Outer-specific surface area as a gauge for absolute purity of single-walled carbon nanotube forests

We present a simple approach to estimate the absolute purity of carbon nanotube (CNT) forests based on outer-specific surface area (SSA). The outer-SSA and absolute purity for diverse forms of CNT forests to increased levels of carbonaceous impurities showed similar behavior and revealed a method to distinguish between CNTs and carbonaceous impurities. Furthermore, these experiments showed a direct proportionality between the outer-SSA and absolute purity which led to a simple analytical model to use outer-SSA as a gauge for absolute purity analysis.