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Silver nanoparticles (AgNPs) were successfully synthesized using [Ag(NH3)2]+ precursors. Ag+ ion sources were obtained from liquid waste samples of laboratory experiments. NaBH4 was used as the reducing agent of Ag+ ions to Ag0. The process of reducing Ag+ ions to Ag0 was carried out at room temperature. The color change of the solution from clear to brown which indicates that AgNPs colloids have been successfully synthesized using NaBH4. The AgNPs colloids were characterized using UV-Vis spectrophotometer, X-ray diffraction (XRD), Particle size analyzer (PSA), Particle zeta charge (PZC), and Transmission electron microscope (TEM). The UV-Vis spectrum showed the absorption peak of AgNPs colloid at 420 nm wavelength. The XRD analysis showed the crystallinity peak of silver nanoparticles at angle diffraction of (2θ): 38.12°; 44.25°; 66.37°; and 78.56° with a crystallite size average of 85 nm. The PSA and PZC characterization showed the average size distribution of AgNPs colloid was ± 85.56 nm and ± 120.21 nm with an inter- particle charge repulsion of -11 mV. TEM analysis showed the image of AgNPs colloids a spherical shape with an average particle size of 82 nm. Based on the results from the characterization data, it can be concluded that the liquid waste from the laboratory containing the Ag+ ion can be used as a source of ions in the synthesis of silver nanoparticles. Additionally, the formed silver nanoparticles have the potential as antibacterial agents in cosmetic products. [ABSTRACT FROM AUTHOR]

In this paper, we report the colloids of silver nanoparticles were successfully prepared using Aquilariamalaccensisleaf extract. The liquid waste from laboratory experiments containing the [Ag(NH3)2]+ complex ion were used as a precursor in the synthesis of silver nanoparticles. The process of reducing Ag+ ions to Ag0 was carried out at room temperature until the solution colour changed to brown. The reduction agent source was using Aquilaria malaccensis leaf extract solution with various concentrations of 0.2:5, 0.2:10, 0.2:15, and 0.2:20 mL ratios, respectively. The silver nanoparticles which formed were optimised and characterised using a UV-Vis Spectrophotometer, Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD) spectroscopy, and Transmission Electron Microscopy (TEM). The UV-Vis analysis showed the absorption peak spectrum of silver nanoparticles at 421 nm wavelength with colloid stability at 5 days. The crystallite size average of silver nanoparticles is 74 nm. Silver nanoparticles have a particle size of 97 nm with a spherical shape. The liquid waste from the laboratory experiments containing the [Ag(NH3)2]+ complex can be used as a source of Ag+ ions to synthesise silver nanoparticles. In addition, overcome the processing of liquid waste by utilizing it sustainable in the future. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (Ag-NPs) are an interesting study because of their good antibacterial abilities. Various methods have been developed for the synthesis of Ag-NPs, but have problems related to their toxicity and high processing costs. The biosynthetic method (green synthesis) was developed to overcome this problem because it is environmentally friendly. This study used jatropha leaf extract produced using the Soxhlet method. The process parameters of reaction temperature and reductant concentration are the focus of this research on the biosynthesis of silver nanoparticles. The temperature variation used is 27℃,40℃, and 60℃, while the reducing agent concentration is 3.0 ml; 3.6 ml; 4.4 ml; 5.0 ml. Indicators of the formation of Ag-NPs were observed by UV-Vis, PSA, and FTIR. The results showed that the higher the reaction temperature the smaller the particle size formed. In this temperature range, Ag-NPs measuring (15.94 – 24.24) nm can be produced. The reducing parameters show that the lower the concentration, the larger the size of the Ag-NPs produced, ie (8.61 – 24.24) nm. FTIR observations showed that jatropha leaf extract contains reducing flavonoid compounds which are characterized by O-H groups, C-H groups, C=C groups, C-O groups, and C=C groups. From the research that has been done, it can be concluded that the reaction temperature and the concentration of the reducing agent are the parameters that determine the size of the resulting particle. [ABSTRACT FROM AUTHOR]

