Journal articles: 'Ag nanoparticles films'

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Macieja, Szymon, Bartosz Środa, Beata Zielińska, Swarup Roy, Artur Bartkowiak, and Łukasz Łopusiewicz. "Bioactive Carboxymethyl Cellulose (CMC)-Based Films Modified with Melanin and Silver Nanoparticles (AgNPs)—The Effect of the Degree of CMC Substitution on the In Situ Synthesis of AgNPs and Films’ Functional Properties." International Journal of Molecular Sciences 23, no. 24 (December 8, 2022): 15560. http://dx.doi.org/10.3390/ijms232415560.

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Green synthesis of nanoparticles for use in food packaging or biomedical applications is attracting increasing interest. In this study, the effect of the degree of substitution (0.7, 0.9 and 1.2) of a carboxymethylcellulose polymer matrix on the synthesis and properties of silver nanoparticles using melanin as a reductant was investigated. For this purpose, the mechanical, UV–Vis barrier, crystallinity, morphology, antioxidant and antimicrobial properties of the films were determined, as well as the color and changes in chemical bonds. The degree of substitution effected noticeable changes in the color of the films (the L* parameter was 2.87 ± 0.76, 5.59 ± 1.30 and 13.45 ± 1.11 for CMC 0.7 + Ag, CMC 0.9 + Ag and CMC 1.2 + Ag samples, respectively), the UV–Vis barrier properties (the transmittance at 280 nm was 4.51 ± 0.58, 7.65 ± 0.84 and 7.98 ± 0.75 for CMC 0.7 + Ag, CMC 0.9 + Ag and CMC 1.2 + Ag, respectively) or the antimicrobial properties of the films (the higher the degree of substitution, the better the antimicrobial properties of the silver nanoparticle-modified films). The differences in the properties of films with silver nanoparticles synthesized in situ might be linked to the increasing dispersion of silver nanoparticles as the degree of CMC substitution increases. Potentially, such films could be used in food packaging or biomedical applications.

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Lian, Xinxin, Yuanjiang Lv, Haoliang Sun, David Hui, and Guangxin Wang. "Effects of Ag contents on the microstructure and SERS performance of self-grown Ag nanoparticles/Mo–Ag alloy films." Nanotechnology Reviews 9, no. 1 (August 30, 2020): 751–59. http://dx.doi.org/10.1515/ntrev-2020-0058.

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AbstractAg nanoparticles/Mo–Ag alloy films with different Ag contents were prepared on polyimide by magnetron sputtering. The effects of Ag contents on the microstructure of self-grown Ag nanoparticles/Mo–Ag alloy films were investigated using XRD, FESEM, EDS and TEM. The Ag content plays an important role in the size and number of uniformly distributed Ag nanoparticles spontaneously formed on the Mo–Ag alloy film surface, and the morphology of the self-grown Ag nanoparticles has changed significantly. Additionally, it is worth noting that the Ag nanoparticles/Mo–Ag alloy films covered by a thin Ag film exhibits highly sensitive surface-enhanced Raman scattering (SERS) performance. The electric field distributions were calculated using finite-difference time-domain analysis to further prove that the SERS enhancement of the films is mainly determined by “hot spots” in the interparticle gap between Ag nanoparticles. The detection limit of the Ag film/Ag nanoparticles/Mo–Ag alloy film for Rhodamine 6G probe molecules was 5 × 10−14 mol/L. Therefore, the novel type of the Ag film/Ag nanoparticles/Mo–Ag alloy film can be used as an ideal SERS-active substrate for low-cost and large-scale production.

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Li, Mei-Xian, Yu Ren, Dasom Lee, and Sung-Woong Choi. "Crystallization Behavior and Electrical Properties of Nanoparticle-Reinforced Poly(lactic Acid)-Based Films." Polymers 14, no. 1 (January 2, 2022): 177. http://dx.doi.org/10.3390/polym14010177.

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Graphene oxide (GO) and multiwalled carbon nanotubes with silver particles (MWNT-Ag) of different concentrations were used as nanofillers to prepare poly(lactic acid) (PLA) nanoparticle films through the solvent casting method. In this study, the effects of nanoparticles on the crystallization behavior, relationships between the dispersion and electrical properties, and hydrolytic degradation behaviors were investigated for the PLA/MWNT-Ag and PLA/rGO films. Differential scanning calorimetry was used to evaluate the crystallization behaviors of the PLA/MWNT-Ag and PLA/reduced GO (rGO) films. Electron probe microanalysis was performed to characterize the dispersion of MWNT-Ag, and X-ray diffraction and Raman spectroscopy were used to determine the degree of dispersion of rGO in the PLA matrix. The results showed that nanoparticles enhanced the crystallization kinetics of PLA as well as the hydrolytic degradation rate. From the measurement of electrical properties, the electrical conductivity of PLA/MWNT-Ag 1.0 wt% was much higher than that of the pure PLA and PLA/rGO films, showing that MANT and Ag nanoparticles contribute greatly to enhancing the electrical conductivity of the PLA/MWNT-Ag films.

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Photiphitak, Chanu, Pattana Rakkwamsuk, Pennapa Muthitamongkol, and Chanchana Thanachayanont. "A Combined Effect of Plasmon Energy Transfer and Recombination Barrier in a Novel TiO2/MgO/Ag Working Electrode for Dye-Sensitized Solar Cells." International Journal of Photoenergy 2015 (2015): 1–10. http://dx.doi.org/10.1155/2015/795138.

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Novel TiO2/MgO/Ag composite electrodes were applied as working electrodes of dye-sensitized solar cells (DSSCs). The TiO2/MgO/Ag composite films were prepared by dip coating method for MgO thin films and photoreduction method for Ag nanoparticles. The MgO film thicknesses and the Ag nanoparticle sizes were in ranges of 0.08–0.46 nm and 4.4–38.6 nm, respectively. The TiO2/MgO/Ag composite films were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The TiO2/MgO/Ag composite electrodes were sensitized by immersing in a 0.3 mM of N719 dye solution and fabricated for conventional DSSCs.J-Vcharacteristics of the TiO2/MgO/Ag DSSCs showed that the MgO film thickness of 0.1 nm and the Ag nanoparticle size of 4.4 nm resulted in maximum short circuit current density and efficiency of 8.6 mA/cm2and 5.2%, respectively. Electrochemical Impedance Spectroscopy showed that such values of short circuit current density and efficiency were optimal values obtained from plasmon energy transfer by 4.4 nm Ag nanoparticles and recombination barrier by the ultrathin MgO film.

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Lee, Kwang Se, Isheunesu Phiri, Sang Hern Kim, Kyeongkeun Oh, and Jang Myoun Ko. "Preparation and Electrical Properties of Silicone Composite Films Based on Silver Nanoparticle Decorated Multi-Walled Carbon Nanotubes." Materials 14, no. 4 (February 17, 2021): 948. http://dx.doi.org/10.3390/ma14040948.

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The electrical properties of silicone composite films filled with silver (Ag) nanoparticle-decorated multi-walled carbon nanotubes (MWNT) prepared by solution processing are investigated. Pristine MWNT is oxidized and converted to the acyl chloride-functionalized MWNT using thionyl chloride, which is subsequently reacted with amine-terminated poly(dimethylsiloxane) (APDMS). Thereafter, APDMS-modified MWNT are decorated with Ag nanoparticles and then reacted with a poly(dimethylsiloxane) solution to form Ag-decorated MWNT silicone (Ag-decorated MWNT-APDMS/Silicone) composite. The morphological differences of the silicone composites containing Ag-decorated MWNT and APDMS-modified MWNT are observed by transmission electron microscopy (TEM) and the surface conductivities are measured by the four-probe method. Ag-decorated MWNT-APDMS/Silicone composite films show higher surface electrical conductivity than MWNT/silicone composite films. This shows that the electrical properties of Ag-decorated MWNT-APDMS/silicone composite films can be improved by the surface modification of MWNT with APDMS and Ag nanoparticles, thereby expanding their applications.

