Low absorption , high absorption

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The discussion revolves around finding materials that are cost-effective, heat-insulating, and highly transparent to various light spectra, including UV and infrared. Quartz is suggested as a potential material for these requirements, though practicality on a large scale is questioned. The possibility of creating a one-way reflective surface is deemed impossible due to the symmetrical nature of light transmission in isotropic materials, as explained by Maxwell's equations. For high absorption with low reflectivity, flat black paint is mentioned, along with the impracticality of using hyperfine carbon films. The project aims to create a solar-powered heating unit using water for heat storage, emphasizing a fun, low-tech approach.
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hi, this might be the wronge place to post this but trying to find this info on the web is exceedingly dificult.
I need a material that is cheap has a heat insulating effect and has high transparency and permeability for al forms of the light spec rum including uv and infared.

That is part one, part two is there a way to increase the reflectivity of one side over the other as in on one side light passes through with the minimal amount of reflection and when it attempts pass through the other way it is reflected back in, I know they make 1 way mirrors but it seems more like its just highly reflective glass with a dark room.

I know this asking for a lot but I have one more question is there a cheap high absorption material with really low reflectivity,I know black paint will absorb a great deal of light and convert it to heat, but I want to absorb as much of the visible and invisible spectrum as possible and convert it to heat.

I'm just working with a project and I can't trust internet sights as they are all just trying to sell there specific products and it seems a waste to spend money on a less effective material
 
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Part 1: quartz

Part 2: impossible. Transmission is symmetrical for any combination of linear isotropic materials. This is a consequence of reciprocity which can be derived from Maxwell's equations.

Part 3: flat black paint. You can vacuum deposit a hyperfine carbon film and improve the absorption but this is not practical for most surfaces.
 
Thanks for the tips, I had a feeling that the might not be a way to have one side reflext while the other doesn't but I had to ask anyway

on another note, quarts is an interesting answer. Hadn't even considered it, but would that be practical on a large scale? Maybe I should clarify scale, the project I'm working on is about as tall as a man.

This is a for fun project to build a solar powered heating unit as a using water to store the hear, just some low tech fun / yard decoration...

I have a lot of free time
 
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