Surface modification of narra wood (Pterocarpus indicus) by ion shower treatment

Abstract

A gas discharge ion source (GDIS) was used as test facility to produce and study the characteristics of diffused, low-energy hydrogen ion showers. Narra wood samples were then exposed to the showers to investigate topographical effects of ion irradiation. Analysis of beam constituents by mass spectroscopy shows H+ ions to be the dominant species suggesting an essential participatory role for this particular monatomic ion in the surface modification process. Low energy irradiation (600-700eV) produced hydrophobic surfaces with scanning electron micrographs showing partial closure of surface pores. Whereas, a reversion to hydrophilicity was observed for higher energy irradiation (>900 eV), with surface images showing exterior degradation believed to be the etching effects of the chemically active H+ species. The irradiated samples absorbency was quantified via the wetting model wherein the contact angle's time rate equation was numerically solved and fitted onto experimental data. The change rate proportionality constant K with value 0.0015 corresponding to 600 eV beam energy, exhibited the longest moisture absorptive inhibition time of more than 10 min. An increasing value of K indicates increased wetting behavior.