Morphology Of Silver Nanoparticles Research Articles

Color Generation and Polarization-Sensitive Encryption by Laser Writing on Plasmonic Reflector Arrays.

Plasmonic color printing presents a sustainable solution for vibrant and durable color reproduction by leveraging the light-manipulating properties of nanostructures. However, the fabrication of plasmonic nanostructures has posed challenges, hindering widespread adoption. In this paper, we introduce plasmonic reflector arrays (PRAs) composed of three layers─Ag nanoparticles (NPs), an Al2O3 spacer, and an Ag reflector─deposited via physical vapor deposition (PVD). By employing nanosecond and femtosecond laser writing techniques, we manipulate the surface morphology of silver nanoparticles on PRAs, resulting in a diverse range of structural colors that are both polarization-insensitive and polarization-sensitive. Furthermore, we demonstrate the versatility of nanosecond laser writing in creating intricate patterns on PRAs. Additionally, we propose a novel two-step method combining nanosecond and femtosecond laser processing to embed QR code patterns into PRAs, showcasing their potential for secure data encryption and transmission. This research underscores the promising applications of PRAs in advanced color printing and secure optical data encoding.

Effect of plasma treatment of Ag/ZnO hybrid photocatalysts on the optical properties and morphology of Ag nanoparticles

Subject of study. This study investigates Ag/ZnO hybrid photocatalysts and the role of silver nanoparticles as the active phase of these hybrid photocatalysts after treatment with low-temperature plasma generated from a dielectric barrier discharge. Aim of study. The aim is to determine how plasma treatment affects the optical properties and morphology of silver nanoparticles in Ag/ZnO hybrid photocatalysts as well as to explore the relationship between plasma-induced morphological changes and the photocatalytic activity of Ag/ZnO in the photodegradation of methyl orange and caffeine. Method. Ag/ZnO hybrid photocatalysts and silver nanoparticle ensembles were treated with dielectric barrier discharge plasma in air at normal pressure. The photocatalytic performances of the original and plasma-treated materials were evaluated through the degradation of methyl orange and caffeine in aqueous solutions under ultraviolet light, and the concentrations of methyl orange and caffeine were measured by spectrophotometry. The effects of plasma modification were analyzed using photoluminescence spectroscopy, spectrophotometry, and atomic force microscopy. Main results. A plasma-induced reduction in the size of silver nanoparticle agglomerates was observed, accompanied by an increase in the number of individual nanoparticles. The nanoparticle size changes were dependent on the energy and duration of plasma treatment. Additionally, the plasma treatment of ZnO-based hybrid photocatalysts led to a marked increase in the fluorescence lifetime of ZnO, contributing to enhanced photocatalytic activity in the degradation of organic pollutants in aqueous media. Practical significance. Improving the efficiency of Ag/ZnO photocatalysts for the removal of organic impurities from aqueous media through photodegradation represents a significant advancement in environmental management.

Silver nanoparticles induced enhanced stability, dielectric anisotropy, and electro-optical parameters of a nematic liquid crystalline material 4-(trans-4-n-hexylcyclohexyl) isothiocyanatobenzene

Nanocomposites of 4-(trans-4-n-hexylcyclohexyl) isothiocyanatobenzene nematic liquid crystals and silver nanoparticles have been prepared. UV absorption spectroscopy, Fourier transform infrared and Raman spectroscopies were used to characterize the morphology of silver nanoparticles (Ag-NPs). Thermodynamic, optical, and dielectric studies have been done to explore the change in the physical parameters of the composites with respect to the pure sample. Due to dispersion of silver nanoparticles, transition temperature, associated enthalpy and order parameters of the nanocomposites have increased. Dielectric study shows enhanced dielectric anisotropy for Ag-NPs dispersed nanocomposites. The relaxation frequency of an observed mode has shifted towards high frequency region for the nanocomposites. Optical band gap for pure and nanocomposites samples has been estimated from UV absorption peaks and it is found that optical properties of the nanocomposites are almost invariant. Threshold (switching) voltage, rotational viscosity and splay elastic constant for pure and dispersed samples have also been obtained from electro-optical studies.