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Shankar, S., L. Jaiswal, P. R. Selvakannan, K. S. Ham, and J. W. Rhim. "Gelatin-based dissolvable antibacterial films reinforced with metallic nanoparticles." RSC Advances 6, no. 71 (2016): 67340–52. http://dx.doi.org/10.1039/c6ra10620j.

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Mohapatra, S., Y. K. Mishra, J. Ghatak, D. Kabiraj, and D. K. Avasthi. "Surface Plasmon Resonance of Ag Nanoparticles Embedded in Partially Oxidized Amorphous Si Matrix." Journal of Nanoscience and Nanotechnology 8, no. 8 (August 1, 2008): 4285–89. http://dx.doi.org/10.1166/jnn.2008.an30.

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Nanocomposite films containing Ag nanoparticles embedded in partially oxidized amorphous Si matrix were deposited on silica glass substrates by co-sputtering of Ag and Si with 1.5 keV neutral Ar atoms. The Ag content and thickness of the nanocomposite films was determined by Rutherford backscattering spectrometry. Optical absorption studies revealed the presence of surface plasmon resonance (SPR) indicating the formation of Ag nanoparticles in the as-deposited films. The position, width and strength of SPR have been found to be strongly dependent on the Ag content of the films. For annealing in oxidizing atmosphere, a significant red shift in the SPR along with a drastic reduction in the resonant absorption has been observed. The amount of red shift has been found to be dependent on the Ag content of the films. Transmission electron microscopy was used to study the size distribution, shape and crystal structure of Ag nanoparticles in the nanocomposite films. TEM analysis of annealed sample revealed the formation of silver oxide nanoshells surrounding Ag nanoparticles.

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Puccetti, Matteo, Anna Donnadio, Maurizio Ricci, Loredana Latterini, Giulia Quaglia, Donatella Pietrella, Alessandro Di Michele, and Valeria Ambrogi. "Alginate Ag/AgCl Nanoparticles Composite Films for Wound Dressings with Antibiofilm and Antimicrobial Activities." Journal of Functional Biomaterials 14, no. 2 (February 1, 2023): 84. http://dx.doi.org/10.3390/jfb14020084.

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Recently, silver-based nanoparticles have been proposed as components of wound dressings due to their antimicrobial activity. Unfortunately, they are cytotoxic for keratinocytes and fibroblasts, and this limits their use. Less consideration has been given to the use of AgCl nanoparticles in wound dressings. In this paper, a sustainable preparation of alginate AgCl nanoparticles composite films by simultaneous alginate gelation and AgCl nanoparticle formation in the presence of CaCl2 solution is proposed with the aim of obtaining films with antimicrobial and antibiofilm activities and low cytotoxicity. First, AgNO3 alginate films were prepared, and then, gelation and nanoparticle formation were induced by film immersion in CaCl2 solution. Films characterization revealed the presence of both AgCl and metallic silver nanoparticles, which resulted as quite homogeneously distributed, and good hydration properties. Finally, films were tested for their antimicrobial and antibiofilm activities against Staphylococcus epidermidis (ATCC 12228), Staphylococcus aureus (ATCC 29213), Pseudomonas aeruginosa (ATCC 15692), and the yeast Candida albicans. Composite films showed antibacterial and antibiofilm activities against the tested bacteria and resulted as less active towards Candida albicans. Film cytotoxicity was investigated towards human dermis fibroblasts (HuDe) and human skin keratinocytes (NCTC2544). Composite films showed low cytotoxicity, especially towards fibroblasts. Thus, the proposed sustainable approach allows to obtain composite films of Ag/AgCl alginate nanoparticles capable of preventing the onset of infections without showing high cytotoxicity for tissue cells.

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Goyal, Alisha, Jyoti Rozra, Isha Saini, Pawan K. Sharma, and Annu Sharma. "Refractive Index Tailoring of Poly(methylmethacrylate) Thin Films by Embedding Silver Nanoparticles." Advanced Materials Research 585 (November 2012): 134–38. http://dx.doi.org/10.4028/www.scientific.net/amr.585.134.

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Nanocomposite films of Poly (methylmethacrylate) with different concentration of silver nanoparticles were prepared by ex-situ method. Firstly, silver nanoparticles were obtained by reducing the aqueous solution of silver nitrate with sodium borohydride then Ag-PMMA films were prepared by mixing colloidal solution of silver nanoparticles with solution of polymer. Thin solid films were structurally characterized using UV-VIS spectroscopy and TEM. The appearance of surface plasmon resonance peak, characteristic of silver nanoparticles at 420 nm in UV-VIS absorption spectra of Ag-PMMA films confirms the formation of Ag-PMMA nanocomposite. TEM showed Ag nanoparticles of average size 8 nm embedded in PMMA matrix. Analysis of absorption and reflection data indicates towards the reduction in optical band gap and increase in refractive index of the resulting nanocomposite. The synthesized Ag-PMMA nanocomposite has been found to be more conducting than PMMA as ascertained using I-V studies. The decrease in band gap and increase in conductivity can be correlated due to the formation of localized electronic states in PMMA matrix due to insertion of Ag nanoparticles. The PMMA thin films with dispersed silver nanoparticles may be useful for nanophotonic devices.

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Lang, Jianghua, Kazuma Takahashi, Masaru Kubo, and Manabu Shimada. "Ag-Doped TiO2 Composite Films Prepared Using Aerosol-Assisted, Plasma-Enhanced Chemical Vapor Deposition." Catalysts 12, no. 4 (March 23, 2022): 365. http://dx.doi.org/10.3390/catal12040365.

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TiO2 is a promising photocatalyst, but its large bandgap restricts its light absorption to the ultraviolet region. The addition of noble metals can reduce the bandgap and electron-hole recombination; therefore, we prepared TiO2-Ag nanoparticle composite films by plasma-enhanced chemical vapor deposition (PECVD) using a mixture of aerosolized AgNO3, which was used as a Ag nanoparticle precursor, and titanium tetraisopropoxide, which acted as the TiO2 precursor. Notably, the use of PECVD enabled a low process temperature and eliminated the need for pre-preparing the Ag nanoparticles, thereby increasing the process efficiency. The structures and morphologies of the deposited films were characterized by ultraviolet (UV)—visible spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and energy-dispersive X-ray spectroscopy, and the effects of the AgNO3 concentration on the photocatalytic activity of the deposited films were determined by assessing the degradation of methylene blue under UV light irradiation. The Ag ions were successfully reduced to metallic nanoparticles and were embedded in the TiO2 film. The best photocatalytic activity was achieved for a 1 wt% Ag-loaded TiO2 composite film, which was 1.75 times that of pristine TiO2.

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Joshi, Rakesh Kumar, and Frank Einar Kruis. "Size-Selected SnO1.8: Ag Mixed Nanoparticle Films for Ethanol, CO, and CH4Detection." Journal of Nanomaterials 2007 (2007): 1–5. http://dx.doi.org/10.1155/2007/67072.

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Mixed nanoparticle films of SnO1.8: Ag prepared by the gas phase condensation method using an aerosol route have been used for the detection of CO and CH4. Particle size as estimated by transmission electron microscopy is 20 nm for both SnO1.8and Ag nanoparticles. The gas-sensing behavior of the films for these gases has been studied in detail as a function of Ag concentration in the films. A study has been made in order to distinguish the size effect and specific surface area effect in the ethanol gas-sensing behavior of SnO1.8: Ag mixed nanoparticle films. This distinction, which has not been possible using the traditional methods of the sensor fabrication, gives evidence of the dominance of size effect of the metal dopant over the surface area effect in the gas sensing of the films. The sensors show also an increased sensor signal with increase of Ag concentration in the films for CO and CH4. It is observed from the comparative study of the sensing behavior of SnO1.8: Ag films for CO and CH4that the sensors are more sensitive towards CO as compared to CH4. The mixed nanoparticle films were also used for the detection of CO at 100 ppm level.

