Carbon‐Nanotube‐Templated Microfabrication of Porous Silicon‐Carbon Materials with Application to Chemical Separations

Carbon‐nanotube‐templated microfabrication (CNT‐M) of porous materials is demonstrated. Partial chemical infiltration of 3D carbon‐nanotube structures with silicon results in a mechanically robust material, structured from the 10 nm scale to the 100 μm scale. The nanoscale dimensions are determined by the diameter and spacing of the resulting silicon/carbon nanotubes, while the microscale dimensions are controlled by the lithographic patterning of the CNT growth catalyst. We demonstrate the utility of this hierarchical structuring approach by using CNT‐M to fabricate thin‐layer‐chromatography (TLC) separations media with precise microscale channels for fluid‐flow control and nanoscale porosity for high analyte capacity. Chemical separations done on the CNT‐M‐structured media outperform commercial high‐performance TLC media.