No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Atmospheric pressure plasma treatment of wool fabric structures
Abstract
Polyaniline-wool (PAN-WF), poly(3,4-ethylenedioxythiophene)-wool (PEDOT-WF), polypyrrole-wool (PPy-WF) fabrics were successfully prepared via atmospheric pressure plasma process. Scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), Fourier Transform Infrared Spectroscopy (FTIR) and four-probe resistance measurements were used to study the properties of the plasma polymer coated wool fabrics. The effects of the addition of iodine doping on the morphology and electrical properties of the fabrics were examined. The lowest electrical resistance was measured to be 7.7×103Ωcm for PEDOT-I2-WF sample after washing with water two times.
... Therefore, extensive efforts have been given to modify the surface of the wool for rapid penetration of chemicals and colorants (natural and synthetic) during dyeing and finishing operations [7,[13][14][15]. Plasma technology is an alternative and cost effective proven method for surface modification of natural and synthetic fibers [16][17][18][19][20]. The treatment of wool with plasma technology can promote the diffusion of organic molecules inside the fibers to enhance the dyeing rate, color fastness, wash resistance, and strong adhesion of coating with fibers. ...
... As shown in figure 3, the FTIR spectrum of the untreated specimen showed intense peak of -OH stretching vibration at 3292 cm −1 . There were symmetrical and asymmetrical stretching bands of CH 2 and CH 3 at 2800-3000 cm −1 [19,27]. The transmittance bands at 1635 and 1519 cm −1 corresponded to the amide I band of the amide carbonyl C=O stretching vibration and the amide II bands of the N-H bending motion [28,29]. ...
Physical and chemical properties of wool surface significantly affect the absorbency, rate of dye bath exhaustion and fixation of the industrial dyes. Hence, surface modification is a necessary operation prior to coloration process in wool wet processing industries. Plasma treatment is an effective alternative for physiochemical modification of wool surface. However, optimum processing parameters to get the expected modification are still under investigation, hence this technology is still under development in the wool wet processing industries. Therefore, in this paper, treatment parameters with the help of simple dielectric barrier discharge plasma reactor and air as a plasma gas, which could be a promising combination for treatment of wool substrate at industrial scale were schematically studied, and their influence on the water absorbency, mechanical, and dyeing properties of twill woven wool fabric samples are reported. It is expected that the results will assist to the wool coloration industries to improve the dyeing processes. © 2018 Hefei Institutes of Physical Science, Chinese Academy of Sciences and IOP Publishing.
... The plasma induced graft polymerization [36] applied to textiles aims to perform a polymerization on a fabric wetted in a monomers solution, by a simple plasma treatment [37,38]. This process has been tested once with conducting polymers on wool fabrics [39]. The plasma treatment seems to introduce enough radicals and functional groups on the textile fibers to promote alone the oxidation polymerization. ...
Hydrophobic and oleophobic resistant coatings are realized on nylon and cotton textiles by plasma induced polymerization of modified pyrrole monomers. This process creates a chemical bond between the polymer and the textile fibers for an improved mechanical adherence. A chemical post-grafting with short fluorinated chains gives the non-wetting properties. Two other improvements are tested and compared in terms of adherence and wetting properties. The first one consists of inducing a crosslinking to improve the adhesion of the coating, and the second one of grafting silica nanoparticles to enhance the amphiphobicity.
... The sheet resistance of PPy-deposited PET samples was shown in Fig.8 and the concentration of Py monomer was 0.0175 M. It is reported that the conductivity of the PPy-deposited fabrics were nearly proportional to the depositon of PPy [28,29]. After deposition process of PPy on PET fabrics, the sheet resistance decreased distinctly with the concentrations of H2SO4 solution increasing. ...
A simple and effective surface modification of polyester fabrics with sulfuric acid to improve the interfacial deposition of polypyrrole was presented in our work. A range of sulfuric acid concentrations were analyzed by studying water contact angle. Effect of sulfuric acid modification on the deposition of polypyrrole was investigated by sheet resistance and color depth of fabric samples. Polyester fabrics coated with polypyrrole layer were confirmed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-Ray diffraction spectra (XRD), Fourier transform infrared spectroscopy (FTIR). XPS showed that sulphur containing functional groups were obviously appeared on the polyester fiber surface after modification, which were advantageous to promote the deposition of polypyrrole onto polyester fabrics. The improved deposition increased electrical conductivity of fabric samples.
... [25][26][27][28] Plasma polymer coatings been used to impart functionalities such as superhydrophobicity and antistatic properties to fabrics. [29][30][31][32] In addition, plasma coatings have been used as means of improving the adhesion of different materials to fabrics. [33][34][35][36][37] Our previous work has demonstrated the antibacterial efficacy of LFS synthesized silver nanoparticles on paper and glass, and that the nanoparticle adhesion can be improved on glass surfaces with a plasma coating. ...
Healthcare associated infections (HAIs) are known as one of the major problems of the modern healthcare system, which result in additional cost and mortality. It has also been shown that pathogenic bacteria are mostly transferred via surfaces in healthcare settings. Therefore, antibacterial surfaces, which include fabrics and textiles, can be used in a healthcare environment to reduce the transfer of pathogenic bacteria, hence reducing HAIs. Silver nanoparticles have been shown to have broad spectrum antibacterial properties, and therefore they have been incorporated into fabrics to provide antibacterial functionality. Liquid flame spray (LFS) nanoparticle synthesis allows nanoparticles to be produced and deposited on surfaces at speeds up to and beyond 300 m/min. Herein, LFS is used to deposit silver nanoparticles onto two fabrics that are commonly used in the hospital environment with the aim of producing antibacterial fabrics. A thin plasma coating on top of the fabrics after silver deposition is used to improve nanoparticle adhesion. Fabrics coated with silver nanoparticles demonstrated antibacterial properties against Escherichia coli. Nanoparticle imaging and surface chemical characterization are performed using scanning electron microscopy and X-ray photoelectron spectroscopy.
The highlights of this research are as follows:
• high-speed synthesis and deposition of silver nanoparticles on fabrics;
• plasma coating onto fabrics with silver nanoparticles;
• antibacterial fabrics for potential use in healthcare environments.
In order to revise the problem of inferior hand-feeling of cashmere textile anti-filling finished with “addition” or “subtraction-addition” technology and indicate the effects of graphene distributed state in the surface on antistatic properties of cashmere fibers, A couple of flexible hydrophilic cationic polyurethanes used as a dispersion medium for graphene purposefully are designed and prepared. In addition, the state of polymer coating and graphene on the fiber is effectively controlled by foam micro-coating technology. The admirable pilling resistance, static resistance, and hand-feeling of cashmere textile attributed to two-layer polyurethane membranes realized through “bottom coating (BC)” and “surface coating (SC)” are definite and reliable. The results show that the cashmere textile obtained 1.0% (o.m.f. on mass of fabric) weight gain rate (WGR) under the foam bottom coating process, correspondingly, obtained 3–4% (o.m.f.) weight gain rate (WGR) under traditional dipping process, the pilling resistance grade of cashmere textile is improved to Grade 4–5 from Grade 1–2. The semi-embed state of graphene in the “surface coating” resin film on cashmere surface results in the decrease of static voltage half-life from 180 s to about 2 s. Clearly, the foam microcoating technology scheme of “BC+ SC@graphene” has achieved good expected results.