Diamond simulators with specified spectral-kinetic characteristics, modeled by luminophores based on zinc and cadmium chalcogenides, have been developed. It is shown that the luminophores FK-110, R-530, FK-1, FK-2, E-515-115, FL-530 have values of spectral and kinetic characteristics that lie in the region of positive diagnostics (detection) at the used separator settings when using dynamic mode. The use of simulators with specified spectral-kinetic characteristics provides experimental verification and selection of modes for preparing diamonds for the X-ray luminescent separation process. Studies carried out on the «Polyus-M» separator using composite and plastic simulators in dynamic mode showed that the spectral-kinetic characteristics closest to natural diamonds are zinc and cadmium sulfides activated by copper and silver ions. The use of simulators using E-515-115 and FK-110 provides a stable reproduction of the spectral and kinetic characteristics of various types of natural diamonds and allows you to select additional recovery modes in existing X-ray luminescent separation of diamond-containing material. [ABSTRACT FROM AUTHOR]

Mariposa Christia vespertilionis (MCV) is also known as butterfly wing plant, or commonly known as 'pokok rerama' in Malaysia. This plant belongs to the Fabaceae family. Its bioactive compounds including triterpenes, alkaloids, fatty acids, phenol, alkanes and alcohol have shown antioxidant activity. The objective of this study is to synthesis silver nanoparticles together with MCV leaves extract using ultrasonic-assisted extraction (UAE) as an extraction method and to evaluate its antioxidative activity. The best conditions (concentration of silver nitrate and incubation temperature) for formation of AgNPs were visualised by UV-Vis spectroscopy. The absorbance peaks for both conditions were 450 nm and 430 nm respectively. Both MCV extract and synthesized nanoparticles have been characterized by Fourier-transform infrared spectroscopy (FTIR) to determine the functional group that responsible in reduction of silver ions. The AgNPs was also characterized by using Transmission Electron Microscopy (TEM) to determine the morphology and size of the synthesised silver nanoparticles (30 to 50 nm). Total phenolic content and total flavonoids content were also conducted for MCV extracts thus the value achieved was 0.429 ± 0.046 mg GAE/g and 0.033 ± 0.033 mg QU/g. Antioxidant activity was done by using DPPH solution. The scavenging activity for MCV extract was higher compared to the synthesised AgNPs. As conclusion, MCV leaves has potential as antioxidant agent which may be beneficial in preventing degenerative diseases. [ABSTRACT FROM AUTHOR]

Antibacterial activity of silver doped TiO2 nanoparticle interacted with chitosan and their application as coating material on cotton have been examined in this study. Nanoparticles of TiO2 with various silver content were synthesized via sol-gel method. The nanoparticles were characterized, and the effect of various silver were analyzed by X-Ray Diffraction (XRD) and UV-Vis Diffuse Reflectance Spectrophotometer. The diffraction pattern showed that pure TiO2 and TiO2-Ag have anatase phase. The effect of various silver content showed in the reduction of crystal grain size from 7.5 to 5.9 nm and the decrease of the bandgap energy from 3.33 to 3.19 eV. The nanoparticles have also been successfully interacted with chitosan and tested their antibacterial activity using disc diffusion method to performed strong activity against Escherichia coli and Staphylococcus aureus with the silver content above 5% (w/w) of up to 12 hours of contact time. Application of the nanoparticles as a antibaterial coating material on cotton fabric via spray coating using air brush showed high percent inhibition of up to 96%. [ABSTRACT FROM AUTHOR]

This research developed a single contrast agent based on hydroxyapatite (HA) [Ca10(PO4)6(OH)2] nanoparticles with Ag+ ions substitution to improve image quality. The samples of Ca10-xAgx(PO4)6(OH)2 with Ag concentrations (0≤x≤ 0.0028) were synthesized by co-precipitation method. The results showed that Ca10-xAgx(PO4)6(OH)2 was successfully synthesized in a single phase which has hexagonal structure. The substitution of Ag+ ions cause the decrease in the crystal size. The biocompatibility of samples decreases compared to pure HA. The contrast level of the samples was confirmed by SEM. The substitution of Ag+ with concentration x=0.0024 is suitable for contrast agents. [ABSTRACT FROM AUTHOR]

