Are silver nanoparticles hazardous?
Along with this antimicrobial activity, silver nanoparticles are showing unacceptable toxic effects on human health and the environment. The chronic exposure to silver causes adverse effects such as permanent bluish-grey discoloration of the skin (argyria) and eyes (argyrosis).
What is surface functionalization of nanoparticles?
Functionalization of NPs involves conjugation of molecules on the surface of the particles. The high surface to volume ratio allows efficient functionalization of particles to suit our needs.
What is surface modification of nanoparticles?
Surface chemical modification refers to a method of changing the structure and state of the surface of a nanoparticle by chemical reaction or chemisorption between the surface of the nanoparticle and the treatment agent to achieve the purpose of surface modification.
How do you get silver toxicity?
You can develop argyria if you have far too much silver in your body, which generally results from prolonged exposure. When silver reaches your stomach, it prompts a chemical reaction. As the silver breaks down, it enters your bloodstream. Within a week, most of the silver we consume leaves the body through our feces.
Why Surface modification of nanoparticles is important?
The surface modification of nanoparticles by chemical treatments (such as the absorption of silane coupling agents) is a useful method to improve the dispersion stability of nanoparticles in various liquid media.
Why is surface modification important?
An optimal surface finish is particularly important for alloys subjected to severe weather conditions, such as for aircraft [10]. The surface modifications should inhibit oxidation, promote adhesion of further coatings, or reduce staining.
What level of silver is toxic?
It is also not known what level of silver causes breathing problems, lung and throat irritation, or stomach pain in people. Studies in rats show that drinking water containing very large amounts of silver (2589 parts of silver per million parts of water, or about 2.6 grams per liter) is likely to be life-threatening.
How do nanoparticles cause toxicity?
One mechanism of toxicity of nanoparticles is likely to be the induction of oxidative stress in cells and organs. Testing for interaction of nanoparticles with proteins and various cell types should be considered as part of the toxicological evaluation.
How do you know if a nanoparticle is toxic?
Histopathology of the cell, tissue or organ after exposure is used to determine the toxicity level caused by a nanoparticle [94]. Histopathology examination has been used to nanoparticles’ exposed tissues such as lung, eyes, brain, liver, kidneys, heart and spleen [93, 95].
What are the different functionalization reactions?
The functional reactions introduced to foreign compounds include N-oxidation, S-oxidation, aromatic and aliphatic hydroxylation, O- and N-dealkylation, hydrolysis, and epoxidation.
What is post functionalization?
Post-functionalization of polyolefin occurs as the name suggests: functionalization occurs after a non-functionalized polyolefin is synthesized. One of the most common way to attach functionality onto a preexisting polymer backbone is through free radical reaction.
What is polymer functionalization?
The introduction of chemical groups into a polymer to exert specific chemical, physical, biological, pharmacological, or other functions.
How can surface engineering be applied to nanomaterials?
The primary goal of SE of nanomaterials is to modify the properties of surface to improve its electrical and thermal properties, and to improve the compatibility of nanomaterials with some matrix when they are used as reinforcing fillers in composites for high performance applications.