Glass, glazing and nanotechnology

Lee Coates of Wrightstyle Limited.

Clear glass that turns opaque and converts solar energy into electricity? What’s next for the building industry? Wrightstyle Limited’s Lee Coates tells CW.

The modern science of nanotechnology, the highly-advanced manipulation of matter at a molecular level, which is set to revolutionise every aspect of our lives in the next decade or so, was in fact invented by a medieval glazier. The trouble was, he was unaware of it.

Given the long history of glass, and the huge strides we have made, it’s surprising therefore that its basic structure - solid or highly viscous liquid - can still be the subject of debate. What some people don’t realise is that glass is multi-functional and is continuing to adapt and become smarter, due to the rise of new technologies.

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Today’s glasses, often with a thin molecular coating on its surface, or sandwiched into glass composites, are able to provide solar control, noise reduction, thermal insulation, and power generation – as well as the mechanical strength to stop fire, ballistic attack, or even a terrorist bomb.

Those developments have been primarily driven by the requirement to provide better insulation and, more recently, to reduce carbon dioxide emissions.

However, it’s not just about reducing energy loss, and much research is now aimed at making glass function in a number of complementary ways. For example, energy efficiency can equally be about balancing the amount of sunlight, and therefore heat, that enters a building. A current technology is photochromatic glass that, just like reactive sunglasses, responds to solar radiation by changing colour.

A smarter technology is electrochromatic glazing.  This responds to electrical current rather than solar radiation and is already widely installed for privacy rooms. At the touch of a switch, the clear glass turns immediately opaque. In the years ahead, more buildings will utilise the technology for the external envelope, with the sunlight balance controlled through a computerised management system.

Also in that envelope will be photovoltaic glass, with integrated solar cells that convert solar energy into electricity and therefore power for that building. The technology involves placing solar cells between two glass panes, with each individual cell having electrical connections to other cells in the module.

However, all of these glasses have to be looked at in terms of the complete glass and glazing system, rather than in isolation because, for example, heat loss can be greater from the frame than through the glass. In other words, in calculating thermal insulation, both the glass and its supporting frame need to be considered.

Another avenue for research has been the development of glass types to mitigate against fire and other threats. Let’s remember that it was only around twenty years ago that the only fire glass on the market was wired glass. Effective, yes, but ugly – and not good if you put your hand through it.

Today’s modern glass composites have near-perfect optical quality and can stop a fire for two hours or more, prevent bullets from passing through and can withstand the detonation of a high explosive charge. Any life-safety application for glass must look at both the glass type and its framing system. Both must be compatible.

These, therefore, are the kinds of technologies and processes that today’s glass and glazing systems can incorporate. However, the next big thing in glass technology is fast approaching – the new dawn of nanotechnology. Every aspect of our lives will be touched by nanotchnology – from communications to manufacturing processes and from super-efficient lightbulbs to super-efficient power-stations.
 

Who is Lee Coates
Lee Coates leads the research, development and continuous testing programme for Wrightstyle Limited, which supplies advanced steel and glass systems for specialised applications such as fire resistance, bomb and blast resistant glazing and bullet/ballistic protection. Coates has 15 years experience in building design and engineering, and is a fully qualified draughtsman, CAD specialist, and engineering designer.