Eshani Hettiarachchi, Ph.D.
I started these projects from the scratch. I had lot of fun learning, planning, designing, and executing experiments, and really carving out the direction of these projects.
Current Research
(1) Adsorption behavior and reactivity of biomolecules at the air-seawater interface
The sea surface microlayer (SML) and airborne microdroplets are enriched with marine biomolecules and organic compounds. The chemistry and reactivity of these microdroplets influence fundamental environmental processes, with implications for human health and marine ecosystems. My research examines how biomolecules such as DNA and proteins interact and react at the air–seawater interface, both with and without marine surfactants. I use a combination of techniques, including infrared reflectance absorption spectroscopy (IRRAS) coupled with a Langmuir trough, ATR-FTIR, tensiometry, O-PTIR, Brewster Angle Microscopy (BAM), and AFM-IR. Through collaborations, we also explore these systems using molecular dynamic simulations to gain deeper mechanistic insights.
Created by E.Hettiarachchi (2025)
Current Research
(2) Adsorption & transformation of environmental DNA at the mineral-water interface
The aqueous geochemical interface is a chemically complex environment shaped by natural organic matter, oxyanions, and biological molecules. In this project, I investigate how environmental DNA (eDNA) and proteins adsorb, interact, and transform on mineral surfaces. Using vibrational and micro-spectroscopic probes alongside mass spectrometry, I study the molecular-level details of these interactions — for example, identifying which nucleotides preferentially bind to specific mineral surfaces. These findings help us understand the stability and fate of eDNA in natural systems.
Created by E.Hettiarachchi (2024) in BioRender
Current Research
(3) Characterization and analysis of atmospheric materials
Earth’s atmosphere contains a diverse mix of fine particulate matter, ranging from inorganic and organic particles to coated, aged, or freshly formed aerosols. My work focuses on characterizing these particles in terms of size, composition, and mechanical properties. I employ atomic force microscopy (AFM) and AFM-IR/PTIR to analyze particle morphology and chemical composition, and use force-curve microscopy to measure stiffness and hardness. This approach provides a detailed picture of the physical and chemical properties of atmospheric materials across different environments.
Postdoctoral Experience
This project examined how volatile and semi-volatile organic compounds react with atmospheric pollutant gases on mineral dust surfaces, processes that drive the formation of secondary organic aerosols. I investigate these reactions using FTIR spectroscopy, high-resolution mass spectrometry, and computational modeling with Spartan to understand reaction pathways and product formation at the molecular level.
Ph.D. Research
1
"Understanding the mineralogy dependent atmospheric processing of mineral dust aerosols and their impact on the growth of marine diatoms. Especially the presence of elevated Ti in mineral dust, either as internally mixed (FeTiO3), or as externally mixed (TiO2) in the presence of different acidic gas compositions and solar radiation can enhance the Fe solubility."
2
"Understanding the solubility of heavy metals in inhaled dust, and the possible health implications. Mining lands usually have higher heavy metal contamination (U, V, As) in the dust and smaller particles containing these heavy metals can be inhaled and dissolve in body fluids thereby causing health risks."
3
"Studying structurally and compositionally tuned metal organic frameworks for understanding their potential on selective gas adsorption. Use of such materials in emission points can selectively adsorb & store gases such as carbon dioxide."
Undergraduate Thesis Study
"Synthesis of activated coconut coir (ACC) via both chemical and heat treatment for desalination of hard water and seawater, and improving the regeneration conditions of the ACC for reuse."
