Synthesis Of Silver Nanowires Research Articles

Statistical models assisted solvothermal synthesis of silver nanowires with controllable morphology

Silver nanowires (AgNWs) are conductive materials used in various applications such as solar panels and electronic skin. The morphology of AgNWs, including length and diameter, significantly affects conductivity. Despite various synthesis methods, a comprehensive understanding of how synthesis factors affect morphology is still lacking. This study focuses on solvothermal synthesis and investigates the influence of different nucleants on morphology. Through statistical analyses, including multivariate control charts and analysis of variance (ANOVA), this work demonstrates the joint effects of nucleants on AgNWs synthesis, thus setting the basis for morphology control.

Synthesis and morphology of Ag nanowires by fiber template method

The synthesis of traditional silver nanowires often uses a polyol method. There are many factors that affect the structure of silver nanowires, such as silver ion concentration, type and amount of reducing agent, oxygen concentration, stirring speed, temperature, and time. The synthesis conditions are harsh and difficult to replicate. In this paper, natural fibers and synthetic fibers were used as templates to assist the polyol reduction method to obtain silver nanowires with uniform structure. The effect of fiber types on the structure of silver nanowires were studied, including hemp fibers, wheat straw fibers, tobacco stem fibers, and polycarbonate fibers. Polycarbonate fibers induced the synthesis of silver nanowires with the highest aspect ratio, highest yield, and most uniform diameter distribution. The effect of polycarbonate fibers concentrations on the morphology and conductivity of silver nanowires were also studied. When the polycarbonate mass concentration was 8.5 × 10−4 g/mL, the aspect ratio of silver nanowires was the highest. The effect of polycarbonate fibers length (2 mm\\5 mm\\7 mm) on the morphology of silver nanowires were also studied. When the length of the template polycarbonate fibers was 7 mm, the length to diameter ratio and conductivity of the nanowires obtained are the best. Furthermore, the reaction kinetics of the reaction were studied via multiple sampling of silver nanowire reaction solutions and characterized by using UV–visible spectroscopy and scanning electron microscopy. The synthesis method of silver nanowires using fiber template is simple and fast, and can be used to synthesize silver nanowires with uniform diameter distribution on a large scale, thus solving the bottleneck problem of harsh synthesis conditions for silver nanowires. The resulting silver nanowires were blended with carboxymethyl cellulose to prepare conductive inks, which were coated on paper and cured at 180 °C for 30 min to achieve good conductivity.

Statistical models assisted solvothermal synthesis of silver nanowires with controllable morphology

Silver nanowires (AgNWs) are conductive materials used in various applications such as solar panels and electronic skin. The morphology of AgNWs, including length and diameter, significantly affects conductivity. Despite various synthesis methods, a comprehensive understanding of how synthesis factors affect morphology is still lacking. This study focuses on solvothermal synthesis and investigates the influence of different nucleants on morphology. Through statistical analyses, including multivariate control charts and analysis of variance (ANOVA), this work demonstrates the joint effects of nucleants on AgNWs synthesis, thus setting the basis for morphology control.

Synthesis of Silver Nitrate by Evaporation Chemical Reduction Process as Potential Materials for Silver Nanowires Application

In this study, we conducted the extraction of silver nitrate (AgNO3) using the chemical reduction evaporation method, involving silver metal (Ag) with a molarity of 7.716 M and nitric acid (HNO3). The heating process via evaporation was carried out at 85oC for 2 hours. Subsequently, the synthesis of silver nanowires (AgNWs) was performed using a 0.3 M of AgNO3 solution in ethylene glycol (EG), polyvinyl pyrrolidone (PVP), and Iron (III) Chloride hexahydrate (FeCl36H2O). XRD analysis of the AgNO3 sample revealed an orthorhombic crystal structure with a single AgNO3 phase peak. In AgNWs, three crystalline phases were observed, with the Ag phase being the most dominant. The average crystal size of AgNO3 and AgNWs was 109.42 nm and 22.06 nm, respectively. The average crystal size of the AgNO3 sample may be influenced by the aggregation between crystal nuclei during the heating process. XRF analysis indicated a 98.84% Ag concentration in AgNO3. SEM-EDS analysis showed that the AgNO3 sample had a non-aggregated morphological structure, with particle size measuring 49.46 μm and an overall AgNO3 purity of 92.68%. The SEM image of the AgNWs sample displayed a very homogeneous diameter of ∼200 nm with a length of around 10-20 μm. Meanwhile, AgNWs exhibited a morphology resembling rod-shaped wires with a purity of 68% for Ag.

