Impacts of titanium dioxide nanoparticles on transformation of silver nanoparticles in aquatic environments

2018 ◽  
Vol 5 (5) ◽  
pp. 1191-1199 ◽  
Author(s):  
Yinqing Zhang ◽  
Liwen Qiang ◽  
Yuting Yuan ◽  
Wei Wu ◽  
Binbin Sun ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Titanium Dioxide ◽  
Titanium Dioxide Nanoparticles ◽  
Aquatic Environments ◽  
Oxidative Dissolution ◽  
Sunlight Irradiation

Under sunlight irradiation, titanium dioxide nanoparticles could promote the oxidative dissolution of silver nanoparticles in aquatic environments.

New insights into the facilitated dissolution and sulfidation of silver nanoparticles under simulated sunlight irradiation in aquatic environments by extracellular polymeric substances

2021 ◽  
Author(s):  
Yi Yang ◽  
Shimei Zheng ◽  
Ruixuan Li ◽  
Xin Chen ◽  
Kunkun Wang ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Extracellular Polymeric Substances ◽  
Aquatic Environments ◽  
Simulated Sunlight ◽  
Sunlight Irradiation

Impacts of extracellular polymeric substances on the dissolution and sulfidation of silver nanoparticles in aquatic environments.

scholarly journals Titanium Dioxide Nanoparticles Elicit Lower Direct Inhibitory Effect on Human Gut Microbiota Than Silver Nanoparticles

2019 ◽  
Vol 172 (2) ◽  
pp. 411-416 ◽  
Author(s):  
Richard T Agans ◽  
Alex Gordon ◽  
Saber Hussain ◽  
Oleg Paliy
Keyword(s):  
Silver Nanoparticles ◽  
Titanium Dioxide ◽  
Gut Microbiota ◽  
Titanium Dioxide Nanoparticles ◽  
Close Association ◽  
Community Diversity ◽  
Bacterial Cells ◽  
Human Gut ◽  
Human Gut Microbiota

Abstract Due to continued technological development, people increasingly come in contact with engineered nanomaterials (ENMs) that are now used in foods and many industrial applications. Many ENMs have historically been shown to possess antimicrobial properties, which has sparked concern for how dietary nanomaterials impact gastrointestinal health via microbial dysbiosis. We employed an in vitro Human Gut Simulator system to examine interactions of dietary nano titanium dioxide (TiO2) with human gut microbiota. Electron microscopy indicated a close association of TiO2 particles with bacterial cells. Addition of TiO2 to microbial communities led to a modest reduction in community density but had no impact on community diversity and evenness. In contrast, administration of known antimicrobial silver nanoparticles (NPs) in a control experiment resulted in a drastic reduction of population density. In both cases, communities recovered once the addition of nanomaterials was ceased. Constrained ordination analysis of community profiles revealed that simulated colonic region was the primary determinant of microbiota composition. Accordingly, predicted community functional capacity and measured production of short-chain fatty acids were not changed significantly upon microbiota exposure to TiO2. We conclude that tested TiO2 NPs have limited direct effect on human gut microbiota.

scholarly journals Homogeneous Coatings of Titanium Dioxide Nanoparticles on Corona-Treated Cotton Fabric for Enhanced Self-Cleaning and Antibacterial Properties

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Mojtaba Aalipourmohammadi ◽  
Abolfazl Davodiroknabadi ◽  
Ali Nazari
Keyword(s):  
Titanium Dioxide ◽  
Pathogenic Bacteria ◽  
Titanium Dioxide Nanoparticles ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Sunlight Irradiation ◽  
Self Cleaning ◽  
Mapping Techniques ◽  
Cellulosic Fabric ◽  
And Staphylococcus Aureus

Abstract This study discusses the effect of corona pretreatment and subsequent loading of titanium dioxide nanoparticles on self-cleaning and antibacterial properties of cellulosic fabric. The corona-pretreated cellulosic fabrics were characterized by field emission scanning electron microscopy, and X-ray mapping techniques revealed that layers of the titania deposited on cellulose fibers were more uniform than the sample without pre-corona treatment. The self-cleaning property of treated fabrics was evaluated through discoloring dye stain under sunlight irradiation. The antibacterial activities of the samples against two common pathogenic bacteria including Escherichia coli and Staphylococcus aureus were also assessed. The results indicated that self-cleaning and antibacterial properties of the corona-pretreated fabrics were superior compared to the sample treated with TiO2 alone. Moreover, using corona pretreatment leads to samples with good washing fastness.

scholarly journals Finding Nano: Challenges Involved in Monitoring the Presence and Fate of Engineered Titanium Dioxide Nanoparticles in Aquatic Environments

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 734
Author(s):  
Simone Heilgeist ◽  
Ryo Sekine ◽  
Oz Sahin ◽  
Rodney A. Stewart
Keyword(s):  
Titanium Dioxide ◽  
Tio2 Nanoparticles ◽  
Inductively Coupled Plasma ◽  
Titanium Dioxide Nanoparticles ◽  
Aqueous Media ◽  
Experimental Studies ◽  
Aquatic Environments ◽  
Nano Tio2 ◽  
Icp Ms ◽  
Modelling Studies

