Thiophene-based dispersant for CNTs and its application in silica composite aerogels

silica (SiO₂) aerogel has the advantages of high porosity and good chemical stability, but its practical application is greatly restricted by poor mechanical strength. Based on this, CNTs/SiO₂ composite aerogels were prepared by doping carbon nanotubes (CNTs), which exhibited distinctively enhanced mechanical strength. A thiophene-based aromatic amphiphilic molecule (DSiTE) was synthesized and used to achieve high-concentration aqueous CNTs dispersion. It can be uniformly mixed with SiO₂ sol, and a series of composite aerogels with different CNTs mass fractions were prepared by alkali catalyzed gel and atmospheric drying. The effects of hydrolysis time and CNTs content on the mechanical properties were studied. The results show that the Si-OH groups of the amphiphilic molecule can participate in the formation of aerogel skeleton, greatly improving the interfacial compatibility between CNTs and SiO₂, without phase separation. Under hydrolysis of 2 h and CNTs mass fraction of 0.18 wt%, the compressive strength of CNTs/SiO₂ aerogel reached 0.93 MPa, which is 1.98 times that of pure SiO₂ aerogel. The integration strategy of this study provides a novel and effective approach for preparing SiO₂ aerogels with good mechanical strength.