Silver Plating Research Articles

Preparation of Silver-Plated Para-Aramid Fiber by Employing Low-Temperature Oxygen Plasma Treatment and Dopamine Functionalization

Direct electroless silver plating of para-aramid (PPTA) is difficult due to its extremely low surface chemical energy. In order to facilitate the deposition of silver nanoparticles and to enhance the washing fastness, oxygen plasma treatment and dopamine modification were conducted before silver plating of PPTA fibers. Various techniques including scanning electron microscopy (SEM), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffractometer (XRD) and thermogravimetric analyzer (TGA) were used to characterize the surface morphology, chemical composition and thermal stability of the silver-plated PPTA fibers. Electrical resistance and silver content of the silver-coated PPTA fibers before and after standard washing were also studied. The results showed that silver nanoparticles were successfully coated onto the surface of PPTA fibers with and without plasma treatment, but the coating continuity and the electrical conductivity of the silver-coated PPTA fibers were greatly enhanced with the assistance of plasma treatment. It was also demonstrated that the washing fastness of silver-coated PPTA fibers was improved after plasma treatment as indicated by electrical resistance and continuity of the silver nanoparticles after various washing cycles. It was found that the electrical resistance of plasma-treated PPTA-PDA/Ag fibers prepared at an AgNO3 concentration of 20 g/L reached 0.89 Ω/cm and increased slightly to 0.94 Ω/cm after 10 standard washing cycles. The silver-coated PPTA fibers also showed stable electrical conductivity under 250 repeated stretching-releasing cycles at a strain of 3%.

A wearable, anti-bacterial strain sensor prepared by silver plated cotton/spandex blended fabric for human motion monitoring

The development of flexible wearable signal monitoring system is an important subject in medical, robotic skin, and smart electronic products. However, the desirable performance and easy-to-produce requirement of strain sensors are difficult to strike a balance. In this paper, we propose to fabricate a sensor based on cotton/spandex blended fabric by electroless silver plating. The resultant fabric has high sensitivity with the gauge factor (GF) 26.11 and robust electrical conductivity 15.7 S/·m, while retaining flexible properties, indicating good potential of the silver-plated fabrics to be used as strain sensing materials. Additionally, because of the silver layer, the fabric also has good anti-bacterial property. Based on the results of a series of performance tests, we find it exhibits regular resistance changes used for human monitoring and can monitor small external deformations with a response time of 0.04 s. Therefore, it can be confirmed that the wearable anti-bacterial strain sensor prepared by means of silver-plated cotton/spandex blended fabric has a good potential prospect in wearable textiles fields.

Optimizing Electrochemical Thermal Control Devices: Investigating the Effect of Water Contamination on Reversible Silver Thin-Film Plating

Reversible Electrochemical Mirror (REM) technology describes a variable emissivity system that can switch between reflective and transmissive states through the application of a voltage to electrodeposit and remove a reflective mirror film. Such a system is an ideal replacement for traditional thermal control methods in space (louvres and radiators), because it is lighter, has no moving parts, and offers a finer degree of tunability. We have investigated various silver-plating systems that achieve this switching effect, including (1) AgNO3 in DMSO solvent, as well as (2) AgI and LiBr salts in γ-Butyrolactone. The effect of water contamination on these systems was determined, and the subsequent enhancement or degradation of the system quantified. While silver nucleation occurs more readily in water-contaminated systems, the presence of water may be detrimental to the stability and reversibility of the system such as more ready oxidation of the deposited film. For the DMSO/AgNO3 system, the addition of water also results in an increase in current during deposition (Figure 1). This is hypothesized to be a result of easier dissociation of AgNO3 in the presence of water which leads to greater silver ion conductivity. Thin film growth will be carried out on various substrates (indium tin oxide (ITO), silver, and gold) to determine the ways in which small amounts of water contamination affect the microstructure, optical reflectivity, reversibility, and stability of the system. Figure 1: Silver plating at -0.05 V in DMSO/AgNO3 systems (WE: ITO, CE: ITO, RE: Ag/AgNO3/0.1M AgNO3 in DMSO) with various amounts of water-doping. As the concentration of water increases, current increases. Figure 1

Silver Plating Applications and Technology Trends

Silver Plating Applications and Technology Trends

‘Sasanian’ silver plate from al-Ṣabāḥ Collection in light of aesthetic features of Sasanian toreutics

