College
College of Engineering and Polymer Science
Date of Last Revision
2026-04-28 12:33:10
Major
Chemical Engineering
Honors Course
CHEE 497
Number of Credits
3
Degree Name
Bachelor of Science
Date of Expected Graduation
Spring 2026
Abstract
The goal of this study is to compare how four different Hofmeister anions (Cl-, SCN-, F-, and I-) affect the Lower Critical Solution temperature (LCST) on two thermo-responsive polymers: poly(N-isopropylacrylamide) (pNIPAAM) and poly(vinyl methyl ether) (PVME). pNIPAAm is commonly used in the environmental applications such as monitoring, oil-water separations, or antifouling materials, and in medical industry from drug delivery to tissue engineering. When pNIPAAM or PVME reaches a temperature above their LCST, they become hydrophobic, and the polymer chains coiled, leading to their aqueous solutions turn opaque. PVME exhibits a similar LCST as that of pNIPAAM, so it can be a more cost-effective alternative to pNIPAAM. In this study, we investigate whether PVME will exhibit similar behaviors as those of pNIPAAM in the presence of a Hofmeister anion, which can be used to adjust the LCST of these polymers. The results from this study showed that Hofmeister ions have a greater effect on the LCST of PVME compared to pNIPAAM and there is a statistically significant difference between the means of the heating and cooling LCSTs of pNIPAAM and PVME at different concentrations and Hofmeister anions.
Research Sponsor
Dr. Bi-min Newby
First Reader
Dr. Edward Evans
Second Reader
Dr. Nic Leipzig
Honors Faculty Advisor
Dr. Bi-min Newby
Proprietary and/or Confidential Information
No
Community Engaged Scholarship
No
Recommended Citation
Joaquin, Joseph, "Effects of Hofmeister Ions on Lower Critical Solution Temperatures of Poly(N-isopropylacrylamide) and Poly(vinyl methyl ether)" (2026). Williams Honors College, Honors Research Projects. 2124.
https://ideaexchange.uakron.edu/honors_research_projects/2124
Included in
Complex Fluids Commons, Other Chemical Engineering Commons, Polymer Science Commons, Thermodynamics Commons