Les surfaces textiles sont les matériaux privilégiés pour la protection du combattant vis-à-vis d’un environnement chimique ou bactériologique contaminant. Le développement de surfaces textiles permettant d’empêcher la pénétration de liquide toxique sous forme de gouttelettes nécessite la conception de surfaces fibreuses amphiphobes. A ce jour, pour obtenir des propriétés oléophobes, il est commun d’utiliser industriellement des composés organofluorés dont le nombre de carbone perfluoré est de huit ou plus. Cependant ces substances sont depuis peu soumises à restriction du fait de leur bioaccumulation chez l’animal. Pour atteindre les propriétés amphiphobes recherchées en se limitant à de faibles longueurs de chaines fluorées, il est donc nécessaire de nano-structurer les surfaces. La technique d'électropolymérisation de monomères conducteurs en solvant organique est une méthode de choix pour la nano-structuration de surface.Dans cette thèse, plusieurs monomères conducteurs ont ainsi été électrodéposés et des stratégies mises en place pour contrôler la morphologie des dépôts et leurs propriétés de mouillabilité. Afin d’optimiser la création de structures à géométries réentrantes, la formation de nanostructures poreuses par électropolymérisation en milieu organique a particulièrement été étudiée. Le mécanisme proposé consiste en la création d'un support de déposition des polymères par auto-assemblage des monomères et électrolytes en micelles inverses. Ces résultats ont été mis à profit pour la nano-structuration de grilles en acier inoxydable. Les surfaces maillées modèles réalisées à partir de courtes chaînes perfluorées présentent des propriétés superhydrophobes et oléophobes. L'application sur des tissus nécessitait de les rendre conducteurs tout en maximisant l'adhérence entre la fibre et les revêtements. Pour cela, plusieurs techniques ont été utilisées, notamment la technologie plasma, mais l’électropolymérisation sur tissu n’a pas donné de résultat convainquant. Néanmoins, des textiles amphiphobes ont été obtenus suite au développement d’un revêtement fortement adhérent à la fibre textile par polymérisation induite par plasma de monomères conducteurs et aux nano-structurations réalisées par gravure plasma. Des nanoparticules de silice greffées ont enfin été ajoutées au revêtement textile, afin d'optimiser ses propriétés amphiphobes.
This research describes a novel method of finishing wool fabric in order to gain sound absorption and water resistance properties. In this study, the surface of samples was modified with plasma and then treated with silica nanospheres. Field emission scanning electron microscope and EDX analysis showed the morphology and present of nanoparticles, and elemental mapping proved the distribution of silica nanospheres without agglomeration. Impedance tube device was used to calculate the sound absorption, and the results showed excellent acoustical performance of prepared samples. However, the water resistance of samples was investigated and the specimens showed good resistance against water.
In this paper, untreated poultry feather (UPF) was used and highly split and hydrophilic poultry feathers were successfully prepared via chemical treatment and low temperature nitrogen plasma treatment. Then, the chemically treated poultry feather (CPF) and chemical-plasm-treated poultry feather (CPPF) were, respectively, used as shorted-fiber reinforcement for keratin composite films. The microscope images showed that CPF was highly splitted. The morphology, evaluated by scanning electron microscopy, indicated that plasma treatment increased the surface roughness of poultry feather. XPS test results showed that chemical treatment removed the biological wax layer on the feather surface, and after being treated by plasma, many functional groups containing N and O were introduced on the fiber surface. The results of wettability test showed that plasma treatment could greatly improve the hydrophilicity of feather fiber. The breaking strength and fracture images of the different kind of composite films, including non-fiber composite film, UPF composite film, CPF composite film and CPPF composite film, indicated that matrix could be better combined with highly bifurcated and hydrophilic poultry feather. The outcome obtained from this study is believed to assist the development of environmentally friendly composites from discarded feathers.
Sustainable’, ‘economical’, and ‘eco-friendly’ production has recently become important issues in textile manufacturing processes. In the world, textile conventional production industry is one of the major industries which cause environmental pollutions. During textile wet process, great deals of wastes are leaved in air, soil and, especially water. Due to these wastes, all species in the ecosystem are negatively affected. In order to manufacture a ton of textile, approximately 230–270 tons water is used. After the textile production, the water is undertaken with heavy chemicals and this waste water is leaved in environment. In textile production industry, there are two efficient methods to decrease the environmental pollution. Constructed of large and highly effective effluent treatment plants is a method to reduce the amount of wastes. The other method is the use of natural raw materials and ecological production methods. Recently, researchers have been seeking for ecological, sustainable, and biodegradable natural raw materials alternatively synthetic raw materials. Especially, natural textile raw materials have been begun to use acceleratingly in compration with synthetic raw materials in textile industry. Furthermore, new natural fibers have been obtained from different source and the use of these fibers has searched in textile industry. In textile wet process, especially, waste water with heavy chemicals load is a major problem. In order to eliminate the negative effect of waste water, researchers have been searching for solutions. In literature, coating, microencapsulation, plasma applications, using of ultrasonic and microwave energy, using of supercritical carbon dioxide and ozone treatment are described as some of the eco-friendly process in textile wet industry. In this study, some eco-friendly production methods in textile wet industry were investigated, separately. Furthermore, the advantages of new production methods were searched.
A simple and effective surface modification of polyester (PET) fabrics with H2SO4 (sulfuric acid) to improve the interfacial deposition of polypyrrole (PPy) on PET fabrics was presented in our work. Effects of H2SO4 concentration on hydrophilicity of PET fabrics were analyzed by water contact angle measurements. Effects of H2SO4 modification on deposition of PPy were investigated by electrical resistivity and color depth of fabrics measurements. Besides, the adhesion of PPy on PET fabrics was also discussed. The PPy-deposited PET fabrics were determined by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). FTIR and XPS results showed that sulfonic acid groups appeared on PET fibers after modification which were contributed to improving deposition of PPy on PET fabrics. The improved deposition increased electrical conductivity of fabrics.
Current research was carried out on hydrophilic wool fibers at three different humidity conditions through atmospheric pressure plasma jet (APPJ). Samples were taken to evaluate surface microscopic morphology, surface roughness, directional friction effect (DFE), and surface chemical composition. The scanning electron microscope (SEM) and fiber friction coefficient test (FFT) results show that wetting pretreatment has significant effect on surface etching and DFE, but very limited effect on surface roughness. Allwörden reaction and X-ray photoelectron spectroscopy (XPS) results reveal that extra moisture changes C, O, N, S contents and their related characteristic functional groups, therefore increases etching degree on wool fiber surface scales. It was concluded that APPJ treatment is effective in processing wool fiber with high moisture contents.
