Monolayer And Its Application In The Synthesis Of Selenium Nanocomposite

The Langmuir monolayer and LB film have been studied with much interest because they can be controlled at molecule level and provided an important technology for assembling organic, organic/inorganic nanocomposite film with mono-/multi layers. The nanoparticles can be assembled or packed to form two and three-dimensional well-ordered arrangements by LB techniques. So in this paper, 3-ferrocenyl-2-butylene acid (FCA) and 2-hexadecyloxyaniline(2-C₁₆OAn) were synthesized and assembled into monolayers and LB films. The octadecylamine (ODA)/ vitamin C(VC), vitamin E (VE) and 2-C₁₆OAn monolayers were used to prepare the nanoselenium and the LB ultra thin film with selenium nanoparticles. The paper is separated into four parts that are shown as follows:1. A new amphiphilic ferrocene derivative (FCA) was synthesized and assembled into FCA/ODA mixed monolayers, whose properties were investigated by suface pressure-molecule area (Ï€-A) isotherms, dÏ€/dA-A curves and the plot of the apparent area of ODA(Aoda) vs x(ODA). The results indicated that the mixed monolayers containing FCA/ODA mixture with mole proportion of 1 to 1 possessed the best stability and the highest incompressibility.2. The properties of ODA monolayer on pure water and H₂SeO₃ aqueous solution at different pH was studied by n-A isotherms and dÏ€/dA-A curves. The results showed that the monolayer was more stable in the basic subphase than that in the acidic subphase. Nanoselenium with various morphologies was prepared by adding vitamin C into the subphase at pH 1, 3, 9, 11. At basic subphase, spherical selenium nanoparticles were prepared with a diameter of about 37nm, with excellent monodispersity. Because the ODA cation adsorbed more SeO₃^2- at pH 9, more selenium nanoparticles were formed. UV-vis spectra and small angle XRD showed that the ODA/selenium nanoparticles composite monolayer can be successively assembled layer by layer during the whole deposition pocess.