A facile method to fabricate Al4B2O9 whiskers on porous SiC substrates for gas–solid separation

Wei Wang,Boya Wang,Hanghui Zhu,Hongwei Li,Shunxi Deng

doi:10.1007/s40145-015-0154-0

Abstract

Al4B2O9 whiskers on the surface of porous SiC substrates were fabricated by chemical reactions between Al(NO3)3 and H3BO3, which is a facile method to prepare cilia-like microstructure for gas–solid separation. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy were employed to investigate the structural morphology and phase compositions. Al4B2O9 whiskers with nanometer-sized diameters and micrometer-sized lengths grew on the surface of SiC substrates, and a self-catalytic mechanism was used to explain Al4B2O9 whisker growth.

Highlights

Porous silicon carbide is a well-suited candidate for diesel particulate filter (DPF) field in vehicle exhaust treatment due to its excellent properties like high temperature stability, low thermal expansion coefficient, high corrosion resistance, high thermal conductivity, and excellent mechanical strength [1,2,3]
Inspired by the bronchial microstructure, we have proposed a new strategy to trap ultrafine particles more efficiently using molten salt reaction synthesis of mullite whishers on the porous SiC substrates [8]
SiC, Al4B2O9, and Al7Si3BO13 crystalline phases are observed in the sintered specimens (800 °C and 900 °C), indicating that Al4B2O9 whiskers could be formed at lower temperature, which is in agreement with the published literature [14]

Summary

Introduction

Porous silicon carbide is a well-suited candidate for diesel particulate filter (DPF) field in vehicle exhaust treatment due to its excellent properties like high temperature stability, low thermal expansion coefficient, high corrosion resistance, high thermal conductivity, and excellent mechanical strength [1,2,3]. Nature experiments with various solutions to its challenges and selects the successful ones, which provide ready answers to scientific and technical problems and inspire us with a series of novel designs and high-performance structures [9,10,11]. A large number of the ciliated cells grow on the surface of bronchial wall, and every ciliated cell has about 300 cilia with the length of 6 μm [12,13]. The harmful substance, such as dust and bacteria, could be filtered by these cilia. Al4B2O9 whiskers have been prepared on the porous SiC surface by sol–gel technology

Experimental

Results and discussion

Conclusions