Naked Science Forum

Non Life Sciences => Technology => Topic started by: Don_1 on 30/08/2008 11:35:51

Title: Is there an alternative to glass that doesn't block UV?
Post by: Don_1 on 30/08/2008 11:35:51

Does anyone know of a substitute for glass which does not filter out UV rays?

Title: Re: Is there an alternative to glass that doesn't block UV?
Post by: Andrew K Fletcher on 30/08/2008 12:13:43

Check out the quartz crystal used in UV sterilization for Koy Carp and ponds.

Title: Re: Is there an alternative to glass that doesn't block UV?
Post by: Don_1 on 31/08/2008 12:08:50

I was really thinking of some sort of polycarbonate or plastic sheeting.

It had occurred to me that a greenhouse with glass will filter out UV rays, and might have a detrimental effect on plants grown in it.

My tortoises enjoy natural sunlight and need UV a & b rays, sitting in a greenhouse in sunny but cold weather conditions would not give them the rays they require, so they have to go under UV lamps. This is costly and environmentally unfriendly. So I thought it might be that commercial growers may use some form or glass substitute in order to give certain plants UV rays that they would ordinarily receive if grown outdoors.

I suppose it asks the question, do plants grown in greenhouses suffer from a lack of UV rays?

Perhaps I should pose this question elsewhere!!!

Title: Re: Is there an alternative to glass that doesn't block UV?
Post by: Bored chemist on 31/08/2008 13:30:54

Most plastics, and polycarbonate in particular, will absorb UV better than glass does.
As far as I know plants don't need UV.

Title: Re: Is there an alternative to glass that doesn't block UV?
Post by: RD on 31/08/2008 13:48:06

UV is generally harmful to plants, but there are exceptions...

Quote

Both plants and phytoplankton vary widely in their sensitivity to UV-B. When over 200 agricultural plants were tested, more than half showed sensitivity to UV-B light. Other plants showed neglible effects or even a small increase in vigor. Even within a species there were marked differences; for example one variety of soybean showed a 16% decrease in growth while another variety of the same soybean showed no effect [R.Parson]. An increase in UV-B could cause a shift in population rather than a large die-off of plants.   

http://www.nas.nasa.gov/About/Education/Ozone/radiation.html

Title: Is there an alternative to glass that doesn't block UV?
Post by: techmind on 07/09/2008 22:10:02

Quote from: Andrew K Fletcher on 30/08/2008 12:13:43

Check out the quartz crystal used in UV sterilization for Koy Carp and ponds.

Quartz is the classic material to use for windows (eg within scientific instruments) which need to pass UV as well as visible wavelengths.
Unfortunately, window-pane sized pieces of quartz-glass sheet are prohibitively expensive (probably 100's of UK pounds).