Showing posts with label Silica. Show all posts
Showing posts with label Silica. Show all posts

Aug 2, 2013

Silicon vs. Silicone

Silicon is a naturally occurring chemical element, and silicone is synthetic.

Silicon has properties of both metals and nonmetals and is the second most abundant element in the Earth's crust, after oxygen. It  is rarely found in nature in its pure form. We usually find silicon dioxide or silica, better known as quartz, the most common component of sand.

As silica, silicon is a key ingredient in bricks, concrete and glass. As silicate, it is used to make enamels, pottery and ceramics. It is also used widely in modern electronics, because it is an ideal semiconductor of electricity. When heated into a molten state, silicon is formed into semi-conductive wafers, which serve as the base for integrated circuits. Silicon Valley, California was named due to the high concentration of computer and electronics companies in the area producing silicon-based semiconductors and chips.

Silicone is a synthetic polymer made up of silicon, oxygen, and other elements, typically carbon and hydrogen. Silicone is generally a liquid or flexible plastic. Its useful properties are low toxicity and high heat resistance. It also provides good electrical insulation.

In the medical field, silicone can be found in implants, catheters, contact lenses, bandages and more. It is also contained in items, such as shampoos, shaving cream, non-stick kitchenware, personal and automotive lubricants, sealants, and sex toys. Silicone is heat resistant and slippery.

Silicone is also used in electronics to make casings that can shield sensitive devices from electrical shocks and other hazards.

Jun 9, 2011

Nanotechnology and Nanoparticles

These tiny little things are used in all sorts of things we never hear about, but are changing our lives. Nanotechnology is a broad term that covers many areas of science, research, and technology. In its most basic form, it can be described as working with things that are small. Things so tiny that they can't be seen with standard microscopes. The same stuff that has always been there, but we just couldn't see it.

Here is a comparison - A nanoparticle size is compared to an ant as an ant is compared to the Indianapolis Motor Speedway.

More relative sizes: (nm is nanometer)
The head of a pin 1,000,000 nm across  You can see these with your eyes unaided
The page of a book 100,000 nm thick
A human hair 40,000 nm thick
A red blood cell 7,000 nm across You can see these using a light microscope
DNA molecule  2 nm wide
Most atoms  0.1–0.2 nm

During the next 20 years, nanotechnology will touch the life of nearly every person on the planet. Below is a guide to uses for some of these nano wonders.

Quantum dots
- are made of semiconducting molecules, they glow fluorescently and are great at absorbing light. Used for more efficient solar cells and microscopy dyes for cell biology research.

Silica - silicon dioxide nanoparticles enable so-called shear thickening fluid to become stronger on impact. Used for stab-resistant Kevlar for body armor.

Zinc oxide - tiny crystals stop UV radiation and are toxic to microscopic life. Used for UV-resistant packaging, sunscreen, and paint and textiles that inhibit bacteria and fungi.
Nano barcodes
- bits of various metals linked into tiny wires make good tags for microscopic things. Used for tracking DNA and cells.

Lithium iron phosphate - particles organize themselves into an anode, which allows batteries to charge and deliver power extremely quickly. Used for electric cars, power tools.

Iron oxide - mini magnets can stick to certain chemicals. Used for steering cancer drugs and genes to targets in the body while minimizing collateral damage. Sometimes smaller is better.