TY - JOUR AU - Popa, Ana Maria AU - Angeloni, Silvia AU - Bürgi, Thomas AU - Hubbell, Jeffrey A. AU - Heinzelmann, Harry AU - Pugin, Raphaël TI - Dynamic Perspective on the Function of Thermoresponsive Nanopores from in Situ AFM and ATR-IR Investigations PY - 2010 JF - Langmuir JA - Langmuir SN - 0743-7463 VL - 26 IS - 19 SP - 15356 EP - 15365 L1 - http://pubs.acs.org/doi/pdf/10.1021/la102611k L2 - http://pubs.acs.org/doi/full/10.1021/la102611k L3 - http://pubs.acs.org/doi/abs/10.1021/la102611k L4 - http://www.unige.ch/sciences/chifi/publis/pics/double/ref01189.png M3 - 10.1021/la102611k UR - http://dx.doi.org/10.1021/la102611k N2 - This article describes the morphological and chemical characterization of stimuli-responsive functionalized silicon surfaces provided in parallel by atomic force spectroscopy (AFM) and Fourier transform infrared spectroscopy (FT-IR) enhanced by the single-beam sample reference attenuated total reflection method (SBSR-ATR). The stimuli-responsive behavior of the surfaces was obtained by grafting-to in melt carboxyl-terminated poly-N-isopropylacryl amides (PNIPAAM) with different degree of polymerization (DP) on epoxide-functionalized silicon substrates. The unprecedented real time and in situ physicochemical insight into the temperature-triggered response of the densely packed superficial brushes allowed for the selection of a PNIPAAM with a specific DP as a suitable polymer for the fabrication of silicon membranes exhibiting switchable nanopores. The fabrication process combines the manufacture of nanoporous silicon surfaces and their subsequent chemical functionalization by the grafting-to in melt of the selected polymer. Then, relevant information was obtained in what concerns the chemical modifications behind the topographical changes that drive the functioning of PNIPAAM-based hybrid nanovalves as well as the timescale on which the opening and closing of the nanopores occur. ID - 1189 ER -