Vacuum radio frequency (RF) plasma treatment was conducted on electropolished and passivated 316 LVM stainless steel (SS) surface by using Ar and O2. Contact angle measurements revealed that both Ar and O2 plasma treatments significantly increased the wettability of the SS surface by water. The physical and chemical effects induced by Ar and O2 plasma on SS were investigated via Atomic Force Microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS). AFM analysis revealed that plasma process exerted similar effects on surface roughness and topography. Both Ar and O2 plasma treatments resulted in smoother surface when compared to reference electropolished sample. XPS investigations of the surfaces with respect to Fe2p, Cr2p, Mo3d and O1s XPS spectra showed that the main role of Ar plasma was thinning of the oxide-hydroxide layer along with the removal of contamination without any definitive difference on the valence states of metal compounds. On the other hand, O2 plasma treatment resulted in thickening of oxide layer along with oxidation of the species to their highest valence states (CrVI, FeIII and MoVI). After washing the plasma treated surfaces with water, contact angles for oxygen plasma treated samples increased dramatically indicating the substantial role of higher valent oxides on wetting process.
Polyaniline is a widely studied conducting polymer and is a useful material in its bulk and thin film form for many applications,
because of its excellent optical and electrical properties. Pristine and iodine doped polyaniline thin films were prepared
by a.c. and rf plasma polymerization techniques separately for the comparison of their optical and electrical properties.
Doping of iodine was effectedin situ. The structural properties of these films were evaluated by FTIR spectroscopy and the optical band gap was estimated from
UV-vis-NIR measurements. Comparative studies on the structural, optical and electrical properties of a.c. and rf polymerization
are presented here. It has been found that the optical band gap of the polyaniline thin films prepared by rf and a.c. plasma
polymerization techniques differ considerably and the band gap is further reduced byin situ doping of iodine. The electrical conductivity measurements on these films show a higher value of electrical conductivity
in the case of rf plasma polymerized thin films when compared to the a.c. plasma polymerized films. Also, it is found that
the iodine doping enhanced conductivity of the polymer thin films considerably. The results are compared and correlated and
have been explained with respect to the different structures adopted under these two preparation techniques.
Polymer materials, such as polymethylmethacrylate (PMMA), are widely used as insulators in vacuum. The insulating performance of a high-voltage vacuum system is mainly limited by surface flashover of the insulators rather than bulk breakdown. Non-thermal plasmas are an efficient method to modify the chemical and physical properties of polymer material surfaces, and enhance the surface insulating performance. In this letter, an atmospheric-pressure dielectric barrier discharge is used to treat the PMMA surface to improve the surface flashover strength in vacuum. Experimental results indicate that the plasma treatment method using Ar and CF4 (10:1) as the working gas can etch the PMMA surface, introduce fluoride groups to the surface, and then alter the surface characteristics of the PMMA. The increase in the surface roughness can introduce physical traps that can capture free electrons, and the fluorination can enhance the charge capturing ability. The increase in the surface roughness and the introduction of the fluoride groups can enhance the PMMA hydrophobic ability, improve the charge capturing ability, decrease the secondary electron emission yield, increase the surface resistance, and improve the surface flashover voltage in vacuum. (C) 2014 AIP Publishing LLC.
Poly 3,4-ethylenedioxythiophene (PEDOT) films were formed on Indium Tin Oxide (ITO)-coated glass by electrodeposition. Cyclic voltammetry, AFM and UV-Vis spectroscopy were employed to investigate the properties of the PEDOT films. Two different types of PEDOT films, i.e., (i) smooth and homogenous surface with pinnacle-like structure and (ii) rough and nonhomogenous with grain-like structure) were produced in two ways. These included varying deposition times and by applying different deposition potentials. The surface roughness of the PEDOT films increased with increasing deposition time and applied potential used. The smooth film prepared at +1.1 V for 15 s has good electrochromicc and optical properties. However, its stability over repetitive usage is inadequate and needs further improvement.
Electrospinning was used for the coating of the polyurethane/silica hybrid solutions on the cotton fabric surface. An ultraviolet curing process was performed on the collector by an ultraviolet lamp positioned inside the electrospinning cabin. In order to investigate the effect of fluorinated, silane-functionalized urethane (inorganic part) content on the water-repellency; five different fluorinated concentrations (10%, 20%, 30%, 40%, and 50% by weight) were used. The disappearance of isocyanate peaks during the silane-functionalized urethane synthesis was observed by Fourier transform infrared spectroscopy. Surface morphology and elemental analysis of the coated cotton fabric surfaces was investigated by scanning electron microscopy and energy dispersive spectroscopy analysis respectively. Water-repellency was evaluated by contact angle measurements. A sample that contained 50% inorganic part showed a contact angle of 154.5°. Samples were thermally characterized by differential scanning calorimetry. Glass transition temperature of the synthesized hybrid polymer increased with increasing inorganic part ratio. Additionally, abrasion resistance and crease recovery angle tests were performed to evaluate the effect of fluorinated part percentage on the mechanical and comfort properties of fabrics. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.
Iodide was investigated using poly(3,4-ethylenedioxythiophene)/glassy carbon electrode (PEDOT/GCE) as an monitoring tool. When this electrode was scanned to the positive potential (+0.7 V) in the presence of 610 -3 M, the redox couple was gradually separated into two redox couples involving the iodide/triiodide and triiodide/iodine redox processes due to the iodide doping behavior occurs easily with the sufficient positive potential and the higher iodide concentration. The I 2 -PEDOT may be the doping result and it lowers the activation energy of iodide redox processes. The PEDOT/GCE shows linear current response (I pa (mA) = 21.553[KI](M) + 8.2602, R 2 = 0.9995, S/N = 3) to iodide. Through the iodide mediator, PEDOT/GCE can determine As(III) with a sensitivity of 303.3 μA mM -1 cm -2 . Particularly, it can enhance the current response for As(III) by increasing the iodide molar ratio. The current ratio of I As(III) /I I -was about 1.66 amplification when molar ratio of n I -/n As(III) was 0.3.
Low-resistance and nonalloyed ohmic contacts to epitaxially grown n-ZnO were formed by exposing n-ZnO to an inductively coupled hydrogen and an argon plasma. Using Ti/Au, the specific contact resistivity of the ohmic contact was drastically decreased from 7.3×10−3 to 4.3×10−5 Ω cm2 by hydrogen plasma treatment. The photoluminescence spectrum of the hydrogen plasma treated ZnO showed a large enhancement in band-edge emission and a strong suppression in deep-level emission. These results suggest that the low contact resistivity can be attributed to an increase in carrier concentration on the ZnO surface. The specific contact resistivity of the Ar-plasma treated sample was also decreased to 5.0×10−4 Ω cm2, presumably due to the formation of shallow donor on the ZnO surface by ion bombardment. © 2001 American Institute of Physics.
