Ultra-violet protection and water repellency of polyester fabrics treated by surface deposition of nickel under the effect of low temperature plasma

This paper is aimed at understanding the textile properties of nickel-deposited polyester fabric after treating with low temperature plasma treatment. Low temperature plasma treatment with oxygen gas was employed in this paper to activate a hydrophilic surface for the polyester fabrics and hence facilitate the nickel deposition through an electroless plating process. The textile properties of plasma-induced electroless nickel-plated polyester fabrics were evaluated by different standard testing methods in terms of both physical and chemical performances. The electroless nickel plating with plasma treatment improved significantly the performance of nickel-plated polyester fabrics as reflected by the scanning electron microscopy, tensile strength, ultraviolet protection as well as fabric weight. On the contrary, it also enhanced the fabric thickness and colour fastness to crocking. In addition, there was no influence on the performance of colour fastness to light and colourfastness to laundering. Moreover, the application of plasma treatment adversely affected slightly the performance of contact angle and wrinkle recovery property.     

Effect of Plasma on the Zeta Potential of Cotton Fabrics

In this work, the effect of a low-temperature plasma on the zeta potential of cotton fabric was studied. The silver particle absorption on cotton fabric when modified by a low-temperature plasma was also investigated. The modification consisted of plasma pre functionalization followed by a one-step wet treatment with silver nitrate solution. The process was performed in a low-temperature plasma medium, using a magnetron sputtering device. Oxygen and nitrogen were used as working gases in the system, and the results were compared. After preparing the samples, the zeta potentials of the untreated and plasma-treated cotton under a constant pH value solution were estimated and compared. Also, Fourier transform infrared spec troscopy (FTIR) was used to examine the functional groups of the corresponding samples. The amounts of silver absorption on plasma treated and untreated cotton were examined using the energy dispersive X-ray (EDX) method. The results show that the amount of zeta potential for the nitrogen plasma treated sample is less and the absorption of silver particles by cotton can be increased strongly with nitrogen plasma treatment.     

辐照接枝改性涤纶织物的亲水性能

利用电子束辐照接枝的方法将丙烯酸(Acrylic acid,AA)单体接枝到涤纶织物上来改善其亲水性。通过改变吸收剂量、接枝单体浓度、阻聚剂浓度、预辐照的吸收剂量以及前处理氢氧化钠浓度等影响因素来获得具有不同接枝率的改性涤纶织物。优化的反应条件:吸收剂量为195 k Gy、AA浓度为50%、阻聚剂(Fe SO4?7H2O)浓度为0.8%、预辐照的吸收剂量为43 k Gy、前处理Na OH浓度为15 g/L。傅里叶红外光谱证明AA已接枝成功;扫描电子显微镜分析表明改性涤纶织物的表面具有覆盖物,且随着接枝率的增大,其覆盖物明显增多;回潮率测试结果表明,改性涤纶的回潮率随接枝率的增加而逐渐增大,当接枝率达到最大值27.84%时,改性涤纶的回潮率可达3.51%。涤纶织物经30次洗涤后减重率仅1%左右,说明接枝牢度优异。     

Surface Treatment of Polypropylene Powders Using a Plasma Reactor with a Stirrer

A radio frequency argon plasma reactor with a stirrer was employed for the surface treatment of polypropylene (PP) powders. The changes in the superficial contact angle and the superficial composition of the un-treated and treated PP powders were analyzed by means of water contact angle (WCA) measurement, X-ray photoelectron spectroscopy (XPS) and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). The water contact angle changed from the original value of 130.2° before plasma treatment to the value of 73.6° after treatment for 5 minutes. With the increase in plasma treating time, there were a decrease in the water contact angle and an increase in the content of oxygen containing polar functional groups (i.e., C-O, C=O and O-C=O). Both XPS and ATR-FTIR results indicated that the plasma treatment led to the formation of oxygen containing polar functional groups due to oxidation on the surface of the PP powders, and the trend of variation of the water contact angle with plasma treating time was related to the concentration of oxygen atom on the treated PP powders surface. Furthermore, the aging of the plasma-treated PP powders was investigated.     