Recently published silver plate from al-Sabah Collection, of unknown provenance, has been firmly attributed as Sasanian. In fact, technically, it is related to the Sasanian silverwork however aesthetic examination allows to raise the doubts whether it is genuine. The plate must be compared not only with central-Sasanian artworks but all ancient ‘Oriental silver’, including pieces attributed as Hephtalite or Sogdian. The design of the plate does not have any relation with any of the known examples of late antique oriental toreutics. Central scene of heroic combat with powerful beast or beasts has never been surrounded with the ring containing other hunting scenes is unknown as well. The disbalanced decorum is even more clear when we remind that the central scene shows hunting on foot and the marginal ones – mounted. The details of fixed aesthetic elements – position of personages, beasts, weapons do not belong to Sasanian canon. The unique nature of the plate might result from many factors but the combination of unknown provenance and lack of relation to legitimate Sasanian canon require utmost cautiousness towards the object.

Facile synthesis of Au-Ag core shell and nanoalloy using femtosecond laser ablation and their optical characterization

We report a facile method for the synthesis of Au-Ag core shell and nanoalloy using femtosecond laser ablation. The method utilizes the variation in ablation time of the silver plate in PVP solution of gold nanoparticles for the synthesis. It has been observed that as the ablation time increases there is a shift from Au-Ag core shell to nanoalloy. The optical absorption spectra of the samples show variation from a complex two plasmon band into a single intermediate band suggesting the formation of core shell and nanoalloy respectively. The size and morphology of the samples are confirmed using TEM analysis. The composition of individual metal nanoparticles in the sample colloid was determined using EDS analysis. Zeta potential measurements suggest good stability of the synthesized samples.

Metal Coating on Ultrafine Polyester Non-woven Fabrics and Their Ageing Properties

The presented research work proposed a simple technique to metalize the milife fabric (very fine thickness) with silver coating. The polyester fabrics were firstly sensitized with copper, and then silver plating was performed on the surface. The presence of silver over the fabric was observed by scanning electron microscope and respective EDX spectra. The change in the electrical conductivity, electromagnetic shielding and joule heating properties were examined for different electroplating time. The electrically conductive fabrics showed low electrical resistance with high EMI shielding over frequency range of 30 MHz to 1.5 GHz. To have an idea about the durability of electrical conductivity under stretch load, the 75 cycles of stretch and release were carried out. Furthermore, the heating performance of silver plated fabric was studied through measuring the change in temperature at the surface of the fabric while applying a voltage difference across the fabric. Lastly, the effect of ageing parameters like washing, oxidation and sulfidation were examined on the functional and comfort properties (i.e. thermal conductivity and stiffness) of conductive fabric.

A flexible, conductive and simple pressure sensor prepared by electroless silver plated polyester fabric

A flexible and lightweight pressure sensor based on polyester (PET) fabric was prepared, and the conductive polymer polyaniline (PANI) was polymerized in situ on the surface of PET fabric to form a film. The reduction performance of PANI was used to reduce Ag+ to form an Ag0 catalytic center, causing subsequent electroless silver plating. The silver-plated PET fabrics can be used as a novel, flexible and simple pressure sensor to produce various of signals based on body movements. This flexible pressure sensor has good linearity, high sensitivity, wide response range and fast response time to distinguish different motions due to the magnitude and frequency of the pressure. We can believe that this flexible sensor is made of electroless silver-plated PET fabric when applied to human body, like palm, plantar and other parts can effectively detect motion in health monitoring.

Resistively loaded ultra‐thin FSS absorbers for radio‐frequency enhancement of spacecraft thermal blankets

This study reports the use of metal-backed frequency selective surface (FSS) absorbers as a means to control the scattering of electromagnetic energy from satellite platforms which are covered with thermal blankets. This is achieved by exploiting the similarity of the physical construction of this class of absorber and the dielectric clad foil-backed outermost layer of space blankets. Simulated results are presented for five absorber designs which are suitable for mechanical integration into the top surface of a multi-layer insulator. These were constructed using polyethylene terephthalate (PET) material with sheet thickness in the range 140 μ m ( λ / 213 ) − 1120 μ m ( λ / 25 ). The optimum performance around 10 GHz was obtained from an array of hexagonal patch elements with the conductivity of the silver plating adjusted to achieve the desired resistive loading. At normal incidence, the FSS-based structures presented −10 dB reflectivity bandwidths that are strongly dependent on the thickness of the PET sheet and vary between 2 and 16%. The design methodology is verified by measuring the radar backscatter from 140 and 1120 μ m thick absorbers in the frequency range 8–12 GHz.