The owing characteristics of silver nanoparticles present many uses in the field of biomedicine. One of the most recent approaches of silver nanoparticles is the synthesis of antiurolithite medication that is effective against renal stone. However, environmentally sustainable methods for their synthesis must be created. The main aim of this work is to put forward a simpler and effective bio synthesis of silver nanoparticles with known antiurolthiatic properties. The green synthesis route is based on the use of Pandanus atrocarpus in aqueous solution at±25 °C as a reducing agent of silver ions. Synthesized silver nanoparticles, characterized by techniques i-e. UV–Vis, FESEM, X-ray diffraction and FT-IR spectroscopy. Antiurolithic behavior by nucleation process of silver nanoparticles was assessed. FESEM analysis revealed pure and clustered silver nanoparticles with a size of 19 nm. The PAE-AgNPs showed significant activity against antiurolithiatic. The findings observed indicated that in-vivo silver nanoparticles can be analyzed with P. atrocarpus [ABSTRACT FROM AUTHOR]

Roses are popular cut flowers in Vietnam. However, it is highly perishable, requiring proper post-harvest preservation to maintain quality and reduce losses. The life of the cut flower is often influenced considerably by the biochemical compositions in the vase. Some chemicals are usually used for preservation (e.g., thiosulfate salt, hydroquinone, benzyladenine, etc.) However, these compounds can expose toxicity to humans and the surrounding environment. Silver ions and Copper ions are considered antibacterial agents, which prolong the life of cut flowers. Because of the high cost of silver solutions, the present study aimed to evaluate the antiaging and antibacterial efficiency of copper ions characterized by environmentally friendly, low cost on cut roses in vases. The sensory evaluation and determination of representative bacteria, i.e., coliform, were carried out during 9 days of the experiments. The result showed that coliform proliferation was decreased when the copper concentration increased from 1 mg L−1 to 3 mg L−1. We suggest that the direct attack mechanism of copper ions on the bacterial body could inhibit their growth and activity on flower cell destruction and that copper ion accumulation into roses increases protection. Consequently, the freshness of cut roses was better in vases using 3 mg L−1 of copper ion than others, and the variability of coliforms exhibited an inverse correlation compared with the morphological and petal color state, and the shape of cut roses in vases using copper ions increased. Our findings clarified that copper ion promises a potential efficiency to increase the longevity of cut flowers at a household scale or large-scale production, and should be considered for further applications on other agricultural products after harvesting. [ABSTRACT FROM AUTHOR]

For the prevention and treatment of diseases of bacterial and viral etiology, currently widely used drugs are chemotherapeutic antibacterial drugs, which, if used incorrectly and haphazardly, lead to the appearance of multi-resistant strains of microorganisms. Therefore, the search for alternative drugs is the primary task of veterinary medicine. Silver-based drugs have a more pronounced bactericidal effect than antibiotics. Silver ions also have the ability to inactivate some viruses. We studied the tolerance of chickens to a silver-based preparation of 0.5% concentration. As a result of our studies, it was found that the use of a silver-based drug in various doses affects hematological parameters and leads to an increase in such indicators as lymphocytes, monocytes, hemoglobin, red blood cells, hematocrit, basophils and eosinophils. [ABSTRACT FROM AUTHOR]

In this study, composite film membranes of different ratios based on local chitosan and Na-carboxymethylcellulose (KMS) were obtained and their silver ion absorption was studied and analyzed using modern physicochemical methods. The obtained polymer membrane is suitable for use in industry for the absorption of various metal ions due to its good sorption properties. [ABSTRACT FROM AUTHOR]