Highly transparent (>80%) and conductive layers (10-6 S/cm) were obtained by the pulsed plasma polymerization of thiophene. The influence of power, pressure, pulse time, duty cycle, and position in the reactor on the conductivity of the resulting plasma polymerized thiophene (PPT) layers was evaluated. In the used ranges, only pressure had a significant influence on the conductivity of the deposited layer. The results could be correlated to the effect of the deposition parameters on the fragmentation of the thiophene monomer. At high pressure there was less fragmentation of thiophene, resulting in a higher conductivity of the layer. It was shown that the use of a pulsed plasma as a means to minimize fragmentation is most efficient when the off time is chosen such that the reactor is replenished with new monomer during the off period.
To make a fair comparison of the conductive properties of plasma polymerised thiophene (PPT) layers deposited under different conditions, optimal doping procedures should be applied. The iodine doping process of PPT layers deposited at high (HP) and low (LP) pressure has been studied in detail. Doping time, thickness, and exposure time to air before and after doping were varied. Iodine doping generates charge carriers by the formation of charge transfer (CT) complexes, which are in equilibrium with absorbed iodine. The conductivity of the LP-PPT layers decreases with increasing thickness due to (vacuum-) UV modification. Upon exposure to air before doping, LP-PPT layers loose their capability to form CT complexes, whereas HP-PPT layers do not. Consequently, the conductivity for LP-PPT layers exposed to air before doping decreases with exposure time. After iodine doping, a lower rate of oxidation upon exposure to air is observed compared with as deposited PPT layers. Furthermore, the conductivity decreases slowly due to diffusion of absorbed iodine out of the PPT layers. The conductivity of the HP-PPT layers increases faster with doping time and shows a higher stability towards exposure to air after doping than LP-PPT layers. Consequently, the optimal doping procedure may vary for PPT layers deposited under different conditions.
Pure and iodine-doped polyaniline thin films are prepared by ac plasma polymerization technique. Doping of iodine is carried out in situ as well as by employing iodine chamber methods. The structural analyses of pure and iodine-doped polyaniline thin films are carried out by FTIR spectroscopic studies. Optical bandgaps of these films are evaluated from UV-VIS absorption studies. Direct and indirect transition energy gaps are determined from Tauc plots. The structural changes of polyaniline upon doping and the reduction of optical bandgap are explained on the basis of the results obtained from FTIR spectroscopic and UV-VIS absorption studies.
Emeraldine base (EB) form of polyaniline (PANI) powder is prepared by chemical oxidative polymerization using different acidic media (HCl or CF3COOH) at different temperatures (-15°C to + 5°C). The chemical structure, thermal characterization and conducting behaviour are studied by means of Fourier transform infra-red (FTIR) spectroscopy, differential scanning calorimetery (DSC) and two-probe conductivity method. These polyanilines are soluble in N-methyl-2- pyrrolidone, dimethyl sulfoxide (DMSO) and dimethylpropylene urea (DMPU). The softening temperatures of different EB range from 87.8-116.4°C, which is believed to be an indication of cross-linking. Conductivity of emeraldine base of PANI is around (0.8-1.5) × 10-6 S/cm and energy band gap is approximately 0.5 eV, and no detectable crystallinity is observed. Wide-angle XRD technique indicates that PANI- EB base is amorphous in nature.
Nanotechnology has become the focus of research for many applications. In the field of electrochromism, nanomaterials have been widely studied providing physical and chemical properties to ensure short response times and fast charge compensation during the redox process leading to high performing electrochromic devices. Different syntheses of nanomaterials have been reported both to inorganic and organic materials. The preparation of inorganic nanoparticles such as nickel hydroxide, nickel oxide, Prussian blue, tungsten oxide and niobium oxide were reported. Some examples of the use of these nanoparticles in electrochromic applications can be found. Moreover, for organics materials, it is possible to find examples with conducting polymers and viologens. The layer-by-layer technique was presented as an interesting way to produce different architectures for electrochromic applications. The development of reliable, low cost methodologies for the immobilization of nanomaterials is required. The chapter discuss comparatively with LbL other interesting type of film formation: Electrophoretic Deposition (EPD), that can be achieved by the motion of charged particles towards an opposite charged surface due an external applied electric field, where parameters such as deposition time, distance between electrodes and applied potential can be easily controlled in order to obtain different morphologies and thicknesses. The films formation and performance of them will be compared since these two different methods for the immobilization of nanoparticles aiming electrochromic electrodes have been reported. An electrostatic layer-by-layer deposition technique is limited due to the lack of electrical connectivity and low ionic diffusion between layers, leading to an irreversible behavior and higher response times, while an electrophoretic deposition technique opens new opportunities of studies in this area overcoming these problems. Thicker films with fast switching times and high durability and reproducibility were obtained.
Knit polyester fabric was successively modified and decorated with chitosan layer and polyaniline polymer nanocomposite layer in this paper. The fabric was firstly treated with chitosan to form a stable layer through the pad-dry-cure process, and then the polyaniline polymer nanocomposite layer was established on the outer layer by in situ chemical polymerization method using ammonium persulfate as oxidant and chlorhydric acid as dopant. The surface morphology of coated fabric was characterized by scanning electron microscopy (SEM), and the co-existence of chitosan layer and granular polyaniline polymer nanocomposite was confirmed and well dispersed on the fabric surface. The resultant fabric was endowed with remarkable electrical conductivity properties and efficient water-repellent capability, which also have been found stable after water laundering. In addition, the photocatalytic decomposition activity for reactive red dye was observed when the multifunctional knit polyester fabric was exposed to the illumination of ultraviolet lamp. These results indicated that chitosan and polyaniline polymer nanocomposite could form ideal multifunctional coatings on the surface of knit polyester fabric.
Atmospheric pressure plasma deposition is a beneficial technology due to its low cost and flexibility in terms of its operation and integration for in-line processing. This paper presents the use of an atmospheric pressure dielectric barrier discharge (DBD) to deposit an amine functional polymer film onto the inner surface of a glass microcapillary. A micro discharge was generated in a DBD chip made from a rectangular borosilicate glass capillary using externally attached parallel plate electrodes. A new microplasma configuration which consists of a perforated high voltage electrode and a ground electrode with large surface area is implemented to sustain a stable glow discharge at atmospheric pressure and a temperature of 35 °C. Polymerization was performed using a laboratory made plasma source working at a frequency of 8 kHz with 50% duty ratio of the inverter. The monomer precursors allylamine and ethylenediamine were selected to optimize the polymerization conditions at atmospheric pressure. The hydrophobicity and philicity of the deposited surface were controlled as functions of plasma power. The atmospheric pressure plasma polymerized (APPP) films were characterized using Fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM), plasma emission spectroscopy, contact angle measurements and growth rate analysis. An average growth rate of 1.18 μg s− 1 for plasma polymerized ethylenediamine (PPEDA) and 1.91 μg s− 1 for plasma polymerized allylamine (PPAA) was obtained at a discharge power of 15 W and 10 sccm of monomer flow rate. The film thickness of 0.9 μm for PPEDA and 2.1 μm for PPAA was determined using AFM for deposition time of 10 min. Polymerization results showed that the properties of APPP films can be controlled through optimization of parameters such as discharge power, treatment time and flow rates of the main gas and monomer vapors.