Plasma treatment for enhancement of the sorption capacity of carbon fabric

In this work we carried out an experimental investigation into enhancement of the sorption capacity of carbon fabric using plasma treatment methods.Carbon fabric is based on viscose fiber and is hydrophobic by nature.Enhancement of the fabric sorption capacity is required for its application in medicine.For this purpose,two plasma treatment methods were considered,i.e.atmospheric nonequilibrium radiofrequency(RF)discharge and a vacuum RF plasma source with an external magnetic field.Samples treated by atmospheric discharge demonstrated aging effects during the first week after treatment.The sorption capacity of samples treated by the RF plasma source was stable over the same period and reached values as high as 0.95.Parameters of the beam created by the vacuum RF plasma source were analyzed and dependences of the fabric sorption capacity and specific surface area on plasma treatment time were investigated.We found that sorption capacity reached its maximum value after 30 min of treatment and did not change significantly if processing was continued,while the specific surface area reached its maximum after 3 min of treatment and quickly decreased after that.It was found that the micropore structure of the fabric remained almost the same during plasma treatment.The volume of mesopores in a unit of the fabric mass(specific volume)doubled during the first 5 min of treatment and returned to initial values after 30 min of treatment.The sorption capacity continued to increase even when the specific surface area decreased after reaching its peak value.This indicates the important role of surface functional groups formed on carbon fibers during plasma treatment.This is consistent with the results of x-ray photoelectron spectroscopy analysis showing changes in surface oxidation during plasma treatment.     

Influences of the cold atmospheric plasma jet treatment on the properties of the demineralized dentin surfaces

Improvement of the bonding strength and durability between the dentin surface and the composite resin is a challenging job in dentistry. In this paper, a radio-frequency atmosphericpressure glow discharge(RF-APGD) plasma jet is employed for the treatment of the acid-etched dentin surfaces used for the composite restoration. The properties of the plasma treated dentin surfaces and the resin–dentin interfaces are analyzed using the x-ray photoemission spectroscopy, contact angle goniometer, scanning electron microscope and microtensile tester.The experimental results show that, due to the abundant chemically reactive species existing in the RF-APGD plasma jet under a stable and low energy input operating mode, the contact angle of the plasma-treated dentin surfaces decreases to a stable level with the increase of the atomic percentage of oxygen in the specimens; the formation of the long resin tags in the scattered clusters and the hybrid layers at the resin–dentin interfaces significantly improve the bonding strength and durability. These results indicate that the RF-APGD plasma jet is an effective tool for modifying the chemical properties of the dentin surfaces, and for improving the immediate bonding strength and the durability of the resin-dentin bonding in dentistry.     

Non-thermal plasma modified growth and differentiation process of Capsicum annuum PP805 Godiva in in vitro conditions

With the aim of evaluating the possible impacts of cold plasma on the structure and growth pattern of Capsicum annuum,the current study was carried out.The seeds were exposed to an argon-derived plasma (0.84 W cm-2 surface power densities) for 0,1 or 2 minutes.Plasma treated seeds were grown in the Murashige and Skoog (MS) medium or MS medium supplemented with BA and IAA.The presence of purple stems was recorded in plasma-treated plants grown in the medium supplemented with hormones.The recorded morphological differences were dependent on the exposure time of plasma treatments and/or the presence of hormones in the culture media.Plasma treatment of 1 minute had an improving effect on the shoot and root lengths as well as total leaf area,whereas plasma treatment of 2 minutes had an adverse effect.In contrast to the 1 minute treatment,plasma treatment of 2 minutes significantly impaired growth and hence reduced the total biomass.Alterations in stem diameter and differences in tissue patterns (especially in the vascular system) occurred,and were mainly dependent on the plasma exposure time and/or the presence of hormones.This is a first report on the effects of cold plasma on plant growth in in vitro conditions.     

Molecular mechanism study of Astragalus adsurgens Pall synergistically induced by plasma and plasma-activated water

The mutagenic effects of discharge plasma and plasma+PAW (plasma and its activated water combined) on Astragalus adsurgens Pall seeds were explored. Needle array-plate dielectric-barrier discharge plasma was used to treat A. adsurgens Pall seeds and PAW was prepared at the same time. The deionized water and the obtained PAW were used to cultivate plasma-treated seeds in groups and the survival rate of each group was counted. Results showed that the survival rate of the treated seeds of A. adsurgens Pall when cultured with deionized water was not significantly different from that of the control check (CK). The culture with PAW had an obvious lethal effect and each group reached the half-lethal dose. Reactive oxygen species (ROS) and RNA-Seq analysis of seedlings in the 3 h treatment group showed that the content of ROS in the 3 d post-treatment group was significantly higher than that of the CK. Because expression of the gene with the function of scavenging superoxide free radicals was upregulated, the ROS content of seedlings on the sixth day was significantly lower than that on the third day. Plasma and plasma+PAW treatments changed a large number of gene expressions; particularly, the plasma+PAW group caused plant-growth genes to be significantly upregulated. After treatment, the seedlings of A. adsurgens Pall may grow faster and have higher nutritional value. This research is of great significance to the wider application of isoelectronic bodies and their activated water physicochemical mutagens in biological effects and breeding research.     

