Real time monitoring of organic monolayer self-assembly by molecular layer epitaxy (MLE) processes was studied by in situ spectroscopic ellipsometry techniques. For the MLE of imide-based organic heterostructures using chemisorption of 3,4,7,8-naphthalenetetracarboxylic dianhydride (NTCDA) and 1,6-diamino-n-hexane (DAH) on prefunctionalized surfaces, in situ ellipsometry reveals that the reaction kinetics can be best fitted to an S-shaped deposition curve with saturated coverage of about 20 min by the Langmuir−Hinshelwood model, with a slow initial phase, followed by a faster second phase. The rate of deposition at each moment is proportional to the number of empty sites multiplied by the number of occupied sites. Calculated deposition rate constants for every pulse are kT = 5.6 × 10-5 s-1 for first deposition of NTCDA on a template (T-layer), decreasing to kA = 1.5 × 10-5 s-1 for NTCDA and to kB = 7.2 × 10-6 s-1 for DAH assembly pulses correspondingly. A modified Rudzinski−Aharoni kinetic model for adsorption that correlates adsorption energy with valid numbers of reactive sites was used to estimate an equilibrium surface absorption energy of 16 kcal for a NTCDA layer and 29 kcal for a DAH layer.

We test poly(4-vinylpyridine) as a new matrix polymer in photorefractive polymer composites. It has excellent compatibility with OH-derivatized electro-optical chromophores due to H-bonding. Due to the slightly higher polarity, the molecular figure-of-merit of the chromophores is enhanced, yielding improved steady-state PR performance compared with PVK-based reference materials. However, because of the H-bonding the orientational mobility of the chromophores is hindered, limiting the dynamics of grating formation.

A monolayer of conducting polymer, polyaniline (PAN), was assembled on hydroxyl-terminated surfaces, such as quartz, glass, indium−tin oxide, and native oxide on Si. The approach for assembling two-dimensional monolayers of PAN is based on a chemical or electrochemical surface polymerization of electrostatically bound anilinium. The latter was bound to the negatively charged sulfonate group of mercaptoethanesulfonate that was previously coupled by an SN2 reaction to an iodopropyl self-assembled monolayer. The consecutive assembling steps were followed by X-ray photoelectron spectroscopy, UV−vis−NIR spectroscopy, variable angle spectroscopic ellipsometry, contact angle, and atomic force microscopy measurements. The characteristic electronic properties of the PAN monolayers were studied by UV−vis−NIR spectroscopy and cyclic voltametry.