Evaluating the mechanism of nucleation and growth of silver nanoparticles in a polymer membrane under continuous precursor supply: tuning of multiple to single nucleation pathway

2019 ◽  
Vol 21 (8) ◽  
pp. 4193-4199 ◽  
Author(s):  
Apurva N. Naik ◽  
Sabyasachi Patra ◽  
Debasis Sen ◽  
Asok Goswami

LaMer type nucleation curve has been experimentally studied for the first time for synthesis of membrane hosted silver nanoparticles under continuous precursor supply. Radiotracer has been uniquely used as a probe in this investigation.

2015 ◽  
Vol 179 ◽  
pp. 59-77 ◽  
Author(s):  
Cornelia M. Völkle ◽  
Denis Gebauer ◽  
Helmut Cölfen

Nucleation and growth of silver nanoparticles has already been investigated with various experimental and computational tools. However, owing to inherent problems associated with the analytical characterization of nucleation processes, there is a general lack of experimental data regarding the earliest precursors and smallest Ag(0) clusters. Here, we address this problem by the application of Synthetic Boundary Crystallization Ultracentrifugation, utilizing a multiwavelength detector for the first time, complemented by a specialized titration assay. These techniques shed new light on silver nanoparticle precursors existing in the pre-nucleation regime, and the initially nucleated ensemble of nanoclusters. For the first time, we present experimental data of UV-Vis spectra for fractionated silver clusters. These allow for unsurpassed insights into the sequence of nucleation and early growth species as well as their optical properties.


2014 ◽  
Vol 118 (31) ◽  
pp. 17655-17661 ◽  
Author(s):  
Sicelo S. Masango ◽  
Lingxuan Peng ◽  
Laurence D. Marks ◽  
Richard P. Van Duyne ◽  
Peter C. Stair

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
M. A. El-Sheikh

The water soluble photoinitiator (PI) 4-(trimethyl ammonium methyl) benzophenone chloride is used for the first time in the synthesis of silver nanoparticles (AgNPs). A new green synthesis method involves using PI/UV system, carboxymethyl starch (CMS), silver nitrate, and water. A mechanism of the reduction of silver ions to AgNPs by PI/UV system as well as by the newly born aldehydic groups was proposed. The synthesis process was assessed by UV-vis spectra and TEM of AgNPs colloidal solution. The highest absorbance was obtained using CMS, PI and AgNO3concentrations of 10 g/L, 1 g/L, and 1 g/L, respectively; 40°C; 60 min; pH 7; and a material : liquor ratio 1 : 20. AgNPs so-obtained were stable in aqueous solution over a period of three weeks at room temperature (~25°C) and have round shape morphology. The sizes of synthesized AgNPs were in the range of 1–21 nm and the highest counts % of these particles were for particles of 6–10 and 1–3 nm, respectively.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Akshay Rajeev Geetha ◽  
Elizabeth George ◽  
Akshay Srinivasan ◽  
Jameel Shaik

Production of silver nanoparticles from the leaf extracts ofPimenta dioicais reported for the first time in this paper. Three different sets of leaves were utilized for the synthesis of nanoparticles—fresh, hot-air oven dried, and sun-dried. These nanoparticles were characterized using UV-Vis spectroscopy and AFM. The results were diverse in that different sizes were seen for different leaf conditions. Nanoparticles synthesized using sun-dried leaves (produced using a particular ratio (1 : 0.5) of the leaf extract sample and silver nitrate (1 mM), resp.) possessed the smallest sizes. We believe that further optimization of the current green-synthesis method would help in the production of monodispersed silver nanoparticles having great potential in treating several diseases.


2018 ◽  
Vol 29 (50) ◽  
pp. 505602 ◽  
Author(s):  
Amirmostafa Amirjani ◽  
Davoud Fatmehsari Haghshenas

2017 ◽  
Vol 18 (1) ◽  
pp. 324-330 ◽  
Author(s):  
Suyue Chen ◽  
Jesse L. Carey ◽  
David R. Whitcomb ◽  
Philippe Bühlmann ◽  
R. Lee Penn

2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Suparna Mukherji ◽  
Sharda Bharti ◽  
Gauri Shukla ◽  
Soumyo Mukherji

Abstract Silver nanoparticles (AgNPs) have application potential in diverse areas ranging from wound healing to catalysis and sensing. The possibility for optimizing the physical, chemical and optical properties for an application by tailoring the shape and size of silver nanoparticles has motived much research on methods for synthesis of size- and shape-controlled AgNPs. The shape and size of AgNPs are reported to vary depending on choice of the Ag precursor salt, reducing agent, stabilizing agent and on the synthesis technique used. This chapter provides a detailed review on various synthesis approaches that may be used for synthesis of AgNPs of desired size and shape. Silver nanoparticles may be synthesized using diverse routes, including, physical, chemical, photochemical, biological and microwave -based techniques. Synthesis of AgNPs of diverse shapes, such as, nanospheres, nanorods, nanobars, nanoprisms, decahedral nanoparticles and triangular bipyramids is also discussed for chemical-, photochemical- and microwave-based synthesis routes. The choice of chemicals used for reduction and stabilization of nanoparticles is found to influence their shape and size significantly. A discussion on the mechanism of synthesis of AgNPs through nucleation and growth processes is discussed for AgNPs of varying shape and sizes so as to provide an insight on the various synthesis routes. Techniques, such as, electron microscopy, spectroscopy, and crystallography that can be used for characterizing the AgNPs formed in terms of their shape, sizes, crystal structure and chemical composition are also discussed in this chapter. Graphical Abstract:


2013 ◽  
Vol 394 (1) ◽  
pp. 113-123 ◽  
Author(s):  
Radoslaw Szmyd ◽  
Anna Grazyna Goralczyk ◽  
Lukasz Skalniak ◽  
Agnieszka Cierniak ◽  
Barbara Lipert ◽  
...  

Abstract Silver nanoparticles (AgNPs) have many biological applications in biomedicine, biotechnology and other life sciences. Depending on the size, shape and the type of carrier, AgNPs demonstrate different physical and chemical properties. AgNPs have strong antimicrobial, antiviral and antifungal activity, thus they are used extensively in a range of medical settings, particularly in wound dressings but also in cosmetics. This study was undertaken to examine the potential toxic effects of 15 nm polyvinylpyrrolidone-coated AgNPs on primary normal human epidermal keratinocytes (NHEK). Cells were treated with different concentrations of AgNPs and then cell viability, metabolic activity and other biological and biochemical aspects of keratinocytes functioning were studied. We observed that AgNPs decrease keratinocyte viability, metabolism and also proliferatory and migratory potential of these cells. Moreover, longer exposure resulted in activation of caspase 3/7 and DNA damage. Our studies show for the first time, that AgNPs may present possible danger for primary keratinocytes, concerning activation of genotoxic and cytotoxic processes depending on the concentration.


RSC Advances ◽  
2014 ◽  
Vol 4 (103) ◽  
pp. 59379-59386 ◽  
Author(s):  
Sabyasachi Patra ◽  
Debasis Sen ◽  
Ashok K. Pandey ◽  
J. Bahadur ◽  
S. Mazumder ◽  
...  

Growth kinetics of membrane stabilized silver nanoparticles have been studied for the first time with time resolved in situ SAXS. The catalytic application of nanocomposite membranes thus formed has also been explored.


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