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Formation of hydrogen peroxide in water microdroplet

Project

Project Details

Program
Environmental Science and Engineering
Field of Study
Physical Chemistry, Electrochemistry, Analytical Chemistry, Microfluidics, high-speed imaging, chemical kinetics
Division
Biological and Environmental Sciences and Engineering
Faculty Lab Link
https://www.kaust.edu.sa/en/study/faculty/himanshu-mishra
Center Affiliation
Water Desalination and Reuse Center

Project Description

Recent reports on the formation of hydrogen peroxide (H2O2) in water microdroplets produced via pneumatic spraying [1] or capillary condensation [2] have garnered significant attention. How covalent bonds in water could break under such mild conditions challenges our textbook understanding of physical chemistry and the water substance. While there is no definitive answer, it has been speculated that ultrahigh electric fields at the air-water interface are responsible for this chemical transformation. We are carrying out a comprehensive experimental investigation of H2O2 formation in (i) water microdroplets sprayed over a range of liquid flow-rates, the (shearing) air flow rates, and the air composition (ii) water microdroplets condensed on hydrophobic substrates formed via hot water or humidifier under controlled air composition. Our experimental results have challenged the putative claims of spontaneous H2O2 generation on the water surface [3, 4]. Additionally, new scientific questions along this theme have emerged that the VSRP intern will contribute to. References: 1. Lee, J. K.; Walker, K. L.; Han, H. S.; Kang, J.; Prinz, F. B.; Waymouth, R. M.; Nam, H. G.; Zare, R. N., Spontaneous generation of hydrogen peroxide from aqueous microdroplets. P Natl Acad Sci USA 2019, 116 (39), 19294-19298. 2. Lee, J. K.; Han, H. S.; Chaikasetsin, S.; Marron, D. P.; Waymouth, R. M.; Prinz, F. B.; Zare, R. N., Condensing water vapor to droplets generates hydrogen peroxide. P Natl Acad Sci USA 2020, 117 (49), 30934-30941. 3. Gallo Jr, A.; Musskopf, N. H.; Liu, X.; Yang, Z.; Petry, J.; Zhang, P.; Thoroddsen, S.; Im, H.; Mishra, H., On the formation of hydrogen peroxide in water microdroplets. Chemical Science 2022, 13 (9), 2574-2583. 4. Musskopf, N. H.; Gallo, A.; Zhang, P.; Petry, J.; Mishra, H., The Air–Water Interface of Water Microdroplets Formed by Ultrasonication or Condensation Does Not Produce H2O2. The Journal of Physical Chemistry Letters 2021, 12 (46), 11422-11429.

About the Researcher

Himanshu Mishra
Associate Professor, Environmental Science and Engineering
Biological and Environmental Science and Engineering Division

Affiliations

Education Profile

  • Elings Prize Postdoctoral Fellow, University of California Santa Barbara, 2013-2014
  • Ph.D., California Institute of Technology, 2013M.S., Purdue University, 2007
  • B.E., Punjab Engineering College, 2005

Research Interests

Biomimetics Chemistries and electrification at water-hydrophobe interfacesSurface forces (hydrophobic interactions, DLVO, structural forces) Superhydrophobic sand mulches and soil amendments for arid land agriculture

Selected Publications

  • Das, R., Ahmad, A., Nauruzbayeva, Mishra, H.*, ""Biomimetic Coating-free Superomniphobicity"" (accepted, Scientific Reports, #2e02d35e-86bd-44e6-b70c-34c82bc49123)
  • Mahadik, G. A., Hernandez Sanchez, J. F., Arunachalam, S., Gallo Jr., A., Farinha, A. S., Thoroddsen, S. T., Mishra, H.*, Duarte, C. M., ""Superhydrophobicity and Size Reduction Allowed Water Striders to Colonize the Ocean"" (accepted, Scientific Reports, SREP-19-11017)
  • Pillai, S., Santana, A., Das, R., Shrestha, B.R., Manalastas, E., Mishra, H*, ""A Molecular- to Macro-Scale Assessment of Direct Contact Membrane Distillation for Separating Organics from Water"" (accepted, Journal of Membrane Science, https://doi.org/10.1016/j.memsci.2020.118140)
  • Gonzalez-Avila, S. R., Nguyen, D. M., Arunachalam, S., Domingues, E., Mishra, H.*, Ohl, C-D., ""Mitigating Cavitation Through a Biomimetic Gas-entrapping Microtextured Surfaces"", Science Advances, 2020, https://advances.sciencemag.org/content/6/13/eaax6192 (https://advances.sciencemag.org/content/6/13/eaax6192)
  • Shrestha, B. R., Pillai, S., Santana, A., Donaldson, Jr., S. H., Pascal, T. A., Mishra, H.*, ""Nuclear Quantum Effects in Hydrophobic Nanoconfinement"", Journal of Physical Chemistry Letters, 2019, 10, 5530-5535 (Journal cover; Featured on Phys.org, Nanowerk.com, KAUST Discovery, etc.)
  • Gallo Jr., A., Farinha, A. S., Dinis, M., Emwas, A-H., Santana, A., Nielsen, S., Goddard III, W. A., Mishra, H.*, ""The Chemical Reactions in Electrosprays of Water Do Not Always Correspond to Those at the Pristine Air-Water Interface"", Chemical Science, 2019, 10, 2566-2577 (Journal Cover; featured on Phys.org, KAUST Discovery, etc.)
  • Domingues, E. M., Arunachalam, S., Nauruzbayeva, Mishra, H.*, ""Biomimetic Coating-free Surfaces for Long-term Entrapment of Air under Wetting Liquids"", Nature Communications, 2018, 9, Article Number: 3606. (Featured on Nature Chemistry Channel 'Behind the Paper', Phys.Org, and Eureka Alert)
  • Domingues, E. M., Arunachalam, S., Mishra, H.*, ""Doubly Reentrant Cavities Prevent Catastrophic Wetting Transitions on Intrinsically Wetting Surfaces"", ACS Applied Materials & Interfaces, 2017, 9, 21532-38 (Featured on Engineers Australia (https://www.engineersaustralia.org.au/portal/news/micro-texture-inspired-nature-makes-surfaces-liquid-repellent) , EurekAlert! (https://www.eurekalert.org/pub_releases/2017-07/kauo-npa073017.php) , Phys.org (https://phys.org/news/2017-07-nature-key-repelling-liquids.html) )

Desired Project Deliverables

• The intern will conduct a comprehensive experimental investigation of H2O2 formation in (i) water microdroplets sprayed over a range of liquid flow-rates, the (shearing) air flow rates, and the air composition (ii) water microdroplets condensed on hydrophobic substrates formed via hot water or humidifier under controlled air composition. This will also entail a comparative assessment of the various H2O2 detection kits/assays available. • Glovebox experiments will be deployed to quantify H2O2 formation in water microdroplets as a function of the air-borne ozone (O3) concentration. • Effects of atmospherically relevant O3(g) concentrations (10–100 ppb) on the formation of H2O2(aq) will be evaluated. • Effects of the gas–liquid surface area, mixing, and contact duration will be quantified.
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