Effect of additives upon freezing points of smart window thermochromic-coating solution for available in winter
발표자
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초록
내용
Thermotropic materials are suitable for applications in solar control glazing. In particular, Poly(N-isopropylacrylamide) (PNIPAm) microgels are temperature sensitive and therefore show great potential for smart window applications. When heated in water above 33 °C, PNIPAm undergoes a reversible lower critical solution temperature(LCST) phase transition from a transparent(swollen state) to a Opaque(shrunken state). PNIPAm's freezing point is only minus 5 degrees, making it difficult to commercialize in winter. In this study, PNIPAm's freezing points were investigated by mixing glycol and ethanol contents, respectively and observed the solution phases and transmittance properties. Below 0.03 wt% of glycol, the freezing point is –15 °C, below 0.1 ml of ethanol, the freezing point is –10 °C are observed. Also, the solution phases and transmittance properties are similar with those of PNIPAm itself.