Electrochromic (EC) properties of tungsten trioxide (WO3) was improved with preparing hybrids of tungsten trioxide-titanium dioxide (WO3–TiO2) and tungsten trioxide-poly(3,4 ethylenedioxythiophene) (WO3–PEDOT) by a rotating capacitively coupled radio-frequency (RF: 13.56 MHz) plasma reactor. Energy-dispersive x-ray spectroscopy mapping results indicated that TiO2 and PEDOT were coated homogenously onto the surface of the WO3 powders. Thin films of hybrid powders have been prepared by the physical vapor deposition method of electron beam evaporation technique. Redox potentials, optical contrast at 700 nm and durability during 2000 cycles of EC devices were investigated, comparatively. Hybrids of WO3 indicated excellent coloration efficiency (cm2 C-1) and switching speed values than untreated WO3. The coloration efficiency values were found to be 85.88 cm2 C-1 and 41.61 cm2 C-1 of WO3–TiO2 and WO3–PEDOT, respectively. Switching speed of WO3 (13.3 s, from bleached state to colored state) increased to 1.4 s for WO3–TiO2.
In this study, corona plasma discharge was applied to desize polyvinyl alcohol (PVA) and starch on cotton fabrics. Plasma treated and non-treated samples were processed in various steps in a textile firm. The samples were tested to evaluate their weight loss, size dissolution, capillarity, dyeability, pilling resistance and strength values. The surface morphology and the chemical structures were examined by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscopy analyses. The experimental results showed that the plasma has positive effects on size removal, hydrophility and the pilling values of the PVA and also starch sized fabrics.
Poly(3,4-ethylenedioxythiophene)/titanium dioxide (PEDOT/TiO2) nanocomposites and poly(3,4-ethylenedioxythiophene) (PEDOT) homopolymers were synthesized chemically in the presence of anionic (sodium dodecylsulfate, SDS) and cationic (tetradecyltrimethylammoniumbromide, TTAB) surfactants. The effect of surfactant on structural and morphological properties of the nanocomposites was investigated using UV–vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), four-probe conductivity measurements and X-ray photoelectron spectroscopy (XPS) measurements. It was observed from SEM study that the nanocomposites show globular particle structure with different particle size. The PEDOT/TiO2 nanocomposite has higher conductivity than that of pure PEDOT homopolymer. The presence of surfactant during PEDOT/TiO2 nanocomposites synthesis influenced thermal stability of the prepared samples.
Dielectric barrier discharge (DBD) can modify the material surface and result in complicated physical and chemical reactions to improve the surface hydrophilicity, which is proved to be an effective method for surface modification. Compared with the traditional ac-excitation DBD, the DBD using unipolar pulses can avoid local overheat of microdischarges and can improve discharge efficiency under some conditions. In this paper, DBD excited by repetitive unipolar nanosecond generator was used to improve the hydrophobicity of Plexiglass (PMMA) surface by means of the interaction between air plasma and silicone oil. The output voltage had a rise time of 40 ns and a full width at half maximum of about 70 ns. The surface hydrophobicity of the PMMA, before and after the surface modification, was evaluated via the contact angle measurement under different experimental conditions. The values of the contact angle shown in this paper were the average of eight measured values, and the standard deviations were also calculated. The surface energy including polar and dispersion components was calculated using the measured average contact angles of distilled water and polyethyleneglycol. The results showed that, as the increase of the discharge voltage, the contact angle increased but the surface energy decreased. With the increase of treatment time, the water contact angle of the modified surface increased at the beginning, and it would reach to a maximum at 7.5 min treatment, and then decreased. The effect of pulse frequency on the modification results was different at various treatment times. In addition, the possible physical and chemical reaction among the DBD plasma, silicone oil and the PMMA surface was discussed.
Polyaniline coated conducting fabrics have been obtained by chemical oxidation of aniline by potassium peroxydisulfate on polyester fabrics. Two different acids have been employed to carry out the synthesis (HCl and H2SO4), obtaining the best results of conductivity with the latter one. The conducting fabrics have been characterized chemically by means of Fourier transform infrared spectroscopy with attenuated total reflection (FTIR-ATR), energy dispersive X-Ray (EDX) and X-ray photoelectron spectroscopy (XPS). The morphology of the coatings has been observed by means of scanning electron microscopy (SEM). The conducting properties of the fabrics have been measured by means of electrochemical impedance spectroscopy (EIS). The electrochemical characterization has been carried out by means of cyclic voltammetry (CV) and scanning electrochemical microscopy (SECM). The conducting fabrics have also shown electrochromic properties, changing its color from green yellowish at −1V to dark green at +2V. The durability of the coating has been evaluated by means of washing and rubbing fastness tests.
A non-thermal, high density atmospheric plasma glow discharge treatment was used to impart functionality to cotton/polyethylene terephthalate (PET) fabric to furnish a surface that is water repellent and then antimicrobial only.In this work, cotton/PET (50/50%) blend fabric was treated with a water repellent treatment through activating the surface with plasma, depositing a vaporized fluorocarbon based monomers, 1,1,2,2-tetrahydroperfluorodecyl acrylate (THPFDA) and 1,1,2,2-tetrahydroperfluorododecyl acrylate (THPFDDA), then graft polymerizing the monomer with a second plasma exposure. Samples were then further treated with an antimicrobial agent, diallyldimethylammonium chloride (DADMAC), a quaternary ammonium salt. Plasma treatment was used to induce free radical chain polymerization of the DADMAC, conferring a graft polymerized network on the fabric with potentially durable antimicrobial properties.It was shown that the water repellent treatment via plasma induced-graft polymerization was successful in yielding a highly hydrophobic fabric with a finish durable to laundering.The results of the antimicrobial tests showed that the treated fabric reduced the activity of both gram positive and gram negative bacteria by more than 99.994%, demonstrating that the antimicrobial agent can function effectively on the water repellent treated fabric. However, despite the evidence of the presence of fluorine containing compounds on the fabric following the antimicrobial treatment, which was confirmed by time-of-flight secondary ion mass spectrometry (TOF-SIMS) analysis, the water repellency was lost, which was attributed to changes in the orientation of the fluorocarbon polymer chains.
