Investigation of Fixed Bed Adsorption of Organic Materials using Carbon Nanomaterials - Most chemical processes that involve separation applications utilize activated carbon in some form due to its resilience and cost-effectiveness. However, the amount of waste produced from activated carbon along with its short lifetime of use requires alternative adsorbents to be investigated as a possible replacement for activated carbon. This project is investigating the replacement of activated carbon in a fixed bed apparatus. Fixed bed operations are typically used in many operations at home and in industry. Therefore, a unique opportunity is available for determining mechanistically how replacement of activated carbon with materials like carbon nanotubes and graphene can be utilized in a fixed bed column. Experiments and theoretical modeling are being utilized to understand the efficacy of the approach. In the end, the aim is to demonstrate how alternatives to activated carbon can be improved adsorption uptake while decreasing cost associated with the adsorbent.
Effect of Functionalization of Hybrid Single-Walled Carbon Nanotube/Graphene Papers on Adsorption - We recently developed a hybrid single-walled carbon nanotube/graphene free-standing paper that can potentially serve as a next generation adsorbent. In order to advance this material, new opportunities exist to modify these materials in order to improve their functionality and adsorption properties. One approach aims to alter the surface of these hybrid structures by adding functional groups that favor adsorption of metal ion and organic compounds. Such functional groups are being tailored to achieve an integrated system that achieve high adsorption capacity and high selectivity.
Adsorption Uptake of Single-Walled Carbon Nanotubes Separated by Chirality and Electronic Type - SWCNTs, when synthesized, generally come in a form that has a mixture of chiralities, lengths, and electronic properties. The ability to separate these carbon nanotubes by chirality, electronic type, or lengths/diameters has long been studied with great success. Harnessing the individualized properties of SWCNTs, one can open an array of possibilities for advancing adsorption technologies. We have been investigating the chirality and electronic vectors to understand (1) which chirality type drives adsorption of various organic compounds, and (2) how the electronic type of the SWCNT aid in improving the adsorption properties. Still in preliminary stages, this project has yielded positive results which will hopefully lead to further studies that potentially involve combining these separated SWCNTs with our hybrid systems.
Development of Carbon Nanomaterial-Based Aerogels for Adsorption Applications - Environmental impacts associated with the production and use of potentially toxic chemical and biological compounds continues to cultivate interest in processes to reduce the amount of these harmful agents that can end up in various watersheds. Nanocarbon-based aerogel are ultralight and highly porous materials, exhibiting promising potential in future adsorption systems due to their large surface area, high hydrophobicity and strong interaction with organic compounds. This project aims to devise a “green” method to fabricate carbon nanotube-graphene hybrid aerogel by drying their hydrogel precursor obtained from heating the aqueous mixture of graphene and carbon nanotubes with vitamin C without stirring. The resulting hybrid aerogel performances will be tested in water purification including batch and fixed bed removal of various organic compounds under different conditions (i.e. initial concentration, pH, agitation, temperature...). The objectives of this project consist of (1) the synthesis of purified nanocarbon hybrid aerogels with controled properties (i.e. pore size, surface area, surface chemistry...) and (2) the implementation of these new materials in our batch and fixed bed aqueous phase adsorption systems. The results from this project will serve as a conduit for advancing knowledge in the fields of carbon nanomaterials as well as environmental applications for future research opportunities.