Fuzzy Assembly and Second Harmonic Generation of Clay/Polymer/Dye Monolayer Films

Abstract

Fuzzy assembled multicompound films consisting of natural and synthetic colloidal clay particles, poly(diallyldimethylammonium chloride) (PDDA) and the dyes methylene blue (MB+) and 4-{4-[N-allyl-N-methylamino]phenylazo}benzenesulfonic acid, sodium salt (NAMO-) have been prepared. The organization of the clay particles was imaged by means of atomic force microscopy. Fuzzy assembled glass/clay/methylene blue films have been investigated by visible spectroscopy, and the spectra were explained in terms of the substrate−clay interaction and clay particle overlap. Glass/clay/PDDA/NAMO films were investigated by means of absorption spectroscopy, polarized absorption spectroscopy, and second harmonic generation. The nonlinear optical properties of the films were found to be determined by the adsorbed amount of NAMO and its noncentrosymmetric organization. These factors are in turn governed by the substrate type, the PDDA concentration, and the clay type. Optimized second harmonic generation for the glass/laponite/PDDA/NAMO films was found in which the clay particles are deposited onto a (3-aminopropyl)trimethoxysilane modified glass surface and PDDA chains are adsorbed from a 0.1 M solution.

Selective adsorption and chiral amplification of amino acids in vermiculite clay-implications for the origin of biochirality

“…In the present case, both the n-propyl NH 3 cations and added amino acids provide organic molecules capable of molecular organization. Polarized UV-visible spectroscopy of clay-alkylammonium-dye multilayers shows that the dye molecules present are preferentially adsorbed on the clay inter-layer and show molecular organization that is non-centrosymmetric 63 . We believe that the organization of amphiphilic organic molecules on clay platelets to form ordered nanofilms that carry important functional properties such as chirality and optical nonlinearity is key to understanding how clays may act in the natural environment to induce chiral selectivity.…”

Nanocomposite-based lignocellulosic fibers 3: polyelectrolyte adsorption onto heterogeneous fiber surfaces

“…Great varieties of materials, including organic or inorganic compounds (Decher and Hong 1991;Hyde et al 2005;Kotov et al 1997;Lvov et al 1996;Lvov et al 1997;van Duffel et al 2001), macromolecules (Cheng and Cox 2001;Onoda and Yoshino 1995;Schmitt et al 1993;Yoon and Kim 2000), biomacromolecules such as protein and DNA (Elbert et al 1999;Lvov et al 1993;Wang and Hu 2001), have been incorporated into the LbL system to create advanced materials with nanoscale architectures with desired properties. The electrostatic attraction between oppositely charged macromolecules, coupled with counter-ion release during the adsorption process serve as the main driving forces for the multilayer assembly process (Ariga et al 2007).…”

Preparation of Oda-Clay Hybrid Films by Langmuir–blodgett Technique

“…[3][4][5] Thin films of clay minerals have been studied in application to modified electrodes, sensors, photochromic devices, nonlinear optical devices, and so on. [6][7][8][9][10][11][12][13][14] One of the outstanding properties of the clay is the simultaneous incorporation of polar or ionic molecules into the interlamellar spaces (intercalation) [15][16][17] resulting in hybrid materials. The property of intercalation makes it easy to prepare the composite materials.…”