The effect of atmospheric pressure glow discharge plasma treatment on the dyeing properties of silk fabric

In this study, the effects of plasma treatment parameters on surface morphology, chemical constituent, dyeability and color fastness of silk fabric were investigated. Atmospheric pressure glow discharge plasma generated with different applied voltages(0 kV to 45 kV) was used to treat the surface of silk fabrics. C I Natural Yellow 3 was used to dye untreated and plasmatreated silk fabrics. The physical analysis based on scanning electron microscopy showed that the surface of silk fabrics was affected by plasma treatment. The chemical analysis was investigated with x-ray photoelectron spectroscopy and attenuated total reflection Fourier transform infrared spectroscopy. The results showed that the content of C 1s decreased with the increasing applied voltage, the content of N 1s and O 1s increased with the increasing applied voltage. The increasing K/S values represented that the dyeability of silk fabrics was improved after plasma treatment. The color fastness to dry and wet rubbing was decreased after plasma treatment.     

紫外线照射对羊毛织物表面理化性能的影响

利用相关表面性能测试方法对紫外线照射前后羊毛织物的表面化学组成、亲水性和微观结构进行表征。结果表明,紫外线照射过程可能是部分破坏了羊毛织物上具有疏水特性的胱氨酸和二硫键及非极性的C-C键,并同时提高了表面羟基、含N基团和C-O键的含量,使织物的亲水性能得到增强,且在紫外线照射羊毛织物静态水接触角降低、毛效提高的结果中得到证实;在低功率、短时间的处理条件下,紫外线照射羊毛织物引起的化学刻蚀未对纤维表面形貌及结晶区结构造成明显变化,仅略微提升了羊毛织物的粗糙程度。综合紫外线照射对羊毛织物表面理化性能的影响,认为该方法利于毛纺染整加工。     

The research about the time-effect of the wettability on the wool surface treated by the Ar plasma jet in the atmospheric pressure

A facility which is called atmospheric pressure and normal temperature plasma jet was introduced in this paper. After the wool surface was treated by this kind of facility with Ar in different irradiating times, the time-effect of the fabric wettability has been weakened, and if the parameters of the irradiating time and the voltage of the facility are appropriate, the time-effect of wettability can be effectively inhibited. With the stable wettability, the fabric can be dressed without PVA (polyvinyl alcohol) which can cause lager pollution in the textile field, so the method without the time-effect of the textile wettability will be useful in the field of clean textile production. Undoubtedly, the stable wettability of textile surface was caused by the stable hydrophilic molecules on the textile surface. Thus, the reaction process and results on the textile surface treated by plasma needs to be studied to optimize the parameters of the irradiating time and the voltage of the plasma jet. So the initial experimental studies on the optimization of the parameters of the plasma jet were discussed in this paper, and the authors believe that the method without the time-effect also can be used in other fields of plasma application.     

Effect of plasma step gradient modification on surface electrical properties of epoxy resin

In this paper, plasma fluorination is combined with plasma silicon deposition to achieve step gradient modification on an epoxy resin surface. The physicochemical characteristics of samples are investigated and the electrical performances measured. The obtained results show that compared with untreated and single treated samples, the samples treated by step gradient modification significantly improve the flashover performance. According to experiment and simulation, the mechanism explanations are summarized as follows. First, it is found that the step gradient conductivity can effectively optimize the electric field distribution of a needle-needle electrode. Then, step gradient modification suppresses the accumulation of surface charge at the triple junction and makes the charge distribution more uniform. Furthermore, it can accelerate the surface dissipation on a high electrical field region and control the dissipation rate on a low electrical field region. All these results can restrain surface discharge and increase the flashover voltage. The step gradient modification method proposed in this paper provides a new idea for improving the surface insulation performance.     