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Mohammad Naim, Norshafadzila, Huda Abdullah, Noor Azwen Noor Azmy, Aidil Abdul Hamid, Mohd Ambar Yarmo, Akrajas Ali Umar, Sahbudin Shaari, Wan Hanna Melini Wan Mokhtar, and Zurina Osman. "Synthesis and Characterization of PVA-Ag Doped Metals (Co, Al) Nanocomposite Thin Films Biosensors for Detection of E. coli in Water." Advanced Materials Research 1107 (June 2015): 706–11. http://dx.doi.org/10.4028/www.scientific.net/amr.1107.706.

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Polyvinyl alcohol (PVA) doped with Ag thin films were synthesized from aqueous solution via sol gel method. The nanoparticle of silver was synthesized by chemical reduction using hydrazine hydrate. PVA-Ag thin films were deposited on the glass substrate by spin coating technique. Samples were varied with different combinations of metals such as Ag-Co and Ag-Al. The solutions and the films were characterized by using XRD, UV-Visible spectroscopy, AFM and TEM. XRD analysis indicates the formation of the single crystal Ag, Co and Al nanoparticles laid on (111) lattice planes. The crystallite sizes decrease when Co and Al are added to the PVA-Ag. UV-Vis absorption spectra confirmed the formation of Ag nanoparticles in the PVA matrix and the resonance plasmon band located at 417, 421 and 429 nm. Surface roughness of PVA-Ag nanocomposite thin film increased with the addition of Co and Al. TEM images show the non-agglomerated spherical particles in all samples. The performance of the sensor has been fabricated usingI-Vmeasurement with and without incubated the sensor electrode intoE. coli. The result shows PVA-Ag nanocomposite thin film performed the higher sensitivity.

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Boonyeun, Nichapat, Ratana Rujiravanit, and Nagahiro Saito. "Plasma-Assisted Synthesis of Multicomponent Nanoparticles Containing Carbon, Tungsten Carbide and Silver as Multifunctional Filler for Polylactic Acid Composite Films." Polymers 13, no. 7 (March 24, 2021): 991. http://dx.doi.org/10.3390/polym13070991.

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Multicomponent nanoparticles containing carbon, tungsten carbide and silver (carbon-WC-Ag nanoparticles) were simply synthesized via in-liquid electrical discharge plasma, the so-called solution plasma process, by using tungsten electrodes immersed in palm oil containing droplets of AgNO3 solution as carbon and silver precursors, respectively. The atomic ratio of carbon:W:Ag in carbon-WC-Ag nanoparticles was 20:1:3. FE-SEM images revealed that the synthesized carbon-WC-Ag nanoparticles with particle sizes in the range of 20–400 nm had a spherical shape with a bumpy surface. TEM images of carbon-WC-Ag nanoparticles showed that tungsten carbide nanoparticles (WCNPs) and silver nanoparticles (AgNPs) with average particle sizes of 3.46 nm and 72.74 nm, respectively, were dispersed in amorphous carbon. The carbon-WC-Ag nanoparticles were used as multifunctional fillers for the preparation of polylactic acid (PLA) composite films, i.e., PLA/carbon-WC-Ag, by solution casting. Interestingly, the coexistence of WCNPs and AgNPs in carbon-WC-Ag nanoparticles provided a benefit for the co-nucleation ability of WCNPs and AgNPs, resulting in enhanced crystallization of PLA, as evidenced by the reduction in the cold crystallization temperature of PLA. At the low content of 1.23 wt% carbon-WC-Ag nanoparticles, the Young’s modulus and tensile strength of PLA/carbon-WC-Ag composite films were increased to 25.12% and 46.08%, respectively. Moreover, the PLA/carbon-WC-Ag composite films possessed antibacterial activities.

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KIM, YOUNG HWAN, CHANG WOO KIM, HYUN GIL CHA, BYOUNG KEE JO, GI WOONG AHN, EUN SUK HONG, and YOUNG SOO KANG. "PREPARATION OF ANTIBACTERIAL SILVER-CONTAINING SILICA NANOCOMPOSITE." Surface Review and Letters 15, no. 01n02 (February 2008): 117–22. http://dx.doi.org/10.1142/s0218625x08011093.

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Ag nanoparticle deposition on the surface of spherical SiO 2 nanoparticles was studied to achieve hybrid structure of Ag – SiO 2 nanocomposite. SiO 2 nanoparticles were served as seeds for continuous Ag metal deposition. The ratio of elements and morphology was studied with scanning electron microscope energy dispersive X-ray and transmission electron microscope. The antibacterial properties of Ag – SiO 2 nanocomposite were examined. The homogeneously formed Ag nanoparticles on the surface of SiO 2 nanoparticles without aggregation of Ag nanoparticles showed excellent antibacterial abilities.

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Huang, Hu, Lingqiong Wu, Shengbin Cheng, Xiaofeng Wu, Shiping Zhan, and Yunxin Liu. "Upconversion nanoparticle–Ag@C@Ag composite films for rapid temperature sensing." CrystEngComm 23, no. 17 (2021): 3133–43. http://dx.doi.org/10.1039/d0ce01873b.

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Liu, Xingzuo, Zhuo Chen, Yue Zhao, Yue Shen, Yun Guo, Jian Huang, Jiahua Min, and Linjun Wang. "The study of metal enhanced fluorescence property of Ag/ZnO composite structure." Modern Physics Letters B 31, no. 07 (March 10, 2017): 1750073. http://dx.doi.org/10.1142/s0217984917500737.

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In this paper, Ag nanoparticles were successfully prepared by chemical reduction, and then Ag/ZnO composite particles were successfully prepared and deposited onto glass substrates to form Ag/ZnO thin films. Hereafter, the structure, the morphology and the metal enhanced fluorescence (MEF) property of Ag nanoparticles and ZnO/Ag composite particles were studied by XRD, SEM, EDS, TEM, UV-vis absorption and fluorescence (FL) spectrometer. The results showed that the average size of Ag nanoparticles increased with the increase of prepared time. Moreover, ZnO layer consisted of polycrystalline structure and amorphous interface layer, but nano-Ag particle was polycrystalline structure. Annealing process was carried out to investigate the influence of annealing process parameters on MEF property of Ag/ZnO composite structure. Due to annealing treatment, the amorphous component of Ag/ZnO thin films was reduced, which might improve the density of Ag/ZnO thin films and the diameter of composite particles. Furthermore, FL enhancement phenomenon of fluorescein isothiocyanate (FITC) molecules might be attributed to the joint influence of the roughness and the density of these films and the average diameter of composite particles.

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Jin, Wei, Shilin Yan, Wen Chen, Shuang Yang, Chunxia Zhao, and Ying Dai. "Preparation and gas sensing property of Ag-supported vanadium oxide nanotubes." Functional Materials Letters 07, no. 03 (June 2014): 1450031. http://dx.doi.org/10.1142/s1793604714500313.

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A facile microwave irradiation was used to synthesize Ag nanoparticle supported on vanadium oxide nanotubes (VONTs) in this paper. The VONTs on alumina tube installed with Pt electrodes were tested for gas sensing towards C 2 H 5 OH , NH 3 and C 6 H 5 CH 3 gases. Detailed studies showed that the sensing capabilities were greatly enhanced in comparison to those of pure nanotubes. It was found that the Ag nanoparticles supported on VONTs sensing films exhibited a high C 2 H 5 OH selectivity compared with NH 3 and C 6 H 5 CH 3 gases. When the sensor is exposed to C 2 H 5 OH , the ethanol molecules interact with the preadsorbed oxygen ions on the Ag nanoparticles surface. The ethanol oxidation on the Ag nanoparticles leads to the transfer of electrons into the semiconducting VONTs and this is reflected as the change in conductance of sensor. The presence of Ag nanoparticles on the surface of VONTs serves to enhance the C 2 H 5 OH oxidation due to a higher oxygen ion-chemisorption on the conductive Ag nanoparticle surfaces.