A microwave (MW) plasma reactor for the synthesis of polythiophene (PTh) thin films as well as in situ doping during polymerization process has been designed and assembled. Plasma polymerization parameters were studied. A good MW power was found to be in the range of 150-250W. PTh films were characterized by various spectrophotometric methods. IR analyses showed absorption frequencies of important functional groups. PTh films exhibited UV-Vis spectra indicative of increased conjugative systems as the MW power increased although at 300 and 380W partial fragmentation was evident. Surface analysis by SEM revealed a uniformly deposited film morphology. EDS results were also suggestive of partial fragmentation of the films at high MW powers. Preliminary conductive measurements revealed that the undoped films exhibit higher conductivity (3 to 9×10-5 s.cm-1) than PTh typically prepared from electrochemical methods.
An alternating current induced plasma generating assembly was constructed for simultaneous polymerization and doping of pyrrole with iodine. Thin films (0.3–2.7µm) of 50HzAC-plasma polymerized polypyrrole and iodine-doped plasma polymerized polypyrrole were synthesized at 800–1500V at an optimized reaction time of 30min. The films were subsequently characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, and ultraviolet-visible spectrophotometry. Electrical conductivities of the films were measured by a two-point probe technique. Infrared spectroscopic analysis shows mainly characteristic polypyrrole peaks with some evidence that pyrrole rings may have been broken by the applied plasma discharge energy. This may have resulted in the loss of a small amount of nitrogen atoms from the rings as evidenced by a slightly lower nitrogen composition. The conductivity of the iodine-doped plasma-polymerized polypyrrole films is in the range of 10−6 to 10−7S/cm. This is approximately 1 order of magnitude higher than those of undoped films from AC-plasma polymerization measured for comparison. Thorough analysis and discussion on the synthesis and properties of PPPy and PPPy/I2 is presented.
Characteristics of nanocomposite films synthesized and deposited by atmospheric pressure Radio-Frequency (RF) (13.56 MHz) uniform glow discharge are examined. The nanocomposite thin film deposition is carried out in the presence of titanium dioxide (TiO2) with polymerization of pyrrole, thiophene and furan monomers in acetonitrile medium containing lithium perchlorate (LiClO4). The chemical, morphological, thermal and electrical characteristics of polypyrrole/TiO2 (PPy/TiO2), polythiophene/TiO2 (PT/TiO2) and polyfuran/TiO2 (PF/TiO2) composites are examined by FTIR spectroscopy, scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX), atomic force microscopy (AFM), thermogravimetry (TGA) and four-probe conductivity measurements. The presence of PT bands in the FTIR spectra of PT/TiO2 indicates that plasma polymerization did not cause thiophene ring opening as was reported in the literature. The thermograms indicate that the PPy/TiO2 composite has the best thermal stability, whereas PT/TiO2 has the best electrical conductivity. Morphology studies reveal that the composite film deposition occurs uniformly through polymerization of the monomer onto TiO2 nanoparticles.
(Si : Ox : Cy : Hz) thin films were deposited on knitted wool fabrics by plasma-enhanced chemical-vapor deposition using hexamethyldisiloxane as a monomer and argon and oxygen as feed gases in low-pressure equipment. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses confirmed the presence of the siloxane coating. The pilling tendency of treated samples was investigated for different deposition powers, ranging from 30 to 50 W. A reduction on pill formation was observed for all treated samples. A silicone-based wet chemical treatment was taken as the reference method for pilling reduction and plasma treatments were compared with it. The pilling grade of treated fabrics was also tested after washing and the results confirmed a good pilling behavior of plasma-treated fabrics. Changes were observed in the bursting resistance of plasma-treated wool samples compared with untreated ones, while no significant differences were found in the whiteness index.
Polyester fabrics were subjected to low temperature plasma (LTP) exposure. The anti-static behaviours of the plasma treated fabric were greatly improved. The discharge power of 50 V and the electrode gap of 4 mm were recommended for an optimum result. Acrylic acid treatment further enhanced the anti-static properties of the specimens. Influences of the acid concentration, the treating duration and the temperate during the acrylic acid treatment on the anti-static properties of the fabric were revealed.
Two methods of obtaining electrically conductive fabrics by in situ polymerization of aniline were compared. Conductive fabrics were prepared by immersing the nylon 6 fabrics in 100% aniline or an aqueous hydrochloride solution of aniline followed by initiating successive polymerization in a separate bath (DPSB) or in a mixed bath (DPMB) of oxidant and dopant solution with aniline. In each case, the polymerization conditions were optimized to obtain the maximum quality of polyaniline (PAn) on the fabrics. The higher conductivity of composite fabrics, whose value reached up to 0.6 × 10−1 s/cm, was obtained by the DPMB process. Moreover, this method induced the least decrease in the degree of crystallinity as compared to the DPSB process. The serviceability of the PAn–nylon 6 composite fabrics was also evaluated. No significant changes in the conductivity were observed after abrading the composite fabrics over 50 cycles and multiple acid and alkali treatment. The stability of conductivity was slightly decreased by less than 1 order after exposure to light for 100 h, but it was significantly decreased after washing with detergent. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2094–2101, 1999
Intensive development work on organic conductors has been carried out world wide. It is only recently that the problem of how to process these conductive materials has been solved. This technology breakthrough led to the first practical applications. Organic conductive material development is briefly reviewed. The PEDT polymer properties of conductivity, stability and processability are described. PEDT's synthesis and the importance of its processability leading to the first practical applications in antistatic use, capacitor design, and printed circuit board are discussed.
The atmospheric pressure radiofrequency (RF) plasma polymerization of furan was carried out with the objective of synthesizing polyfuran thin film. The structure, compositions and morphology of the plasma deposited polyfuran film were investigated by Fourier transform infrared (FTIR), atomic force microscopy (AFM), ultraviolet‐visible absorption spectroscopy (UV‐vis) and thermogravimetric analysis (TGA). The formation of polyfuran was confirmed using FTIR and UV‐visible analysis. The properties of plasma‐deposited polyfuran were compared with those of chemically synthesized polyfuran. Although the plasma deposited thin film polyfuran shows lower thermal stability than that of chemically synthesized polyfuran. It has better solubility in CHCl3, also. Thin uniform polyfuran films are obtained in plasma assisted polyfuran deposition, while particles are obtained in chemical polyfuran polymerization.
A general mechanism for the plasma polymerization of unsaturated hydrocarbon monomers in a flow reactor has been developed. Polymerization is postulated to occur via free-radical intermediates, formed as a result of electron-monomer collisions in the plasma. Material balances relating monomer and radical concentrations to reactor axial position were solved and used to predict the polymerization rate. By adjusting the magnitudes of the rate coefficients appearing in the model, good agreement was obtained between polymerization rates predicted by the model and those measured experimentally for a variety of unsaturated monomers. The magnitudes of the fitted rate coefficients describing the initiation of polymerization and gas phase oligomerization were found to be in good quantitative agreement with independently observed rated coefficients. Variations in the fitted rate coefficients with changes in polymerization conditions followed trends anticipated on the basis of elementary discharge physics.