Flame Retardant Properties of Plasma Pretreated/Metallic Salt Loaded Cotton Fabric Before and After Direct Dyeing

In this research work, cotton fabrics were pretreated with low temperature plasma (LTP) and then inoculated in various metallic salts and flame retardancy of cotton fabric was investigated. More polar functional groups were present on the substrate surface after LTP pretreatment. Titanium dioxide (TiO₂), zinc sulfate (ZnSO₄), lead (II) acetate [Pb(C₂H₃O₂)₂], aluminium sulfate [Al₂(SO₄)₃] and silver nitrate (AgNo₃) were used as metallic salts. The flame retardancy of the samples was characterized by limiting oxygen index (LOI) and char yield. Good flame retardant activity for Al₂(SO₄)₃ and AgNo₃ treated fabrics were achieved, however, the effect of TiO₂ and ZnSO₄ on flame retardany of cotton fabrics was moderate. It was concluded that, nitrogen plasma pretreatment, improve the flame retardant properties of cotton samples. The plasma treated and Aluminium sulfate loaded cotton fabric sample has a LOI value of 23.3. It shows that, nitrogen plasma pretreatment has synergistic effect on metallic salts for improving the flame retardant properties of cotton samples. In this research work, the dyeability of samples after loading with metallic salts was investigated. Also effect of dyeing on flame retardant properties was studied. The cotton fabrics treated with metallic salts demonstrate an excellent dyeability property. Color intensities of the dyed fabrics were measured by using a UV VIS–NIR Reflective Spectrophotometer, over the range of 200–800 nm. The results showed that, by using silver nitrate as mordant before dying, the relative color strength (K/S values) of the dyed fabrics has been increased. Water drop test and wash fastness determination (ISO 105-C01) were conducted. Also Electronic Crock meter/Rubbing Fastness Tester AATCC 8 was used to determine the color fastness of textiles. We also concluded that dyeing the plasma treated and inoculated cotton fabrics do not have any negative effect on flame retardancy of cotton fabric.     

First-principles study on the mechanical properties and thermodynamic properties of Mo–Ta alloys

The mechanical properties, thermodynamic properties and electronic structure of Mo_(1-x)Ta_x(Mo–Ta) alloys(x?=?0, 0.0625, 0.125, 0.25, 0.3125, 0.5 and 1) were calculated by using firstprinciples. The electronic structure of Mo–Ta alloys was analysed by the projected density of states(PDOS). The low temperature heat capacity was estimated by Fermi energy and Debye temperature.It is shown that the formation enthalpy will decrease with the increase of Ta content, and the cohesive energy will increase with the increase of the Ta content. On the other hand, the addition of Ta atoms will reduce the strength and improve the ductility of Mo–Ta alloys, the Debye temperature will decrease and the low temperature heat capacity will be improved with the increase of the Ta content. All these results will be useful for the research of new plasma grid(PG) materials, which is mainly used in neutral beam injection(NBI) systems to produce negative hydrogen ions.     

联用紫外线辐射改性的羊毛织物茶色素同浴媒染工艺

以茶色素/金属媒染剂同浴媒染法为基础,对分别应用不同金属媒染剂的羊毛织物茶色素同浴媒染工艺进行筛选,对比经紫外线辐射改性前后的羊毛织物染色性能。结果表明,茶色素/铜媒同浴媒染的改性前后羊毛织物K/S值与固色率均较其余工艺高,并通过对比实验数据证实紫外线辐射有利于提升羊毛织物染色性能,故将其与茶色素/铜媒同浴媒染工艺联用进而增强茶色素染色效果。通过单因素分析对联用紫外线辐射改性的羊毛织物茶色素/铜媒同浴媒染工艺进行讨论并选择紫外线辐射改性时间、铜媒用量及染色时间等因子的优化范围,进而利用3因子二次通用旋转组合设计进行优化,从而确定优化工艺为(用量/对织物重(o.w.f)):紫外线辐射改性9 min,茶色素5.0%,铜媒1.7%,HCOOH 2.0%,pH=3.5~4.0,浴比1:50,95℃条件下染色60 min。与常规茶色素后铬媒染工艺相比,该优化工艺具有更好的染色效果和较低的金属媒染剂用量。     

Effect of Atmospheric Pressure Plasma Treatment/Followed by Chitosan Grafting on Antifelting and Dyeability of Wool Fabric

Effect of chitosan on antifelting and dyability of dielectric barrier discharge (DBD) pretreated wool fabric were evaluated. We have used a DBD, working in an atmospheric pressure air for pretreatment of wool fabric. The chitosan was applied to pretreated wool fabrics by using pad-dry cure technique. The anti-felting properties of the wool samples were studied and it was shown that the shrink resistance and anti-felting behavior of the wool had been significantly improved by the DBD pretreatment followed by chitosan grafting. In addition, dye ability of wool fabrics after plasma/chitosan treatment is improved. Some analytical skills such as Fourier transform infrared spectroscopy and scanning electron microscope were used to characterize the different aspects of the treated fabric.     

