Waterproof fabric

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In order to understand how waterproof clothing works, we have to understand what waterproof fabrics are and what they are made of. Waterproof fabrics, or breathable fabrics, as they are often called, are fabrics that have been treated to become resistant to penetration by water and wetting. What is special about them is that they keep water from passing through, but allow water vapor to evaporate. Usually they are natural or synthetic fabrics that are laminated or coated with waterproofing material, such as rubber, polyvinyl chloride (PVC) and polyurethane (PU). These are materials that are used in Mackintosh jackets, sauna suits, inflatable boats and even in footballs and glasses. 

What is PVC and PU?

PVC clothing is shiny clothing made of the plastic polyvinyl chloride. PU clothing consists out of waterproof fabric, typically polyester, but may be cotton or a polyblend material that has been heat-laminated to a polyurethane layer. It is lightweight and extremely durable. These fabrics are used in several industries, from medical companies to the manufacture of diapers and active wear.

How can waterproof fabrics keep water from passing through, but allow water vapor to move through its fabric?

Making a material breathable and waterproof is often accomplished by using a membrane or substance that consists of many tiny holes. These pore-like holes are too small for a water droplet to pass through it, but are large enough for air molecules to evaporate. This allows a breathable waterproof jacket to protect underclothes from getting wet, while allowing sweat to pass through and escape from a person’s skin or clothes.

Detailed description

All in all there are three layers: 

Inside

The interior or underside of WP/BR rainwear uses one of the following techniques and technologies to become waterproof and breathable: 

Laminates are formed when a WP/BR membrane is bonded to the underside of a garment's face fabric, as if wallpaper was applied to a wall. In other words: membrane (or wallpaper) + fabric (or wall) = a laminate. 

Coatings are liquid solutions that provide WP/BR characteristics when spread across the interior of a garment. It is like applying an ultrathin coat of paint to a wall. 

All rainwear exteriors, also known as face fabrics are treated with a durable water repellent (DWR) finish. A DWR affects only the exterior of rainwear and is separate from the laminate or coating. Its purpose is to protect the face fabric from becoming saturated, weighing it down and causing any sensation of dampness. It (DWR) accomplishes this by causing water to bead up and roll off the garment's exterior. DWRs however do not inhibit fabric breathability.  

www.impactlab.net

Sources: 

http://www.wisegeek.com/what-is-breathable-waterproof-fabric.htm

http://www.bicycleapparel.com/quick-reference/rain-gear/waterproof-fabrics.html

http://www.campinglife.com/camping-gear/high-tech-outdoor-fabrics/

http://www.dickiesstore.co.uk/blog/2013/10/08/waterproof-fabric-history/

http://specialtyfabricsreview.com/articles/0810_ep80_transhield.html

http://dogblog.ruffwear.net/2010/06/01/the-difference-between-waterproof-and-water-resistant/

http://www.rei.com/learn/expert-advice/rainwear-how-it-works.html

More on carbon nanotubes

We have talked about carbon nanotubes before, but I think they deserve a more detailed explanation, as they do an incredible job. We have already heard that carbon nanotubes are the strongest and stiffest material yet discovered, but why? What is the reason for the strength of these tiny molecules? Let us take a closer look:

Carbon nanotubes, measuring about one ten-thousandth of the thickness of human hair, are members of the fullerene structural family. A fullerene is any molecule composed entirely of carbon. They are called nanotubes because of their long, hollow structure, with their walls formed by one-atom-thick sheets of carbon, called graphene. A carbon nanotube consists either of one cylindrical graphene sheet (single-wall nanotube, SWNT) or of several cylindrical graphene sheets (multiwall nanotube, MWNT).