Permanent fixation of chitosan or monochlorotriazinyl-β-cyclodextrin (MCT-β-CD) onto cotton/polyester and polyester fabrics was carried out and all parameters controlling the efficiency of both fixation reactions were studied. The amounts of MCT-β-CD or chitosan fixed onto the treated fabrics were estimated in terms of percent nitrogen content. Results obtained reveal that finishing the said fabrics with either MCT-β-CD or chitosan generally improves the water uptake capacity of the finished fabrics without harmful effect on their physico-mechanical properties. The water uptake capacities of MCT-β-CD finished fabrics were found to be higher than the corresponding values recorded for chitosan finished fabrics. The general improvement in water uptake of the finished fabrics is attributed to the hydroxyl groups introduced to the fabric structure through finishing with either MCT-β-CD or chitosan, which increase the fabric's ability to absorb more water and moisture from air. The presence of more water in such fabrics increases their electrical conductivity and thus improving their antistatic properties.
Doped and de-doped nanotubes and nanowires of polypyrrole, polyaniline, and poly(3,4-ethylenedioxythiophene) were synthesized by the electrochemical polymerization method, using Al 2 O 3 nanoporous templates. The electrical and optical properties of the nanotubes and nanowires were controlled through various synthetic conditions, such as doping level, dopant, and template-dissolving solvents. The diameters and wall thicknesses of the nanotubes were 100–200 nm and 10–30 nm, respectively. To determine the electrical and optical properties of the nano-systems, I–V characteristic curves with gate bias, dc conductivity, and UV–vis spectra were measured. We observed that the nano-systems were transformed from a conducting state to a semiconducting (or insulating) state through the process of de-doping using the template-dissolving solvents. Possible applications of these nanotubes and nanowires in the construction of nanotip emitters in field emission displays and polymer-based transistors are presented.
The effect of plasma treatment on the surface characteristics and conductivity of polyaniline–nylon 6 composite fabrics was investigated. Plasma surface modifications with oxygen, ammonia, and argon were performed on the nylon 6 fabrics to improve the adhesion and rate of polymerization. The surface morphology of the fiber was observed with scanning electron microscopy, and functional groups introduced onto the surface of nylon 6 fibers by various plasma treatments were characterized by X-ray photoelectron spectroscopy. With oxygen plasma treatment, the fiber surface was effectively etched; polar groups such as OH and OOH were introduced onto the surface of nylon 6 fiber, and they increased surface activity, promoted oxidation polymerization, and resulted in higher add-on and electrical conductivity. However, the introduced amine and amide groups with ammonia treatment caused a reduction in conductivity. Argon did not significantly alter the surface characteristics of the nylon 6 fibers. In addition, to control fabric conductivity and cover as wide a range of conductivity as possible, we observed the effects of the monomer concentration and number of deposits on the fabric conductivity. The results showed that fabric conductivity increased as the monomer concentration increased up to 0.5M and then leveled off, and further increases were achieved with an increase in the number of multiple deposits. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 684–694, 2001
Plasma deposition of conjugated polymer films under atmospheric pressure is described. Three thiophene derivatives (thiophene, 3-methylthiophene, and 3,4-ethylenedioxythiophene) are used as monomers. The plasma depositions with the various precursors are compared using analytical techniques such as X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, UV-vis spectroscopy, and resistance measurements. Good results are obtained with pulsed plasma depositions of poly(3,4-ethylenedioxythiophene). Conductivities of up to 1 × 10—2 S cm–1 are measured.
Plasma treatment of polymers is gaining more and more popularity as a surface modification technique, since it offers numerous advantages over the conventional chemical processes. Plasma surface treatment is an environmentally benign, fast and versatile technology. However, it has one major disadvantage: the induced modification of the surface is not permanent, since the surface tends to recover to the untreated state. This ageing effect is due to the reorientation of induced polar chemical groups into the bulk of the material. In this paper, the ageing of polypropylene (PP) and polyethylene terephthalate (PET) films, treated with a dielectric barrier discharge operating at medium pressure (5.0 kPa) in air, helium and argon, is studied. This study is performed using contact angle measurements and X-ray photoelectron spectroscopy (XPS). Results show that the working gas used during plasma treatment has a significant influence on the ageing behaviour of both PP and PET films. The air-, helium- and argon-plasma treated PP films have a loss in treatment efficiency of 47%, 35% and 25% respectively, while the air-, helium- and argon-plasma treated PET films have a loss in treatment efficiency of 39%, 34% and 29% respectively. These results can be explained by the different cross-linking degrees of the polymer films after plasma treatment. Increasing the cross-linking degree will hinder the movement of the polymer chains and reduce the ageing effect.
The use of an atmospheric pressure glow discharge (APGD) plasma was used at Kennedy Space Center (KSC) to increase the hydrophilicity of spaceport materials to enhance their surface charge dissipation and prevent possible electrostatic discharge (ESD) in spaceport operations. Significant decreases in charge decay times were observed after tribocharging the materials using the standard KSC tribocharging test. The polarity and amount of charge transferred was dependant upon the effective work function differences between the respective materials. In this study, PE and PTFE were exposed to a He+O2 APGD. The pre and post-treatment surface chemistries were analyzed by X-ray photoelectron spectroscopy and contact angle measurements. Semi-empirical and ab initio calculations were performed to correlate the experimental results with some plausible molecular and electronic structure features of the oxidation process. For the PE, significant surface oxidation was observed, as indicated by XPS showing C–O, CO, and O–CO bonding, and a decrease in the surface contact angle from 98.9° to 61.2°. For the PTFE, no C–O bonding appeared and the surface contact angle increased indicating the APGD only succeeded in cleaning the PTFE surface without affecting the surface structure.The calculations using the Parametric Method 3 (PM3) and Density Function Theory (DFT) methods were performed on single and multiple oligomers to simulate a wide variety of oxidation scenarios. Calculated work function results suggest that regardless of oxidation mechanism, e.g. –OH, O or a combination thereof, the experimentally observed levels of surface oxidation are unlikely to lead to a significant change in the electronic structure of PE and that its increased hydrophilic properties are the primary reason for the observed changes in its electrostatic behavior. The calculations for PTFE argue strongly against significant oxidation of that material, as confirmed by the XPS results.
The polymers PET, PA6, PVDF, HD-PE, and PP are activated by a commercially available plasma jet system at atmospheric pressure to improve adhesive bondability. The adhesion properties of the activated surfaces are evaluated by lap shear tests. The results are correlated with the surface properties that are investigated by XPS, AFM, and contact angle measurements. In addition the influence of operational parameters of the plasma treatment is studied. The activated samples exhibit a substantially increased bonding strength. The improvement can be related to an increase of oxygen concentration, and to changes of the topology of the substrate surface induced by the thermal component of the plasma. The most influential parameters in the plasma treatment are the distance between substrate and nozzle exit and the treatment time.
