Preparation of stacked organosiloxane bilayers on hydrophilic and hydrophobic silicon substrates by spin coating.

In: Thin Solid Films (Thin Solid Films), Jg. 488 (2005) ; Nr. 1-2, S. 124-131
ISSN: 0040-6090
Zeitschriftenaufsatz / Fach: Chemie
A simple one-step procedure for the prepn. of stacked organosiloxane bilayers is demonstrated. Millimolar solns. of long-chain alkyl- and alkenyltrichlorosilanes, resp., have been spin coated onto silicon samples with distinct hydrophilicity. After coating, the samples are characterized using optical microscopy, at. force microscopy (AFM) and contact angle measurements. Generally, the procedure yields thin films consisting of highly aligned bilayers. The wettability of the substrates by the silane soln., however, strongly affects both the macroscopic and the microscopic homogeneity of the coatings across the surface. Crosslinking via Si-O-Si bonds appears to set in after some weeks and stabilize the films. For several days, however, the bilayers show a remarkable flexibility, i.e. using the AFM tip the self-assembling entities can be easily shifted between the distinct levels maintaining their vertical alignment.