To date, various studies have been carried out to determine the amount of different bioelements in the soil. In our study, inversion voltamperometric methods were used to determine the content of copper (II) ions, lead, zinc, cadmium, nickel, cobalt, silver ions in the soil. the effects of background electrolytes, buffer compounds, solution pH environment, and adjacent cations were studied. Based on the results obtained, an inversion voltamperometric method for the determination of copper (II) ions from soil composition was developed. [ABSTRACT FROM AUTHOR]

New silver nanocomposites (AgNCs) based on copolymers of N-methyl-2-azanorbornene-5 (MAN), N-benzyl- 2-azanorbornene-5 (BAN), N-allyl-2-azanorbornene-5 (AAN) and N-(2-azanorbornene-5)methylacetate (MAAN) with N-vinylpyrrolidone (VP) have been developed. The reduction of silver ions into silver nanoparticles was achieved using NaBH4 as reducing agent. UV- spectroscopy and scanning electron microscopy techniques were used to characterize the formation of silver nanoparticles in copolymers. The average silver particle size ranged from 22 to 32 nm, with the corresponding UV-vis absorption peak position at 400-415 nm. The AgNCs have exhibited cytotoxic activity towards rhabdomyosarcoma line cells. [ABSTRACT FROM AUTHOR]

The lasing potency of the doped rare earth ions (REIs) in the metallic nanoparticles (MNPs) incorporated various host materials (amorphous, crystalline or mixed phases) was shown to be governed mainly by their surrounding structures. In our opinion, by interplaying the REIs (operate as activator) and MNPs (act as sensitiser) contents in the host matrix an enhanced lasing action may be achieved. To validate this outlook, two series of holmium ions (Ho3+) activated zinc-sulfo-boro-phosphate glass-ceramic (GC) with different concentration of silver nanoparticles (AgNPs) were synthesised following the celebrated melt-quenching strategy under the controlled user-defined heating and cooling conditions. In the first GC series the AgNPs were created from the AgCl via thermal annealing assisted redox reaction and in the second series pure AgNPs were directly included. These two series revealed different localised surface plasmon resonance (LSPR) effect due to dissimilar mean size of the NPs. As-quenched samples were thoroughly characterized to determine the influence of the activator and sensitizer on their structural and optical attributes. The XRD results of these samples revealed their GC nature and the TEM images showed the existence of the AgNPs within the host network where the LSPR bands of the AgNPs reaffirmed such disclosure. The GC containing 0.8 mol% of AgNPs (mean diameter of 20 nm) exhibited the optimum photoluminescence (PL) intensity enhancement and most intense LSPR band. The achieved AgNPs size dependent improvement in the green and red PL intensity of the Ho3+ clearly validated the intrinsic structural-optical correlation in the studied GCs which was attributed to the synergy of Ho3+ and AgNPs. For the first time we demonstrated that by carefully manipulating the REIs and MNPs contents the lasing potential of these new types of GC hosts can be enhanced. The present knowledge may be beneficial for the development of the efficient photonic devices based on Ho3+-doped boro-phosphate GCs sensitized by morphology tuned AgNPs. [ABSTRACT FROM AUTHOR]

In this work, we have used radio frequency (RF) plasma for depositing an ultrathin layer of Al2O3 above Ag nanoislands film to tune the surface plasmon resonance (SPR) and to passivize the surface silver atoms from oxidizing. The surface morphology of the films show nanoislands feature with uniform film coverage on the substrate. The temporal stability of SPR is compared for both Al2O3 coated and bareAg thin films from optical absorption. In the absence of a passivizing layer the bare Ag films lose their SPR peak centered at 435 nm after a four week atmospheric storage, whereas the Al2O3 overlayer protected Ag films shows a consistent SPR with the peak maximum red shifted to 460 nm. Along with red shift, there is an increase in the strength and broadening of SPR which ranges from 360 to 550 nm. Surface-enhanced Raman studyshows the detectionof methylene blue at a concentration of 10-3 and 10-4 M from the prepared films. [ABSTRACT FROM AUTHOR]