Heterogeneous nucleation optimization from AgCl and reduction control in ethylene glycol for fast and reproducible synthesis of silver nanowires

Silver nanowires synthesized by the most commonly used polyol method are typically accompanied by nanoparticles and nanorods, which have a negative impact on the performance of silver nanowire-based devices. Herein, we report a reproducible and easy method for preparing silver nanowires with yields exceeding 70% by optimizing the heterogeneous nucleation of silver from silver chloride precursors and regulating the reduction in ethylene glycol. The yield of silver nanowires depended on the morphology and concentration of silver chloride and the decomposition time of ethylene glycol. The Raman spectra were used to study the effect of the decomposition time of ethylene glycol on the concentration of acetaldehyde in solution, which influenced the reduction rate of silver ions. Then, the reaction time of silver nanowires was further reduced from 24 min to 10 min by increasing the reaction temperature from 160 °C to 170 °C. On the basis, the silver nanowire based capacitive screen with a good capacitive response and anti-aging performance was further fabricated. This method provides a new way for the macro preparation of silver nanowires with high yields.

Optimizing Silver Nanowire Synthesis for In-Body Applications

Optimizing Silver Nanowire Synthesis for In-Body Applications

Preparation of anisotropic AgNWs/PVA/Ag2S nanocomposites via a vapor-phase sulfidation process.

This study used a modified polyol technique to synthesize silver nanowires (AgNWs), which were subsequently mixed with polyvinyl alcohol (PVA) polymer and air-dried under ambient conditions. As a result, AgNWs/PVA nanocomposites with a concentration of 2% were prepared by a casting process. After that, the upper surface of the produced samples was treated with H2S gas, as a result of which asymmetric structures were formed depending on the gas concentration, exposure time and penetration into the layers. The structural, morphological, and optical properties of these asymmetric structures were analyzed. Changes in the sample structure were studied using X-ray diffraction (XRD), their optical properties were studied using ultraviolet-visible (UV-Vis), Raman spectroscopy, and their morphology using Transmission electron microscopy (TEM). A simple technique involving H2S gas was used for the sulfidation process of the samples, marking the first exposure of AgNW/PVA nanocomposites to such treatment. Examination of the structural and optical properties of the surfaces revealed clear differences in their physical properties after sulfidation. These obtained results were also supported by TEM images. Finally, the successful production of AgNWs/PVA/Ag2S anisotropic structure was achieved by this method.

Chemically-stable flexible transparent electrode: gold-electrodeposited on embedded silver nanowires

Silver nanowires (AgNWs) with a low diameter, high aspect ratio, stable suspension, and easy synthesis have recently attracted the optoelectronic industry as a low-cost alternative to indium tin oxide transparent conductive films. However, silver nanowires are not chemically stable, and their conductivity diminishes over time due to reactions with atmospheric components. This is a bottleneck for their wide industrial applications. In this study, we aim to address this issue by synthesizing silver nanowires with an average diameter of approximately 65 nm and a length of approximately 13 µm. The prepared Ag nanowires are then applied to fabricate transparent, flexible, and chemically stable conductive films. The fabrication includes spraying of silver nanowires suspension on a glass substrate followed by Dr. blade coating of polystyrene (PS) solution and delamination of the PS-AgNWs film. The resulting film exhibits an optimum sheet resistance of 24 Ω/□ and transmittance of 84%. To further enhance the stability of the transparent conductive film, the facial and scalable double pulse electrodeposition method is used for coating of gold on the exposed surface of the AgNWs embedded in PS. The final transparent film with gold coating demonstrates a remarkable stability under harsh conditions including long exposure to UV light and nitric acid solution. After 100 min of UV/Ozone treatment, the increase in sheet resistance of the optimal PS-AgNW@Au sample is 15.6 times lower than the samples without gold coating. In addition, the change in sheet resistance after 2000 bending cycles in the optimal PS-AgNW@Au electrode is measured and it showed an increase of only 22% of its initial sheet resistance indicating its good flexibility. The proposed electrode performs an excellent chemical stability, good conductivity, transparency, and flexibility that makes it a potential candidate for various optoelectronic devices.

