Preparation of a silver nanoparticle-based dual-functional sensor using a complexation–reduction method

2015 ◽  
Vol 17 (33) ◽  
pp. 21243-21253 ◽  
Author(s):  
Fwu-Long Mi ◽  
Shao-Jung Wu ◽  
Wen-Qi Zhong ◽  
Cheng-Yu Huang
Keyword(s):  
Silver Nanoparticles ◽  
High Temperature ◽  
Low Temperature ◽  
Silver Nanoparticle ◽  
Reduction Method ◽  
Ag Nps ◽  
Two Stage ◽  
Temperature Reduction ◽  
Dual Functional

A dual-functional sensor based on silver nanoparticles was synthesized by a two-stage procedure consisting of a low-temperature chitosan–Ag+ complexation followed by a high-temperature reduction of the complex to form chitosan-capped silver nanoparticles (CS-capped Ag NPs).

scholarly journals Effects of Double-Ageing Heat Treatments on the Microstructure and Mechanical Behaviour of a Ti-3.5Al-5Mo-4V Alloy

Materials ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 209
Author(s):  
Xuanming Ji ◽  
Panpan Ge ◽  
Song Xiang ◽  
Yuanbiao Tan
Keyword(s):  
Electron Microscopy ◽  
High Temperature ◽  
Low Temperature ◽  
Mechanical Behaviour ◽  
Ageing Time ◽  
Two Stage ◽  
Ageing Treatment ◽  
Ω Phase ◽  
Α Phase ◽  
Temperature Ageing

In this work, the effect of double-ageing heat treatments on the microstructural evolution and mechanical behaviour of a metastable β-titanium Ti-3.5Al-5Mo-4V alloy is investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The double-ageing treatments are composed of low-temperature pre-ageing and high-temperature ageing, where the low-temperature pre-ageing is conducted at 300 °C or 350 °C for different times, and the high-temperature ageing is conducted at 500 °C for 8 h. The results show that the phase transformation sequence is altered with the time spent during the first ageing stage, the isothermal ω phase is precipitated in the pre-ageing process of the alloy at 300 °C and 350 °C with the change in the ageing time, and the ω phase is finally transformed into the α phase with the extension of pre-ageing time. The existence time of the ω phase is shortened as the pre-ageing temperature increases. The microhardness of the alloy increases with increasing pre-ageing time and temperature. Compared with single-stage ageing, the ω phase formed in the pre-ageing stage changes the response to subsequent high-temperature ageing. After the two-stage ageing treatment, the precipitation size of the α phase is obviously refined after the double-ageing treatment. A microhardness test shows that the microhardness of the two-stage aged alloy increases with extended pre-ageing time.

The plasma-chemical formation of polysorbate 80-coated silver nanoparticles and composite materials for water treatment

2019 ◽  
Vol 48 (5) ◽  
pp. 431-438 ◽  
Author(s):  
Margarita Ivanovna Skiba ◽  
Viktoria Vorobyova
Keyword(s):  
Silver Nanoparticles ◽  
Water Treatment ◽  
Low Temperature ◽  
Polysorbate 80 ◽  
Low Temperature Plasma ◽  
Colloidal Solutions ◽  
Ag Nps ◽  
Temperature Plasma ◽  
Content Type ◽  
Water Treatment Process

Purpose This paper aims to propose a simple, eco-friendly method for obtaining colloidal solutions of silver nanoparticles (Ag NPs) by using of contact non-equilibrium low-temperature plasma in presents polysorbate-80 and to assess their antibacterial activity in composite materials (beads) for water treatment process. Design/methodology/approach Silver nanoparticles were prepared in aqueous AgNO3 solution by using of contact non-equilibrium low-temperature plasma in the present of nonionic surfactant polysorbate-80 (Tween 80) as capping agent. Ultraviolet–visible (UV) spectroscopy, X-ray diffraction and zeta potential analysis were used to study the formation and properties of silver nanoparticles. Findings The formation of silver colloidal solutions in the presence of capping agent under plasma discharge is characterized by the presence of peak λmax = 380 – 402 nm in the spectra. The addition of sodium alginate into the reaction mixture allows synthesizing stable colloidal silver solutions. The average size of formed silver particles is up to 50 nm. Ag NPs exhibited an excellent bactericidal activity against both gram-positive and gram- negative bacteria. Composite beads prepared using nonionic surfactant were found to be effective in disinfecting the Staphylococcus aureus to different extents. Research limitations/implications Further studies are necessary for confirmation of the practical application, especially of the toxicity of Ag NPs, as well as the sorption properties of the alginate beads with Ag NPs. Practical implications The method provides a simple and practical solution to improving the synthesis of colloidal solutions of Ag NPs for water treatment process. Originality/value Contact nonequilibrium low-temperature plasma can be used as an effective technique for synthesis of nanomaterials.

scholarly journals Interaction of Pulses of Different Duration with Chemically Prepared Silver Nanoparticles: Analysis of Optical Nonlinearities

