Synthesis and application of light management with thermochromic hydrogel microparticles

A hydrogel thin-film device for use in light management, the device comprising:

• a layer comprising temperature-responsive hydrogel microparticles, wherein each of the temperature-responsive hydrogel microparticles (i) has a homogeneous cross-link density, and (ii) comprises poly (N-isopropylacrylamide)-2-Aminoethylmethacrylate hydrochloride (pNIPAm-AEMA),
• wherein the homogeneous cross-link density and pNIPAm-AEMA enable the hydrogel thin-film device to achieve an infra-red (IR) transmittance reduction of at least 70% at temperatures above 34° C.;
• wherein solar gain is regulated in the device by tuning light scattering in the layer by controlling particle size of the pNIPAm-AEMA microparticles, and
• wherein an average size of the pNIPAm-AEMA microparticles varies from 1388 nm at 25° C. to 546 nm at 35° C.

A hydrogel thin-film device for use in light management, the device comprising:

• a layer comprising temperature-responsive hydrogel microparticles, wherein each of the temperature-responsive hydrogel microparticles (i) has a homogeneous cross-link density, and (ii) comprises poly (N-isopropylacrylamide)-2-Aminoethylmethacrylate hydrochloride (pNIPAm-AEMA),
• wherein the homogeneous cross-link density and pNIPAm-AEMA enable the hydrogel thin-film device to achieve (i) a luminous transmittance over 85% at 25° C., and (ii) an IR transmittance reduction of at least 70% at temperatures above 34° C.;
• wherein solar gain is regulated in the device by tuning light scattering in the layer by controlling particle size of the pNIPAm-AEMA microparticles, and
• wherein the temperature-responsive hydrogel microparticles can undergo a phase transition under solar irradiance due to the low critical solution temperature (LCST) at 32° C., and
• wherein an average size of the pNIPAm-AEMA microparticles varies from 1388 nm at 25° C. to 546 nm at 35° C.