Self-assembly of Eucalyptus gunnii wax tubules and pure ß-diketone on HOPG and glass

[摘要] Eucalyptus trees and many plants from the grass family (Poaceae) and the heather family (Ericaceae) have a protective multifunctional wax coating on their surfaces made of branched ß-diketone tubules. ß-diketone tubules have a different size, shape, andchemical composition than the well-described nonacosanol tubules of the superhydrophobic leaves of lotus (Nelumbo nucifera).Until now the formation process of ß-diketone tubules is unknown. In this study, extracted wax of E. gunnii leaves and pure ß-diketone were recrystallized on two different artificial materials and analyzed by scanning electron microscopy (SEM) and atomicforce microscopy (AFM) to study their formation process. Both the wax mixture and pure ß-diketone formed tubules similar tothose on E. gunnii leaves. Deviating platelet-shaped and layered structures not found on leaves were also formed, especially onareas with high mass accumulation. High-resolution AFM images of recrystallized ß-diketone tubules are presented for the firsttime. The data showed that ß-diketone tubules are formed by self-assembly and confirmed that ß-diketone is the shape-determiningcomponent for this type of tubules.

[学科分类] 环境监测和分析

[关键词] ß-diketone tubules;eucalyptus;plant wax;recrystallization;self-assembly