Ag/ZIF‐8/polyacrylonitrile flexible SERS substrate with high sensitivity for the surface corrosion analysis

AbstractThe development of a novel and reliable surface‐enhanced Raman scattering (SERS) substrate for the surface corrosion analysis of bronze relics is an attractive research topic in cultural relic protection. A high‐performance SERS substrate was developed in the current investigation using Ag/ZIF‐8/Polyacrylonitrile (Ag/ZIF‐8/PAN) nanofibers. Silver nanoparticles were grown in situ by zeolite imidazolate framework‐8 (ZIF‐8) nanoparticles, and the substrate was examined in the surface corrosion analysis of bronze relics. In situ, growth of silver nanoparticles was ensured by the porous structure and active centers on ZIF‐8, coated on PAN nanofibers. Simultaneously, the adsorption of harmful rust‐alkaline copper chloride was enhanced on the surface of bronze relics. The extensive metal network was perturbed by the deposits, which substantially increased the intensity of the Raman characteristic peaks of the test objects. The signal strength of alkaline copper chloride at 118 cm−1 on the bronze surface increased from 1094 to 20,790. The exceptional SERS performance of silver nanoparticles with sharp edges demonstrates that the synergistic effect of ZIF‐8 nanoparticles and PAN nanofibers offers a considerable number of Raman‐enhanced hot spots. These results indicate that MOF‐based nanostructures offer a novel approach to enhancing the morphology of silver nanoparticles and expanding their potential applications in the field of cultural relic protection.

Influence of Pongamia pinnata Leaf Extract based Silver Nanoparticles Towards the Degradation of Safranin O Dye

Use of medicinal herbs for green synthesis of nanoparticles has attracted researchers owing to their valuable influence on mankind. Benefit of consuming plants aimed at greener production of nanomaterials relies on the less toxicity and cost-effective protocol. Herein, we reported the synthesis of biocompactible silver nanoparticles using Pongamia pinnata leaf extract. The biomolecules existing in leaf extract of Pongamia pinnata played dual role for capping and equilibrium of silver nanoparticles. Phenomena of surface plasmon resonance was observed from the UV-Vis spectrum around 426 nm. The FTIR peaks revealed the significance of biomolecules in the formation of stable silver nanoparticles. From XRD pattern, peaks attained has better covenant with Ag in metal form with face-centeredcubic feature. Morphology of silver nanoparticles from SEM and TEM studies revealed that the particles are spherical in shape. Degradation of safranin O dye using green synthesized silver nanoparticles exhibited better degradation efficiency. Without much advent process, this method for synthesizing silver nanoparticles provides an inexpensive and environmentally responsible approach.

The Effect of Surface Morphology of Silver Nanoparticles on the Selectivity of Styrene Epoxidation

Catalytic materials at the nanoscale level have an enormous impact on sustainable environmental protection, which is important for the future. Therefore, the researchers will intensively carry out the design of catalytic materials with well-ordered surface structures. In more detail, morphology-controlled nanoparticles have special interactions with the reactants that increase catalytic performance and influence the selectivity for catalytic reactions. For those reasons, obtaining specifically surface structure-tuned nanocrystals having different surface arrangements is a significant priority that promises the best model relationship between well-oriented surface structure and catalytic performance. In this study, silver nanocrystals shaped with cubes, truncated octahedrons, and octahedrons were produced. Their catalytic behaviors were examined as an innovation for epoxidation/oxidation reactions of styrene in mild conditions. The morphological and surface characterizations of nanocrystals were determined by analytical and instrumental methods such as high-resolution transmission electron microscopy energy dispersive X-ray (HR-TEM-EDX), X-ray diffraction (XRD), as well as inductively coupled plasma mass spectroscopy optical emission spectrometry (ICP-OES), and gas chromatography-mass spectrometry (GC-MS). According to the results, nanoparticles having different surface-facets fractions can be employed to increase the selectivity of styrene epoxide.

Synthesis and Characterization of Silver Nanoparticles from Ethanol Extract of Meniran (Phyllanthus Niruri L.) Using Bioreduction Method

The synthesis of silver nanoparticles by the bioreduction method has been successfully carried out using the meniran (P. niruri) as bioreductor. The synthesis was started by varying the volume of AgNO3 in the ethanol extract of meniran 1:1, 1:2, 1:3, and 1:4, so that the optimal volume was 1:1 based on the results of UV-Visible spectrophotometer analysis with an absorbance of 0.306 at maximum wavelength of 409 nm. Based on the measurement using Zetasizer Nano ZS, the resulting silver nanoparticles has paticle size of 740.4 nm. The FTIR analysis showed that there was an increase in the percentage of transmittance of the hydroxyl group which proved the reduction of Ag+ ions to Ag0 and the formation of silver nanoparticles. The Scanning Electron Microscopy proved that the morphology of silver nanoparticles varies in shape and the surface is smooth due to their tendency to agglomerate.

