Tag
#nanomaterials
Every article tagged “nanomaterials”.
12 articles
Environmental Science
A virus is far smaller than the gaps in an N95. The mask catches it anyway, and it catches it better than a bigger particle
The argument that a mask cannot stop a virus because the virus is smaller than the holes assumes a filter is a sieve. It is not. Four separate capture mechanisms operate, and the size a filter struggles most with is in the middle — which is why very small particles are caught more easily than medium ones.
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Physics
Grind up a peacock feather and the blue disappears. There was never any blue in it
Some of the most intense colours in nature contain no pigment at all. They are produced by structures the size of a wavelength of light — which means the colour is in the geometry, cannot fade, and can be engineered into paint, packaging and banknotes.
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Energy
A supercapacitor charges in seconds and survives a million cycles. It is still not going in your phone
A supercapacitor stores charge by parking ions against a surface rather than by pushing them into a material, which makes it fast and nearly immortal and also means it holds far less energy. This is the one device where surface area per gram is not an improvement but the entire product.
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Physics
Two flat metal surfaces touch across about one per cent of their area. The rest is air, and that is what cooks your laptop
A processor does not overheat because copper is a poor conductor. It overheats at the joins — and at the nanoscale, heat behaves in a way that is exactly opposite to the usual assumption that smaller is better. That inversion is a problem for chips and the entire basis of thermoelectrics.
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Chemistry
Most of a journey's pollution leaves the exhaust in the first two minutes, before the converter has woken up
A catalytic converter contains a few grams of platinum-group metal divided so finely that most of its atoms sit on a surface. It is a remarkable piece of nanoscale engineering that does nothing at all until it is hot — which is why short trips pollute far more than their distance suggests.
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Energy
A battery ages even when you never use it. The reason is a film a few nanometres thick
A lithium-ion cell loses capacity on a shelf, not only in a pocket. The reason is a layer that forms on the anode during the very first charge, keeps growing for the rest of the battery's life, and quietly eats lithium the whole time. Understanding it explains almost every piece of battery advice that actually works.
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Nanotechnology
The label says 40 nm, your instrument says 180 nm, the microscope says 40 nm. All three are right
You cannot see a nanoparticle with light — the physics forbids it. So every number on a nanomaterial datasheet comes from an instrument that measures something adjacent to size and converts. Knowing what each one actually measures explains why they disagree, and which one to believe for your question.
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Environmental Science
Boiling concentrates fluoride rather than removing it. What actually takes it out is a metal oxide surface
Fluoride and arsenic in Indian groundwater pass straight through boiling, chlorination and every candle filter, because they are dissolved ions rather than particles or microbes. Here is what removes them, why arsenic must be oxidised first, and where 'nano' genuinely helps rather than merely appearing on the box.
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Electronics
Your air quality monitor cannot smell anything. It watches oxygen cling to a grain of tin oxide
The gas sensor in an LPG alarm or a ₹2,000 indoor air monitor is a heated speck of metal oxide whose electrical resistance changes when a gas burns off the oxygen stuck to its surface. Understanding that one sentence explains why the readings drift, why humidity confuses them, and why the 'CO₂' number is usually not a measurement at all.
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Nanotechnology
Two bottles both say 40 nm zinc oxide. They are not the same powder, and the reactor is why
Every nanomaterial datasheet describes what arrived. Almost none describes how it was made — and the synthesis route decides the size distribution, the defect count, the impurities and a price that can differ by four orders of magnitude for the same compound.
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Nanotechnology
A carbon nanotube is stronger than steel. A rope of them is not — and the reason is worth understanding
A single carbon nanotube is among the strongest things ever measured. Fibres spun from billions of them come in an order of magnitude weaker. The gap is not a manufacturing failure — it is physics, and it explains what nanotubes are actually good for today.
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Nanotechnology
Why materials behave differently at the nanoscale
Gold that is not gold-coloured, carbon stronger than steel, sunscreen that stops being white. At the nanoscale a material's properties stop depending only on what it is made of and start depending on how big it is. Here is why.
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