Chitosan-magnetic composites are widely used as catalyst and as adsorbent for various metal ions. In this work, microparticles containing magnetite nanoparticles dispersed in ionically cross-linked chitosan matrix were prepared in one single step by spray drying two separate colloidal solution consisting of chitosan, magnetite NPs and sodium tri-polyphosphate together using a three-fluid nozzle. Subsequently, silver ions were adsorbed on these composite microparticles and reduced. The composite was characterized using SEM, HR-TEM, SQUID, XRD, TGA and FTIR techniques. Finally, the catalytic activity of silver nanoparticle loaded chitosan-magnetite composite microparticles were tested on the reduction reaction of 4-nitrophenol to 4-aminophenol by sodium borohydride. [ABSTRACT FROM AUTHOR]

Diospyros discolor Willd. (Bisbul) is known to have an activity as a reducing agent to reduce silver ions into silver nanoparticles. These abilities affected by the phytochemical content in the extract, such as phenolics and flavonoids compounds, which makes the synthesis process to be environmentally friendly. In this study, various concentrations of crude water extract from Bisbul leaves were used at concentration 0.01, 0.025, and 0.05 % (w/v), with the ratio between the extract and 1 mM AgNO3 was 1:9 (v/v). The formation of silver nanoparticles are confirmed by the presence of absorption spectra between 350-450 nm using UV-Vis spectrophotometer. Based on the results of phytochemical tests, it showed that the extract contains phenols and flavonoids compound. Furthermore, the total flavonoid content (TFC) and total phenolic content (TPC) were measured to know their presence in the extract. The amount of those compounds in each extract concentration tend to increase with the increasing of extract concentration. The extract with concentration 0.05 % had a narrower peak width based on the Full Width at Half Maximum (FWHM) value, which can indicate the monodispersity in silver nanoparticles size and distribution. [ABSTRACT FROM AUTHOR]

Nanotechnology plays a major role in the field of medicine nowadays due its multifunctional properties. Medical textiles are one of the most expanding sectors in the technical textile market. Nanoparticles make a huge impact on healthcare sector and increasingly used in wound dressings and house hold products due to their antimicrobial activity. In this study, silver nanoparticles (Ag nps) were synthesized by using Ficus carica fruit extract as reducing agent and it was conjugated with chitosan nanoparticles stabilized with PEG molecules. The conjugated Ch – PEG – Ag nanoparticles were characterized by UV – Vis, FTIR, DLS - Particle Size & Zeta Potential to understand their physicochemical properties. Then conjugated Ch – PEG – Ag nanoparticles were test for antimicrobial activity. Further, the conjugated nanoparticles will be incorporated into medical textile due to their excellent properties [ABSTRACT FROM AUTHOR]

In this study, colloidal silver nanoparticles (AgNPs) were synthesized in situ using Bombyx mori silk sericin. The synthesized nanoparticles were analyzed using UV-Visible spectroscopy (UV-Vis), the absorption spectra showed peak at λ=413 nm. Fluorescence spectroscopy (FL) study, the morphological study was carried out using fluorescence spectrophotometer and field emission scanning electron microscopy (FESEM). The size and shape of the silver nanoparticles were analyzed using high resolution transmission electron microscopy (HR-TEM). The obtained results indicated the silk sericin as a bio template for the reduction of silver ions to silver neutral atoms. [ABSTRACT FROM AUTHOR]

Poly methyl methacrylate (PMMA) is a transparent polymer often used in optical devices. In the present study magnetic cobalt (Co) nanoparticles have been embedded in PMMA film matrix followed by non magnetic silver (Ag) nanoparticles deposition as overcoat to obtain PMMA/Co/Ag magnetic nanocomposite film. The PMMA film was prepared from PMMA solution by spin coating on float glass. Cobalt (Co) nanoparticles layer of 10 nm thick was embedded in PMMA film using ion beam sputtering (IBS) technique. An overcoat of 4 nm silver nanoparticles (Ag) was then deposited using IBS to obtain PMMA/Co/Ag film. GIXRD record shows peaks of PMMA as well as of Co and Ag metal nanoparticles. The particle sizes of Co and Ag nanoparticles are found to be about 3.25 nm and 4.74 nm respectively. Both Co and Ag are found to be in the metallic form. Magnetic measurements were done using longitudinal magneto-optical Kerr effect (L-MOKE). The coercivity value of the sample was found to be 180.07 Oe. [ABSTRACT FROM AUTHOR]