MICROWAVE-ASSISTED GREEN SYNTHESIS OF SILVER NANOPARTICLES USING EXTRACT OF SPONDIAS PINNATA BARK

Formation of silver nanoparticles with irradiation of microwaves using biological agents such as plant extracts is one of the eco-friendly green synthesis approaches which is economical in comparison with the physical and chemical methods. This study is focused at preparation of silver nanoparticles silver using Spondias pinnata bark extract by microwave irradiation and its comparison with aging method. Formation of silver nanoparticles was identified by observing the surface plasmon resonance absorption band peak at ~432 nm by UV-visible spectrophotometer. Optimization of the synthesis procedure was carried out using different amount of extract, concentration of substrate and microwave irradiation time and morphological features were characterised. A solution containing 8ml plant extract and 8 mM silver nitrate exposed to 90 sec microwave irradiation time was identified as optimised condition for the production of spherical shaped silver nanoparticles with a size of 34.52 nm which indicates that faster formation of silver nanoparticles compared to the aging method. Present research shows the importance of optimization of bio reduction conditions and the amount of reactants required for regulation of the morphology of silver nanoparticles as well as to obtain homogenous solution which is the main problem encountered in plant- mediated production of silver nanoparticles.

Role of mixed surfactants system in preparation of silver nanoparticles

Abstract Different morphologies of silver nanoparticles (AgNPs) are prepared by reducing silver nitrate with hydrazine hydrate in an aqueous solution in the presence of the anionic surfactant sodium 6,6′-((oxybis(ethane-2,1-diyl))bis(oxy))bis(3-dodecanoylbenzenesulfonate) (SOBS), the cationic surfactant cetyltrimethylammonium bromide (CTAB) and mixtures of these two surfactants as template. By mixing these cationic and anionic surfactants, different aggregates (template) were formed. The properties of the nanoproducts are studied by X-ray diffraction, transmission electron microscopy, energy dispersive X-ray analysis and Fourier transform infrared spectroscopy. The results show that the morphology of the nanosilver can be controlled by changing the ratio of cationic to anionic surfactant in the mixture, resulting in silver nanoparticles with high crystallinity and low aggregation.

Proficient mycogenic synthesis of silver nanoparticles by soil derived fungus Aspergillus melleus SSS-10 with cytotoxic and antibacterial potency

The present study aimed at evaluating the extracellular synthesis of silver nanoparticles by soil fungus Aspergillus melleus SSS-10 for antibacterial and cytotoxic activity. In this study, the formation of silver nanoparticles (AgNPs) was estimated by the colour change in cell free extract from pale yellow to golden yellow after 24 h of the reaction. UV‐Vis study showed the absorbance maxima at 410 nm. Tauc plot analysis revealed the band gap energy as 2.34 eV. Dynamic Light Scattering (DLS) data revealed polydisperse anisotropic silver nanoparticles with average hydrodynamic diameter of 92.006 nm. Zeta potential of − 19.6 mV provided evidence of stable silver nanoparticles. X-ray diffraction (XRD) analysis revealed four prominent Bragg peaks corresponding to (111), (200), (220) and (311) planes characteristic of silver (Ag) in FCC structural configuration. Average crystallite size was found to be 87.3 nm from Scherrer equation. Scanning Electron Microscope (SEM) analysis revealed irregular morphology of silver nanoparticles. EDS analysis displayed characteristic energy peaks of silver from 2.72 keV to 3.52 keV confirming the presence of silver nanoparticles. Biosynthesized AgNPs exhibited strong cytotoxic potential on MG-63 cells. AgNPs also showed antibacterial activity against both Staphylococcus aureus and Escherichia coli. In conclusion, this study provides a platform to explore the utility of fungal mediated silver nanoparticles synthesized for various pharmaceutical and cosmeceutical applications.

Fabrication of anti-bacterial cotton bandage using biologically synthesized nanoparticles for medical applications.

