UNDERSTANDING DIFFERENT LCST LEVELS OF POLY(N-ALKYLACRYLAMIDE)S BY MOLECULAR DYNAMICS SIMULATIONS AND QUANTUM MECHANICS CALCULATIONS
2011
Poly(N-alkylacrylamide) is a group of thermo-sensitive polymers that include poly (N-isopropylacrylamide), poly(N-n-propylacrylamide), poly(N-isopropylmethacryl-amide), and so on. The polymers exhibit different levels of lower critical solution temperatures (LCST) in aqueous solutions. In this article, their monomers and oligomers with 10 repeating units are selected, respectively, to demonstrate the cause of different LCST levels of the polymers in aqueous solutions using molecular dynamics simulations and quantum mechanics calculations. The monomers have functional groups of different steric volume that greatly affect the conformational transition of chains and LCST levels of the polymers. A branched chain of N-propyl group in N-isopropylacrylamide and an additional methyl group at α-carbon in N-isopropylmethacrylamide both increase the steric effect, making it more difficult for monomers to draw closer and resulting in higher LCST levels of the polymers. In addition, the simulated results from their corresponding oligomers exhibit the similar trend to those from the monomers.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
38
References
8
Citations
NaN
KQI