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Ke Zhang ◽  
Rashid A. Ganeev ◽  
Konda Srinivasa Rao ◽  
Sandeep Kumar Maurya ◽  
Ganjaboy S. Boltaev ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Nonlinear Absorption ◽  
Nonlinear Optical ◽  
Reduction Method ◽  
Chemical Reduction ◽  
Nonlinear Refraction ◽  
Optical Nonlinearities ◽  
Chemical Reduction Method ◽  
Ag Nps ◽  
Picosecond Pulses

The nonlinear optical properties of the aqueous solutions of silver nanoparticles (Ag NPs) prepared by chemical reduction method are analyzed using femtosecond and picosecond pulses at different wavelengths. In the case of 800 and 400 nm, the growths of nonlinear absorption and nonlinear refraction with the increase of Ag NP concentration, as well as a change at the signs of nonlinear optical processes, are determined. The nonlinear absorption coefficient and nonlinear refractive index of Ag NP solutions measured using picosecond pulses were a few orders of magnitude larger than those in the case of femtosecond probe pulses. We also demonstrate the optical limiting properties of Ag NPs using 800 nm, 60 fs pulses.

Effect of Surfactant on the Morphology of Silver Nanoparticles

2007 ◽  
Vol 124-126 ◽  
pp. 1205-1208 ◽  
Author(s):  
Keun Ju Park ◽  
Dong Seok Seo ◽  
Woo Yang Jang ◽  
Jong Kook Lee
Keyword(s):  
Silver Nanoparticles ◽  
Ascorbic Acid ◽  
Low Temperature ◽  
Reduction Method ◽  
Chemical Reduction ◽  
Sodium Dodecyl ◽  
Capping Agent ◽  
Silver Particles ◽  
Chemical Reduction Method ◽  
20 Nm

Nano-sized silver particles are considered to apply a silver paste for electrode because of its high conductivity on sintering at low temperature. In this study, silver nanoparticles as seeds were prepared by chemical reduction method with capping agent. Silver particles were prepared using SDS (Sodium dodecyl sulfate) as a surfactant and silver nanoparticles as seeds and reacted with ascorbic acid as a reduction agent. The silver seeds with 10-20 nm in size with uniform distribution were formed and the size and shape of silver particles were strongly dependent on the concentration of surfactant.

Effect of Ce3+/Ce4+ Couple on Selective Hydrogenation of Crotonaldehyde over Pt/CeO2 Catalyst

2011 ◽  
Vol 233-235 ◽  
pp. 1592-1596
Author(s):  
Guan Qun Xie ◽  
Yan Hui Dai ◽  
Xi Jing Liu ◽  
Meng Fei Luo ◽  
Xiao Nian Li
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Low Temperature ◽  
Selective Hydrogenation ◽  
Temperature Reduction ◽  
Crotyl Alcohol

By pretreatment of Pt/CeO2catalysts with high temperature reduction and subsequent low temperature reoxidation, the concentration of Ce3+species in the Pt/CeO2catalysts could be adjusted, while at the same time the Pt particle size remained constant. Thus the pure effect of Ce3+/Ce4+couples on the selective hydrogenation of crotonaldehdye could be explored. The investigation provided direct proofs supporting that Ce3+species favors the crotyl alcohol selectivity.

scholarly journals Silver nanoparticles sintering at low temperature on a copper substrate: In situ characterization under inert atmosphere and air

2012 ◽  
Vol 48 (1) ◽  
pp. 63-71 ◽  
Author(s):  
J. Sopousek ◽  
J. Bursik ◽  
J. Zalesak ◽  
Z. Pesina
Keyword(s):  
Silver Nanoparticles ◽  
Low Temperature ◽  
Copper Substrate ◽  
Simultaneous Thermal Analysis ◽  
Inert Atmosphere ◽  
Ag Nps ◽  
Scanning Calorimetry ◽  
External Conditions ◽  
Wet Synthesis

Silver nanoparticles (Ag-NPs) were prepared by wet synthesis. The Ag-NPs suspension and the copper substrate plate were used for a preparation of substrate-nanoparticle-substrate samples. The sandwich like samples Cu/Ag/Cu were prepared and investigated in-situ at the isothermal external conditions (IEC) and inside apparatus for simultaneous thermal analysis STA409 (DSC). The in-situ results of the electrical resistance were recorded during the Cu/Ag/Cu (IEC) sample preparation and heat treatment. Thermal effects of the Ag-NPs sintering between copper substrates were measured by differential scanning calorimetry (DSC) under different atmospheres. The prepared Cu/Ag/Cu sandwich samples were characterised by means of both optical and electron microscopy. The process of the low temperature sintering inside calorimeter of the Ag-NPs was monitored using both thermogravimetry (TG) and DSC technique under inert gas and under synthetic air. The exothermic heat effect of nanosilver sintering was evaluated.

