In this letter, we report results of a hydrosilylation carried out on bifunctional molecules by using two different approaches, namely through thermal treatment and photochemical treatment through UV irradiation. Previously, our group also demonstrated that in a mixed alkyne/alcohol solution, surface coupling is biased towards the formation of Si–O–C linkages instead of Si–C linkages, thus indirectly supporting the kinetic model of hydrogen abstraction from the Si–H surface (Khung, Y. L. et al. Chem. – Eur. J.2014,20, 15151–15158). To further examine the probability of this kinetic model we compare the results from reactions with bifunctional alkynes carried out under thermal treatment (<130 °C) and under UV irradiation, respectively. X-ray photoelectron spectroscopy and contact angle measurements showed that under thermal conditions, the Si–H surface predominately reacts to form Si–O–C bonds from ethynylbenzyl alcohol solution while the UV photochemical route ensures that the alcohol-based alkyne may also form Si–C bonds, thus producing a monolayer of mixed linkages. The results suggested the importance of surface radicals as well as the type of terminal group as being essential towards directing the nature of surface linkage.
In this study, we demonstrate that porous silicon films can be ablated by the pulsed nitrogen laser of a commercial MALDI mass spectrometer. The extent of laser‐induced ablation was found to depend on the doping level and surface chemistry of the porous silicon film. Using direct laser writing with or without a mask, micropatterns were generated on the porous silicon surface. These micropatterns were subsequently used to guide the growth of mammalian cells including neuroblastoma. Excellent selectivity of cell growth toward the laser‐ablated regions was established.
26 September 2014 in Chemistry – A European Journal