Nonwoven Nanofiber Mat
OwnerHal P. Greenbergerinventor
Life of this patent
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Abstract
Nonwoven nanofiber mats for use in radiative cooling applications must have high emissivity in the atmospheric window (where the atmosphere is relative transparent to EM radiation), and relatively lower emissivity elsewhere. Materials with this emissive property are referred to as selective emitters (SEs). Materials used in nanofiber nonwoven mats used for SEs should have low absorbance to solar radiation, so they are not heated by incident solar irradiation. Properties of the mat are chosen to exploit Mie scattering to achieve high reflectance to solar radiation. A coating can be applied to the top layer of the SE to enhance its emissivity, and to mechanically bind fibers in the layer. Emissivity enhancing particles can be added to the coating to improve emissivity.
Claims23
A selective emitter for radiative cooling comprising:
- a reflective layer comprising a nonwoven fiber mat, and;
- a binder coupled to the nonwoven fiber mat,
- wherein the binder bonds fibers together within at least a first layer of the nonwoven fiber mat,
- wherein the reflectance of the selective emitter averaged over a first wavelength range from about 350 nm to about 1400 nm is at least 90%, and the emittance of the selective emitter averaged over a second wavelength range from about 8 μm to about 14 μm is at least 0.8,
- wherein the binder has an optical absorbance averaged over the first wavelength range of less than 5%.
A nonwoven fiber mat comprising:
- a reflective layer, wherein the reflectance of the reflective layer averaged over a first wavelength range from about 350 nm to about 1400 nm is at least 90%, and;
- a binder coupled to the fiber nonwoven mat,
- wherein the binder bonds fibers together within at least a top layer of the nonwoven mat,
- wherein the binder has an optical absorbance averaged over the first wavelength range of less than 5%.
An optically reflective and thermally insulating mat comprising:
- a nonwoven ceramic fiber mat,
- wherein a shape is impressed onto the nonwoven mat by a tool, the shape maintained via self-reinforcement of the nonwoven ceramic fiber mat, and;
- a binder comprising a PDMS coating,
- wherein the coating is diffused into the self-reinforced nonwoven ceramic fiber mat to coat fibers within mat interior.
Dependencies are inferred from the claim text.