(256ah) A One-Step Method for Transferring Single Wall Carbon Nanotubes Onto a Hydrogel Substrate for Biomedical Applications

In recent years, significant progress has been made in elucidating the unique properties of carbon nanotube (CNTs)-hydrogel nanocomposites for biomedical applications. Due to the extremely hydrophobic nature of CNTs and the hydrophilic nature of the hydrogels, there are impediments to developing nanocomposites, including attaining a homogeneous dispersion of CNTs in the polymer solutions or alignment and patterning of CNTs in the hydrogels. Several approaches have been reported on patterning CNTs on various polymeric substrates. However, these methods include high temperature, high vacuum or the use of a sacrificial layer and hence, are incompatible with hydrogel substrates as they can lead to irreversible collapse in hydrogel structure. In this study, we designed a novel method to transfer CNTs onto the hydrogels with a single-step stamping technique. First, dense and aligned single wall carbon nanotubes (SWCNTs) were grown on single-crystal quartz substrate. Subsequently, polyethylene glycol (PEG), poly acrylamide (PA), and polyvinyl alcohol (PVA) hydrogel solutions were deposited on the CNTs grown on the quartz substrate. Upon hydrogel gelation, the CNTs were transferred from the quartz onto the hydrogel. The successful transfer of CNTs was confirmed by scanning electron microscopy (SEM). The transferring efficiency was found to be ~99%. Furthermore, results showed efficient cell attachment on the CNT-hydrogel composites that indirectly confirmed the successful transfer. CNT-hydrogel nanocomposites, such as the ones presented here, can be applied for various biomedical applications such as tissue engineering, drug delivery, and biomedical devices.