Over the last few decades, there has been an increasing interest in the study of charged polymers for applications such as desalination of water, flocculation, sewage treatment, and enhanced oil recovery. Polyelectrolyte chains containing both positively and negatively charged units (polyampholytes) have been recently studied as viscosity-control agents in enhanced oil recovery, and as entrapping macromolecules for protection and delayed release of enzymes in hydraulic fracturing. In this study we performed Monte Carlo molecular simulations in a grand canonical ensemble to study the behavior of a weak polyampholyte in a dilute regime. Weak polyampholytes have the ability to dissociate in a limited pH, which makes them interesting for applications that require a pH-triggerable response. The titration behaviors of diblock and random polyampholytes are simulated as a function of solvent quality, electrostatic strength, and salt concentration. For diblock polyampholyte chains in hydrophobic solvents, transition between tadpole-like and globule conformation occurs with variations in the solution pH. Random polyampholytes present extended, globule, and pearl-necklace conformations at different solvent conditions and pH values. At high ionic strength, electrostatic interactions in the polyampholytes become screened and the chains are mostly in globule state.
| Identifer | oai:union.ndltd.org:kaust.edu.sa/oai:repository.kaust.edu.sa:10754/610540 |
| Date | 05 1900 |
| Creators | Jimenez, Arturo Martinez |
| Contributors | Sun, Shuyu, Physical Science and Engineering (PSE) Division, Hoteit, Ibrahim, Knio, Omar, Nair, Arun Kumar |
| Source Sets | King Abdullah University of Science and Technology |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Rights | 2016-05-22, At the time of archiving, the student author of this thesis opted to temporarily restrict access to it. The full text of this thesis became available to the public after the expiration of the embargo on 2016-05-22. |
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