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Wassfi, Ahmad S. "Characterization of silver polyaniline nanocomposite thin films prepared by microwave induced plasma." Iraqi Journal of Physics (IJP) 13, no. 28 (February 4, 2019): 1–9. http://dx.doi.org/10.30723/ijp.v13i28.237.

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Polyaniline (PANI) and Ag/PANI nanocomposite thin films have prepared by microwave induced plasma. The Ag powder of average particle size of 50 nm, were used to prepare Ag/PANI nanocomposite thin films. The Ag/PANI nanocomposite thin films prepared by polymerization in plasma and characterized by UV-VIS, FTIR, AFM and SEM to study the effect of silver nanoparticles on the optical properties, morphology and structure of the thin films. The optical properties studies showed that the energy band gap of the Ag/PANI (5%wt silver) decreased from 3.6 to 3.2 eV, where the substrate location varied from 4.4 to 3.4 cm from the axis of the cylindrical plasma chamber. Also the optical energy gap decreased systematically from 3.3 to 3 eV with increasing Ag nanoparticles, where Ag concentration increased from 5% to 11%wt. The FTIR measurement showed a shifting in the FTIR absorption peaks with Ag concentration. AFM and SEM images indicate that there are a few clusters of Ag and there is a uniform distribution of the Ag nanoparticles in the PANI matrix. It can be concluded that Ag/PANI nanocomposite thin films with controlled optical energy band gap can be prepared by microwave induced plasma technique.

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Ghosh, S., and Arpita Ray. "Silver nano particles from low dilution homeopathic medicine." American Journal of Applied Bio-Technology Research 2, no. 1 (January 1, 2021): 34–48. http://dx.doi.org/10.15864/ajabtr.215.

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Recently there have been many attempts for the biosynthesis of silver or gold nano particles from plant (root, leaves, stem etc.) extracts. In the present article, we have shown, for the first time, that low dilution China or Cina (Homeopathic medicines both of strength theta) can also dissociate AgNO3 producing Ag nanoparticles. We have stabilized these Ag nanoparticles in some bioactive polymers (like polyvinyl alcohol ,PVA) and studied their electrical and dielectric properties. Enhancement of conductivity and dielectric constants of these Ag stabilized polymer nanocomposite films compared to those of the corresponding pure polymer films indicated the presence of Ag nanoparticles in the films.

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Dimitrijevic, R., O. Cvetkovic, Z. Miodragovic, M. Simic, D. Manojlovic, and V. Jovic. "SEM/EDX and XRD characterization of silver nanocrystalline thin film prepared from organometallic solution precursor." Journal of Mining and Metallurgy, Section B: Metallurgy 49, no. 1 (2013): 91–95. http://dx.doi.org/10.2298/jmmb120111041d.

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The Ag nano-structured thin films prepared on flat glass substrates have been studied. The ball-like silver nanoparticles have been synthesized in large quantity by using a modified method of hydrolytic decomposition of silver complexes with amino types ligands formed in ethanol aqueous solution. SEM analysis revealed that Ag nanoparticles are all sphere shaped with bimodal size (40 and 70 nm) distribution. The results of XRD powder pattern examination show that Ag nanoparticles are pure phase, well crystallized. The unit cell dimensions measured on synthesized Ag nano films show small but frequent contraction in comparison to Ag metal standard.

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Badán, Juan Agustín, Elena Navarrete-Astorga, Rodrigo Henríquez, Francisco Martín Jiménez, Daniel Ariosa, José Ramón Ramos-Barrado, and Enrique A. Dalchiele. "Silver Nanoparticle Arrays onto Glass Substrates Obtained by Solid-State Thermal Dewetting: A Morphological, Structural and Surface Chemical Study." Nanomaterials 12, no. 4 (February 11, 2022): 617. http://dx.doi.org/10.3390/nano12040617.

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Silver nanoparticles (NPs) on glass substrates were obtained by a solid-state thermal dewetting (SSD) process using vacuum-evaporated-silver precursor layers. An exhaustive investigation of the morphological, structural, and surface chemistry properties by systematically controlling the precursor film thickness, annealing temperature, and time was conducted. Thin silver films with thicknesses of 40 and 80 nm were deposited and annealed in air by applying a combined heat-up+constant temperature–time program. Temperatures from 300 to 500 °C and times from 0 to 50 min were assayed. SSD promoted the morphological modification of the films, leading to the Ag NPs having a discrete structure. The size, shape, surface density, and inter-nanoparticle distance of the nanoparticles depended on the initial film thickness, annealing temperature, and time, exhibiting a cubic silver structure with a (111) preferred crystallographic orientation. The prepared NPs were found to be highly enriched in the Ag{111}/Ag{110}/Ag{100} equilibrium facets. SSD not only promotes NP formation but also promotes the partial oxidation from Ag to AgO at the surface level. AgO was detected on the surface around the nanoparticles synthesized at 500 °C. Overall, a broad framework has been established that connects process factors to distinguish resultant Ag NP features in order to develop unique silver nanoparticles for specific applications.

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Shen, Xingwang, Junjie Li, and Shuang Xi. "High Strength Die-Attach Joint Formation by Pressureless Sintering of Organic Amine Modified Ag Nanoparticle Paste." Nanomaterials 12, no. 19 (September 26, 2022): 3351. http://dx.doi.org/10.3390/nano12193351.

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Sintered silver (Ag) die-attach has attracted much attention in power systems with high power density and high operating temperature. In this paper, we proposed a novel surface modification method for Ag nanoparticles with organic amines as a coating agent for enhancing the pressureless sintering performance. This work systematically introduced the Ag nanoparticle modification process, Ag paste preparation, and sintering process and compared the changes in the sintering performance of Ag nanoparticles after modification with four different alkyl chain lengths of amines. The study showed that the sintered films of Ag nanoparticle pastes modified with n-octylamine (NOA) can achieve the lowest resistivity of the sintered film and the highest shear strength of the bonded joints. The resistivity of the sintered Ag film is affected by the grain size and microscopic morphology, and the strength of the bonded joints is also related to the sintering density and the amount of organic residues. The thermal behavior of the Ag particles coated with different amines is measured by thermal analysis. Finally, the mechanism of NOA-modified Ag nanoparticles to improve the sintering performance is proposed. This study can provide effective data and theoretical support for the further promotion and application of nano-Ag pressureless sintering.

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Bourfaa, Fouzia, Abderhamane Boutelala, Mohamed Salah Aida, Nadir Attaf, and Fateh Merouane. "Antibacterial activity of zinc oxide with silver nanoparticles." World Journal of Environmental Research 7, no. 2 (January 3, 2018): 98–107. http://dx.doi.org/10.18844/wjer.v7i2.2971.

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Nanoscale materials and their unique properties make them attractive for research and health -related applications. Silver nanoparticles were synthesised and incorporated in zinc oxide (ZnO) thin films on glass and tissue, in order to study their effect on antibacterial activity. ZnO films with various contents of Ag nanoparticles were prepared by the sol –gel method. Xray diffraction revealed the polycrystalline structure of the films, scanning electron microscopy exhibited their dense and continuous structure and UV-visible spectroscopy for measurement and transmittance was at more than 87%. The absorbance peak of Ag NPS was centred at 351 nm. The diameter of Ag NPS was analysed by Zeta Sizer and the colloids ranged from 2 to 110 nm. The results indicate that ZnO with Ag NPs on tissue can resist the growth of this kind of bacteria, with the zone of inhibition of the bacteria ATTC 700603 at between 8 and 18 mm .Keywords: Ag nanoparticles, zinc oxide, tissue, antibacterial activity.

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Suphasorn, Pawanrat, Intuorn Appamato, Viyada Harnchana, Prasit Thongbai, Chalathorn Chanthad, Chomsri Siriwong, and Vittaya Amornkitbamrung. "Ag Nanoparticle-Incorporated Natural Rubber for Mechanical Energy Harvesting Application." Molecules 26, no. 9 (May 6, 2021): 2720. http://dx.doi.org/10.3390/molecules26092720.

