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This paper discusses the effect of forming gas (93%N2 + 7%H2) plasma treatment for sol-gel methyl-silsesquioxane (MSQ) as a dielectric film towards the grain morphology of a solution processable pentacene. Atomic force microscopy and X-ray diffractometer results confirm that a brief (10 s) plasma treatment for MSQ increases the grain size of pentacene and encourages its growth in thin-film phase. This paper also demonstrates that the presence of large Si(CH3)3 bonds on the MSQ surface are very important to encourage the growth of pentacene’s molecules in thin-film phase. In addition, this paper also suggests that there is no strong relationship between the grain size and ordering of pentacene molecules.

Polyaniline (PANI) nanotubes configured as a field effect transistor (FET) exhibits a p–n junction diode behavior. The forward-bias current can be modulated by a gate voltage; turning on at negative gate voltage and turning off at positive gate voltage. An energy band diagram model has been proposed to explain the rectifying effect of the PANI nanotubes FET (PNT-FET). All the four different forward bias conduction mechanisms of a typical p–n junction diode can be identified for this PNT-FET using a semi-log graph to confirm this resemblance.

Titanium dioxide (TiO2) has attracted numerous attentions due to its high photocatalytic property. TiO2 as photocatalyst is best to be coated over large area substrate (walls, windows, etc.). In this case, cold spray process is the most suitable technique, not only because its simplicity and efficiency for large area deposition, but also because it is a low temperature process that would retain the high photocatalytic anatase phase of TiO2 in the coating. However, cold spraying of hard ceramic materials, such as TiO2, is widely known to be difficult. In this study, we are reporting a novel synthesis method of TiO2 powder for cold spray via the hydrolysis of titanyl sulphate (TiOSO4) with addition of ammonium sulphate ((NH4)2SO4). It is a relatively simple synthesis method that can obtain pure anatase structure even without high temperature treatment, although post treatments, such as hydrothermal and calcination further increase the crystallinity and change the morphology of synthesised TiO2. It is believed that the synergetic effect of post treatments and adsorption of NH4+ and SO42− ions on the surface of TiO2 causes the alteration in morphology of TiO2 powder. Finally, the cold spray spot test shows that the TiO2 powders can be cold sprayed. This is a remarkable finding as the difficulty of cold spraying TiO2 is widely known.