(407e) Altering Physico-Chemical Properties of Pine-Derived Carbon Quantum Dots By Changing Hydrothermal Treatment Conditions

Carbon quantum dots (CQD) are a relatively new and exciting material that are finding their place in a vast range of industries. These dots are aptly named as they exist within a diameter range of 0-10 nanometers. They are being utilized in everything from material coatings that self-clean or self-repair, to medicines that deliver cancer treatments to targeted areas in the body using UV light, to use in home entertainment systems to produce high quality screen visuals. Efficient methods and sources for producing these quantum dots are still being studied. It is found that the properties of the dots largely depend upon the surface functional groups and the size of the dots. Typically depending upon the method used to develop the dots (top-down or bottom-up) and the feed source the products are derived from will determine the surface groups and sizing.

A large amount of attention has recently been given to producing carbon quantum dots in the environmentally friendly manner of hydrothermal treatment. Many feedstocks have been studied and almost everyone has produced a variant dot. The goal of this research is to determine the effects of varying the hydrothermal treatment temperature and residence time on the characteristics of CQDs. Loblolly pine was chosen is chosen for this study due to abundancy and low cost. The experimental procedure focuses on three different reaction temperature conditions of 180, 220, and 260 °C. The time also varies in increments of 30 min up to 3 hours. After hydrothermal treatment the process fluid will undergo vacuum filtration followed by dialysis in order to separate the dots for characterization. Next the dots will be freeze dried for characterization that requires dry samples. The process fluid and the hydrochar itself will be analyzed for carbon quantum dots and these will be characterized using Fourier Transform Infra-Red Spectroscopy, Ultraviolet-Visible Spectroscopy, Fluorometry, Tunneling Electron Microscopy, and X-Ray Diffraction to determine trends. Altering the treatment time and temperature/pressure the quantity, surface functionalization, and the size can be controlled due to altering the formation of the passivation layer and condensation mechanism that forms the dots. As a result the quantum yield, absorbance, emission, and applicability of the dots are altered and can be fine tuned per application in industry.