Continuous Flow Microwave-Assisted Synthesis as a Potentially Scalable Nanomanufacturing Approach

Type
Thesis
Year of Publication
2017
Authors
Gustavo Henrique T. de Albuquerque
Date Published
Jan. 1, 2017
Abstract

The development of nanomaterials and the potential enhancement of their chemical, mechanical, electrical, and optical properties have led to the investigation of methods for their synthesis at lower cost with enhanced performance for next generation devices. Along with the pursuit of new materials that exhibit properties of interest, industry requires scalable methods that enable high control over the final products properties. This work presents a promising approach in which microwaves are utilized in a continuous flow setup for the synthesis of nanomaterials. Microwaves induce the fast formation of nuclei and the rapid consumption of reagents leading to a separation of nucleation events from growth processes and consequent results in the formation of products with high uniformity. This method was employed in the synthesis of a metal-organic framework (MOF), and silver nanocubes. Both materials still present synthetic scalability issues. MOFs are hybrid porous materials that can have extremely high surface areas and low densities, making them suitable for gas storage applications. The continuous flow microwave reactor (CFMR) setup was used to synthesize MOF-74(Ni) particles with mild conditions of temperature and pressure while obtaining high yields and high reagent utilization. This method provides a breakthrough in producing MOFs at larger scale. Silver nanocubes have exhibited enhanced catalytic and sensing performances that make them of scientific and industrial interest. The CFMR was used to allow the formation of highly monodisperse particles with high selectivities to the cubic shape. Formally, Cu3SbS4, or Famatinite, is a low band gap material with high absorption coefficients that can potentially be used in a tandem solar cell devices. High vacuum techniques are typically employed in deposition processes for solar cells, however a solution-based processing approach was performed with Cu3SbS4 nanoparticles to develop a potentially cost-effective technique in fabricating solar cells. This dissertation will present an innovative and potentially scalable synthetic approach of nanomaterials and the use of inexpensive deposition steps that can potentially be used in applications including electronic, catalytic, gas storage, and membrane absorption systems.