The influence of chain length and ripening time on the self-assembly of alkylamines on mica

Abstract

The influence of chain length and ripening time on the self-assembly of tetradecyl

C 14

, hexadecyl

C 16

, and octadecylamine

C 16

on mica has been studied by atomic force microscopy. The overall process can be described in three stages characterized by different time scales. First, alkylamine molecules adsorb in a process controlled by water mediated interactions of the NH 2 head groups and mica. Second, surface diffusion and aggregation into islands takes place, driven by energy interactions between alkyl chains. The third stage consists of a progressive tilt of the self-assembled molecules towards the surface, driven by relaxation of the electrostatic repulsion between protonated amino groups due to water uptake from atmosphere.