Bio-Inspired Ceramic/Carbon Composites
Abstract
The influence of different parameters including catalyst concentration, infiltration time, and carbon sources on the quality and homogeneity of the in situ grown carbon nanotubes (CNTs) was evaluated. The synthesis approach we used was based on in situ aerosol assisted chemical vapour deposition using alumina scaffolds (supplied by Imperial) as substrate materials. Fe2O3 nanoparticles with sizes between 5-7nm were freshly prepared, dispersed in cyclohexane and, used as metal catalysts. The infiltration of the scaffolds with catalyst particles was conducted for different times and concentrations. The as-infiltrated scaffold placed in a quartz tube inside a furnace and heated to 800 C at a rate of 10 C/min in an Ar flow of 1000 sccm. Once the furnace reached 800 C and the temperature was stable the substrate was kept for a further 10-15 min, then the gases were switched to Ar 200 sccm, H2 150 sccm, and 50 sccm acetylene (C2H2) which was used as carbon source. Following the synthesis, the sample was cooled down at a rate of ca. 2.5 C/min under Ar (1000 sccm, more details about the infiltration process and the synthesis are in the previous report). Fe2O3 nanoparticles with concentrations ranging from 0.2 to 0.02 M were used. As a first approach, the infiltration time was 7 days for all the samples. For 0.2, 0.1 and 0.06M concentrations the results were very similar. The outside of the scaffold (directly in contact with the catalyst solution) appeared completely covered with CNTs while the inside walls showed less CNT coverage with a high trend to agglomerate at the grain boundaries. Figure 1 shows the scanning electron micrograph (SEM) images of the as-synthesized hybrid scaffold/CNTs for 0.1M Fe2O3 nanoparticles concentration.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2013
- Accession Number
- ADA592382
Entities
People
- Nicole Grobert
- Richard Todd
Organizations
- University of Oxford