Calculation of Electrical Potential and Dust Particle Charge in a Double Dusty Plasma Device

Dusty plasma consists of macroscopic particles of nanometer to micrometer size immersed in a gaseous plasma environment. It can be observed by introducing a flow of molecular impurity in a double plasma device. The impurity particles will be charged quickly, while keeping relatively in low temperature. The particles typically attain several hundred or thousand elementary charges due to the inflow of plasma electron and ions. The dust particles potential and electrical charge in plasma with two ions at different temperatures is calculated. Electrical charge of dust particles is self consistently determined by local plasma electron and ion currents. It is found out that the dust particle potential is strongly affected by the mass and temperature difference of plasma ions.     

Quality enhancement and microbial reduction of mung bean (Vigna radiata) sprouts by non-thermal plasma pretreatment of seeds

Mung bean (Vigna radiata) sprouts are widely consumed worldwide due to their high nutritional value. However, the low yield and microbial contamination of mung bean sprouts seriously reduces their economic value. This study investigates the effects of non-thermal plasma on the quality and microbial reduction of mung bean sprouts by pretreatment of seeds in water for different times (0, 1, 3 and 6 min). The quality results showed that short-time plasma treatment (1 and 3 min) promoted seed germination and seedling growth, whereas long-time plasma treatment (6 min) had inhibitory effects. Plasma also had a similar dose effects on the total flavonoid and phenolic contents of mung bean sprouts. The microbiological results showed that plasma treatment achieved a reduction of native microorganisms ranging from 0.54 to 7.09 log for fungi and 0.29 to 6.80 log for bacteria at 96 h incubation. Meanwhile, plasma treatment could also efficiently inactivate artificially inoculated Salmonella typhimurium (1.83–6.22 log) and yeast (0.53–3.19 log) on mung bean seeds. The results of seed coat permeability tests and scanning electron microscopy showed that plasma could damage the seed coat structure, consequently increasing the electrical conductivity of mung bean seeds. The physicochemical analysis of plasma-treated water showed that plasma generated various long- and short-lived active species [nitric oxide radicals (NO·), hydroxyl radicals (·OH), singlet oxygen (1O2), hydrogen peroxide (H2O2), nitrate (${{\rm{NO}}}_{3}^{-}$), and nitrite (${{\rm{NO}}}_{2}^{-}$)] in water, thus the oxidizability, acidity and conductivity of plasma-treated water were all increased in a treatment time-dependent manner. The result for mimicked chemical mixtures confirmed the synergistic effect of activity of H2O2, ${{\rm{NO}}}_{3}^{-}$ and ${{\rm{NO}}}_{2}^{-}$ on bacterial inactivation and plant growth promotion. Taken together, these results imply that plasma pretreatment of mung bean seeds in water with moderate oxidizability and acidity is an effective method to improve the yield of mung bean sprouts and reduce microbial contamination.     

粉末矿样射气系数与湿度的关系

本文报道了粉末矿样射气系数与矿样湿度关系的研究结果。实验发现在低湿度(接近天然风干状态)条件下,射气系数随矿样湿度的增加而显著增加,这说明在测定射气系数时或在研究射气系数及有关的氡析出特性的变化规律时,必须充分考虑矿样湿度的影响。     

Plasma Modification of Activated Carbon Fibers for Adsorption of SO_2

Viscose-based activated carbon fibers(VACFs)were treated by a dielectric-barrier discharge plasma under the feed gas of N_2.The surface functional groups of VACFs were modified to improve the adsorption and catalysis capacity for SO_2.The surface properties of the untreated and plasma-treated VACFs were diagnosed by SEM,BET,FTIR,and XPS,and the adsorption capacities of VACFs for SO_2 were also compared and discussed.The results show that after the plasma treatment,the external surface of VACFs was etched and became rougher,while the surface area and the total pore volume decreased.FTIR and XPS revealed that nitrogen atoms were introduced onto the VACFs surface and the distribution of functional groups on the VACFs surface was changed remarkably.The adsorption characteristic of SO_2 indicates that the plasmatreated VACFs have better adsorption capacity than the original VACFs due to the nitrogen functional groups and new functional groups formed in modification,which is beneficial to the adsorption of SO_2.