Due to its environmental stability, high degree of processability and interesting redox properties associated with its chain heteroatom, polyaniline (PANi) has been one of the most extensively studied electroactive (conductive) polymers during the past ten years. A number of fine reviews on the synthesis, physicochemical and electrochemical properties of the polymer have also appeared during this period. The ability of aniline polymers to exist in a large number of intrinsic redox states makes them a unique and interesting class of polymeric materials. The present review attempts for the first time to summarize the explicit and quantitative dealings with the various intrinsic oxidation states of PANi and its derivatives that have been made during the past decade.
DBD-induced surface modification is very versatile to increase the adhesion or hydrophilicity of polymer films. In this paper, the DBD is produced by repetitive unipolar nanosecond pulses with a rise time of 15 ns and a full width at half maximum of about 30 ns. The power densities of the homogeneous and filamentary DBDs during plasma treatment are 158 and 192 mW/m2, respectively, which are significantly less than that using ac DBD processing, and the corresponding plasma dose is also mild compared to AC DBD treatment. Surface treatment of polyimide films using the homogeneous and filamentary DBDs is studied and compared. The change of chemical and physical modification of the surface before and after plasma processing has been evaluated. It can be found that both surface morphology and chemical composition are modified, and the modification includes the rise of hydrophilicity, surface oxidation and the enhancement of surface roughness. Furthermore, the homogeneous DBD is more effective for surface processing than the filamentary DBD, which can be attributed to the fact that the homogeneous DBD can modify the surface more uniformly and introduce more polar functional groups.
Without any preprocessing, polyester fabric has lower ability to hold on water due to the smooth morphology and chemistry property of polyester fibers. Therefore, patterns directly printed with pigment inks have poor color yields and easily bleed. In this paper, atmospheric pressure plasma was used to pretreat polyester fabric in order to provide an active surface for the inkjet printing. The results showed that surface-modified polyester fabrics could obtain the effects of features with enhanced color yields and excellent pattern sharpness. SEM images indicated that the rough surface of plasma treated fibers could provide more capacities for the fabric to capture inks and also facilitate the penetration of colorant particles into the polyester fabric. XPS analysis revealed that air + 50%Ar plasma introduced more oxygen-containing groups onto the fabric surface than air plasma. Although AFM images indicated that etching effects generated by air plasma treatments were more evident, the air/Ar plasma treated sample has higher K/S value and better color performance. These studies have also shown that the chemical modification of plasma appears to be relatively more significant for improving the effect of inkjet printing.
The increase in the interaction between man and machine has made display devices indispensable for visual communication. The information which is to be communicated from a machine can be often in the form of color images. Electrochromic display device (ECD) is one of the most powerful candidate for this purpose and has various merits such as multicolor, high contrast, optical memory, and no visual dependence on viewing angle. A large number of electrochromic materials are available from almost all branches of synthetic chemistry. In this review, we have tried to describe the fundamentals of such electrochromic materials and their use in EDDs. The most important examples from major classes of electrochromic materials namely transition metal oxides, Prussian blue, phthalocyanines, viologens, fullerenes, dyes and conducting polymers (including gels) are described. Examples of their use in both prototype and commercial electrochromic devices are given.
Pyrrole and thiophene polymers prepared via chemical means or plasma polymerization at different radio frequency (RF) power input on different substrates were compared using X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy and UV–visible absorption spectroscopy. These polymers were deposited as thin films on either low-density polyethylene (LDPE) or LDPE surface graft copolymerized with acrylic acid (AAc). The results indicate that the structures of plasma polymerized pyrrole and thiophene are rather different from those of polymers synthesized by conventional chemical methods, due to a higher degree of crosslinking and branching reactions in plasma polymerization. A higher and more stable conductivity can be obtained with chemically synthesized polypyrrole and polythiophene, but the thin films generated from the plasma polymerization process are much smoother and more uniform. The lack of stability in the plasma polymerized samples’ conductivity may be due to the unstable nature of the charge transfer complex with the dopant (iodine) resulting in a greater ease of diffusion of the iodine from the film. Under the conditions tested, the thickness of plasma polymerized pyrrole and thiophene thin layers increases almost linearly with the RF power. The modification of the LDPE substrates using AAc-graft copolymerization can enhance the growth and adhesion of the thin film and its conductivity.
The radio-frequency-induced plasma polymerization of allylamine has been investigated in the plasma-gas phase by mass spectrometry and at the plasma-solid interface by means of an ion flux probe and a quartz mass balance. The surface chemistry of the deposits has been determined by X-ray photoelectron spectroscopy. The objective of this study was to unravel the mechanism(s) by which allylamine plasma polymers form. The results are compared with those obtained in an earlier investigation of the plasma polymerization of acrylic acid. In the plasma-gas phase, evidence is provided for reactions between cations and intact neutral monomers (allylamine). These oligomerization reactions were found to be relatively power-insensitive compared with those seen in plasmas of acrylic acid, as was the gas-phase concentration of the intact neutral monomer. At the polymer surface, ion fluxes were found to increase with plasma input power (P) from 6.6 × 1016 ions m-2 s-1 at 1 W to 1.4 × 1018 ions m-2 s-1 at 14 W. The ionic mass transport to the polymer surface (ion mass flux) was calculated by multiplying the measured ion flux by the average ion mass (determined by mass spectrometry). At P = 1 W, the ion mass flux was 11.7 m m-2 s-1, and at 14 W, the ion mass flux was 226.6 m m-2 s-1. These values differed from the total mass deposition rates measured by the quartz mass balance, which were 18.7 and 127.1 m m-2 s-1, respectively. However, the relationship found between the ion mass flux, the mass deposition rate, and P was complex, and it is shown that, at very low P (<1 W), the ion mass flux is sufficient to account for all of the deposit.
- M Kiristi
- F Bozduman
- A Uygun
- L Oksuz
- A Oksuz
- Hala
M. Kiristi, F. Bozduman, A. Uygun Oksuz, L. Oksuz, A. Hala, Solid state electrochromic devices of plasma modified WO3 hybrids, Ind. Eng. Chem. Res. 53
(2014) 15917e15922.
- E Eren
E. Eren et al. / Journal of Electrostatics 77 (2015) 69e75
- M Kiristi
- F Bozduman
- A Uygun Oksuz
- L Oksuz
- A Hala
M. Kiristi, F. Bozduman, A. Uygun Oksuz, L. Oksuz, A. Hala, Solid state electrochromic devices of plasma modified WO3 hybrids, Ind. Eng. Chem. Res. 53
(2014) 15917e15922.