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The energy conversion performance of the triboelectric nanogenerator (TENG) is a function of triboelectric charges which depend on the intrinsic properties of materials to hold charges or the dielectric properties of triboelectric materials. In this work, Ag nanoparticles were synthesized and used to incorporate into natural rubber (NR) in order to enhance the dielectric constant for enhancing the electrical output of TENG. It was found that the size of Ag nanoparticles was reduced with the increasing CTAB concentration. Furthermore, the CTAB surfactant helped the dispersion of metallic Ag nanoparticles in the NR-insulating matrix, which promoted interfacial polarization that affected the dielectric properties of the NR composite. Ag nanoparticle-incorporated NR films exhibited an improved dielectric constant of up to almost 40% and an enhanced TENG performance that generated the highest power density of 262.4 mW/m2.

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Delgado González, Diana Catherine, Andrés Di Donato, Paolo Nicolas Catalano, and Martín Gonzalo Bellino. "Silver Nanoparticle-Based Arrays into Mesoporous Thin Films Structures for Photoelectronic Circuits." Current Nanoscience 15, no. 3 (February 19, 2019): 304–8. http://dx.doi.org/10.2174/1573413714666180716153501.

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Background: Silver nanosystems have attracted considerable attention for numerous applications in optoelectronics. The localized surface plasmon of silver nanoparticles embedded into mesoporous titania gives rise to an enhancement of local optical field in the vicinity of Ag nanoparticles which act as efficient light-trapping components, resulting in a visible wavelength-dependent photocurrent. Objective: In this paper, we synthetized patterned nanocomposites formed by titania mesoporous thin films loaded with alkanethiol functionalized Ag nanoparticles and we demonstrated that these stable and accessible nanostructures possess a photocurrent response. Method: Mesoporous thin films are created by combining sol-gel synthesis and template selfassembly. Based on a photolithography technique, silver nanoparticles were selectively photodeposited and then stabilized with octanethiols. Current vs. voltage curves with and without light were compared, where selective light wavelength measurements were achieved by using visible bandpass filters. The optofluidic behavior was evaluated by placing a drop of solutions on the mesoporous film. Results: We demonstrate photocurrent in these mesoporous thin film structures decorated with chemistabilized Ag nanoparticle-based conductive arrays, with significantly enhanced photocurrent peak at the plasmon resonant wavelength around 540 nm. Our findings offer a possibility to perform improved fluid detection with silver-mesoporous titania electronic devices. Conclusion: We showed that an optofluidic sensitive nanocomposite circuit consisting of alkanethiol- functionalized metal nanoparticles embedded in a mesoporous oxide thin film matrix can be produced.

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Chang, Gang, Ichiro Tanahashi, and Munetaka Oyama. "Localized surface plasmon resonance sensing properties of photocatalytically prepared Ag/TiO2 films." Journal of Materials Research 25, no. 1 (January 2010): 117–23. http://dx.doi.org/10.1557/jmr.2010.0012.

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Photocatalytic deposition of Ag nanoparticles from a mixed aqueous solution of AgNO3 and polyvinylpyrrolidone (PVP) onto TiO2 film supported on indium-tin oxide-coated glass slide (Ag/TiO2 film) was carried out by using UV light irradiation. The size and shape of the Ag nanoparticles were controlled by the addition of PVP during the photodeposition. In the optical absorption spectra of the Ag/TiO2 film, the localized surface plasmon resonance (LSPR) absorption of the Ag nanoparticles was observed. When the film was immersed in various kinds of alcohols with the refractive index at 20°C (), ranging between 1.3292 and 1.4103, the peak LSPR absorption was shifted to longer wavelengths and the peak absorbance increased with increasing . The spectral change of the Ag/TiO2 film with larger spherical Ag nanoparticles was more prominent than that with smaller ones.

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CHA, HWA JIN, YOUNG HWAN KIM, HYUN GIL CHA, and YOUNG SOO KANG. "PREPARATION AND CHARACTERIZATION OF Ag(CORE)/SiO2(SHELL) NANOPARTICLES." Surface Review and Letters 14, no. 04 (August 2007): 693–96. http://dx.doi.org/10.1142/s0218625x07009943.

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Ag nanoparticles were synthesized by using thermal decomposition of Ag +–oleate complex. The mean size of Ag nanoparticle was confirmed as 10 nm with transmission electron microscopy (TEM). The crystal structure and optical property of Ag nanoparticles were studied with X-ray powder diffraction (XRD) and UV–vis spectroscopy, respectively. The Ag nanoparticles were used as seeds for Ag (core)/ SiO 2(shell) nanocomposite particles. TEM images of Ag (core)/ SiO 2(shell) nanocomposite particles showed that silver core was coated with 15 nm thickness of SiO 2 shell. The thickness of SiO 2 shells could be conveniently controlled by changing the concentration of sol–gel precursor or reaction time. The composition of Ag (core)/ SiO 2(shell) nanocomposite particle was investigated with energy-dispersive X-ray (EDX) spectrometer.

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Zong, Rui Long, Ji Zhou, Shi Kao Shi, and Long Tu Li. "Synthesis and Optical Properties of Metal Nanoparticles Embedded in Porous Anodic Alumina Oxide." Materials Science Forum 475-479 (January 2005): 4093–96. http://dx.doi.org/10.4028/www.scientific.net/msf.475-479.4093.

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We have improved an electrochemical process in which the alternate current (AC) electrodeposition combined with the etching of substrate to prepare transparent metallic nanoparticles and anodic alumina oxide (AAO) composite films. The new process greatly simplifies the direct current (DC) electrodeposition process to get transparent composite films. Moreover, the electrocrystallization mechanism has been analyzed. The Ag, Cu and Ag-Cu co-deposited nanoparticles/AAO films have distinct absorption peaks, which can be ascribed to the surface plasmon resonance (SPR) of these noble metal nanoparticles.

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Yokoyama, Eisuke, Hironobu Sakata, and Moriaki Wakaki. "Sol-gel synthesis and characterization of Ag nanoparticles in ZrO2 thin films." Journal of Materials Research 24, no. 8 (August 2009): 2541–46. http://dx.doi.org/10.1557/jmr.2009.0314.

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ZrO2 thin films containing silver nanoparticles were prepared using the sol-gel method with Ag to Zr molar ratios [Ag]/[Zr] = 0.11, 0.25, 0.43, 0.67, 1.00, 1.50, and 2.33. After dip coating on glass substrate, coated films were annealed at 200 and 300 °C in air. X-ray diffraction peaks corresponding to crystalline Ag were observed, but a specific peak corresponding to ZrO2 was not observed. At the molar ratio [Ag]/[Zr] = 0.25, the particle size of Ag distributed broadly centered at 17 nm for an annealing temperature of 200 °C and at 25 nm for 300 °C. The films annealed in air at 200 °C showed an absorption band centered at 450 nm because of the silver surface plasmon resonance, whereas films heated at 300 °C in air caused a red shift of the absorption to 500 nm. The absorption peak was analyzed using the effective dielectric function of Ag-ZrO2 composite films modeled with the Maxwell-Garnett expression.

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Nasar, Gulfam, Hazrat Amin, Fawad Ahmad, and Shahbaz Nazir. "Structural and Thermal Behavior Evaluation of Ag-PVA Nanocomposites Synthesized via Chemical Reduction Technique." Journal of Materials and Physical Sciences 1, no. 1 (June 30, 2020): 19–25. http://dx.doi.org/10.52131/jmps.2020.0101.0003.

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Silver nanoparticles were prepared via process of chemical reduction using sodium borohydride as reductant. The prepared nanoparticles were then utilized for synthesizing various compositions of nanocomposites with polymeric matrix of poly (vinyl alcohol). For doing so, the nanoparticles were dispersed in the polymer solution by vigorous stirring. The solutions of the nanocomposites were cast in films. The nanocomposite films were used for various characterization techniques; out of which three are being reported in this communication; XRD, TGA/DTA and SEM. The upshot of XRD proposes a semi-crystalline nature of synthesized nanocomposite. The crystalline character of the nanocomposite enhances with an increasing doping concentration of the prepared nanoparticles. Thermal analysis suggests the degradation pattern of the polymer nanocomposite material and represents that thermal stability improves as the silver nanoparticles are added. The SEM micrograph reveals a uniform surface with a well dispersed nanoparticle in the polymer matrix.