Preparation of hollow silver-polymer microspheres with a hierarchical structure for SERS

The Surface-enhanced Raman scattering (SERS) effect on the surface of metal conductors can significantly improve the sensitivity of molecular detection. Therefore, it is widely used in the field of chemical sensors. The nanostructure of the metal surface strongly influences the strength of the SERS by adsorption and surface electric field. Herein, we combine microfluidic technology with electroless silver plating to produce hollow microspheres with different wall thicknesses. The microspheres have a diameter of 400 μm and a spherical shell thickness of 40–100 μm. The spherical shell has a porous structure formed by phase separation, on which nanosilver particles can be deposited. The silver-polymer hybrid microspheres can adsorb dyes in aqueous solution and produce significant SERS effects, and the Raman signal enhancement factors can be up to 7.11 × 1011. Computational simulations and experimental results show that the Raman enhancement effect is related to the distance between the silver particles on the surface and the hollow structure of the microspheres.

Analysis of the Principles for Representation of Sassanian Kings Archery in Silver Plates

Analysis of the Principles for Representation of Sassanian Kings Archery in Silver Plates

Hybrid Electrodeposition and Characteristics of Ag-Graphene Composite Films on Cu Sheets Toward High-Performance Electric Connectors

Recently, silver (Ag) plating for automotive connector has been attracted extensively attention due to the fast progress of HEV/EV system and as a promising candidate material to substitute the costive gold (Au) plating. The Ag plating film possesses the highest conductivity among the metals and excellent corrosion resistance next to Au plating. However, Ag plating suffers a low wear resistance problem because of the soft nature of Ag metal (~80 Hv). Because an oxidation film is difficult to form on silver surface, the corrosion resistance is good. More serious problem of Ag plating is that an adhesion phenomenon often occurs during sliding wear actions as terminal mating materials, because an oxidation film is difficult to form on Ag surface owing to the good corrosion resistance as a noble metal. To solve those problems, many studies focused on fabricate hard Ag plating by adding some alloy elements like Co, Sb, and Se or adding graphite powder into Ag plating films, which improved wear resistance but sacrificed electric conductivity. Here, we propose a new Ag-graphene electro-plating film, with the graphene functioning as solid lubricant and electric component, which may reinforce the wear resistance while without lowering its electric conductivity. The Ag-graphene composite films were fabricated on Cu sheets by a hybrid electrodeposition method, i.e., combining electrodeposition of Ag and electrophoric deposition of graphene nano-flakes, in a non-cyanate plating bath. The graphene nano-flakes were prepared by an electrochemical peeling method from a graphite material. The microstructures, chemical composition, and crystalline structure of the anodized specimens before and after annealed were investigated FE-SEM (EDS), XRD, GD-OES, FT-IR, and Raman spectroscopy. Moreover, the electric resistance meter and wear resistance were also investigated, compared to commercial Ag plating as reference.Figs. 1a and 1b show the surface FE-SEM images of as-electrodeposited pure Ag and Ag-graphene films respectively. It can be seen that, except for the featured Ag nano-particles, some blurry films can be observed on the Ag film in Fig. 1b. The EDS analysis result in Fig.1c demonstrates a strong C peak, indicating the co-deposition of carbon clearly. Moreover, the inclusion of graphene in Ag films were also confirmed by Raman spectra and XRD measurements. The electric resistance of Ag-graphene composite films was equivalent to the commercial Ag films, and the detail results will be reported on the meeting. Figure 1

A Single-Crystalline Silver Plasmonic Circuit for Visible Quantum Emitters.

Plasmonic waveguides are key elements in nanophotonic devices, serving as optical interconnects between nanoscale light sources and detectors. Multimode operation in plasmonic two-wire transmission lines promises important degrees of freedom for near-field manipulation and information encoding. However, highly confined plasmon propagation along gold nanostructures is typically limited to the near-infrared region due to ohmic losses, excluding all visible quantum emitters from plasmonic circuitry. We report on the top-down fabrication of complex plasmonic nanostructures in single-crystalline silver plates. We demonstrate the controlled remote excitation of a small ensemble of fluorophores by a set of waveguide modes and the emission of the visible luminescence into the waveguide with high efficiency. This approach opens up the study of a nanoscale light-matter interaction between complex plasmonic waveguides and a large variety of quantum emitters available in the visible spectral range.

