Accelerated Chemistries in High-voltage Sprays of Water

Accelerated Chemistries in High-voltage Sprays of Water

Internship Description

Electrospray ionization (ESI) is a process that entails flowing  liquids though metallic capillaries, typically held at voltages > 3 kV, leading to the formation of a fine spray of charged droplets (due to the imbalance between the cohesive surface tension and repulsive electrostatics). ESI is extensively used to characterize a diverse array of solutes, from simple ions to complex macromolecular complexes, using mass spectrometry (MS) - together, the platform is known as ESIMS. In the recent years, using ESIMS, researchers have reported that a number of chemical reactions accelerate by orders of magnitude, when carried out in ESI droplets in comparison to the reactions in the bulk phase. Examples include, the phosphorylation of glucose and ribose, Pomeranz-Fritsch synthesis of isoquinoline, the reaction between o-phthalaldehyde and alanine, and the ozonation of oleic acid. However, the mechanisms underlying these dramatic rate accelerations remain hotly debated. Most recently, using a variety of experimental and computational tools, we have demonstrated that ESI of solutions of water lead to gas-phase reactions, which are not representative of the air-water interface at thermodynamic equilibrium. 1

 Now, we would like to develop an reactor based on ESI to investigate acid-catalyzed reactions towards the goal of producing high-value chemicals, for instance, of interest to the pharmaceutical industry.Specifically, the Summer Intern will investigate operational parameters, including the ionic strength and pH of water, ESI voltage, coaxial gas-flow rate, length of the reactor, etc., to optimize conditions based on reactions, such as the Fries Rearrangement of phenylacetate. We will analyze the reaction products through nuclear magnetic resonance and chromatography techniques.

 References:

1. Gallo, et al., Chemical Science (2019) DOI: 10.1039/C8SC05538F​

Deliverables/Expectations

The VSRP intern will work with a senior graduate student and learn the following skills:
      Laboratory experiments: ESI-MS, ESI reactions, voltage sources, identifying reactions of interest
      Theory: basic electrostatics, data analysis, scientific writing
We expect the intern to be knowledgeable in chemical engineering, driven by curiosity, hard-working, and thrive in a multicultural work environment.​

Faculty Name

Himanshu Mishra

Field of Study

Environmental and Materials Science​