The critical adsorption points (CAP) for ring and linear polymers are determined and compared using Monte Carlo simulations and liquid chromatography experiments. The CAP is defined as the coelution point of ring or linear polymers with different molecular weights (MW). Computational studies show that the temperature at the CAP, T CAP, for rings is higher than T CAP for linear polymers regardless of whether the chains are modeled as random walks or self-avoiding walks. The difference in the CAP can be attributed only to the architectural difference. Experimentally, four pairs of linear and ring polystyrenes (PS) of different MW were synthesized and purified. Care was taken to account for the difference between the end-groups in linear polymers and the linkage unit in ring polymers. Elution of these polymers using a C18 bonded silica stationary phase and a CH2Cl2/CH3CN mixed eluent were studied. The temperature at the coelution point, T CAP, and the coelution time at the CAP, t E,CAP, were determined for both ring and linear polymers. Experimentally, it was found that T CAP of linear PS is lower than T CAP of cyclic PS and t E,CAP of linear PS is shorter than t E,CAP of ring PS. Therefore, at the CAP of linear polymers, ring polymers elute later in order of increasing MW while, at the CAP of ring polymers, linear polymers elute earlier in order of decreasing MW. This is in excellent agreement with the Monte Carlo computer simulation results. We also found that the functionality effect can interfere in the LCCC separation of ring polymers from their linear precursors.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.