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dc.contributor.advisorMishra, Himanshu
dc.contributor.authorMaharjan, Nischal
dc.date.accessioned2022-11-17T09:17:49Z
dc.date.available2022-11-17T09:17:49Z
dc.date.issued2022-11
dc.identifier.citationMaharjan, N. (2022). Effects of Common Osmolytes on Electrostatic and Hydrophobic Surface Forces [KAUST Research Repository]. https://doi.org/10.25781/KAUST-3Z9B0
dc.identifier.doi10.25781/KAUST-3Z9B0
dc.identifier.urihttp://hdl.handle.net/10754/685832
dc.description.abstractSurface forces due to electrostatics and hydrophobic interactions in aquatic media are implicated in numerous phenomena in natural and applied contexts, such as protein folding, ATP synthesis, flocculation, froth flotation, food and beverage industry, and separation and purification processes. Although the effects of hard ions like K+ and Cl- on such surface forces have been extensively studied and well understood, the effects of common osmolytes such as urea, TMAO, betaine, sarcosine, and glycine on electrostatics and the hydrophobic interaction are not entirely clear. In the recent years, direct surface force measurements are being utilized to probe these effects. The expectation is that these findings will bring us one step closer to understanding the balance of surface and molecular forces in extremophiles, e.g., Escherichia coli, Sepia officinalis, and Dasyatis americana. In this thesis, we have utilized Atomic Force Microscopy (AFM) and complimentary techniques to directly quantify the effects of common osmolytes on (i) electrostatic interactions between the charged silica surfaces; and (ii) hydrophobic interactions between perfluorinated surfaces. Urea, TMAO, betaine, sarcosine, and glycine enhanced the magnitude of electrostatic interaction. We provide some clues towards mechanistic insight. For hydrophobic surfaces, urea increased adhesion when perfluorinated surfaces were brought into contact, whereas TMAO, betaine, and sarcosine reduced it in the following order: TMAO > betaine > sarcosine. Advancing/receding contact angles were measured to check whether the osmolytes adsorbed onto the hydrophobic surfaces. Contact angle hysteresis data revealed that the adsorption was not significant, and these findings were corroborated via Quartz Crystal Microbalance with Dissipation experiments. Taken together, our findings advance the current understanding of osmolytes’ effects on electrostatic and hydrophobic interactions.
dc.language.isoen
dc.titleEffects of Common Osmolytes on Electrostatic and Hydrophobic Surface Forces
dc.typeThesis
dc.contributor.departmentBiological and Environmental Science and Engineering (BESE) Division
dc.rights.embargodate2023-11-17
thesis.degree.grantorKing Abdullah University of Science and Technology
dc.contributor.committeememberNunes, Suzana Pereira
dc.contributor.committeememberFatayer, Shadi P.
thesis.degree.disciplineEnvironmental Science and Engineering
thesis.degree.nameMaster of Science
dc.identifier.orcid0000-0003-4429-7355
dc.rights.accessrightsAt the time of archiving, the student author of this thesis opted to temporarily restrict access to it. The full text of this thesis will become available to the public after the expiration of the embargo on 2023-11-17.
refterms.dateFOA2022-11-17T09:17:50Z
kaust.request.doiyes
kaust.gpcameen.ghawanmeh@kaust.edu.sa
kaust.availability.selectionEmbargo the work for one year and then release for public access* on the internet through the KAUST Repository.
kaust.thesis.readyToSubmitYes, I confirm that I am ready to upload the following 3 documents (in PDF format): 1) Final thesis or dissertation. 2) Completed Defense Results form showing “pass” or “pass with conditions”. 3) Final Advisor Approval confirmation email (received after advisor completed the digital form).


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