| Popis: |
This dissertation explores the synthesis of carbon nanotube (CNT) hybrid fabric synthesized from the floating catalyst chemical vapor deposition (FC-CVD) method. The FC-CVD reactor operational parameters such as fuel injection temperature, fuel injection rate, and gas flow rate are optimized to improve process yield. Our current reactor is best-tuned for high yield at a fuel injection temperature of 400 °C, a fuel injection rate of 30 ml/h, and a gas flow rate of 1500 sccm of argon and 100 sccm of hydrogen. Additionally, the effect of mixing three transition metals (Fe, Ni, Co) catalyst for CNT synthesis on the process yield was studied. Although using a combination of transition metal catalysts has shown improvement for the substrate-based CVD process, mixing catalysts did not improve the process yield for the FC-CVD CNT synthesis process. However, combining two or three catalysts reduced catalyst impurity in the final product compared to using just one catalyst. Furthermore, mixing two or three catalysts also observed a slight improvement in the carbon conversion. However, the improvement did not translate into an overall improvement in the process yield rate. Another consideration is that ferrocene is significantly cheaper than the other transition metal metallocenes used for catalysts. Therefore, ferrocene as a catalyst for the FC-CVD method is ideal for large-scale commercial production. Following process optimization, three different methods were explored to integrate nanoparticles into the CNT sock, of which two are single-step in situ methods, and one is a two-step ex-situ method. This dissertation also successfully tests hybrid nanofabric for the potential development of lightweight lead-free x-ray shielding fabric to protect healthcare workers and to develop an apron for protecting aircrew members from cosmic radiation. |
