Porous SiO2 Hollow Spheres as a Solar Reflective Pigment for Coatings.
Porous SiO2 Hollow Spheres as a Solar Reflective Pigment for Coatings.
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DOI：
10.1021/acsami.6b16760
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发表时间：
2017-04
影响因子：
9.5
通讯作者：
Zheng Xing;S. Tay;Y. Ng;L. Hong
中科院分区：
文献类型：
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作者：
Zheng Xing;S. Tay;Y. Ng;L. Hong
本研究首先利用原位合成的聚苯乙烯（PS）微球作为模板，合成二氧化硅空心球（hs），沉积二氧化硅（SiO2）外壳，然后在空气中缓慢气化以去除PS核心。通过改变PS乳胶的合成条件和溶胶-凝胶沉积条件，可以调节HS的尺寸和多孔SiO2壳的厚度。采用紫外-可见-近红外（UV-vis-NIR）光谱法对HS粉末样品进行了表征，测定了其漫反射特性。此外，它们被用作丙烯酸聚合物基体的填料，用于在太阳光谱反射计上测量太阳反射率。结果表明，空腔尺寸和SiO2壳的结构分别对近红外光和紫外-可见光的反射有影响。此外，本研究还考察了一种具有SiO2 HS的选定金属氧化物对太阳反射率的影响。综上所述，HS的空腔尺寸对近红外光的反射率有较大影响，而壳体本身对紫外蓝光的反射率有较大影响。
This study starts with the synthesis of silica hollow spheres (HSs) by utilizing in situ synthesized polystyrene (PS) microspheres as the template for the deposition of a silica (SiO2) shell, followed by a slow gasification step in air to remove the PS core. The size of HS and the thickness of the porous SiO2 shell are tuned by varying the synthesis conditions of the PS latex and those of the sol-gel deposition, respectively. Various HS powder samples are characterized by ultraviolet-visible-near infrared (UV-vis-NIR) spectroscopy to determine their diffuse reflectance. Furthermore, they are used as the filler in an acrylic polymer matrix for the measurement of solar reflectivity on a solar spectrum reflectometer. It turns out that both cavity size and the structure of the SiO2 shell are influential in the reflection of NIR and UV-vis light, respectively. In addition, this study examines the effect on solar reflectivity of a selected metal oxide with a SiO2 HS. In conclusion, the cavity size of the HS has a strong impact on the reflectivity to NIR light whereas the shell itself affects the reflection of UV-blue light.