Development mechanism of Ce-doped red zirconia ceramics prepared by a high-temperature reduction method

2019 ◽  
Vol 797 ◽  
pp. 931-939 ◽  
Author(s):  
Haodong Lv ◽  
Jinxiao Bao ◽  
Luomeng Chao ◽  
Xiwen Song ◽  
Shengli An ◽  
...  
Keyword(s):  
High Temperature ◽  
Reduction Method ◽  
Zirconia Ceramics ◽  
Temperature Reduction ◽  
Development Mechanism

A novel silver nanoparticle embedded mesoporous polyaniline (mPANI/Ag) nanocomposite as a recyclable catalyst in the acylation of amines and alcohols under solvent free conditions

RSC Advances ◽  
2014 ◽  
Vol 4 (80) ◽  
pp. 42670-42681 ◽  
Author(s):  
Usha Mandi ◽  
Anupam Singha Roy ◽  
Biplab Banerjee ◽  
Sk. Manirul Islam
Keyword(s):  
Silver Nanoparticles ◽  
Acetic Acid ◽  
Catalytic Activity ◽  
Silver Nanoparticle ◽  
Solvent Free ◽  
Organic Polymer ◽  
High Catalytic Activity ◽  
Ag Nps ◽  
Solvent Free Conditions ◽  
Highly Dispersed

Highly dispersed silver nanoparticles (Ag NPs) have been embedded into a mesoporous organic polymer (mPANI) and the material showed high catalytic activity in the acylation of amines and alcohols using acetic acid.

Artificial Neural Network Modelling of Green Synthesised Silver Nanoparticles in Bentonite/Starch Bio-Nanocomposite

2018 ◽  
Vol 14 (3) ◽  
pp. 239-251 ◽  
Author(s):  
Anupama Thapliyal ◽  
Roop Krishen Khar ◽  
Amrish Chandra
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Silver Nanoparticles ◽  
Mean Square Error ◽  
Reduction Method ◽  
Mean Square ◽  
Ann Model ◽  
Ag Nps ◽  
Feed Forward ◽  
Artificial Neural

Background: In this study, computational Artificial Neural Network (ANN) model is applied for optimisation and evaluation of silver nanoparticles (AgNPs) size in the bionanocomposite matrix. The primary purpose of this study is used a feed-forward ANN model to create a connection between the output as the size of Ag–NPs, with four inputs variables, including AgNO3 concentration, the weight percentage of starch, Bentonite amount and Gallic acid concentration. Method: Silver nanoparticles were synthesised via biogenic green reduction method. The fast Levenberg– Marquardt (LM) backpropagation algorithm applied for the training of ANN model in this research. The optimised ANN is a multilayer perceptron (MLP) which is a kind of feed forward (4- 10-1) network has an input layer with 4 nodes, hidden layers with 10 neurones, and an output layer with 1 node found a fitness function. Results: The output results of developed computational ANN model were compared to its predictive values of the size of silver nanoparticles regarding two statistical parameters, the coefficient of determination (R2) and mean square error (MSE) of data set. It observed that ANN predicted values are close to the actual values and well fitted to the data. The mean square error(MSE) is 0.03, and a regression is about 1. Conclusion: AgNO3 concentration has the most likely factor affecting the size of silver nanoparticles (Ag–NPs) and this makes possible to develop a green reduction method for the preparation of silver nanoparticles. This study confirms that employing ANN method with LM feed forward (4-10-1) network is a useful tool with cost-effective for predicting the results of analysis and modelling of the chemical reactions.

scholarly journals Nanocomposite Inks Based on Nickel–Silver Core–Shell and Silver Nanoparticles for Fabrication Conductive Coatings at Low-Temperature Sintering

2021 ◽  
Vol 5 (1) ◽  
pp. 15
Author(s):  
Anna Pajor-Świerzy ◽  
Franciszek Szendera ◽  
Radosław Pawłowski ◽  
Krzysztof Szczepanowicz
Keyword(s):  
Silver Nanoparticles ◽  
Low Temperature ◽  
Low Cost ◽  
Future Application ◽  
Core Shell ◽  
Low Temperature Sintering ◽  
Ag Nps ◽  
Conductive Coatings ◽  
Nickel Silver ◽  
Silver Core

Nanocomposite inks composed of nickel–silver core–shell and silver nanoparticles (NPs) can combine the advantages of lower cost, high conductivity, and low-temperature sintering processes, which have attracted much attention in the development of materials for printed flexible electronics. In this context, in the present paper, we report the process of preparation of nanocomposite ink containing nickel–silver core–shell nanoparticles, as the main filler, and silver nanoparticles, as doping material, and their application for the fabrication of conductive coatings. It was found that the addition of a low concentration of Ag NPs to ink formulation based mainly on low-cost Ni-Ag NPs improves the conductive properties of coatings fabricated by ink deposition on a glass substrate. Two types of prepared nanocomposite ink coatings showed promising properties for future application: (1) doped with 0.5% of Ag NPs sintered at 200 °C as low cost for larger industrial application and, (2) containing 1% of Ag NPs sintered at 150 °C for the fabrication of conductive printed patterns on flexible substrates. The conductivity of such nanocomposite films was similar, about of 6 × 106 S/m, which corresponds to 35% of that for a bulk nickel.

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