The underlayer and overlayer play an important role in the evolution of structural and optical properties of thin films. The present work describes the structural and optical behaviour of Poly (vinyl alcohol) (PVA) film with cobalt (Co) and silver (Ag) embedded in it, where Ag (a nonmagnetic element) is the underlayer and Co (a magnetic element) is overlayer. The PVA film was deposited on float glass by solution casting technique then a 4nm layer of Ag was sputter deposited followed by 10 nm of Co using ion beam sputtering (IBS). The pristine and metal embedded film were characterized using grazing incidence x-ray diffraction (GIXRD) and UV-visible spectroscopy (UV-VIS) to study its structural and optical properties. GIXRD study revealed that the prominent peak at 2θ =19.9° belonging to PVA has shifted slightly compared to pristine PVA indicating some interaction of OH groups of PVA with the metal nanoparticles. Ag and Co both are present in metallic phase. UV visible absorption spectra show SPR peak of Ag and Co metal confirming their presence in nanosize level. Band gap of PVA decreases on incorporation of metal nanoparticles. [ABSTRACT FROM AUTHOR]

Colloidal silver nanoparticles (AgNPs) were synthesized in situ under UV-radiation environment at room temperature using silk fibroin (SF) extracted from Bombyx mori silk. Some amino acids of SF were involved in the biological synthesis, acting the dual function of Ag ion reduction and stabilization of silver nanoparticles. The UV-vis spectroscopy revealed the formation of AgNPs by showing a typical surface plasmon resonance (SPR) band at 426 nm. The particle diameter was around 35-40 nm. Further the X-ray diffraction (XRD) study confirms the nanocrystalline phase of silver with FCC crystal structure. The biogenic silver nanoparticles exhibited significant antibacterial activity against gram-positive and gram-negative bacteria. [ABSTRACT FROM AUTHOR]

In this study, silver nanoparticles (AgNPs) were synthesized by adding Origanum Vulgar to silver nitrate (AgNO3) in addition to the use of cold plasma. The OV-Ag NPs formation process can be monitored once the color turns red as a base marker; the color change of the solution represents the withdrawal of nitrate salts from the compound and the occurrence of surface plasmids. Part of the NPs of cold plasma is a second extract that can be used in treatment. Factors such as size and shape characteristics, plasmodium surface, structure and optical properties were studied by UV spectroscopy, FE-SEM, FT-IR and AFM. The average particle size distribution is found identical for both (44.2 - 88.1) nm in (AgNPs)1, while the average particle size distribution was (44.2 - 86.1) nm in (AgNPs)2. Then, OVAg NPs were added to the L20B tumor cell lines. The results showed that NPs were effective in inhibiting human pathogens in the presence of (NPs)1. The inhibition efficacy was found to be better for (NPs)1 compared to (NPs)2, because of a combination in the compound after exposure to plasma energy. The results also showed that NPs response based on dose concentration used against L20B tumor cell lines. Antioxidants were also identified in all cell groups. In addition, the resulting damage rate was calculated in the DNA of L20B tumor cells. The rate of damage in the DNA of cancer cells increased after exposure. The results showed that NPs located on living cell lines gave better results than control. [ABSTRACT FROM AUTHOR]

Currently, much attention is paid to noble metal nanoparticles, which exhibit promising optical properties. These properties depend on many factors, including synthesis conditions, which raises interest to study the formation of such nanoparticles. In this work the results of research of silver ions stable local atomic structure, which were placed in a glass matrix by Ag(+) ↔ Na(+) ion exchange procedure, are presented. Subsequently, these structures can be reduced by heat treatment or laser irradiation, to form nanoparticles. Research is supported by results of X-Ray absorption spectroscopy and computer modeling by density functional theory methods. [ABSTRACT FROM AUTHOR]

