Mechanism of ice nucleation inhibition of PVA and PVP in aqueous glycerin solution

In order to find effective anti-ice nucleation agents, polyvinyl pyrrolidone (PVP) and polyvinyl alcohol (PVA) as additives in glycerin – water solution was froze and investigated by Differential Scanning Calorimeter (DSC). The results show that PVA has stronger inhibition effect than PVP, and the effect can be enhanced with increasing of the additive concentration. The solution nucleation temperature was found to be 216.61 K at PVA concentration of 3 wt%. Radial distribution function (RDF) was established by molecular dynamics simulation to find that PVA molecule forms stronger and more stable hydrogen bonds with water molecules than PVP. Therefore, the PVA performs better in decreasing nucleation temperature than PVP. For PVA concentration of 3 wt%, the phase transition temperature was predicted to be 213.15 K–218.15 K based on the value of mean squared displacement (MSD). This is in close agreement with the experimental results.