Control of the molecular density in a chemically adsorbed thiophene system monolayer

Abstract

Chemically absorbed monolayers (CAM) of thienyl functionalized n-alkyltrichlorosilane 11-(3-thienyl) undecyltrichlorosilane (TUTS) have been prepared with two methods which are the standard technique (TUTS-STD) and the twice adsorption method (TUTS-TAM). The existence of TUTS-CAM was confirmed with water contact angle measurements, calculation of thickness with ellipsometry, fourier transform infrared reflection adsorption spectroscopy (FTIR-RAS). Here are described is the comparison of TUTS-STD and TUTS-TAM characterized by using Electron Spectroscopy for Chemical Analysis (ESCA) and ultraviolet visible (UV-vis) absorption spectroscopy. TUTS-TAM showed more densely packing than TUTS-STD by these measurements. Moreover, these TUTS-CAM polymerized by chemical oxidative polymerization and UV-Vis absorption spectra was measured to confirm the conjugated bond length of the polymerized thienyl groups. UV-vis spectra of the polymerized TUTS-CAM showed a new broad absorbance band at longer wavelength than 700nm.