Metal nanoclusters (MNCs) are small aggregates of metal atoms with a mean diameter up to 2 nm, that when excited by electromagnetic radiation of suitable energy present an intense florescence. This optical property can be exploited in many fields such as bioimaging, drug delivery and optical sensing in environmental monitoring. In the present work, we synthesized silver nanoclusters (AgNCs) in water starting from AgNO3 and exploiting poly (methacrylic acid) (PMAA) as capping agent. The reduction of the silver ions Ag(I) to Ag(0) was promoted by the exposition of the solution to UV light radiation for 6 minutes. We studied the UV-Vis absorption and the fluorescence spectra for different pH values. The morphological characterization of the solution was accomplished by Transmission Electron Microscopy (TEM) and the statistical analysis showed that the mean diameter of the AgNCs was around 2 nm for the solution at pH = 4 which presented also the strongest fluorescence. Moreover, we studied the time stability of the absorption and fluorescence spectra. AgNCs stored in the dark at 4 °C were stable for more than 60 days. A possible application of the synthesized AgNCs deals with water monitoring by optical sensing based on the change of the fluorescence property in presence of heavy metal ions. Preliminary investigations show a high sensitivity to Pb(II) ions. [ABSTRACT FROM AUTHOR]

Silver nanoparticles embedded Polyvinyl alcohol (PVA) nanocomposites samples were prepared by in‒situ chemical reduction of silver nitrate (AgNO3) in an aqueous solution of PVA. The prepared nanocomposite films were exposed to ultraviolet (UV) radiations for different times at room temperature. The UV irradiation induced modification has been studied through optical spectroscopy and electrical measurements. The appearance of Surface Plasmon Resonance (SPR) band at 425 nm in the UV-Visible absorption spectra of PVA/Ag nanocomposite confirms the presence of the silver nanoparticles in PVA matrix. The optical energy gap values were found to reduce from 4.92 eV in pure PVA to 4.61 eV for PVA/Ag nanocomposites without UV irradiation, which further reduces to 4.40 eV after UV irradiation for 240 minutes. Such a reduction in optical energy gap may be linked to the increased conjugation in PVA matrix as an effect of embedding of silver nanoparticles. The value of conductivity increases from 4.16 × 10‒9 S/m for pure PVA to 3.64 × 10‒8 S/m for PVA/Ag nanocomposites which further enhances with the increase of UV exposure. [ABSTRACT FROM AUTHOR]

The research paper describes the in situ synthesis of silver nanoparticles (AgNPs) using Bombyxmorisilk sericin (SS). The formation of silver nanoparticles in the SS solution was confirmed by using UV-Visible spectroscopy (UVVis), X-ray diffraction measurements (XRD), transmission electron microscopy (TEM) and dynamic light scattering (DLS) experiments. The UV-Vis absorption spectra of the SS-AgNPs colloids showed surface Plasmon resonance in the wavelength range of 418-425 nm confirms the silver nanoparticles formation. The XRD scan revealed the nanocrystalline phase of silver with FCC crystal structure. The TEM images shown the formed silver nanoparticles are spherical in shape with smooth edges and diameter of the particles around 5-20 nm. The DLS results indicated the average size of the nanoparticles is slightly bigger in size compared with TEM values. All the results support the sericin as a prominent biotemplate for reduction of silver ions to silver neutral atoms. [ABSTRACT FROM AUTHOR]

Nano-sized particles of W-type hexaferrites having chemical composition SrCo2AgxFe16-xO27 (x = 0.0, 0.1, 0.2, 0.3) was synthesized by sol gel auto-combustion technique. The structural, morphological and elemental distribution of synthesized nanohexaferrites was studied by using techniques such as XRD, FESEM, EDS. From the XRD analysis, the crystallite size is found to be in the range of 51-61 nm calculated by using Debye-Scherrer formula which means crystallite size increases with increase in silver concentration. FESEM analysis revealed that grains are hexagonal in shape. The EDS spectra of the prepared samples confirming the formation of pure nanohexaferrites and elemental composition infer that no elements except strontium, cobalt, silver, iron and oxygen are present in the synthesized samples. [ABSTRACT FROM AUTHOR]

