What is the difference between perovskite and conventional solar cells?
Conventional solar cells are often made of silicon dioxide, which is used in amorphous or crystalline form. It takes a lot of know-how and money to produce it, and the yield of light energy conversion in commercial products is less than 25% . Therefore, solar cells are also made from other elements. Among the most prominent representatives here are GaAs (gallium arsenide), CdTe (cadmium tellurium) and CIGS (copper indium gallium selenium) solar cells. These elements are controversial, as some are e.g. toxic, only difficult to obtain from socially / ethically acceptable sources and usually very expensive.
Therefore, sustainable alternatives are being sought: perovskite solar cells could be cheaper to produce and the starting materials easier to obtain. However, they also contain toxic elements (status 2022). Intensive research is therefore being conducted into less toxic perovskite solar cells. Good luminous efficiencies have already been achieved in the laboratory, and in particular the possibility of building semi-transparent cells could lead to very high yields in light energy conversion if perovskite and conventional solar cells are arranged one above the other (tandem solar cell or multi-junction solar cell).
- US National Renewable Energy Laboratory (NREL) – Best Research-Cell Efficiency Chart
Nanosilver in food packaging – can the nanoparticles migrate from the packaging into the food?
Silver nanoparticles impart antimicrobial properties to plastic packaging materials and can prevent the growth of food-damaging microorganisms via the targeted release of silver ions. There is a possibility that, in addition to silver ions, silver nanoparticles are being released from the packaging and migrate into the food. From a research perspective, this issue has not yet been conclusively resolved and is being further investigated. Nanosilver, one of the most prominent examples, which is commonly used in the USA, Asia or Australia, is currently not allowed to be used in plastic food packaging in the EU.
- For more information on this topic, please refer to the article in our cross cutting section “Nanomaterials in food packaging”
Are nanomaterials used as food additives dangerous to human health?
Currently no intentionally produced nanomaterials are used in food & feed applications in the EU. The occurring nanomaterials are byproducts of the production process of approved food additives such as silicon dioxide. In Asia and North America however, nanomaterials are used specifically in food products, e.g. for the encapsulation of vitamins. Based on the majority of existing studies, current approved food additives pose no health risk for humans. Since EU law allows only harmless (safe) additives to be used in food, every food additive has to be tested and legally approved prior to any products’ application. This decision is based on latest developments in science and technology and is therefore constantly under revision.
- For more information on this topic, please refer to the article in our cross cutting section “Nanomaterials in Food”
Does Acrylic resin contain nanoparticles?
Acrylic resins are particularly durable synthetic resins and are used in various adhesives, paints and coatings. Before curing, they are present as monomers in liquid form and therefore not nanoparticles. Due to the wide range of possible applications, they may contain various additives e.g. consisting of nanoparticles. However, there is no health risk associated to nanoparticles containing acrylic resins as the nanoparticles are firmly bound in both the liquid and cured form and cannot be released into the environment.
Nanosilver in the mattress – what is the purpose and is it safe?
In many cases, silver threads are woven into the mattress’ cover and the fabric can be additionally impregnated with a silver solution.
The aim of these enhancement methods for textiles is an antimicrobial effect: Under moist or humid conditions, positively charged silver ions are being released by the metallic silver surface exerting their biocidal effects against bacteria, yeast or fungi. This behaviour is independent of size and origin of the silver ions, stemming either from silver salts or from metallic silver particles. However, due to higher specific surface area, silver nanoparticles are able to release much more silver ions, which in turn cause a stronger antimicrobial effect compared to larger particles. At the present state, nanosilver-equipped textiles like those used in mattresses, present no risk or danger to human health.
- Further information on this topic “nano in textiles” can be found in our cross-cutting section!!!