Surface Modification of Macroporous SiO2-TiO2 Ceramic Foams via HF-etching and the Application in the Hydrogenation of Commercial Polystyrene
首发时间:2015-03-04
Abstract:Hydrogenation of polystyrene (PS) to produce hydrogenated polystyrene, also known as polycyclohexylethylene, is an important polymer modification process to improved heat and UV resistance of PS. Owning to the large size of PS coils and high viscosity of the system, macroporous ceramic foam (CF) had good industrial potential. However, the CF usually possessed low specific surface area (<1 m2/g) due to high-temperature sintering. In this paper, the SiO2-TiO2 CF (STCF) was prepared using synthetic template replica method, and further HF-etching was applied to increase the specific surface area. The effect of HF etching on the mechanical and structural properties of STCF was investigated by strength test, SEM, EDX, and XRD, respectively. By optimizing the treatment time, HF-etching could remove the SiO2 on the surface of CF sample while the SiO2 inside the struts was remained, leaving interspaces on the etched CFs struts (0.5 - 1.0 μm). The obtained 0.1STCF-HF5 with increased specific surface area could facilitate the dispersion of Pd. The Pd-supported HF-etched STCF catalyst exhibited enhanced hydrogenation activity with negliable internal diffusion of PS coils.
keywords: Catalytic reaction engineering Ceramic foam Polystyrene hydrogenation HF-etching
点击查看论文中文信息
SiO2-TiO2复合泡沫陶瓷的表面蚀刻及其在聚苯乙烯加氢中的应用
摘要:聚苯乙烯(PS)催化加氢制备氢化聚苯乙烯,又称作聚环己烷基乙烯,是一种重要的聚合物改性方法,可以提高PS的热稳定性以及光学稳定性。由于PS加氢体系具有分子尺寸大、粘度高的特点,大孔泡沫陶瓷(CF)在其中具有很好的工业应用前景,然而通常大孔泡沫陶瓷由高温烧结得到,比表面积小。对比,本文采用有机模板复制法制备了SiO2-TiO2泡沫陶瓷,并采用HF酸进行蚀刻处理以增加陶瓷的表面积。通过强度测试、SEM、EDX和XRD等方法研究了HF蚀刻对于泡沫陶瓷表面及体相结构的影响。通过控制HF蚀刻时间,可以选择性移除SiO2-TiO2泡沫陶瓷表面的SiO2,体相中的SiO2含量几乎不变,在陶瓷表面产生0.5 - 1.0 μm的孔隙。所制备得到的0.1STCF-HF5表面积明显增加,有利于活性组分Pd的负载。与未经HF蚀刻的催化剂相比,制备得到的Pd/0.1STCF-HF5的加氢活性明显提高,并且可以消除PS线团在其空隙中的内扩散。
基金:
论文图表:
引用
No.4632379518241423****
同行评议
共计0人参与
勘误表
SiO2-TiO2复合泡沫陶瓷的表面蚀刻及其在聚苯乙烯加氢中的应用
评论
全部评论0/1000