Deontrell Marshall Master’s Thesis Defense, Friday, May 1, 2026 @ 11:00 am Central Time
May 1 @ 11:00 am - 12:00 pm
COMMITTEE CHAIR: Dr. Yunxiang Gao
TITLE: OPTIMIZATION AND SCALE-UP SYNTHESIS OF INDUSTRIAL GRADE CARBON NANOTUBE/ MICROGEL COMPOSITES
ABSTRACT: The development of nanocomposite microgels using multi-walled carbon nanotubes (MWCNTs) presents significant opportunities in controlled release systems and soil enhancement technologies. However, limitations in nanotube dispersion, cost, process reproducibility, and large-scale synthesis of PAAm microgel and industrial grade (IG) MWCNT/PAAm microgel composite continue to hinder practical applications. This study investigates the scale-up synthesis of PAAm microgel and IG MWCNTs-PAAm microgel composite and their optimization using probe ultra[1]sonication technologies for practical industrial production, with an emphasis on sonication power, sonication time, probe degradation, and reproducibility were also investigated. Dynamic light scattering (DLS) and UV-Visible spectroscopy were used to evaluate particle size reduction and urea release behavior. The results demonstrate that sonication probe condition plays a dominant role in dispersion efficiency, with newer probes achieving smaller and more uniform particle size distributions. Sonication power exhibited a non-linear relationship with dispersion, with an optimal operating range identified near 60–70% of power, beyond which improvements diminished. Scale-up experiments revealed thermal instability associated with exothermic free-radical polymerization, resulting in rapid expansion attributed to heat accumulation and gas evolution. Process modifications involving staged thermal control improved reproducibility and mitigated runaway reactions. UV-Visible analysis confirmed that MWCNT composites exhibit more controlled and consistent release behavior compared to pure soil systems. Moreover, we successfully reduced the amount of IG MWCNT with shipping packing peanuts by 70%. These findings establish a framework for optimizing nanocomposite hydrogel systems for industrial production and emphasize the importance of integrating materials chemistry with process engineering principles.
Keywords: Carbon Nanotubes, Microgel, Composites, Industrial Scale-up Production, Fertilizing Efficiency
Room Location: E.E. O’Banion Building, Room 203
