Xu Tao, Xiao Qiangqiang, Chen Jiayu, Li Li, Yang Xiongjun, Liu Lifang, Yuan Wenhui, Zhang Bingjian, Wu Huijun
Academy of Building Energy Efficiency, School of Civil Engineering, Guangzhou University, Guangzhou 510006, China.
Key Laboratory of Enhanced Heat Transfer and Energy Conservation, The Ministry of Education, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, China.
Polymers (Basel). 2019 Feb 3;11(2):255. doi: 10.3390/polym11020255.
This study proposes to utilize modified Nano-SiO₂/fluorinated polyacrylate emulsion that was synthesized with a semi-continuous starved seed emulsion polymerization to improve the hydrophobicity, thermal stability, and UV-Vis absorption of polyacrylate emulsion film. To verify the proposed method, a series inspection had been conducted to investigate the features of the emulsion film. The morphological analysis indicated that Nano-SiO₂ was surrounded by a silane molecule after modification, which can efficiently prevent silica nanoparticles from aggregating. Fourier transform infrared spectra confirmed that modified SiO₂ and dodecafluoroheptyl methacrylate (DFMA) were successfully introduced to the copolymer latex. The particle size of latex increased with the introduction of modified Nano-SiO₂ and DFMA. UV-Vis absorption spectra revealed that modified silicon nanoparticles can improve the ultraviolet shielding effect obviously. X-ray photoelectron spectroscopy illustrated that the film⁻air interface was richer in fluorine than film section and the glass side. The contact angle of modified Nano-SiO₂/fluorinated polyacrylate emulsion containing 3 wt % DFMA was 112°, slightly lower than double that of polyacrylate emulsion, indicating composite emulsion films possess better hydrophobicity. These results suggest that introducing modified Nano-SiO₂ and fluorine into polyacrylate emulsion can significantly enhance the thermal stability of emulsion films.
本研究提出利用通过半连续饥饿种子乳液聚合法合成的改性纳米二氧化硅/含氟聚丙烯酸酯乳液，以改善聚丙烯酸酯乳液膜的疏水性、热稳定性和紫外可见吸收性能。为验证所提出的方法，已进行一系列检查以研究乳液膜的特性。形态分析表明，改性后的纳米二氧化硅被硅烷分子包围，这可以有效地防止二氧化硅纳米颗粒聚集。傅里叶变换红外光谱证实改性二氧化硅和甲基丙烯酸十二氟庚酯（DFMA）已成功引入共聚物胶乳中。随着改性纳米二氧化硅和DFMA的引入，胶乳的粒径增大。紫外可见吸收光谱表明，改性硅纳米颗粒能明显提高紫外线屏蔽效果。X射线光电子能谱表明，膜-空气界面的氟含量比膜截面和玻璃面更丰富。含3 wt% DFMA的改性纳米二氧化硅/含氟聚丙烯酸酯乳液的接触角为112°，略低于聚丙烯酸酯乳液的两倍，表明复合乳液膜具有更好的疏水性。这些结果表明，将改性纳米二氧化硅和氟引入聚丙烯酸酯乳液中可显著提高乳液膜的热稳定性。
