卡拉胶/聚(N-异丙基丙烯酰胺)基热致变色凝胶的构建与应用

Construction and application of carrageenan/poly(N-isopropylacrylamide)-based thermochromic gel

刺激变色材料的动态透明-不透明转变行为使其具有太阳光调制能力,可以降低建筑物的能源消耗。然而,这些材料通常涉及高生产成本、操作复杂性及额外电能消耗等问题。在此,通过分散聚(N-异丙基丙烯酰胺)(PNIPAM)凝胶微球到卡拉胶(KCA)基质中,制备一种低成本且具有优异太阳光调制能力和高稳定性的复合凝胶(KCA/PNIPAM)。其中,KCA具有多孔的3D网络结构,可以有效管控PNIPAM微球,实现PNIPAM在凝胶体系中的均匀分散,并能够抑制PNIPAM微球的团聚沉降行为。KCA/PNIPAM凝胶展示出优异的太阳光调制能力(ΔT=86%,不同温度下透光率之差),在暴露到氙灯和太阳光照射中,KCA/PNIPAM智能窗较普通玻璃窗可分别降低温度5℃和4℃。总之,KCA/PNIPAM具有响应温度低(31.7℃)、太阳光调制能力优异、稳定性持久、成本低及制造简单等优点,使之能够成为节能建筑材料的潜在候选者。

The dynamic transparent-opaque transition behavior of the stimuli-chromic materials makes themselves have the ability to modulate the sunlight,which can reduce the energy consumption of the building.However,these materials usually involved some weak points such as high manufacturing costs,complex operation,and additional power consumption.Herein,a low-cost composite gel(KCA/PNIPAM)with excellent solar modulation ability and high stability was prepared by dispersing poly(N-isopropylacrylamide)(PNIPAM)gel microspheres into a carrageenan(KCA)matrix.In this hydrogel.KCA has a porous 3D network structure,which can effectively support PNIPAM particles,realizing the uniform dispersion and inhibiting the agglomeration and sedimentation of PNIPAM.KCA/PNIPAM gel exhibits the excellent solar modulation ability(ΔT=86%,difference in transmittance at different temperatures),when exposed to xenon lamp and sunlight,KCA/PNIPAM smart windows can lower the temperature by 5℃ and 4℃ respectively compared with ordinary glass windows.In conclusion,KCA/PNIPAM has the advantages of low response temperature(31.7℃),excellent solar modulation ability,long-term stability,low cost and simple manufacturing,making it a potential candidate for energy-saving materials of building.