Understanding the Nucleation and Growth Kinetics of the Microwave-Assisted Synthesis of Silver Nanowires

Understanding the Nucleation and Growth Kinetics of the Microwave-Assisted Synthesis of Silver Nanowires

Optimizing silver nanowire synthesis: machine learning improves and predicts yield for a polyol, millifluidic flow reactor

Optimizing silver nanowire synthesis: machine learning improves and predicts yield for a polyol, millifluidic flow reactor

Three as-synthesized silver nanowires (Ag NWs) with different size on renal cancer treatment

In this paper, three as synthesized silver nanowires (Ag NWs 1–3) have been successfully synthesized via the one-step polyol synthesis at 150 °C for 8 h, which use the NaCl, ZnCl2 and CuCl2 as the inorganic control agents to control the size and length of the Ag NWs. Three Ag NWs sample have been characterized by the scanning electron microscope (SEM) and powder X-ray diffraction (PXRD). The novel Ag NWs application on anti-renal cancer was explored and the specific mechanism was determined simultaneously. The results suggested that Ag NWs inhibited renal cancer by decreasing renal cancer cell proliferation and up-regulating SUCLG1 and PCK2 expression. The Ag NWs showed the potential to be developed as the anti-tumor drug.

Tetrabutylammonium Tribromide-Induced Synthesis of Silver Nanowires with Ultrahigh Aspect Ratio for a Flexible Transparent Film.

Silver nanowires (AgNWs) have gained significant attention from researchers as a promising material for producing flexible transparent conductive films, which can be utilized in touch and display screens. Thereinto, the ultrahigh aspect ratio AgNW network can theoretically decrease the contact resistance effectively while still retaining considerable mechanical and optical properties. However, fabrication of high-quality AgNWs with a fine diameter and high aspect ratio is still challenging. Herein, a simple and robust approach to synthesize ultrahigh aspect ratio AgNWs is presented. This study successfully fabricated AgNWs with the highest aspect ratio up to ∼4000 and an average length of ∼72 μm by utilizing tetrabutylammonium tribromide as an auxiliary additive. The manifestation of tetrabutylammonium tribromide was proven to be beneficial for the generation of silver seeds and the expansion of AgNWs. The obtained AgNWs were utilized to create a transparent conductive film that showed low sheet resistance of 22.4 Ω/sq and high transmittance and low haze of 87.71 and 4.15%, respectively. The transmittance and haze of the vacant poly(ethylene terephthalate) support were 90.13 and 2.05%, thereby offering great potential for application in flexible transparent electrodes.

Synthesis of Silver Nanowires with Different Morphologies for Lung Cancer Treatment

In this publication, three silver nanowires (Ag NWs) with different morphologies were prepared via the polyol process synthesis method by changing the amount and kinds of inorganic agents in the synthesis procedure. The as-synthesized Ag NWs showed high yield and purity. The samples were fully characterized by scanning electron microscopy (SEM) and powder X-ray diffraction (PXRD). The SEM results revealed that Ag NWs 1–3 have diameters of 95, 70, and 55–65 nm, respectively, and lengths of 20–30, 30–40, and 40–50 μm, respectively. The PXRD experiments showed that the as-synthesized samples display four typical diffraction peaks at 38.2°, 44.5°, 64.5°, and 77.4°, which are consistent with the face-centered cubic lattice for Ag. The inhibitory activities of the Ag NWs on the viability of lung cancer cells was measured with cell counting kit-8 assay. The activation activity of the vascular endothelial growth factor signaling pathway in the cancer cells was measured with real-time polymerase chain reaction.

Preparation of highly pure and homogeneous silver nanowires via a secondary heating method

In recent years, silver nanowires (AgNWs) have been widely studied and used as nanofillers in various advanced composite materials due to their excellent properties. The addition of AgNWs can lead to electronic devices with enhanced performance; thus, it is highly desirable to synthesize silver nanowires with high purity. However, the AgNWs synthesized by the conventional polyol method inevitably produce impurities that weaken the performance of these materials. For this reason, the conventional polyol method was improved into a secondary heating method, and AgNWs with high purity, excellent homogeneity, and an aspect ratio of 2000 were obtained via the secondary heating method. In addition, the AgNWs synthesized by the secondary heating method were compared with those synthesized by the direct heating method, and the AgNWs produced by the secondary heating method had higher purity and fewer impurities. The principles of AgNWs production via the secondary heating method were investigated, and the conditions required for the synthesis of AgNWs with high purity, great homogeneity, and high aspect ratio, such as reaction time, starting temperature, secondary temperature, and the molar ratio of NaCl to AgNO3, were also investigated.