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Sharma, Shikha, and Fehmeeda Khatoon. "Bio-Synthesis and Characterization of CS–Ag Nano Hydrogel for Antibacterial Application." Advanced Science, Engineering and Medicine 12, no. 4 (April 1, 2020): 542–47. http://dx.doi.org/10.1166/asem.2020.2543.

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An environmental technique of herbal mediated blend of Ag nanoparticles is a substantial stage in the ground of nanotechnology. Chitosan (CS) is a polymer which is biocompatible and antibacterial. In this work, we have synthesized CS–Ag Nano hydrogel which is form with chitosan-based hydrogel merged in the herbal synthesized Ag nanoparticles. These green synthesized Ag-nanoparticles made from Polygonum bistorta plant leaves and described with the assistance of UV-vis spectrophotometer, and Dynamic Light Scattering (DLS). In this work our main focus to synthesized CS–Ag Nano hydrogel. These hydrogel was described by Fourier transform infrared (FTIR) spectroscopic method, X-ray diffraction (XRD) method, and contact angle. Nanoparticle size distribution was within 1 to 100 nm by DLS and the optimum wavelength was noted in 400 to 450 nm by UV-vis spectroscopic readings. A good antibacterial behavior has been displayed by these synthesized CS–Ag Nano hydrogel films against both E. coli (gram –ve) and S. aureus (gram +ve) with the maximum 7 mm inhibition zone.

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Gao, Can, Tan Guo, Xiu Shen Ye, Hui Fang Zhang, Hai Ning Liu, and Zhi Jian Wu. "Adsorption of Silver Nanoparticles on Modified Surfaces." Key Engineering Materials 645-646 (May 2015): 75–79. http://dx.doi.org/10.4028/www.scientific.net/kem.645-646.75.

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Uniform films of silver nanoparticles (Ag NPs) were fabricated by self-assembly on 3-aminopropyltriethoxysilane (APTES) and [3-(2-aminoethyl) aminopropyl] trimethoxysilane (AEAPTES) modified glass slides. A stable Ag NPs suspension was synthesized via the reduction of silver nitrate using sodium citrate. Bulk characteristics of Ag NPs in aqueous solution were carried out by measuring their absorption spectrum, morphology and particle shape using the UV-vis absorption spectroscopy and transmission electron microscopy (TEM), respectively. The average diameter of Ag NPs is about 50 nm. The coverage of adsorbed particles on the modified glasses was measured by scanning electron microscopic imaging (SEM). The SEM images indicate that the Ag NPs films on the glasses are uniform. It is supposed that the adsorption processes are mainly controlled by electrostatic interactions. The adsorption amount of Ag NPs on APTES modified glass slides is much more than the amount on AEAPTES modified glass slides.

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Hosseinpour-Moghadam, Reza, Shahram Rabbani, Arash Mahboubi, Sayyed Abbas Tabatabai, and Azadeh Haeri. "Prevention of abdominal adhesion by a polycaprolactone/phospholipid hybrid film containing quercetin and silver nanoparticles." Nanomedicine 16, no. 27 (November 2021): 2449–64. http://dx.doi.org/10.2217/nnm-2021-0209.

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Aim: To develop quercetin-loaded poly(caprolactone) (PCL)/soybean phosphatidylcholine (PC) films coated with silver (Ag) to prevent the formation of postoperative adhesions (POA). Materials & methods: Films were prepared using the solvent casting method, coated with Ag, and underwent in vitro tests. In vivo studies were conducted employing an animal model of sidewall defect and cecum abrasion. Results: Films showed sustained release behavior of quercetin and Ag. Coating films with Ag improved their antimicrobial activity. In vivo studies confirmed superior antiadhesion properties of films compared with the control groups evaluated by gross observation, histochemical staining and immunohistochemistry analyses. Conclusion: Ag-Q-PCL-PC films are a potential candidate to prevent POA by acting as a sustained release delivery system and physical barrier.

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Sartale, S. D., and A. A. Ansari. "Growth of Ag Nanoparticles by Spin Coating." Journal of Nano Research 24 (September 2013): 163–67. http://dx.doi.org/10.4028/www.scientific.net/jnanor.24.163.

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Ag nanoparticles were grown on glass substrate by spin coating of Ag ions (AgNO3) solution followed by either chemical reduction, in aqueous hydrazine or NaBH4 solution, or by thermal reduction in H2 environment. Effects of different reducing agent have been explained. Morphology and absorbance spectra ofAg nanoparticles films, measured by using Scanning Electron Microscopy (SEM) and UV-visible Spectrophotometer techniques, are used to understand effect of reduction process on growth of Ag nanoparticles. To grow uniformly size distributed Ag nanoparticles thermal reduction in H2 is better than chemical reduction by aqueous either NaBH4 orhydrazine hydrate solutions.

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Zhao, Zhuo. "Fabrication of Ag-InVO₄ Thin Films and Photocatalytic Degradation of Methylene Blue under Visible Light Irradiation." Advanced Materials Research 578 (October 2012): 69–72. http://dx.doi.org/10.4028/www.scientific.net/amr.578.69.

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InVO4 films were supported on glass springs via a sol-gel method. Ultrafine Ag nanoparticles, with a particle size of 5~10nm, were deposited on the surface of InVO4 films by a photoreduction process. XRD results revealed that high temperature phase of InVO4 (orthorhombic phase) could be obtained at a relatively low temperature (<500°C). The surface of InVO4 films was rough with numerous small grooves and edges. The visible light induced photocatalytic activity of InVO4 films increased by deposition of Ag nanoparticles. Under visible light irradiation, the excited electrons in conduction band of InVO4 could be trapped by small Ag particles, thus limiting the recombination of photogenerated electron-hole pairs.

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Puišo, Judita, Diana Adliene, Algimantas Paškevičius, and Artūras Vailionis. "Investigation of the Antimicrobial Properties of Beetroot–Gelatin Films Containing Silver Particles Obtained via Green Synthesis." Applied Sciences 13, no. 3 (February 2, 2023): 1926. http://dx.doi.org/10.3390/app13031926.

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Silver nanoparticles are produced using various physical, chemical or physicochemical methods. Simple low-cost nontoxic environmentally friendly, or “green”, chemistry methods are important, especially for their invasive application in the medicine and food industries. Silver-nanoparticle-enriched biocompatible films were produced at room temperature from fresh beetroot juice, AgNO3 and gelatin–water solution using the photoreduction method. The optical, morphological and structural characteristics of the experimental samples were analyzed using UV-VIS, XRD and SEM techniques. The antimicrobial activity of newly produced films was investigated using the agar diffusion method. The synthesis of nanoparticles was approved their characteristic LSPR peaks in the UV-VIS absorbance spectra. According to the XRD patterns of the films, these nanoparticles were assigned to the cubic phase of metallic Ag. It was found that the antimicrobial activity of the silver nanoparticles in the beetroot–gelatin films might be effective; however, it depends on the silver ion concentrations used for the production of these films and on the medium’s pH.

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Morales-Luna, Gesuri, and Michael Morales-Luna. "Extinction Coefficient Modulation of MoO3 Films Doped with Plasmonic Nanoparticles: From an Effective Medium Theory Description." Nanomaterials 11, no. 8 (August 12, 2021): 2050. http://dx.doi.org/10.3390/nano11082050.