Recently the use of plant-derived extracts for the green synthesis of nanoparticles has drawn considerable attention. In the present study silver and copper nanoparticles were synthesized using extracts of Andrographis paniculata which is found to possess various pharmacological properties. The synthesized nanoparticles were characterized using UV spectroscopy, SEM with EDS, XRD, TEM and DLS. Furthermore, an attempt is made to impregnate these nanoparticles onto cotton bandages. The structure and morphology of silver nanoparticles impregnated onto the cotton bandages were confirmed by SEM. The anti-bacterial activity of cotton bandages loaded with silver and copper nanoparticles was tested against Escherichia coli, Bacillus cereus, and Staphylococcus aureus using a modified disc diffusion assay. The results indicate that the cotton bandages biofabricated with nanoparticles exhibited anti-bacterial activity in terms of zone of inhibition of growth of tested bacteria suggesting their usage as medical textiles in various biomedical applications for the prevention of infections. Hence, the nanoparticles impregnated cotton fibers can be applied for the development of masks, aprons, etc. to protect against bacterial penetration and as well to counteract the present situation of the world.

Enhancing mechanical and antibacterial performances of organic cotton materials with greenly synthesized colored silver nanoparticles

PurposeFunctionalization of organic cotton fabrics (OCFs) by in situ deposition of chitosan reduced-stabilized silver nanoparticles (AgNPs). No other toxic chemicals used to warrant an ecofriendly synthesis protocol. Human toxicity of silver systematically avoided to use as textile clothing. Primary colors (nearly-red, yellow and blue) were imparted on OCFs via localized surface plasmon resonance (LSPR) of AgNPs. Decent mechanical properties and laundering durability in terms of antibacterial/fastness test improved mechanical properties.Design/methodology/approachSilver nanoparticles can be synthesized by using silver nitrate along with commercially available chitosan. Due to the surface LSPR property of silver nanoparticles, it exhibits versatile colors depending on the synthesizing procedures. The coloration occurs due to the electrostatic interaction between the AgNPs and chitosan-treated OCF. The nanotreated fabrics provide excellent mechanical properties with improved antibacterial effects.FindingsX-ray fluorescence (XRF) analysis quantifies the developed materials in the substrates. Scanning electron microscopy (SEM) characterization indicates the appearance and morphologies of silver nanoparticles into the fabric surface after the coloration process. It proves that the treated cotton knit fabric exhibits the LSPR optical features of AgNPs. The antibacterial and mechanical properties confirm the improved functionality of products.Originality/valueImproved mechanical properties, antibacterial performances and coloration effects on organic cotton substrates in terms of chitosan-mediated nanosilver are not yet studied.

Comparison of antimicrobial and wound-healing effects of silver nanoparticle and chlorhexidine mouthwashes: an in vivo study in rabbits

The objective is to formulate a silver nanoparticle mouthwash and then evaluate its antimicrobial and wound-healing effects in rabbit animal models. Microbial samples were collected from the oral cavity of 60 rabbits. Thereafter, standardized wounds were created in the lateral border of the tongue on the right side for all rabbits. After surgery, digital photographs were obtained from the wounds with standardized settings. To characterize the silver nanoparticles used in the synthetic mouthwash, transmission electron microscopy (TEM) and digital light scattering analysis were used. The animal models were then randomly divided into 4 groups: group 1 received 9.80 wt% silver nanoparticle mouthwash; group 2 received all the ingredients of the formulated mouthwash except for silver nanoparticles; group 3 received chlorhexidine 2.0% mouthwash; and the negative control group did not receive any postoperative mouthwash. Microbial samples were collected from oral cavity of the rabbits each day for four postoperative days. Colony-forming unit (CFU) counts were compared post-operatively with the pre-operative counts. In addition, standardized digital photographs were taken each day from the wounds and the area of the wounds was compared in postoperative and pre-operative images. Data were statistically analyzed using one-way ANOVA and repeated measures variance analysis (α = 0.05). TEM revealed spherical morphology of silver nanoparticles and digital light scattering showed an average size of 5 nm and optimal distribution of the nanoparticles. CFU count significantly decreased in groups 1 and 3 (P < 0.001), while it significantly increased in groups 2 and 4 (P < 0.001). Moreover, a significant difference was observed between the experimental groups (P < 0.001). In addition, wound area decreased significantly in all groups (P < 0.001). However, the difference between wound areas in the groups was not significant, except for the 4th postoperative day (P < 0.001). However, the antibacterial effects and the wound-healing characteristics of the synthetic silver nanoparticle and chlorhexidine mouthwashes were not significantly different (P > 0.05). Silver nanoparticle mouthwash possesses favorable antibacterial and wound-healing effects. The formulated 9.80 wt% silver nanoparticle mouthwash with a particle size of 5 nm can be a promising alternative for application after oral surgical procedures.

Colorimetric and naked-eye detection of arsenic(iii) using a paper-based microfluidic device decorated with silver nanoparticles.

