Debord, Saet Byul.
Phase Behavior of Multiresponsive Microgel Dispersions.
Degree: PhD, Chemistry and Biochemistry, 2005, Georgia Tech
We present the phase behavior of soft sphere colloidal dispersions. The pH responsive and thermoresponsive microgels, poly(N-isopropylacrylamide-co-acrylic acid) (pNIPAm-co-AAc), were used as a new building block of colloidal crystals. The phase behavior of microgel dispersions was studied by different methods such as optical microscopy, particle trajectories, mean squared displacement (MSD) vs. lag time plots and radial distribution function. The results show that the phase of the sample relies on the particle concentration for dispersions of the same pH. As the pH approaches the pKa of microgels, the microgel dispersions show unusual crystalline phase at lower effective volume fraction than hard sphere melting transition. Also, at this pH regime, the microgel dispersions undergo slow and spatially heterogeneous crystal growth. The cooperative multi-body type attractive forces were proposed to explain the unusual stability at low effective volume fraction. Ion-dipole interactions were proposed to be the origin of the attractive forces. The melting point of bulk crystals at this pH regime is much higher than the volume phase transition temperature of the building block. These results are supportive of the attractive forces hypothesis.
Advisors/Committee Members: L. Andrew Lyon (Committee Chair), Marcus Weck (Committee Member), Mohan Srinivasarao (Committee Member), Thomas Orlando (Committee Member), Victor Breedveld (Committee Member).
Subjects/Keywords: Effective volume fraction; Attractive interacion; Soft interaction potential; Microgel dispersions; Phase behavior
to Zotero / EndNote / Reference
APA (6th Edition):
Debord, S. B. (2005). Phase Behavior of Multiresponsive Microgel Dispersions. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/10458
Chicago Manual of Style (16th Edition):
Debord, Saet Byul. “Phase Behavior of Multiresponsive Microgel Dispersions.” 2005. Doctoral Dissertation, Georgia Tech. Accessed January 20, 2021.
MLA Handbook (7th Edition):
Debord, Saet Byul. “Phase Behavior of Multiresponsive Microgel Dispersions.” 2005. Web. 20 Jan 2021.
Debord SB. Phase Behavior of Multiresponsive Microgel Dispersions. [Internet] [Doctoral dissertation]. Georgia Tech; 2005. [cited 2021 Jan 20].
Available from: http://hdl.handle.net/1853/10458.
Council of Science Editors:
Debord SB. Phase Behavior of Multiresponsive Microgel Dispersions. [Doctoral Dissertation]. Georgia Tech; 2005. Available from: http://hdl.handle.net/1853/10458