Tuning Material Properties of Nanoemulsion Gels by Sequentially Screening Electrostatic Repulsions and Then Thermally Inducing Droplet Bridging
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acs.langmuir.0c00199.pdf
Description
Published version
Size
5.05 MB
Format
Adobe PDF
Checksum (MD5)
a0d97fa4bd6dc897a9ac6a7fe869576b
Author(s)
Cheng, Li-Chiun
Doyle, Patrick S
Date Issued
March 2020
Journal
Langmuir
Publisher
American Chemical Society (ACS)
Citation
Cheng, Li-Chiun, Signe Lin Kuei Vehusheia and Patrick S. Doyle. “Tuning Material Properties of Nanoemulsion Gels by Sequentially Screening Electrostatic Repulsions and Then Thermally Inducing Droplet Bridging” Langmuir, vol. 36, no. 13, 2020, pp. 3346-3355 © 2020 The Author(s)
Version
Final published version
Abstract
Nanoemulsions are widely used in applications such as food products, cosmetics, pharmaceuticals, and enhanced oil recovery for which the ability to engineer material properties is desirable. Moreover, nanoemulsions are emergent model colloidal systems because of the ease in synthesizing monodisperse samples, flexibility in formulations, and tunable material properties. In this work, we study a nanoemulsion system previously developed by our group in which gelation occurs through thermally induced polymer bridging of droplets. We show here that the same system can undergo a sol-gel transition at room temperature through the addition of salt, which screens the electrostatic interaction and allows the system to assemble via depletion attraction. We systematically study how the addition of salt followed by a temperature jump can influence the resulting microstructures and rheological properties of the nanoemulsion system. We show that the salt-induced gel at room temperature can dramatically restructure when the temperature is suddenly increased and achieves a different gelled state. Our results offer a route to control the material properties of an attractive colloidal system by carefully tuning the interparticle potentials and sequentially triggering the colloidal self-assembly. The control and understanding of the material properties can be used for designing hierarchically structured hydrogels and complex colloid-based materials for advanced applications.
MIT Department
Massachusetts Institute of Technology. Department of Chemical Engineering
Terms of Use
Creative Commons Attribution 4.0 International license
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DOI of Published Version
https://doi.org/10.1021/acs.langmuir.0c00199