Arsenic (As) as a metal ion has long-term toxicity and its presence in water poses a serious threat to the environment and human health. So, rapid and accurate recognition of traces of As is of particular importance in environmental and natural resources. In this study, a fast and sensitive colorimetric method was developed using silver nano prisms (Ag NPrs), cysteine-capped Ag NPrs, and methionine-capped Ag NPrs for accurate detection of arsenic-based on transforming the morphology of silver nanoparticles (AgNPs). The generated Ag atoms from the redox reaction of silver nitrate and As(iii) were deposited on the surface of Ag NPrs and their morphology changed to a circle. The morphological changes resulted in a change in the color of the nanoparticles from blue to purple, which was detectable by the naked eye. The rate of change was proportional to the concentration of arsenic. The changes were also confirmed using UV-Vis absorption spectra and showed a linear relationship between the change in adsorption peak and the concentration of arsenic in the range of 0.0005 to 1 ppm with a lower limit of quantification (LLOQ) of 0.0005 ppm. The proposed probes were successfully used to determine the amount of As(iii) in human urine samples. In addition, modified microfluidic substrates were fabricated with Ag NPrs, Cys-capped Ag NPrs, and methionine-capped Ag NPrs nanoparticles that are capable of arsenic detection in the long-time and can be used in the development of on-site As(iii) detection kits. In addition, silver nanowires (AgNWs) were used as a probe to detect arsenic, but good results were not obtained in human urine specimens and paper microfluidic platforms. In this study, for the first time, AgNPs were developed for optical colorimetric detection of arsenic using paper-based microfluidics. Ag NPrs performed best in both optical and colorimetric techniques. Therefore, they can be a promising option for the development of sensitive, inexpensive, and portable tools in the environmental and biomedical diagnosis of As(iii).

Antioxidant and antimicrobial studies of silver nanoparticles synthesized via chemical reduction technique

Chemical synthesis is used to create silver nanoparticles (Ag-NPs). Silver nanoparticles were made via reducing silver salt with sodium borohydride in a chemical reaction (NaBH4). XRD, SEM, UV–Visible spectra, and FT-IR are exploited in the investigation of the structural and surface morphology of silver nanoparticles. Silver nanoparticles have been tested for their antibacterial properties. The findings demonstrate that silver nanoparticles as manufactured have greater antibacterial action against E.Coli and staphylococcus aureus germs. Silver nanoparticles have enhanced antioxidant activity as evidenced by DPPH assay results.

Improving Afterglow Properties of Sral2o4:Eu2+,Dy3+ by Changing the Morphology of Silver Nanoparticles

Improving Afterglow Properties of Sral2o4:Eu2+,Dy3+ by Changing the Morphology of Silver Nanoparticles

Synthesis, Characterization and studies on antibacterial activity of colloidal silver nanoparticles from Artocarpus hirsutus fruit extract

The present work reports the synthesis, characterization and antibacterial properties of colloidal silver nanoparticles using the fruit extract of Artocarpus hirsutus commonly known as wild jack. It is a tropical evergreen tree species that is native to Kerala and Karnataka, India. The Artocarpus hirsutus fruit extract was mixed with aqueous AgNO3 solution under constant agitation at room temperature for 9 to 12hrs. The reduction of silver ions by phytochemicals present in the fruit extract leads to the formation of stable colloidal Artocarpushirsutus silver nanoparticles (AHAg NPs). Characterization of AHAgNPs was carried out by UV Vis spectrum, FTIR, XRD, DLS and TEM. The peak obtained at 430nm using UV-VIS spectroscopy confirmed the formation of silver nanoparticles. The results of DLS indicated that the average size of AHAg NPs obtained from Artocorpushirsutus fruit extract was 100 nm. The FTIR spectra of AHAg NPs, where the peaks were obtained at 3305 cm-1, 2930 cm-1, 2158 cm-1, 1648 cm-1, 1393 cm-1, 1149 cm-1, 1015 cm-1, corresponded to OH group of alcohols or phenols, C-H of alkanes, CC group of alkynes, C=C group of alkenes, C=O, C-N group of aliphatic amine, C-O group of alcohols, carboxylic acids, esters or ethers. These peaks depict stretching vibrations responsible for polyphenols such as flavonoids, terpenoids and fatty acids and also proteins XRD analysis confirmed the homogeneous crystalline nature of the AHAg NPs with size of about 32 nm. Transmission electron microscopy analysis showed the spherical morphology of silver nanoparticles with particle size 20 nm. DLS analysis was also done to measure the particle size and its distribution. The silver nanoparticles demonstrated potent antibacterial activity against Streptococcus pneumoniae, Salmonella typhi, Pseudomonas aeruginosa etc.