In recent years, titanium dioxide (TiO2) has increasingly been used as an inorganic ultraviolet (UV) filter for sun protection. However, nano-TiO2 may also pose risks to the health of humans and the environment. Thus, to adequately assess its potential adverse effects, a comprehensive understanding of the behaviour and fate of TiO2 in different environments is crucial. Advances in analytical and modelling methods continue to improve researchers’ ability to quantify and determine the state of nano-TiO2 in various environments. However, due to the complexity of environmental and nanoparticle factors and their interplay, this remains a challenging and poorly resolved feat. This paper aims to provide a focused summary of key particle and environmental characteristics that influence the behaviour and fate of sunscreen-derived TiO2 in swimming pool water and natural aquatic environments and to review the current state-of-the-art of single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) approaches to detect and characterise TiO2 nanoparticles in aqueous media. Furthermore, it critically analyses the capability of existing fate and transport models to predict environmental TiO2 levels. Four particle and environmental key factors that govern the fate and behaviour of TiO2 in aqueous environments are identified. A comparison of SP-ICP-MS studies reveals that it remains challenging to detect and characterise engineered TiO2 nanoparticles in various matrices and highlights the need for the development of new SP-ICP-MS pre-treatment and analysis approaches. This review shows that modelling studies are an essential addition to experimental studies, but they still lack in spatial and temporal resolution and mostly exclude surface transformation processes. Finally, this study identifies the use of Bayesian Network-based models as an underexplored but promising modelling tool to overcome data uncertainties and incorporates interconnected variables.

Silver and Titanium Nanoparticles Used as Coating on Polyurethane Catheters

2017 ◽  
Vol 47 ◽  
pp. 17-23 ◽  
Author(s):  
S. Heilman ◽  
L.G.A. Silva
Keyword(s):  
Silver Nanoparticles ◽  
Titanium Dioxide ◽  
Inductively Coupled Plasma ◽  
Titanium Dioxide Nanoparticles ◽  
Sol Gel ◽  
Antimicrobial Properties ◽  
Optical Emission ◽  
Venous Catheter ◽  
Emission Spectrometry ◽  
Raman Spectrometry

Silver nanoparticles have been used in the medical area due to their remarkable antimicrobial properties. In this sense titanium dioxide nanoparticles obtained by the sol-gel method were used as coating of catheters for subsequent impregnation of silver nanoparticles with gamma irradiation and electron beam at 25 and 50 kGy. This work aimed to study the use of the silver nanoparticles and titanium dioxide as coating of polyurethane Central Venous Catheter (CVC) for antimicrobial activity. Furthermore the amounts of titanium and silver present in the coated catheters had been evaluated by Inductively Coupled Plasma – Optical Emission Spectrometry (ICP OES). Therefore the Raman spectrometry was used to identify the polymorph of titanium oxide, rutile.

scholarly journals Titanium dioxide/silver nanoparticle bilayers prepared in self-assembly processes

2016 ◽  
Vol 71 (1) ◽  
pp. 29
Author(s):  
Julia Maciejewska ◽  
Magdalena Oćwieja ◽  
Zbigniew Adamczyk ◽  
Elżbieta Bielańska ◽  
Bogna Napruszewska
Keyword(s):  
Silver Nanoparticles ◽  
Titanium Dioxide ◽  
Ionic Strength ◽  
Silver Nanoparticle ◽  
Self Assembly ◽  
Electrostatic Interactions ◽  
Titanium Dioxide Nanoparticles ◽  
Chemical Reduction ◽  
Supporting Layer ◽  
Phosphate Salts

<p>A new method for the preparation of TiO<sub>2</sub>/Ag bilayers via colloid <br /> self-assembly process using well-characterized titanium dioxide and silver suspensions was developed. The titanium dioxide nanoparticles, forming a supporting layer, were 46 nm in diameter, exhibiting an isoelectric point at pH 6.4. The silver nanoparticles, forming an external layer of the diameter of 50 nm were prepared via a chemical reduction method with the presence inorganic phosphate salts. The electrophoretic mobility measurements revealed that the zeta potential of silver nanoparticles was highly negative for a broad range of pH and ionic strengths. By explaining this information, the optimum condition for the silver nanoparticle immobilization on TiO<sub>2</sub> supporting layers were selected. The coverage of the first layer was adjusted by ionic strength of the suspensions and by the deposition time. Afterward, the silver nanoparticle monolayers of controlled coverage were deposited under the diffusion-controlled transport. Their coverage was determined by a direct enumeration of deposited nanoparticles from AFM images and SEM micrographs. The experimental results showed that for extended deposition times, the coverage of silver nanoparticle layers significantly increases with ionic strength. Therefore, it was proven that the formation of bilayers is mainly controlled by electrostatic interactions and that it is feasible to produce uniform TiO<sub>2</sub>/Ag materials of desired coverage and structure.</p>

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