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This work focused on the application of the effective medium theory to describe the extinction coefficient (Qext) in molybdenum trioxide (MoO3) doped with different kinds of plasmonic nanoparticles, such as silver (Ag), gold (Au), and copper (Cu). Usually, in studies of these materials, it is normal to analyze the transmission or absorption spectra. However, the effect of this type or size of nanoparticles on the spectra is not as remarkable as the effect that is found by analyzing the Qext of MoO3. It was shown that the β-phase of MoO3 enhanced the intensity response of the Qext when compared to the α-phase of MoO3. With a nanoparticle size of 5 nm, the Ag-doped MoO3 was the configuration that presents the best response in Qext. On the other hand, Cu nanoparticles with a radius of 20 nm embedded in MoO3 was the configuration that presented intensities in Qext similar to the cases of Au and Ag nanoparticles. Therefore, implementing the effective medium theory can serve as a guide for experimental researchers for the application of these materials as an absorbing layer in photovoltaic cells.

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Hu, Chen Yang, Xiao Bo Zhang, Xiao Yun Li, and Hui Chen. "Catalytic Membrane and their Photocatalytic Properties." Applied Mechanics and Materials 204-208 (October 2012): 4215–18. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.4215.

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A solution method was developed to synthesized heteronanostructure of Ag nanoparticles on titanate nanowires, and then flexible photocatalytic Films were made by these nanowires. The nanowire is about 50 nm in diameter, several hundreds micrometers in length. The size of the Ag nanoparticle grafted on the nanowire is about 50 to 100 nm. The nanowire Film showed excellent photocatalytic activity to decompose the methamidophos and satisfactory antibacterial effect to kill Escherichia coli.

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Rubish, V. M., V. K. Kyrylenko, M. O. Durkot, L. I. Makar, M. M. Pop, A. A. Tarnaj, M. L. Trunov, S. I. Mudry, and I. I. Shtablavyi. "Rapid formation methods of arrays of randomly distributed Au and Ag nanoparticles, their morphologies and optical characteristics." Physics and Chemistry of Solid State 22, no. 4 (December 30, 2021): 804–10. http://dx.doi.org/10.15330/pcss.22.4.804-810.

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By the method of rapid radiation heating (at a speed of 20-25 K/s) of Au and Ag films with a thickness of 4-35 nm to temperatures of 573-693 K in air and in the process of vacuum deposition of silver on heated (up to 700 K at a heating rate of 10 K/s ) glass substrates formed Au and Ag NPs arrays with nanoparticle sizes from several tens to hundreds of nanometers, the position λSPR of which is in the range of 520-597 nm for Au NPs and 424-509 nm for Ag NPs. It is established that the average size of nanoparticles depends on the thickness of gold and silver films and the annealing temperature. The results testify that glass substrates with arrays of randomly distributed gold NPs can be used as effective SERS-substrates for the investigation of Raman spectra of nanosized (50-100 nm) chalcogenide films.

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Hu, Yang, Chao Pan, Cai Xia Gao, Jun Fan, and En Zhou Liu. "Photocatalytic Water Splitting over Ag/TiO₂ Nano-Wire Films." Applied Mechanics and Materials 665 (October 2014): 288–91. http://dx.doi.org/10.4028/www.scientific.net/amm.665.288.

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Plasmonic Ag decorated TiO2 nano-wire film was firstly prepared by the combination of a hydrothermal method and a microwave-assisted chemical reduction process. The results show that Ag deposited TiO2 film exhibits obvious visible light absorption due to surface plasmon resonance absorption of Ag nanoparticles. Besides, fluorescence quenching is observed in the composite film under the excitation of 250 nm. Photocatalytic tests show that Ag deposited TiO2 exhibits enhanced photocatalytic activity for H2 production by water splitting due to the synergistic effect between charge transfer and surface plasmon resonance absorption properties of Ag nanoparticles.

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WAKAKI, MORIAKI, and EISUKE YOKOYAMA. "DIELECTRIC ANALYSIS ON OPTICAL PROPERTIES OF ZrO2 THIN FILMS DISPERSED WITH SILVER NANOPARTICLES." Journal of Nonlinear Optical Physics & Materials 19, no. 04 (December 2010): 835–47. http://dx.doi.org/10.1142/s0218863510005789.

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ZrO2 thin films containing silver nanoparticles were prepared using the sol-gel method with silver volume fractions from 5.3 to 53.9 %. An amorphous phase was observed for the ZrO2 matrix and a cubic crystalline phase was identified for the Ag nanoparticles by the XRD measurement. The diameter of silver nanoparticles distributed over 25 to 75 nm was analyzed by TEM measurement. The films showed an absorption band centered at 450 nm due to the surface plasmon resonance of silver nanoparticles. The absorption peak was analyzed using the effective dielectric function modeled with both Maxwell-Garnett and Bruggeman expressions. In the small Ag volume fractions, the calculated spectra using Maxwell-Garnett theory agreed well with the measured spectra. In the large Ag volume fraction, the calculated absorption spectra using the Bruggeman model gives a relatively good fitting to the experimental spectrum.

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Fahmy, Alaa. "Silver/Polyethylene Glycol Nanocomposite Thin Films and its Biological Applications." JOURNAL OF ADVANCES IN CHEMISTRY 11, no. 5 (April 18, 2015): 3597–608. http://dx.doi.org/10.24297/jac.v11i5.4478.

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The synthesis of silver nanoparticles with different sizes and concentrations was carried out using NaBH4 as a reducing agent and polyethylene glycol (PEG) as a stabilizer. The thin films of PEG embedded with Ag nanoparticles (Ag NPs) were deposited by electrospray deposition technique (ESD) and the morphology of subsequent prepared films was studied by AFM. Structure-property relationships of the colloid and subsequent films were discussed in dependence on the concentration of NaBH4. The synthesized Ag/PEG nanocomposite solution was characterized by UV-visible spectroscopy and Transmission electron microscopy (TEM). Chemical composition in the whole and on the surface of films were investigated by Fourier transform infrared (ATR-IR) and X-ray photoelectron microscopy (XPS), respectively. The UV-visible results indicate to the formation of spherical Ag NPs where the absorption peak was observed at wavelengths around 395 nm. TEM images showed the well dispersion of Ag NPs in the PEG matrix with average particle size of 13 nm. Furthermore, the antimicrobial activity of the nanocmposite was studied. The Ag NPs released from the polymer matrix proven to have a significant antimicrobial activity against S. Pneumonia, B. Subtilis, E. Coli, and A. Fumigates.

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Liu, Xiang-Sheng, Wei-Chen Tu, Ming-Yi Lin, and Chun-Yin Huang. "Surface Plasmon Resonance of Graphene/Ag Nanoparticles and Reduced Graphene Oxide/Ag Nanoparticles Hybrid Films." Journal of Nanoelectronics and Optoelectronics 12, no. 8 (August 1, 2017): 868–71. http://dx.doi.org/10.1166/jno.2017.2071.

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Fu, Qing, Xiaolin Zhang, Peipei Yan, Shichao Wang, Xinzhi Wang, Yao Wang, Linjun Huang, et al. "SPR-Enhanced Fluorescence of Solid Organic Dye Films." Journal of Nanomaterials 2018 (August 23, 2018): 1–9. http://dx.doi.org/10.1155/2018/5268458.

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This paper presents strong fluorescence of spin-coated fluorescent solid organic dye films (SODF) enhanced by surface plasmonic resonance (SPR). In order to manifest the influence of SPR effect on enhancement of organic dye (OD) fluorescence, the organic dye embedded Ag@SiO2 fluorescent films were developed on the glass sheet substrate, in which Ag@SiO2 nanoparticles were embedded in the middle and organic dye was as upper layer. The morphology of the SODFs with and without Ag@SiO2 particles was studied by SEM and EDX, and the tests revealed that the Ag@SiO2 nanoparticles distributed evenly between glass sheet and OD layer. Optical properties were characterized by UV absorption and fluorescence spectroscopy; the lifetime of SODF was tested to discuss the mechanism of SPR enhancement of fluorescence. The results proved that the existence of Ag@SiO2 particles enhanced the fluorescence intensity for 7 times and thus proved the SPR effect for organic dye, especially when the organic dye is the solid films. Therefore, the most important is the creation that the SPR effect of Ag@SiO2 particles works very well under solid organic dye coverage.

