Ultraviolet Irradiation Effects on and Depth Profiles in X-ray Photoelectron Spectra of Poly(vinylpyridine) Thin Films

Abstract

The N 1s core binding energies of spin-coated poly(vinylpyridine) (PVPy), quaternized PVPy, and UV-irradiated PVPy were determined using X-ray photoelectron spectroscopy, and the depth profiles were determined using Ar þ beam etching. In typical N 1s spectra, cationic nitrogen atoms appeared at a binding energy 2 -3 eV higher than that of neutral pyridine (Py). Changes in alkylpyridiniums in N 1s and bromide in Br 3p were determined according to etching cycles. In our PVPy cases, two types of nitrogen appeared at a region of high energy compared with that of neutral Py, and the differences in the binding energies between those states and neutral Py were all less than 2 eV. These nitrogens can be assigned to hydrogen-bonded Py and a complex formed among Py rings. Neutral Py, the complex Py, and hydrogen-bonded Py are very close together, and they were located at 399.0, 399.7, and 400.6 eV, respectively. Traces of ionic species were observed only in IR spectra.

A one-dimensional network from the self-assembly of gold nanoparticles by a necklace-like polyelectrolyte template mediated by metallic ion coordination

“…In spite of the successful assembly, the method for the adsorption of the gold particles on the molecular chains is 3(a)), corresponding with bare and protonated nitrogen atoms, respectively [29]. After the assembly, the peak for bare nitrogen atom moves to 399.5 eV.…”