Modeling of vapor sorption in polymeric film studied by surface plasmon resonance spectroscopy

Sorption process by surface plasmon resonance (SPR) was studied by exposing polymeric film made from anthracene labeled poly(methyl methacrylate) (An-PMMA) chains to various concentrations of saturated chloroform vapor. It was observed that the reflectivity changes were fast and reversible. The changes in reflectivity implied the swelling behavior of polymeric film during adsorbtion and can be explained by capturing of chloroform molecules. When clean air is introduced into gas cell similar behavior is observed but this time in the opposite direction as a result of desorption. Fick's law for diffusion was used to quantify real time SPR data for the swelling and desorption processes. It was observed that diffusion coefficients (D-s) for swelling obeyed the t(1/2) law and found to be correlated with the amount of chloroform content in the cell. Diffusion coefficients (D-d) during desorption were also measured and found to be increased as the saturated chloroform vapor content is increased in the cell. Published by Elsevier Inc

Characterisation and vapour sensing properties of spin coated thin films of anthracene labelled PMMA polymer

In the present article thin films of poly (methyl methacrylate) (PMMA) polymer labelled with anthracene (Ant-PMMA) prepared by spin coating are characterised by UV-visible spectroscopy, surface plasmon resonance (SPR), spectroscopic ellipsometry (SE) and Atomic Force Microscopy (AFM) and their organic vapour sensing properties are investigated. Ant-PMMA films' thickness are determined by performing theoretical fitting to experimental data measured using SPR and SE. Results obtained show that the spin-cast films are of good uniformity with an average thickness of 6-8 nm. Organic vapour sensing properties are studied using SPR technique during exposures to different volatile organic compounds (VOCs). Ant-PMMA films' response to the selected VOCs has been examined in terms of solubility parameters and molar volumes of the solvents, and the films were found to be largely sensitive to benzene vapour compared to other studied analytes. (C) 2008 Elsevier B.V. All rights reserved

Crystal and molecular structures of 1-[3-(3,4-dimethoxyphenyl)-2-propenoyl]pyrrolidine

kabak, mehmet/0000-0001-6097-9394WOS: 000185433000025PubMed: 14516096The crystal structure of 1-[3-(3,4-dimethoxyphenyl)-2-propenoyl]pyrrolidine (C15H19NO3) (I) has been determined by X-ray analysis. It crystallizes orthorhombic space group Pbca with a = 24.295(3), b = 15.086(3), c = 7.552(3)A, V = 2768(1)Angstrom(3), Z = 8, D-calc = 1.254 g/cm(3), mu = (Mo K-alpha) = 0.87 cm(-1). The title compound has analgesic activity of cycloaliphatic amine part. The molecule is deviated from planar configuration

Skin Localization of Lipid Nanoparticles (SLN/NLC): Focusing the Influence of Formulation Parameters

In this study, fluorescein labeled SLN and NLC formulations were prepared for improving the dermal distribution of the hydrophilic active ingredients and for enhancing the skin penetration. To determine skin distribution of the lipid nanoparticles ex-vivo penetration/permeation experiments were performed using full thickness rat skin by means of Franz diffusion cells. Studies on the localization of fluorescence labeled nanoparticles were performed by confocal laser scanning microscopy (CLSM). Cellular uptake studies were performed on human keratinocyte cell line (HaCaT) and visualized by fluorescence microscope. Both tissue and cell uptake were also quantitatively determined by means of fluorimetric method in the skin extract or cell extract. Both imaging and quantification studies suggest that the dermal localization of the lipid nanoparticles depends on their dimensions and particle size distribution. The CLSM images clearly show that the Tripalmitin based lipid nanoparticles have higher accumulation in the skin. It is possible to overcome the stratum corneum barrier function with T-NLC05 coded lipid nanoparticle formulation. Additionally cellular uptake of this NLC formulation is time dependent

Electrical properties of a novel 1,3-bis-(p-iminobenzoic acid) indane langmuir-blodgett films containing ZnS nanoparticles

ZnS nanoparticles have been formed in a newly synthesized 1,3-bis-(p-iminobenzoic acid) indane (IBI) by exposing Zn2+ doped multilayered Langmuir-Blodgett (LB) film to H2S gas after the growth. The formation of ZnS nanoparticles in the LB film structure was verified by measuring UV-Visible absorption spectra. DC electrical measurements were carried out for thin films of IBI prepared in a metal/LB films/metal sandwich structure with and without ZnS nanoparticles. It was observed that ZnS nanoparticles in the LB films cause a blue-shift in the absorption spectra as well as a decrease in both capacitance and conductivity values. By analysing I-V curves and assuming a Schottky conduction mechanism the barrier height was found to be about 1.13 eV and 1.21 eV for IBI LB films without and with ZnS nanoparticles, respectively. It is thought that the presence of ZnS nanoparticles influences the barrier height at the metal-organic film interface and causes a change in electrical conduction properties of LB films