TOWARD RATIONAL DESIGN OF CARBON NANOMATERIALS: DECOUPLING THE ROLE OF MATERIAL STRUCTURE AND SURFACE CHEMISTRY ON ELECTROCHEMICAL AND ANTIMICROBIAL ACTIVITY

摘要

There has been a steady growth in the use of carbon nanomaterials (CNMs) for novel applications in the environmental field due to their unique structural and tunable physiochemical properties. Carbon nanotubes (CNTs) and graphene are at the forefront of this growing interest motivated by their interaction with environmental media to detect, remove or degrade contaminants [1, 2]. However, at the same time, there is concern that these applications can result in unintended release of these materials to the environment and human exposure with the potential to impart adverse consequences [3-5]. Realizing pathways towards safe design of CNMs while meeting performance specifications is essential for sustainable development of promising CNM-enabled products. At the foundation of this approach, is the establishment of relationships that relate material properties to both functional performance and inherent hazard. These relationships are termed here as structure-property-function (SPF) and structure-property-hazard (SPH), respectively [6]. Decoupling the causative mechanisms of material structure and surface chemistry in relation to electrochemical and biological activity is a critical step towards developing this informative design approach. The safe design of CNMs should be devoted to take advantage of material modifications that increase the electrochemical activity while decreasing the inherent hazard. While our previous work demonstrated the ability to control the electrochemical activity by manipulating surface chemistry (i.e., oxygen functional group composition) of multi-walled carbon nanotubes (MWNTs), there were synchronous trends in antimicrobial activity [7, 8]. This correlation between enhanced electrochemical activity and increased cell inactivation for bacteria is informative from a design perspective and demonstrates the opportunity to further elucidate the underlying mechanisms by which the material reactivity can be tailored and separated from hazard. Given the chemical similarity, structural and electronic differences of CNTs and graphene oxide (GO), they serve as ideal CNM allotropes to investigate structure- and surface-driven impacts on electrochemical and biological behavior. In doing so, the aim is to further resolve SPF and SPH relationships to inform development of CNMs that are functional and benign by design.