Table 2.

Mixing of pristine ZnO during PU/ZnO dispersion preparation.

ZnO Premixed with Solvent		Mixing Stage of ZnO				Reference
Yes	No	Mixed with Ready PU	Mixed In Situ Polymerization
			Polyol	Isocyanate	Prepolymer
…	✓	✓	…	…	…	[31,48,51,54,59,60,61,65,68,69,78,79,85,86,89,91,92,93]
…	✓	…	…	…	✓	[32,52,82]
✓	…	…	…	…	✓	[43,50]
…	✓	…	✓	…	…	[38,63,70,80]
✓	…	✓	…	…	…	[39,40,45,46,47,53,56,62,66,87]