Robust water repellent ZnO nanorod array by Swift Heavy Ion Irradiation: Effect of Electronic Excitation Induced Local Chemical State Modification

Tailoring the surface properties by varying the chemistry and roughness could be of interest for self-cleaning applications. We demonstrate the transformation of hydrophobic ZnO Nano rod (NR) array into superhydrophobic nature by changing the local chemical state and without altering the surface roughness by swift heavy ion (SHI) irradiation. The aligned ZnO NR arrays were irradiated using 150 MeV Ag ions with different fluences from 5E10 to 3E12 ions/cm2. The observed static water contact angles of ZnO NRs samples were 103° ± 3°, 152° ± 4°,161° ± 3°, 164° ± 2°, 167° ± 2°,154 ± 3° and 151° ± 2° for the pristine, ion fluencies of 1E11, 3E11, 5E11, 7E11, 1E12 and 3E12 ions cm−2, respectively. The change in local surface chemistry via formation of surface oxygen related defects due to electronic excitations induced by ion irradiation determine the water dewetting properties. It is found that surface oxygen related defects could be tuned by varying the fluence of the SHIs. Durability tests show that the SHI induced surface oxygen-deficient ZnO NRs have the stable superhydrophobic behavior for more than a year

Ion-Energy Dependency in Proton Irradiation Induced Chemical Processes of Poly(dimethylsiloxane)

In this paper, we present a study of chemical changes in poly(dimethylsiloxane) (PDMS) induced by proton irradiation of various energy and fluence. It has been found that the forming products vary as the energy of the proton changes, which means that the energy of the incident ions can influence the chemical mechanism. This is probably caused by the variations in the ion–molecule interactions, that is, the change of probability of ionization and excitation of the molecules. We propose reaction mechanisms for the processes taking place in PDMS by different energy proton irradiation. This unique effect may be used for various purposes, such as to create advanced materials with buried ion-induced modifications or to understand better the heavy ion irradiation induced reactions which have crucial importance for example in proton therapy. The chemical changes created in PDMS were characterized by universal attenuated total reflectance infrared spectroscopy (UATR-FTIR)