Detecting carbon in carbon: Exploiting differential charging to obtain information on the chemical identity and spatial location of carbon nanotube aggregates in composites by imaging X-ray photoelectron spectroscopy

摘要: To better assess risks associated with nano-enabled products including multiwalled carbon nanotubes (MWCNT) within polymer matrices, it is important to understand how MWCNT are dispersed throughout the composite. The current study presents a method which employs imaging X-ray photoelectron spectroscopy (XPS) chemically detect spatially segregated rich regions at an epoxy composites surface by exploiting differential charging. do not charge due high conductivity and have previously been shown energetically separate from their insulating surroundings when characterized XPS. XPS in mode revealed that these conductive were separated micrometer-scale aggregation poor dispersion during formation of Three concentrations studied; (1, 4 5) % mass matrix. Images acquired periodic energy intervals processed using custom algorithms designed efficiently extract spectra interest. As result, chemical electrical information on aggregate non-aggregate portions composite was extracted. Raman scanning electron microscopy employed as orthogonal techniques for validating this XPS-based methodology. Results demonstrate differentially charging samples effective means assessing quality.