Hierarchical self-assembly of 3D lattices from polydisperse anisometric colloids

Colloids are mainly divided into two types defined by size. Micron-scale colloids are widely used as model systems to study phase transitions, while nanoparticles have physicochemical properties unique to their size. Here we study a promising yet underexplored third type: anisometric colloids, which integrate micrometer and nanometer dimensions into the same particle. We show that our prototypical system of anisometric silver plates with a high polydispersity assemble, unexpectedly, into an ordered, three-dimensional lattice. Real-time imaging and interaction modeling elucidate the crucial role of anisometry, which directs hierarchical assembly into secondary building blocks—columns—which are sufficiently monodisperse for further ordering. Ionic strength and plate tip morphology control the shape of the columns, and therefore the final lattice structures (hexagonal versus honeycomb). Our joint experiment–modeling study demonstrates potentials of encoding unconventional assembly in anisometric colloids, which can likely introduce properties and phase behaviors inaccessible to micron- or nanometer-scale colloids.

Fit and Counterfeit: The Volatile Values of Epilepsy in Wilkie Collins’s Poor Miss Finch

Abstract This paper explores Victorian culture’s persistent associations between epilepsy and bodily expenditure to locate the place of the epileptic body within the Victorian ‘libidinal economy’. It centres on a reading of Wilkie Collins’s Poor Miss Finch (1872) as a highly original meditation on the implications of disability and visibility. In this novel, a reclusive silversmith named Oscar Dubourg curbs his post-traumatic seizures with silver nitrate, a remedy that causes a dark-blue discoloration of the skin. Behind the narrative necessity of this device, I locate an epistemological desire to render the condition of epilepsy visibly evident by saturating (and implicitly racializing) Oscar so that the inside shows through. The sporadic visibility of epilepsy confers a radically unstable identity upon its sufferer, one represented by the fluidity and anonymity of the unshaped silver and gold plates that Oscar moulds in his workshop. These plates inspire rumours throughout the community that Oscar is a counterfeiter. Oscar’s valuable metals, along with his health, are stolen in one fell swoop; the thieves brutally attack him, precipitating his traumatic epilepsy. The silver does not disappear, then, but is transmuted into Oscar’s affliction; these shifting metaphorical values of silver can be productively read in light of Victorian discourses of pathology, not least the widespread concern about malingerers ‘counterfeiting’ epilepsy. Can an afflicted body ‘pass’ as healthy? Can healthy bodies perform affliction? These are questions that Oscar’s story raises, with the help of a twin brother who exchanges identities with him in order to retain his fiancée’s affections. Collins’s sensational marriage plot, peopled with a cast of ‘problem bodies’, pulls the novel into critical conversation with a nexus of nineteenth-century medical and eugenic discourses dedicated to the surveilling of physical difference and the ‘policing’ of legitimate and illegitimate disabilities.

Preparation of highly electrically conductive carbon-fiber composites with high interlaminar fracture toughness by using silver-plated interleaves

Structural carbon-fiber composites with high electrical conductivity and high interlaminar toughness are important for the next generation of aircraft. Highly electrically conductive and simultaneously high toughness carbon fiber reinforced epoxy composites were hence developed by interleaving silver-plated veils. Two electrically conductive veils of nylon and Kevlar fibers were prepared by electroless silver plating, respectively. The effect of the veil structure and silver-plating on the conductivity and interlaminar fracture toughness was studied. It was found that the in-plane electrical conductivity perpendicular to the fiber direction (RY) and the through-thickness conductivity (RZ) increases from about 0.21 S/cm to 333 S/cm and 0.122 S/m to over 3.45 S/cm for the both samples interleaved with the nylon and Kevlar veils, respectively. The improvement is attributed to the electrical contact of the highly conductive veils in the interlayer's, forming an electrical network throughout the media. At the same time, the Mode I and Mode II interlaminar fracture toughness were also increased for the both composites, and it was more effective for the nylon-interleaved samples than for the Kevlar interleaved ones. Mechanism study showed that the interlaminar fracture mechanism can be controlled by the structural design of the veils. The failure mechanism of the nylon-interleaved composites was dominantly affected by the restraint of the fusion-bonded dots and pre-cracking which may compensate the negative effect of Ag-plating on the toughening, whereas the weak interfaces were responsible for the relatively lower toughness performance of the system interleaved with the Kevlar veils.

