Evaluation of Critical Parameters in the Separation of Single-Wall Carbon Nanotubes through Selective Adsorption onto Hydrogels

Abstract

The electronic-type separation of single-wall carbon nanotubes (SWCNTs) by selective adsorption onto hydrogel surfaces has become a highly researched method. However, large variations in both SWCNT dispersion and separation protocols have been reported, making it difficult to elucidate whether changes to dispersion state or separation parameters are responsible for the observations reported in the literature. This study systematically evaluates the role that hydrogel type (dextran- or agarose-based) and SWCNT loading concentration have on separation quality, throughput, and reproducibility. For dextran-based gels, increased dextran concentration rather than cross-linker concentration improves retention and selectivity, suggesting that hydroxyl groups rather than linker molecules are the active adsorption sites. SWCNTs have much stronger interactions with agarose- than dextran-based gels. This stronger adsorption capacity combined with the improved retention of SWCNTs at higher agarose concentration sugges...