Search for specific near infrared transparent materials

defrag said:

- be as thermally insulating as possible, and resistant to a temperature of at least 100°C
- transparent to near-infrared light (~1µm wavelength)

defrag said:

Hello everyone,

I am looking for a material with the following characteristics:

- It must be machinable
- be as thermally insulating as possible, and resistant to a temperature of at least 100°C
- transparent to near-infrared light (~1µm wavelength)
- relatively resistant to deformation, for use in a centrifuge.

I'm open to any suggestions, even if they don't exactly meet the above requirements.
Is there a more suitable forum for this kind of question?

Thanks to all

practicalphysicsnoob said:

TL;DR Summary: I'm working on building panels that reflect heat trying to create sub ambient temperatures. I need to create a cover out of something transparent that allows IR passthrough

Trying to create a version of mass producible radiative cooling panels
At first I want to start off with something able to be created at home relatively cheaply as I dive further in I will start trying to find more durable materials with the same capabilities
In order for the system to work the cover needs to block airflow and use air as the insulator but allow infrared passthrough.

I have seen cling wrap used because it is made out of polyethylene which does a decent job at it and its cheap, the only problem is durability. You can use more layers because it begins to absorb and block the passthrough of more IR.
If anyone has any ideas or suggestions that would be awesome.

My end goal is to create mass producible panels that require no electricity to passively cool, and if scaled big enough could reduce global warming and reduce energy usage across the globe by roughly 10%. Not only would that reduce the green house effect and pollution purely based on usage of fossil fuels, it would also relieve some of the pressure on energy grids across the world especially during summer months with the population getting more dense in big cities. (side note the greenhouse effect is part of the reason more methane is being released from the glaciers that are now melting which in turn is rapidly increasing the rate they melt. The panels I am working on reflect part of the radiation and instead of making the surrounding areas warmer and cooling the target area it gets reflected out into space instead of getting caught in the ozone layer.)

All credit for any of these ideas goes to Tech Ingredients and Nighthawkinlight they have already made videos on how to do this from home my goal is to come up with prototypes create a company and be able to sell them at scale while being cheap enough that almost everyone can use them.
I want to be absolutely transparent I do want to patent the prototype but the only reason I want to patent it is so a huge company doesn't come along and do it first causing artificial inflation and charging to much for the end product.

This can be made relatively cheaply, I do not care for profit margins when a product like this could do a huge part to help our earth. Every dollar I make from this idea will go back into being able to spread it far and wide. All the ingredients in making the panels are non toxic besides the polyethylene which is very little. Also if you want to reach out to me privately or ask any questions you can send an email to me [Personal information redacted by the Mentors]
Link to the original video where I got the idea

Baluncore said:

Welcome to PF.It seems to me that those are contradictory requirements.
You need to specify the minimum transmission and reflection spectra as minimum and maximum bounded graphs.

.Scott said:

For the uV transmissibility, looks like Polystyrene (PS - melts at 240C) and Polyethylene terephthalate (PET - melts at 260C) are the best candidates.

Making them taut (as a drum head) and multilayered may give you the rigidity and thermal resistance you are looking for.

berkeman said:

Are you related to this other new poster or their application?

defrag said:

Thank you for your reply. From what I've found, the glass transition of PET is 67-81°C and that of polystyrene 100°C. Does this mean that the material becomes soft and loses its initial shape?

What do you think of polycarbonate? It can be used up to 120°C and has good infrared transmission. Do you know if it's easy to machine?

.Scott said:

As far as machining is concerned, are you going to try to machine the transparent surfaces themselves? Wouldn't it be better to by the plastic in sheet form and machine only the frame to hold it. The frame itself shouldn't need to be transparent. Or perhaps I do not have a good picture of what you are trying to do.

defrag said:

I've also think about make two cylinders, a small one and a large one (the small one would go into the large one) and fill the space between the two with air, argon or an insulating gas (or vacuum?).