groups onto the surface of silk fabrics without causing damage.Meanwhile,the gas temperature is rather low during the whole processing procedure,suggesting the non-equilibrium characteristics of DBD plasma.The influence on fabrics of the processing parameters(PFDS concentration,plasma treatment time and plasma discharge power)was systematically investigated.An optimum processing condition was determined to be a PFDS concentration of 8wt%,a plasma processing time of 40 s and a plasma power of 11.87 W.However,with prolonged plasma processing time or enhanced plasma power,the plasma-grafted PFDS films could be degraded.Further study revealed that plasma processing of silk fabrics with PFDS would lead to a change in their chemical composition and surface roughness.As a result,the surface energy of the fabrics was reduced,accompanied by improved water and oil repellency as well as enhanced antifouling performance.Besides,the plasma-grafted PFDS films also had good durability and stability.By extending the method to polyester and wool against different oil-/water-based stains,the DBD plasma surface modification technique demonstrated good versatility in improving the antifouling properties of fabrics.This work provides guidance for the surface modification of fabrics using DBD plasma to confer them with desirable functionalities.
文摘The aging effects of the contact angle and surface energy on polyethylene terephthalate (PET) have been investigated with surface modification by water vapor plasma. The experimental results show that the contact angle of water and PET decreases obviously and surface energy increases. However, with the increase of the aging time, the contact angle and surface energy change back gradually to original state.
基金supported by National Natural Science Foundation of China(Nos.50725519,51271048,51321004)
文摘The inner surface modification process by plasma-based low-energy ion implantation（PBLEII）with an electron cyclotron resonance（ECR）microwave plasma source located at the central axis of a cylindrical tube is modeled to optimize the low-energy ion implantation parameters for industrial applications.In this paper,a magnetized plasma diffusion fluid model has been established to describe the plasma nonuniformity caused by plasma diffusion under an axial magnetic field during the pulse-off time of low pulsed negative bias.Using this plasma density distribution as the initial condition,a sheath collisional fluid model is built up to describe the sheath evolution and ion implantation during the pulse-on time.The plasma nonuniformity at the end of the pulse-off time is more apparent along the radial direction compared with that in the axial direction due to the geometry of the linear plasma source in the center and the difference between perpendicular and parallel plasma diffusion coefficients with respect to the magnetic field.The normalized nitrogen plasma densities on the inner and outer surfaces of the tube are observed to be about 0.39 and 0.24,respectively,of which the value is 1 at the central plasma source.After a 5μs pulse-on time,in the area less than 2 cm from the end of the tube,the nitrogen ion implantation energy decreases from 1.5 keV to 1.3 keV and the ion implantation angle increases from several degrees to more than 40°;both variations reduce the nitrogen ion implantation depth.However,the nitrogen ion implantation dose peaks of about 2×10^（10）-7×10^（10）ions/cm^2 in this area are 2-4 times higher than that of 1.18×10^（10）ions/cm^2 and 1.63×10^（10）ions/cm^2 on the inner and outer surfaces of the tube.The sufficient ion implantation dose ensures an acceptable modification effect near the end of the tube under the low energy and large angle conditions for nitrogen ion implantation,because the modification effect is mainly determined by the ion implantation dose,just as the mass transfer process in PBLEII is dominated by low-energy ion implantation and thermal diffusion.Therefore,a comparatively uniform surface modification by the low-energy nitrogen ion implantation is achieved along the cylindrical tube on both the inner and outer surfaces.
基金Project supported by the National Natural Science Foundation of China(Grant No.11175157)the Zhejiang Provincial Key Innovation Team,China(Grant No.2012R10038)the 521 Talent Project of Zhejiang Sci-Tech University,China
文摘Three different low-temperature plasma-based methods were used to improve the surface hydrophilicity of polyethy- lene （PE） films, and all the modification processes were carried out by employing an atmospheric pressure plasma jet （APPJ） system. （a） PE films were directly modified by APPJ using a gas mixture of He and 02. （b） Acrylic acid （AA） was introduced into the system and a polymer acrylic acid （PAA） coating was deposited onto the PE films. （c） AA was grafted onto the PE surface activated by plasma pre-treatment. It was found that the hydrophilicity of the PE films was significantly improved for all the three methods. However, the samples modified by Process （a） showed hydrophobicity recovery after a storage time of 20 days while no significant change was found in samples modified by Process （b） and Process （c）. The Fourier transform infrared spectroscopy （FTIR） results indicated that the most intensive C=O peak was detected on the PE surface modified by Process （c）. According to the X-ray photoelectron spectroscopy （XPS） analysis, the ratios of oxygen-containing polar groups for samples modified by Process （b） and Process （c） were higher than that modified by Process （a）.
基金supported by National Natural Science Foundation of China(No.51977110)。
文摘To understand the characteristics of the plasma sheath within small tubes,a 2D numerical model of He discharge within dielectric tubes is developed.During plasma propagation for a tube diameter of 0.05 mm,the sheath thickness in the plasma head is almost equal to the tube radius.It decreases rapidly to several micrometers at an axial distance of 0.05 mm behind the plasma head,and then slightly increases and saturates at the axial position far behind the plasma head.A plasma-gas sheath surrounding the central plasma column is observed for a tube diameter equal to or greater than 0.8 mm.It is replaced by a plasma-wall sheath for smaller tubes.With the decrease in the tube diameter,the sheath thickness far behind the plasma head decreases while the ion flux increases significantly.However,when O_(2)gas with a proportion of 2%is added,both the sheath thickness and ion flux decrease.
文摘With consideration of the effects of the atomic process and the sight line direction on the charge exchange re-combination spectroscopy （CXRS）, a code used to modify the poloidal CXRS measurement on Tokamak-60 Upgrade （JT-60U） in Japan Atomic Energy Research Institute is developed, offering an effective tool to modify the measurement and analyse experimental results further. The results show that the poloidal velocity of ion is overestimated but the ion temperature is underestimated by the poloidal CXRS measurement, and they also indicate that the effect of observation angle on rotation velocity is a dominant one in a core region （r/a 〈 0.65）, whereas in an edge region where the sight line is nearly normal to the neutral beam, the observation angle effect is very small. The difference between the modified velocity and the neoclassical velocity is not larger than the error in measurement. The difference inside the internal transport barrier （ITB） region is 2-3 times larger than that outside the ITB region, and it increases when the effect of excited components in neutral beam is taken into account. The radial electric field profile is affected greatly by the poloidal rotation term, which possibly indicates the correlation between the poloidal rotation and the transport barrier formation.