Solution blowing spinning technology and plasma-assisted oxidation-reduction process toward green development of electrically conductive cellulose nanofibers.

Cellulose fibers have been one of the most common fibers due to their biodegradability, excellent mechanical properties, biocompatibility, high absorption ability, cheapness and renewability. In this study, novel, simple and green method is concerned with the production of multifunctional cellulose nanofibers (CNFs). Nanocomposites consisting of silver nanoparticles (AgNPs) and polyaniline (PANi) were in situ synthesized into plasma-pretreated cellulosic nanofibers fabricated by solution blowing spinning technique. The produced cellulose acetate nanofibers were then subjected to deacetylation followed by plasma-activation followed by a treatment with aniline and silver nitrate (AgNO3) in the presence of ammonium acetate. Plasma-assisted oxidation polymerization process of aniline into PANi associated with a reduction of Ag+ into AgNPs results in their permanent insolubility into the surface of the cellulose nanofibers. The morphologies and elemental contents were determined by polarizing optical microscope (POM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), energy-dispersive X-ray patterns and scanning electron microscopy (SEM). Additionally, transmission electron microscope (TEM) was applied to explore the morphologies of silver nanoparticles and PANi showing particle diameter between 12 and 25 nm. The antimicrobial Ag NPs were formed from an aqueous medium of silver nitrate by taking the reduction ability advantage of the electrically active PANi. The immobilization of polyaniline and silver nanoparticles into the surface of the cellulose nanofibers enhanced its electrical conductivity. The produced CNFs demonstrated a high UV protection as well as antibacterial activity.

Characterization of carbon nanotube decorated silver nanoparticles

Silver nanoparticles (Ag NPs) prepared using the exploding wire process has been decorated with carbon nanotubes (MWCNTs, SWCNTs). Well dispersion of silver NPs is achieved by a simple chemistry process on the surface of CNTs. The structure, optical and morphology of silver nanoparticles decorated with carbon nanotubes were characterized by x-ray diffraction, Atomic force microscopy, and field emission scanning electron microscopy. The illustrated outcome that the UV-Visible absorption and electrical conductivity properties effectively improved for CNT/Ag NPs. The absorption spectrum of silver nanoparticles shows absorption at ultraviolet wavelength zone and there is low peak between (300-900nm) while the absorption of CNT/silver nanoparticles (Ag NPs) increased significantly from UV to near IR region. Field emission scanning electron microscopy analysis shows that silver nanoparticles are decorated on carbon nanotubes without any impurities, with average particle size about (50-80nm) for Ag-NPs, 44nm for MWCNTs/Ag-NPs and 30 nm for SWCNTs/Ag NPs. It was observed that Ag NPs enhanced the electrical conductivity of CNTs from (2.36 ×10-1 (1/Ω.cm) to (1.03×104 (1/Ω.cm)) for SWCNTs/Ag NPs and (8.83×104 (1/Ω.cm)). It is observed that Ag NPs adding enhanced the electrical properties of CNTs. The results show that Ag-coated CNTs have important optoelectronic applications such as solar cell and photodetector.

Eco-Friendly Synthesis and Applicability to Silver Ink of Silver Nanoparticles Prepared via Stepwise-Modified Tollens Method.

Silver nanoparticles were eco-friendly synthesized at room temperature via a Tollens process modified with the stepwise method using eco-friendly precursors (citric acid and acetic acid). The field emission scanning electron spectroscopy was used to study the morphology of silver nanoparticles. The mean size of silver nanoparticles and the components of products were theoretically determined using UV-Vis and X-ray Diffraction spectra. The mole ratio between the silver ion, citric acid and the buffer acid solution (acetic acid) strongly influences the mean size and the composition of the product. The appearance of acetic acid in the buffer acid solution helped increase the efficiency of silver nanoparticles preparation. With the mole ratio n[Ag+]:ncitric:nacetic = 1.0:2.5:2.5, the highest preparation efficiency was obtained, the silver nanoparticles had an average dimension of ˜11 nm and narrow size distribution. The silver nanoparticles were dispersed into different solvents to examine their applicability to silver ink. The silver ink using propylene glycol solvent showed good applicability to silver ink which could work at room temperature.