Original Article | 2006, Vol.28, No.2, pp. 351-359
A smart surface from natural rubber: the mechanism of entropic control at the surface monitored by contact angle measurement
Sureurg Khongtong
pp. 351 - 359
Abstract
Surface oxidation of crosslinked natural rubber provided a hydrophilic substrate (sticky surface) that became more hydrophobic (less sticky) when equilibrated against hot water. This unusual temperaturedependent surface reconstruction is interpreted as the result of recoiling of entropic unfavorable uncoiled chains induced when rubber surface was oxidized. Subsequent equilibration of these annealed samples against water at room temperature returned their original hydrophilicity. The degree of this surface reconstruction and its kinetics are also dependent on the amounts of crosslinking of the samples.