scholarly journals Antibacterial polymeric nanocomposites synthesized by in-situ photoreduction of silver ions without additives inside biocompatible hydrogel matrices based on N-isopropylacrylamide and derivatives

2017 ◽  
Vol 11 (12) ◽  
pp. 946-962 ◽  
Author(s):  
M. Monerris ◽  
M. Broglia ◽  
I. Yslas ◽  
C. Barbero ◽  
C. Rivarola
Keyword(s):  
Silver Ions ◽  
Polymeric Nanocomposites

Silver Ions Release from Antibacterial Chitosan Films Containing in Situ Generated Silver Nanoparticles

2012 ◽  
Vol 61 (1) ◽  
pp. 260-267 ◽  
Author(s):  
Gracia López-Carballo ◽  
Laura Higueras ◽  
Rafael Gavara ◽  
Pilar Hernández-Muñoz
Keyword(s):  
Silver Nanoparticles ◽  
Silver Ions ◽  
Chitosan Films

scholarly journals Enhanced Antibacterial Activity of Silver Doped Titanium Dioxide-Chitosan Composites under Visible Light

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1403 ◽  
Author(s):  
Jie Li ◽  
Bing Xie ◽  
Kai Xia ◽  
Yingchun Li ◽  
Jing Han ◽  
...  
Keyword(s):  
Particle Size ◽  
Antibacterial Activity ◽  
Titanium Dioxide ◽  
Visible Light ◽  
Silver Ions ◽  
Antibacterial Activities ◽  
Nano Tio2 ◽  
Inverse Emulsion ◽  
Potential Applications

Nano titanium dioxide (TiO2) with photocatalytic activity was firstly modified by diethanolamine, and it was then doped with broad spectrum antibacterial silver (Ag) by in situ method. Further, both Ag doped TiO2-chitosan (STC) and TiO2-chitosan (TC) composites were prepared by the inverse emulsion cross-linking reaction. The antibacterial activities of STC composites were studied and their antibacterial mechanisms under visible light were investigated. The results show that in situ doping and inverse emulsion method led to good dispersion of Ag and TiO2 nanoparticles on the cross-linked chitosan microsphere. The STC with regular particle size of 1–10 μm exhibited excellent antibacterial activity against E. coli, P. aeruginosa and S. aureus under visible light. It is believed that STC with particle size of 1–10 μm has large specific surface area to contact with bacterial cell wall. The increased antibacterial activity was attributed to the enhancement of both electron-hole separations at the surface of nano-TiO2 by the silver ions under the visible light, and the synergetic and sustained release of strong oxidizing hydroxyl radicals of nano-TiO2, together with silver ions against bacteria. Thus, STC composites have great potential applications as antibacterial agents in the water treatment field.

scholarly journals Nanoclay Intercalation During Foaming of Polymeric Nanocomposites Studied in-Situ by Synchrotron X-Ray Diffraction

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2459
Author(s):  
Victoria Bernardo ◽  
Mikel Mugica ◽  
Saul Perez-Tamarit ◽  
Belen Notario ◽  
Catalina Jimenez ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Catalytic Effect ◽  
Decomposition Temperature ◽  
Melt Blending ◽  
Polymeric Nanocomposites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Foaming Process ◽  
Key Parameter

The intercalation degree of nanoclays in polymeric foamed nanocomposites containing clays is a key parameter determining the final properties of the material, but how intercalation occurs is not fully understood. In this work, energy dispersive X-ray diffraction (ED-XRD) of synchrotron radiation was used as an in-situ technique to deepen into the intercalation process of polymer/nanoclay nanocomposites during foaming. Foamable nanocomposites were prepared by the melt blending route using low-density polyethylene (LDPE), polypropylene (PP), and polystyrene (PS) with surface treated nanoclays and azodicarbonamide (ADC) as the blowing agent. Foaming was induced by heating at atmospheric pressure. The time and temperature evolution of the interlamellar distance of the clay platelets in the expanding nanocomposites was followed. Upon foaming, interlamellar distances of the nanocomposites based on LDPE and PP increase by 18% and 16% compared to the bulk foamable nanocomposite. Therefore, the foaming process enhances the nanoclay intercalation degree in these systems. This effect is not strongly affected by the type of nanoclay used in LDPE, but by the type of polymer used. Besides, the addition of nanoclays to PP and PS has a catalytic effect on the decomposition of ADC, i.e., the decomposition temperature is reduced, and the amount of gas released increases. This effect was previously proved for LDPE.

In situ reduction of antibacterial silver ions to metallic silver nanoparticles on bioactive glasses functionalized with polyphenols

2017 ◽  
Vol 396 ◽  
pp. 461-470 ◽  
Author(s):  
S. Ferraris ◽  
M. Miola ◽  
A. Cochis ◽  
B. Azzimonti ◽  
L. Rimondini ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Silver Ions ◽  
Metallic Silver ◽  
In Situ Reduction ◽  
Bioactive Glasses

Core–Shell γ-Fe2O3/SiO2/PCA/Ag-NPs Hybrid Nanomaterials as a New Candidate for Future Cancer Therapy

2014 ◽  
Vol 13 (01) ◽  
pp. 1450008 ◽  
Author(s):  
R. Soleyman ◽  
A. Pourjavadi ◽  
N. Masoud ◽  
A. Varamesh
Keyword(s):  
Silver Nanoparticles ◽  
Cancer Therapy ◽  
Silver Ions ◽  
Core Shell ◽  
Capping Agent ◽  
Hybrid Nanomaterials ◽  
Ag Nps ◽  
Core Nanoparticles ◽  
Size And Structure

In the current study, γ- Fe 2 O 3/ SiO 2/ PCA / Ag -NPs hybrid nanomaterials were successfully synthesized and characterized. At first, prepared γ- Fe 2 O 3 core nanoparticles were modified by SiO 2 layer. Then they were covered by poly citric acid (PCA) via melting esterification method as well. PCA shell acts as an effective linker, and provides vacancies for conveying drugs. Moreover, this shell as an effective capping agent directs synthesis of silver nanoparticles ( Ag -NPs) via in situ photo-reduction of silver ions by sunlight-UV irradiation. This system has several benefits as a suitable cancer therapy nanomaterial. Magnetic nanoparticles (MNPs) can guide Ag -NPs and drugs to cancer cells and then Ag -NPs can affect those cells via Ag -NPs anti-angiogenesis effect. Size and structure of the prepared magnetic hybrid nanomaterials were characterized using FTIR and UV-Vis spectra, AFM and TEM pictures and XRD data.

scholarly journals Reagent Free Electrochemical-Based Detection of Silver Ions at Interdigitated Micro Electrodes Using in Situ pH Control

2020 ◽  
Author(s):  
Luiza Adela Wasiewska ◽  
Ian Seymour ◽  
Bernardo Patella ◽  
Catherine Burgess ◽  
Geraldine Duffy ◽  
...  
Keyword(s):  
Drinking Water ◽  
Tap Water ◽  
Linear Sweep Voltammetry ◽  
Silver Ions ◽  
Ph Control ◽  
Consumer Products ◽  
Electrode Arrays ◽  
Linear Calibration ◽  
Control Approach

<p>Silver ions, the most toxic form of silver, can be present in drinking water due to their release from silver nanoparticles which are widely used in consumer products. Due to their adverse health effects, a quick portable approach for detection in drinking water is needed. Herein we report on the development of an electrochemical sensor for silver ions detection in tap water using linear sweep voltammetry with in situ pH control; enabled by closely space interdigitated electrode arrays. The in situ pH control approach, allows the pH of a test solution to be tailored to pH 3 thereby eliminating the current need for acid addition. A calibration curve between 0.2 - 10 µM was established for silver detection in sodium acetate when 1.25 V and 1.65 V was applied at the protonator electrode during deposition and stripping, respectively, as a proof of concept study. For the final application in tap water, 1.65 V was applied at the protonator electrode during deposition and stripping. The chlorine ions, present in tap water as a consequence of the disinfection process, facilitated the silver detection and no additional electrolyte had to be added. Combination of complexation of silver ions with chlorine coupled with in situ pH control resulted in linear calibration range between 0.25 and 2 µM in tap water without the need for acidification.</p>

scholarly journals Reagent Free Electrochemical-Based Detection of Silver Ions at Interdigitated Micro Electrodes Using in Situ pH Control

2020 ◽  
Author(s):  
Luiza Adela Wasiewska ◽  
Ian Seymour ◽  
Bernardo Patella ◽  
Catherine Burgess ◽  
Geraldine Duffy ◽  
...  
Keyword(s):  
Drinking Water ◽  
Tap Water ◽  
Linear Sweep Voltammetry ◽  
Silver Ions ◽  
Ph Control ◽  
Consumer Products ◽  
Electrode Arrays ◽  
Linear Calibration ◽  
Control Approach

<p>Silver ions, the most toxic form of silver, can be present in drinking water due to their release from silver nanoparticles which are widely used in consumer products. Due to their adverse health effects, a quick portable approach for detection in drinking water is needed. Herein we report on the development of an electrochemical sensor for silver ions detection in tap water using linear sweep voltammetry with in situ pH control; enabled by closely space interdigitated electrode arrays. The in situ pH control approach, allows the pH of a test solution to be tailored to pH 3 thereby eliminating the current need for acid addition. A calibration curve between 0.2 - 10 µM was established for silver detection in sodium acetate when 1.25 V and 1.65 V was applied at the protonator electrode during deposition and stripping, respectively, as a proof of concept study. For the final application in tap water, 1.65 V was applied at the protonator electrode during deposition and stripping. The chlorine ions, present in tap water as a consequence of the disinfection process, facilitated the silver detection and no additional electrolyte had to be added. Combination of complexation of silver ions with chlorine coupled with in situ pH control resulted in linear calibration range between 0.25 and 2 µM in tap water without the need for acidification.</p>

scholarly journals Non-Invasive Approaches for the Evaluation of the Functionalization of Melamine Foams with In-Situ Synthesized Silver Nanoparticles

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 996 ◽  
Author(s):  
Suset Barroso-Solares ◽  
Paula Cimavilla-Roman ◽  
Miguel Angel Rodriguez-Perez ◽  
Javier Pinto
Keyword(s):  
Polymeric Nanocomposites ◽  
Free Standing ◽  
X Ray ◽  
Color Changes ◽  
Non Invasive ◽  
Silver Nps ◽  
Promising Solution ◽  
The Stability

The use of polymeric nanocomposites has arisen as a promising solution to take advantage of the properties of nanoparticles (NPs) in diverse applications (e.g., water treatment, catalysis), while overcoming the drawbacks of free-standing nanoparticles (e.g., aggregation or accidental release). In most of the cases, the amount and size of the NPs will affect the stability of the composite as well as their performance. Therefore, a detailed characterization of the NPs present on the nanocomposites, including their quantification, is of vital importance for the optimization of these systems. However, the determination of the NPs load is often carried out by destructive techniques such as TGA or ICP-OES, the development of non-invasive approaches to that aim being necessary. In this work, the amount of silver NPs synthesized directly on the surface of melamine (ME) foams is studied using two non-invasive approaches: colorimetry and X-ray radiography. The obtained results show that the amount of silver NPs can be successfully determined from the luminosity and global color changes of the surface of the foams, as well as from the X-ray attenuance.

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