CHEN Gong, ZHU Jingying, GE Jun, et al. Molecular simulation: temperature responsiveness of block copolymer PEO-PPO-PEO and underpinned mechanism[J]. CIESC Journal, 2014, (10): 4157-4167.
CHEN Gong, ZHU Jingying, GE Jun, et al. Molecular simulation: temperature responsiveness of block copolymer PEO-PPO-PEO and underpinned mechanism[J]. CIESC Journal, 2014, (10): 4157-4167.DOI: 10.3969/j.issn.0438-1157.2014.10.054.
Molecular dynamics simulation at all atoms level was used to probe the temperature induced phase transition behavior of single-chain block copolymer PEO-PPO-PEO
represented by Pluronic P85
in different solutions. A negative temperature responsiveness of Pluronic P85 in polar solvent such as water and methanol was observed
in which the increase in temperature promoted the breakage of hydrogen bonds between the PPO and PEO respectively with the solvents and thus resulted in the desolvation of PPO and PEO. This thus led to collapse of the polymer as a result of enhanced intramolecular interaction and the release of solvent molecules. On the contrary
a positive temperature responsiveness of Pluronic P85 was shown in toluene
in which the increase in temperature weakened the intramolecular interaction and thus enabled conformational flexibilities. The temperature responsiveness of the solvation of PEO and PPO block was also simulated
which offered a theoretical basis for the molecular design and applications of these PEO-PPO-PEO block copolymers.