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Cieniek, Bogumił, Ireneusz Stefaniuk, Ihor Virt, Roman V. Gamernyk, and Iwona Rogalska. "Zinc–Cobalt Oxide Thin Films: High Curie Temperature Studied by Electron Magnetic Resonance." Molecules 27, no. 23 (December 2, 2022): 8500. http://dx.doi.org/10.3390/molecules27238500.

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The material with a high Curie temperature of cobalt-doped zinc oxide embedded with silver-nanoparticle thin films was studied by electron magnetic resonance. The nanoparticles were synthesized by the homogeneous nucleation technique. Thin films were produced with the pulsed laser deposition method. The main aim of this work was to investigate the effect of Ag nanoparticles on the magnetic properties of the films. Simultaneously, the coexisting Ag0 and Ag2+ centers in zinc oxide structures are shown. A discussion of the signal seen in the low field was conducted. To analyze the temperature dependence of the line parameters, the theory described by Becker was used. The implementation of silver nanoparticles causes a significant shift of the line, and the ferromagnetic properties occur in a wide temperature range with an estimated Curie temperature above 500 K.

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Bonyár, Attila, Zsanett Izsold, Alexandra Borók, István Csarnovics, László Himics, Miklós Veres, and Gábor Harsányi. "PDMS-Au/Ag Nanocomposite Films as Highly Sensitive SERS Substrates." Proceedings 2, no. 13 (November 26, 2018): 1060. http://dx.doi.org/10.3390/proceedings2131060.

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Polydimethylsiloxane (PDMS)–gold/silver nanoparticle composite films were synthetized in situ by using a simple method, which is based on the reduction of chloroauric acid (HAuCl4) or silver nitrate solution (AgNO3) by the PDMS membrane. A method to monitor the development of the plasmonic absorbance peak in situ (during the synthesis of the nanoparticles) is introduced in order to provide a convenient way to investigate the effect of the technological parameters on the position of the resulting peak. The resulting composite films were tested as SERS substrates at two excitation wavelengths (488 nm, 785 nm) and the preliminary results indicate that they are promising candidates for this application, with high sensitivities accompanied by cheap fabrication costs.

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Sun, Haoliang, Xinxin Lian, Yuanjiang Lv, Yuanhao Liu, Chao Xu, Jiwei Dai, Yilin Wu, and Guangxin Wang. "Effect of Annealing on the Microstructure and SERS Performance of Mo-48.2% Ag Films." Materials 13, no. 18 (September 22, 2020): 4205. http://dx.doi.org/10.3390/ma13184205.

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Mo-48.2% Ag films were fabricated by direct current (DC) magnetron sputtering and annealed in an argon atmosphere. The effects of annealing on the surface morphology, resistivity and surface-enhanced Raman scattering (SERS) performance of Mo-48.2% Ag films were investigated. Results show a mass of polyhedral Ag particles grown on the annealed Mo-48.2% Ag films’ surface, which are different from that of as-deposited Mo-Ag film. Moreover, the thickness and the resistivity of Mo-48.2% Ag films gradually decrease as the annealing temperature increases. Furthermore, finite-difference time-domain (FDTD) simulations proved that the re-deposition Ag layer increases the “hot spots” between adjacent Ag nanoparticles, thereby greatly enhancing the local electromagnetic (EM) field. The Ag layer/annealed Mo-48.2% Ag films can identify crystal violet (CV) with concentration lower than 5 × 10−10 M (1 mol/L = 1 M), which indicated that this novel type of particles/films can be applied as ultrasensitive SERS substrates.

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Al Mohammad, Ahmad, and Mohamad B. Alsous. "Effect of Surface Structure on Heteroepitaxial Growth of Silver Nanoparticles on WO₃ Thin Films." Advanced Materials Research 324 (August 2011): 137–40. http://dx.doi.org/10.4028/www.scientific.net/amr.324.137.

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The effect of surface structures of annealed WO3 thin films on heteroepitaxial growth of molecular beam epitaxy (MBE) deposited silver nanoparticles (Ag NPs) has been investigated. Hexagonal WO3 (h-WO3) and monoclinic WO3 (m-WO3) thin films were used in (1x1) stoichiometric forms. The structure, the density, the particle size and the morphology of Ag NPs on WO3 films were determined by transmission electron microscope (TEM) and selected area electron diffraction (SAEC). Ag NPs on the m-WO3 surface created the (111)Ag//(001)m-WO3 interface without preferred orientations while the epitaxial relationships between Ag NPs and the h-WO3 films were formed as (111)Ag//(0001)h-WO3 and Ag[01-1]//[21-30]h-WO3. It was observed that the particle density, the mean size and the size dispersion of Ag NPs were controlled by either atom diffusion or by particle migration on the substrates. The maximum cluster density method and the Lifethenz theory of Van der Waals energy were used to investigate the Ag NP morphology and Ag//WO3 interface parameters at saturation particle density of NPs.

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Yan, Ya, Shi-Zhao Kang, and Jin Mu. "Preparation of high quality Ag film from Ag nanoparticles." Applied Surface Science 253, no. 10 (March 2007): 4677–79. http://dx.doi.org/10.1016/j.apsusc.2006.10.039.

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Demchenko, V. L., M. V. Iurzhenko, S. M. Kobylinskyi, and L. A. Goncharenko. "Synthesis and characterization of nanocomposites based on polylactide/silver nanoparticles, obtained by thermochemical reduction of Ag+ ions by natural or synthetic polymers." Himia, Fizika ta Tehnologia Poverhni 12, no. 4 (December 30, 2021): 365–73. http://dx.doi.org/10.15407/hftp12.04.365.

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The addition of silver ions or nanoparticles to impart antimicrobial properties to polymeric or other materials is a widely used method. However, it should be noted that the antiviral and antimicrobial effect of silver nanoparticles that come into contact with the environment, associated with their size, with a decrease in the size of nanoparticles, their effectiveness increases sharply. In the present work, we used a biodegradable polymer polylactide (PLA), which is obtained by condensation of lactic acid or ring-opening polymerization of lactide. These studies will further contribute to the development of new safe materials, in particular for food packaging, which is undoubtedly an urgent problem. The work aims is to obtain the silver-containing polymer composites based on polylactide by thermochemical reduction of Ag+ ions using natural (chitosan) and synthetic (polyethyleneimine (PEI)) polymers and to study the structure, morphology, thermomechanical and antimicrobial properties of the obtained nanocomposites. Thermochemical reduction of Ag+ ions in the bulk of polymer films, containing PLA, silver palmitate as a precursor of Ag NP and reducing agent (PEI or chitosan), has been performed by keeping them at 100–170 °C within 5 minutes. The polymeric film composites, cast from chloroform solution, were heated in an oven using precise thermal regulator VRT-3. As a result of reduction, the films get attained silver color, the Ag content in the bulk of films varied from 1 to 4 wt. %, and the thickness of the films was 110 μm. Structure, morphology, thermomechanical and antimicrobial properties of two types of nanocomposites – PLA-Ag-PEI and PLA-Ag-chitosan, formed by the thermochemical reduction of Ag+ in polymer films have been studied using wide-angle X-ray scattering (WAXS) (a DRON-4-07 diffractometer), a transmission electron microscope (TEM) (JEM-1230 JEOL, Japan), and thermomechanical analysis (a UIP-70M device). Antimicrobial activity of the obtained nanocomposites was investigated applying reference strains of opportunistic bacteria Staphylococcus aureus and Escherichia coli. It has been found that thermochemical reduction of Ag+ ions in the bulk of polymer films, when using synthetic or natural polymers (PEI or chitosan) as a reducing and stabilizing agent of silver nanoparticles occurs at 160 °C during 5 minutes. It has been found that the average size of Ag nanoparticles in the polymeric matrix is equal to ~ 7 and ~ 4 nm for PEI and chitosan, respectively. It has been shown that PLA-Ag-chitosan nanocomposites have much higher antimicrobial activity against S. aureus and E. coli strains as compared to PLA-Ag-PEI nanocomposites.

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Journal articles on the topic 'Ag nanoparticles films'

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