Rapid Synthesis of Silver Nanowires in the Polyol Process with Conventional and Microwave Heating

Silver nanowires (AgNWs) represent an excellent material for many advanced applications due to their thermal and electrical properties. However, synthesising materials with the desired characteristics requires knowledge of the parameters affecting their size and an appropriate fabrication method. This paper presents a study on the synthesis of silver nanowires using the polyol process by conventional and microwave heating. Various polyols (1,2-ethanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol) with different viscosities and dielectric properties were used as reductants. It resulted in nanowires with an average diameter of 119–198 nm. It was found that, in contrast to the viscosity and dielectric constant of the alcohol used, the heating method had a limited effect on the average diameter and length value of the final product. The performed studies indicate an optimal strategy for fabricating one-dimensional silver nanostructures using the polyol method.

Controlled Synthesis of Silver Nanowires: Production and Characterization

Controlled Synthesis of Silver Nanowires: Production and Characterization

Simple Recycling of Ag+, Surfactant, and Solvent for Repeatable Synthesis of Silver Nanowires for Applications as Flexible Transparent Heaters

Silver nanowires (AgNWs) have shown great potential in various optical and electronic applications, especially in flexible and wearable devices. Polyol method is now a mainstream strategy to synthesize AgNWs. However, unreacted reagents including silver salt, surfactant, and solvent are usually discarded after the collection of products, resulting in a huge waste as well as a burden to the environment. In this work, we demonstrate a simple recycle method to reuse these reagents based on a two-step direct centrifugation protocol. Larger nanowires are separated, while remaining small nanowires and nanoparticles provide nucleation sites and likely function as catalysts to achieve a three-times faster nanowire growth. The cyclic synthesis can maintain at least five consecutive rounds to produce AgNWs with similar size and yield and more rounds under suitable adjustment of Ag+ supply. Transparent conductive films based on AgNWs grown from recycled reagents show excellent and consistent optoelectronic performance, namely, a sheet resistance of 141.3 Ω/sq at a transmittance of 99.7% and 9.48 Ω/sq at 92.9%. A transparent heater with a PDMS/AgNWs/PET structure exhibits a resistance of 8.6 Ω at a total transmittance of 76.5% and is heated to 75.8 °C at a 3.5 V power supply. A fast-defrosting process is demonstrated. The recycling method significantly reduces the cost of AgNW production and may widen their application in high-performance flexible devices.

Halide-Salt-Free Synthesis of Silver Nanowires with High Yield and Purity for Transparent Conductive Films.

To date, silver nanowires (AgNWs) are routinely synthesized. However, the controllable preparation of AgNWs without any halide salts has not reached a similar level. In particular, the halide-salt-free polyol synthesis of AgNWs commonly occurs above 413 K, and the property of AgNWs obtained is not so easy to control. In this study, a facile synthesis of AgNWs with a yield of up to ∼90% in an average length of 75 μm was successfully performed without any halide salts. The fabricated AgNW transparent conductive films (TCFs) show a transmittance of 81.7% (92.3% for the AgNW network only without substrate) at a sheet resistance of 12.25 Ω/square. In addition, the AgNW films show distinguished mechanical properties. More importantly, the reaction mechanism for AgNWs was briefly discussed, and the importance of reaction temperature, the mass ratio of poly(vinylpyrrolidone) (PVP)/AgNO3, and the atmosphere was emphasized. This knowledge will help enhance the reproducibility and scalability of polyol synthesis of high-quality AgNWs.

Synthesis of Silver Nanowires Using a Polyvinylpyrrolidone-Free Method with an Alpinia zerumbet Leaf Based on the Oriented Attachment Mechanism.

In this study, silver nanowires (AgNWs) were successfully synthesized by using a polyvinylpyrrolidone (PVP)-free hydrothermal method with an Alpinia zerumbet leaf chunk as a reducing agent and template. Meanwhile, the mechanism of biomass synthesis of AgNWs is also explored. The AgNWs have a diameter of ∼77 nm and a length of ∼10 μm. During the hydrothermal process, the biomass initially serves as a reducing agent to reduce silver ions. As the reaction proceeds, the biomass will form a pipe-shaped soft template by hydrothermal carbonization. Silver ions are adsorbed and reduced along the pipe-shaped soft templates to form silver nanorods, and adjacent nanorods are merged to AgNWs. Thus, AgNWs are grown along the pipeline soft template based on the oriented attachment mechanism. Inspired by this, the mechanism of the polyol method was further investigated. In the initial growth stage, AgNWs synthesized by the polyol method have a V-shaped notch. Therefore, AgNWs synthesized by the polyol method may also grow on the basis of the oriented attachment mechanism with PVP as a template.

银纳米线的可控合成及其应用

银纳米线的可控合成及其应用