Papers by Keyword: Octadecylamine

Abstract: Porous surface of silica gel (SG) have been modified with alkyl fatty amine compounds (octadecylamine, ODA) via wet impregnation process. The ODA-based adsorbents were physically characterized by XRD. The presence of crystalline peaks on ODA/SG diffractograms were ascertained the well-dispersion of ODA on the SG surface. XRD analysis displayed the increasing intensity of crystalline ODA with higher percent amine loaded and shifting of the several crystalline peaks of ODA verified the interaction of SG600-ODA. Capacity of CO₂ capture by prepared solid adsorbents were evaluated using CO₂ adsorption-desorption isotherms. This study shows that increasing percentage of ODA were improved the amount of CO₂ uptake by following this trend: 35ODA/SG > 25ODA/SG > 15ODA/SG > SG > 5ODA/SG. However, promotion of 5 wt.% ODA unabled to enhance the capacity of CO₂ captured due to pore blockage and reduction in SG pore surface, thus hindered the physisorption between CO₂ and SG.

Abstract: This work attempted to elucidate the corrosion inhibition mechanism of a supramolecular complex formed between β-cyclodextrin (β-CD) and octadecylamine (ODA) for mild steel in the condensate water. Molecular mechanics simulation was applied to determine the energy favored configuration of the complex and the possible orientation of ODA inside the β-CD cavity. Based on the results of gravimetric measurements, thermodynamics parameters for the adsorption process were calculated through Arrhenius and transition state equations. Scanning electron microscopy and X-ray photo electron spectroscopy were used for surface characterization. Density functional theory calculations (Mulliken charges and molecular electrostatic potential plot) were performed to clarify the adsorption mechanism of β-CD/ODA complex on the steel surface. It was found that four possible configurations of β-CD/ODA complex might be concurrent in the supramolecular system with the stable state in the aqueous solution. ODA molecules could break away from the β-CD cavity and chemically adsorbed on the metal surface, which obeyed the Langmuir adsorption isotherm. The inherent molecular electrostatic properties resulted in the tilted adsorption of ODA.

Abstract: The hydrophobic gold nanoparticles with monodispersity are synthesized by using n-butanol reduction in situ under the condition of alkali promotion in cetyltrimethylammonium bromide (CTAB)/n-butanol/n-heptane/HAuCl₄/NaOH(aq) W/O microemulsion at 30°C. The CTAB-stabilized gold nanoparticles are characterized by UV-vis, TEM , XRD and so on. The replacement of simple surfactant (CTAB ) with mixed surfactant CTAB/ octadecylamine can weaken the direction of CTAB to the growth of gold nanopartices and increase the monodispersity of gold nanoparticles. The effects of components of the microemulsion system on the shape, size and monodispersity of gold nanoparticles are also explored. The results show that the size of gold particles is changed by the amount of CTAB and C₁₈NH₂.

Abstract: It has a significant practical value to research a compound inhibitor for low temperature for the protecting of power plant devices with low working-temperature. In this paper, a new kind of film-forming inhibitor based on octadecylamine for low temperature has been proposed. Coupon test has been taken with autoclave simulating the on-site water-vapor environment; the film-forming effect of the metal specimen has been evaluated by hydrophobic test, acid copper sulfate drip test and AC impedance test. The result shows that the inhibitor filmed well after compounded, and has an important practical value.

Abstract: With regard to a deep-extend oxidized refractory lead-zinc ore from Yunnan province, containing 4.55% Pb and 17.09% Zn, a test study was carried out. By adopting single-stage roughing, single-stage scavenging, two-stage cleaning in the flotation of lead oxide ores, and single-stage cleaning, single-stage cleaning in the reverse flotation of zinc oxide ores, bulk concentrate of lead and zinc containing 36.60% Pb, 19.63% Zn with the Pb recovery of 82.45%, zinc concentrate containing 36.52% Zn, 0.44%Pb with the Zn recovery of 73.18% were obtained in the closed circuit experiment.

Abstract: Abstract. Hydrogels based on poly (N-vinyl-2-pyrrolidone) (PVP) obtained by ionizing radiation are sterile, biocompatible can be used as topics dressings. Due to the high degree of hydration of the gel, it has a low mechanical strength, which is one of the biggest problems in its application. The objective of this work was to study the properties of the hydrogel based on PVP / sodium alginate containing pseudoboehmites nanoparticles treated with octadecylamine for pharmaco applications, order drug release when immobilized on a matrix of PVP/sodium alginate/pseudoboehmite. Pseudoboehmite nanoparticles were obtained by sol-gel route, from aluminum nitrate and ammonia as precursors, and subsequently were treated with octadecylamine. The hydrogels based on PVP/sodium alginate/pseudoboehmite treated were prepared by ionizing radiation with doses of 30 and 35kGy. The characterization of hydrogels obtained was made by means of thermomechanical (tensile tests, DTA and TG) and physicochemical (swelling, sol-gel fraction) tests. The results obtained showed that the hydrogel based only on PVP and sodium alginate showed highest tensile strength. The presence of pseudoboehmite in the hydrogels decreases the formation of crosslinks, while the presence of PEG in the agar and causes a decrease in Tg of the polymer matrix.

Abstract: In this study, Octadecylamine Modified montmorillonites (ODAMMT) were used to prepare polylactide/polycaprolactone (PLA/PCL) clay nanocomposites. PLA and PCL were blend using an internal mixer by melt blending method. The other sample was blend with natrium monmorillonite (NaMMT) and Octadecylamine modified monmorillonite to produce PLA/PCL-NaMMT and PLA/PCL-ODAMMT. To characterize the polymer nanocomposite, X-ray diffraction (XRD), FTIR and SEM analysis were conducted. Comparison of morphology were made up between neat PLA/PCL, PLA/PCL with presence of of montmorillonite and octadecylamine modified monmorillonite respectively based on SEM micrograph. The number-average diameter was calculated for PLA/PCL, PLA/PCL-NaMMT, and PLA/PCL-ODAMMT.

Abstract: Nanocomposites are nanometrical material particles embedded in a specific matrix. The degree of organization of the nanostructures and their properties depend on the nature of the organic and inorganic components of the structure that can generate synergic interactions. Polymeric nanocomposites are related to a class of hybrid materials where inorganic substances of nanometric dimensions are dispersed in a polymeric matrix. In the present work, nanocomposites of nylon 6,12 with different concentrations of pseudoboehmite obtained by sol-gel process were prepared with and without the presence of octadecylamine. After preparation, the samples were irradiated with a 200 kGy radiation dose in an electron accelerator. The pseudoboehmite nano particles were characterized by X-ray diffraction, scanning electron microscopy, differential thermal analysis and thermo gravimetric analysis. The nanocomposites were characterized by thermal and mechanical tests. The addition of pseudoboehmite promoted a reduction of the melting flow during the production of the composites evidencing the interaction of pseudoboehmite with the polymeric matrix, probably modifying its crystalline structure.