KAUST DepartmentEnvironmental Science and Engineering (EnSE) Program, Biological and Environmental Science and Engineering (BESE) Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
Interfacial Lab (iLab), Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
Environmental Science and Engineering Program
Water Desalination and Reuse Research Center (WDRC)
Biological and Environmental Science and Engineering (BESE) Division
KAUST Grant NumberBAS/1/1070-01-01
Permanent link to this recordhttp://hdl.handle.net/10754/673269
MetadataShow full item record
AbstractThe role of ionic electrostatics in colloidal processes is well-understood in natural and applied contexts; however, the electrostatic contribution of zwitterions, known to be present in copious amounts in extremophiles, has not been extensively explored. In response, we studied the effects of glycine as a surrogate zwitterion, ion, and osmolyte on the electrostatic forces between negatively charged mica-mica and silica-silica interfaces. Our results reveal that while zwitterions layer at electrified interfaces and contribute to solutions' osmolality, they do not affect at all the surface potentials, the electrostatic surface forces (magnitude and range), and solutions' ionic conductivity across 0.3-30 mM glycine concentration. We infer that the zwitterionic structure imposes an inseparability among positive and negative charges and that this inseparability prevents the buildup of a counter-charge at interfaces. These elemental experimental results pinpoint how zwitterions enable extremophiles to cope with the osmotic stress without affecting finely tuned electrostatic force balance.
CitationRidwan, M. G., Shrestha, B. R., Maharjan, N., & Mishra, H. (2022). Zwitterions Layer at but Do Not Screen Electrified Interfaces. The Journal of Physical Chemistry B. https://doi.org/10.1021/acs.jpcb.1c10388
SponsorsH.M. thanks Changzi Wang, a student from his course on Aquatic Chemistry (EnSE 202) at KAUST, for bringing this problem to his attention. The authors are indebted to Masha Belyi (Research Scientist, Amazon’s Team Alexa) for creating a Python script for analyzing hundreds of AFM force–distance curves generated in this work to pinpoint the trends in Debye lengths and surface potentials. M.G.R. thanks Mohammad Abbas (KAUST) for discussions on cell physiology; B.R.S. thanks Dr. Bruno Torres (KAUST) for providing colloidal probes for AFM experiments. The co-authors thank Ana Rouseva (KAUST) and Paulus Buijs (KAUST) for assisting with osmotic pressure measurements presented in C; Dr. Farizal Hakiki (KAUST) and Prof. Carlos Santamarina (KAUST) for characterizing dielectric responses of solutions presented in D; and Heno Hwang, KAUST Illustrator, for preparing and and TOC. H.M. acknowledges KAUST for funding (grant no. BAS/1/1070-01-01).
PublisherAmerican Chemical Society (ACS)
PubMed Central IDPMC8900129
Except where otherwise noted, this item's license is described as Archived with thanks to The Journal of Physical Chemistry B under a Creative Commons license, details at: https://creativecommons.org/licenses/by/4.0/
- Effect of pH on the interaction between zwitterions and titanium oxide.
- Authors: Tanaka Y, Saito H, Tsutsumi Y, Doi H, Nomura N, Imai H, Hanawa T
- Issue date: 2009 Feb 1
- Correlation between Electrostatic and Hydration Forces on Silica and Gibbsite Surfaces: An Atomic Force Microscopy Study.
- Authors: Klaassen A, Liu F, Mugele F, Siretanu I
- Issue date: 2022 Jan 25
- Precise control of surface electrostatic forces on polymer brush layers with opposite charges for resistance to protein adsorption.
- Authors: Sakata S, Inoue Y, Ishihara K
- Issue date: 2016 Oct
- Interaction forces between DPPC bilayers on glass.
- Authors: Orozco-Alcaraz R, Kuhl TL
- Issue date: 2013 Jan 8
- Direct force measurements between cellulose surfaces and colloidal silica particles.
- Authors: Radtchenko IL, Papastavrou G, Borkovec M
- Issue date: 2005 Nov-Dec