A Study on the Oxygen Percent and the Crystalline Structure of Silver Nanoparticles Obtained by Electrochemical Method

In this paper silver nanoparticles (NPs) which are synthesized by a simple plasma arc discharge method, that is a kind of electrochemical methods, are examined. The method is very simple and silver NPs are obtained very fast by means of two polished silver plates and electrochemical cell. The effects of changing some terms of the experiment including using Hydrogen peroxide (H2O2), temperature and the medium of experiment on oxygen percent and crystalline structure of silver NPs have been studied by transmission electron microscopy, UV-visible spectrophotometery, and X-ray diffraction. Water medium gets larger nanoparticles with less oxygen content compare to air medium. The size of synthesized nanoparticles become smaller and they also become more spherical by using H2O2 in air medium. In water medium, the size and concentration of the silver crystallite increase by temperature growth and adding H2O2 respectively.

Preparation of silver-plated Hollow Glass Microspheres and its application in infrared stealth coating fabrics

The infrared stealth fabric was prepared using silver-plated Hollow Glass Microspheres (HGMs) doped with aluminum powder by coating. Silver-plated HGMs was produced by in-situ polymerization of polyaniline (PANI) firstly and followed by electroless silver plating. The surface morphology was characterized by scanning electron microscopy (SEM). FT-IR and XRD analysis were further carried out to verify the preparation of silver-plated HGMs and coated fabrics during the reaction. Thermal infrared imaging device was used to test infrared radiation intensity of coating cotton fabric. Anti-electromagnetic radiation tester was used to evaluate shielding effectiveness. The surface temperature difference of the heated coating fabric was measured. Thermogravimetric (TG) analysis was carried out to study thermal stability. Only a little temperature rises after heating the coating fabric with low infrared radiation, and the shielding effectiveness (SE) can reach 26.8 dB. The results demonstrated this material was endowed with outstanding infrared stealth, electromagnetic interference (EMI) shielding and thermal radiation protection properties.

Occurrence and characteristics of perfluoroalkyl substances (PFASs) in electroplating industrial wastewater.

The potential negative effects of perfluoroalkyl substances (PFASs) discharged into aquatic environments are drawing increasing attention. However, little research has been undertaken on PFASs in wastewater from electroplating industrial parks. In this study, the concentration profiles and geographical distribution of 11 PFASs were analyzed in water samples collected from different production workshops and an artificial landscaped lake. The total concentrations of PFASs (Σ11PFASs) at various points in the production drainage system range from 229.5 to 5410.6 ng/L, and are mainly contributed by nickel plating, pickling, and the cyanide bright silver plating procedure, which correspond to cyanide-containing and acid-alkali wastewater conditioning tanks. Wastewater treatment by oxidation and precipitation removed 52.6% and 20% of PFASs, respectively. Σ11PFASs in effluents is about 538 ng/L, which consists of perfluorooctanoic acid (PFOA, 430.5 ng/L), followed by perfluorooctane sulfonate (PFOS, 35.27 ng/L), perfluorohexane sulfonate (PFHxS, 28.05 ng/L), and perfluorohexanoic acid (PFHxA, 18.3 ng/L). Principal component analysis suggests that the Σ11PFASs in electroplating wastewater is very high and short-chain (C4-C8) PFASs have high detection and contribution rates. As a result, much attention should be paid to the increase in short-chain substitution effects and pollution around the factory area.

Benigno lectori salutem.

The idea of this special Journal of Thoracic Disease ( JTD ) issue was born at the European Society of Thoracic Surgery (ESTS) School in Kazan, Russian Federation in early 2016 and was completed at a roundtable discussion in the Hemicycle of Council of Europe, Strasbourg, France on the terror-related professional tasks of thoracic surgeons in November 2017. The array and scope of the questions to discuss were served on a silver plate by Mother Contemporary History. Our age of the war on terror or indiscriminate and seemengly random attacks on non-belligerents is a call for trauma awareness among all surgeons. Our professional, social and moral responsibilities are challenged and obligations of the global thoracic surgical society dictate the need to reply this dramatic question: mass casualty situation: are we ready?