Tailoring surface properties of polymeric blend material by ion beam bombardment

• Effect of ion beam on the surface properties of LDPE/SBR blend was investigated.
• Optical absorption edge shifted towards lower energy region after bombardment.
• Increase in oxygen uptake with increasing the ion fluence was observed.
• Contact angle decreases with increasing the ion fluence of bombarded polymer.
• Ion beam bombardment improves the surface properties of the LDPE/SBR blend.

In this work, LDPE/SBR polymer blend samples were bombarded with 130 keV He and 320 keV Ar ions at different fluencies ranging from 1×1013 to 2×1016 ions cm−2. The changes in surface properties of the ion-bombarded polymers were investigated with ultraviolet–visible (UV–vis) spectroscopy, Photoluminescence (PL) and energy dispersive X-ray (EDX) techniques. The variations in the wettability, surface free energy and spreading coefficient of ion beam bombarded LDPE polymer blend samples have been studied. The UV–vis analysis revealed that the transmission spectra shifted towards lower energy region after bombardment with increasing ion fluence. This shift clearly reflects decrease in optical band gap. A remarkable decrease in the PL intensity with increasing ion beam fluence was observed. The EDX study indicates the oxygen uptake increases with increasing ion fluence. Contact angle measurements showed that wettability, surface free energy and spreading coefficient of LDPE blends samples have increased with increasing ion fluence. This increase in the wettability and surface free energy of the bombarded samples are attributed to formation of oxidized layer on the polymer surface, which apparently occurs after exposure of bombarded samples to the air.