There are several different possibilities to form a cylinder with a graphene sheet: The sheet can be rolled along one of the symmetry axis, which gives either a zig-zag tube or an armchair tube or in a direction that differs from the axis, which forms a chiral nanotube, and its properties strongly depend on this geometry. All in all, carbon nanotubes show a unique combination of stiffness, strength and tenacity, as well as thermal and electrical conductivity. 

http://ipn2.epfl.ch

Thanks to their tubular structure and the chemical bond between the carbon atoms (known as sp2 carbon atoms) which are considered the strongest of all atomic bonds, carbon nanotubes have a measured strength 117 times higher than metal. Carbon nanotubes are made entirely of this stable bond, which makes it strong against bending and stretching. Because of the differences in the way the familiar chicken-wire patterns of carbon atoms line up across the surface, nanotubes can either act as conductors of electricity or semiconductors. The lattice-like arrangement of carbon atoms thus, makes them not only extremely strong, but gives them a high thermal and electrical conductivity, meaning that electrons and heat are able to pass through them without destroying them. Nanotubes can stretch considerably like toffee before breaking. This makes them ideal for a variety of futuristic applications, such as Conductive plastics, gas storage, batteries with improved lifetime, flat-panel displays and of course technical textiles (to name only a few of them). 

Sources:

http://www.theguardian.com/nanotechnology-world/carbon-nanotubes-tiny-revolution

http://www.org-chem.org/yuuki/nanotube/nanotube_en.html

https://www.asme.org/engineering-topics/articles/nanotechnology/carbon-nanotube-super-fabric

http://physics.aps.org/story/v2/st27

http://www.nanocyl.com/en/CNT-Expertise-Centre/Carbon-Nanotubes

http://www.news-medical.net/news/20100916/Carbon-nanotubes-are-117-times-stronger-than-steel.aspx

Here some other useful links:

http://physicsworld.com/cws/article/multimedia/2013/feb/18/why-are-carbon-nanotubes-so-strong

https://www.youtube.com/watch?v=4XDJC64tDR0

Narrative article: A vicious "Ring of Fire"

It is three o‘clock in the morning. Joaquin Gonzales, a 23-year-old man from Chile is lying in his bed. Suddenly the earth starts shaking. Glass, plates, everything is smashed on the floor and shatters into thousand pieces. Car alarms and barking dogs can be heard from the distance. „Go and get the girls“, Joaquin‘s wife screams desperately. He runs, when all of a sudden the lights go out.

www.inhabitat.com

A few hours later the aftershocks have finally stopped as well. Joaquin and his family are lucky, they survived, but many died. All in all 200 people fell victims to Mother Nature in this night. The earthquake left a trail of destruction: destroyed buildings and snapped power poles are now defining the landscape.

www.boston.com

This is not a rare thing to happen in Chile. The country lies in the middle of the Ring of Fire, an arc of volcanoes and fault lines in the Basin of the Pacific Ocean that is prone to frequent earthquakes and volcanic eruptions.

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Rhetorical analysis: Carbon nanotubes make your suit bulletproof!

http://www.gizmag.com/bulletproof-suit-carbon-nanotube-garrison/29677/

The article presents the new and fashionable bullet-proof business suit from Garrison Bespoke. The author, Brian Dodson, explains how a normal looking suit can protect a human being from being killed and provides lot of details on the material out of which this suit consists. He states that it contains several sheets of carbon nanotube fabric in its lining. These sheets of carbon nanotubes are thinner and lighter than other materials, like Kevlar, normally used for the production of bulletproof vests. The author explains that the resistance of the suit to bullets and stabbing is due to carbon nanotubes, the strongest and stiffest materials yet discovered. There strength stems from the layers of carbon atoms. Carbon tends to form a very strong bond to itself. The more layers are used, the stronger the bond. As they tend to tighten their weave when a point force tries to "cut" them, they cause the knife to blunt and in this vein stop it from penetrating the fabric. The author tries to undermine these statements by providing the results of tests, that showed that not even a 9mm round can penetrate the different layers. 

www.dailymail.co.uk

You might want to watch this :)
https://www.youtube.com/watch?v=RJ8VLYGLKPM