Nanocrystalline particles of strontium W-type hexaferrites having chemical composition SrCo2AgxFe16-xO27 (x = 0.0, 0.1, 0.2, 0.3) were synthesized by sol-gel technique. The optical and magnetic study was done by using Fourier transform infrared spectroscopy (FTIR) and vibrating sample magnetometer (VSM). The FTIR spectra consisting of absorption peaks within range of 603.9-607 cm-1 confirmed the formation of hexagonal structure for the prepared samples. From the magnetic hysteresis loops, the four magnetic parameters such as saturation magnetization (Ms), remanent magnetization (Mr), coercivity (Hc) and magnetic moment (nB) were calculated. It was reported that saturation magnetization (Ms) and magnetic moment (nB) increases for lower values of silver dopant (x = 0.0, 0.1, 0.2) but for the highest concentration of silver (x = 0.3), values of these two parameters decreases. Also, the values of coercivity (Hc) were found to be in range of 6-54 Oe indicating soft character of synthesized nanohexaferrites. [ABSTRACT FROM AUTHOR]

We present a computational study on phonon thermal transport in zigzag and armchair edge shaped nanoribbons of gold and silver with the aim to investigate the effect of edge and ribbon width on thermal transport. For this purpose, we have preformed lattice dynamics calculations based on force field methods as implemented in GULP code, followed by a Nonequilibrium Green’s Function approach. It is found that the thermal conductance varies linearly with the width of ribbon. At comparable width, nanoribbons of Au shows higher phonon thermal conductance than that of Ag. Moreover, zigzag edged nanoribbons are found to have higher thermal conductance than armchair edged nanoribbons. [ABSTRACT FROM AUTHOR]

The present report shows the optical changes due to the top Ag layer inter diffusion into bottom GeS matrix prepared by thermal evaporation method. The thermal energy facilitates the Ag+ ion into GeS which enhances the Ag-Ge-S solid solution formation that brings changes in optical constants as probed by various experimental techniques. The drastic increase in transmission accompanied by increase in optical gap is explained on the basis of density of localized states and disorderness. The non linear refractive index is found to be reduced with decrease in absorption coefficient. The structural change is not noticed by the thermal induced diffusion mechanism and the surface morphology is influenced by this process. [ABSTRACT FROM AUTHOR]

The present paper reports the suitability of bulk samples / thin films of Se90Sb10-xAgx (where x is varied from 0 to 8) for device applications. These glasses have been prepared by quenching technique, well known vacuum evaporation technique have been used for the preparation of thin films of present glassy system. Space charge limited conduction technique is used for this purpose. An ohmic behavior is observed at low electric fields upto 10² V/cm. However, super ohmic behavior is observed at high electric fields (10³ - 104 V/cm). High-field conduction theory of space charge limited conduction for uniform distribution of localized states in the mobility gap fits well with the experimental data. The results indicate that thin films have density of defect states higher than bulk samples except 4 at. % of Ag, which is explained in terms of average co-ordination number. [ABSTRACT FROM AUTHOR]

Core shell nanoparticles have become an interesting topic of research because of their enhanced optical, catalytic and antibacterial property. Several alloy type nanoparticles have been synthesized like gold-silver, silver-gold, gold–silica, silver–silica, gold-platinum etc. In the present study we have demonstrated a new wet chemical route to synthesize gold-silver core shell nanoparticles using a medicinal plant extract, which act both as reducing agent and stabilizing agent. The method is facile and very fast. In the synthesis process, pre–synthesized spherical gold nano particles of 20-30 nm size served as nucleation sites for silver ions that formed coating over the gold core. The synthesized gold nano particles have been characterized by uv-vis spectroscopy, Transmission Electron Microscope (TEM) and zeta-potential analyser. [ABSTRACT FROM AUTHOR]