Iodine values were determined as described by . This involves the titration of 0.1 M sodium thiosulphate solution against 60.0 ml of sample free liquot solution (prepared by centrifuging 0.5 g of ZnO/Kaolin Composite NP sample in 75.0 ml of 0.086 M iodine solution using 5 ml of freshly prepared starch indicator. The iodine value (IV) was calculated using the formula: