scholarly journals Characterization, Acid Activation, and Bleaching Performance of Ibeshe Clay, Lagos, Nigeria

ISRN Ceramics ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
M. A. Usman ◽  
V. I. Ekwueme ◽  
T. O. Alaje ◽  
A. O. Mohammed

This paper investigated the possibility of using clay characterization as a major tool to predict its suitability for bleaching of vegetable oil, namely, palm oil. The clay sample collected from Ibeshe deposit was characterized by X-ray diffraction (XRD). The results of the XRD showed that the clay is composed of dioctahedral kaolinite and dickite, silica, ilmenite, and merlinite. The compositional analysis using atomic absorption spectroscopy (AAS) showed that the Na2O : CaO ratio is 0.22, a value less than one and indicative of the absence of bentonite which presence, just like montmorillonite, confers bleaching activity to clays. Furthermore, the SiO2 : Al2O3 ratio of 1.12 (greater than one) is suggestive of a clay suitable not for bleaching but for zeolite development. Actual laboratory tests for bleaching performance evaluation confirmed the prediction above that the clay indeed has poor bleaching action as shown by percent colour reduction. The colour reduction for natural clay was 9.1%. This value only increased to 27.3% after 3M HCl activation, a value still very low for effective bleaching.

1999 ◽  
Vol 77 (2) ◽  
pp. 199-204
Author(s):  
Stephen A Westcott ◽  
Nicholas J Taylor ◽  
Todd B Marder

Reactions of (η5-C9H7)Rh(η2-C2H4)2 (1) with quinones were investigated. Substitution of the labile ethylene ligands was observed upon addition of either duroquinone (2,3,5,6-tetramethyl-1,4-benzoquinone) or 1,4-benzoquinone to complex 1. The molecular structure of neutral (η5-C9H7)Rh(2,3,5,6-C6O2(CH3)4) (3), determined by X-ray diffraction, shows that the duroquinone ligand lies in a plane nearly parallel to the indenyl group. The carbonyl moieties of duroquinone lie in a plane incorporating Rh, C2, and the midpoint between C3a and C7a of the indenyl ring. The slip parameter (Δ= d(average Rh-C3a,7a) -d(average Rh-C1,3)) was calculated to be 0.112(2) Å; whereas a value of ca. 0.05 Å had been obtained previously from film data. Values for the hinge angle (HA = angle between normals to the least-squares planes defined by C1, C2, C3 and C1, C7a, C3a, C3) and fold angle (FA = angle between normals to the least-squares planes defined by C1, C2, C3 and C3a, C4, C5, C7, C7a) are 7.2° and 4.0°, respectively.Key words: indenyl, rhodium, quinones, ring-slippage, ground-state distortion.


2006 ◽  
Vol 59 (2) ◽  
pp. 225-232 ◽  
Author(s):  
Pierre Yves Jouan ◽  
Arnaud Tricoteaux ◽  
Nicolas Horny

The aim of this paper is first a better understanding of DC reactive magnetron sputtering and its implications, such as the hysteresis effect and the process instability. In a second part, this article is devoted to an example of specific application: Aluminium Nitride. AlN thin films have been deposited by reactive triode sputtering. We have studied the effect of the nitrogen contents in the discharge and the RF bias voltage on the growth of AlN films on Si(100) deposited by triode sputtering. Stoichiometry and crystal orientation of AlN films have been characterized by means of Fourier-transform infrared spectroscopy, X-ray diffraction and secondary electron microscopy. Dense and transparent AlN layers were obtained at high deposition rates. These films have a (002) orientation whatever the nitrogen content in the discharge, but the best crystallised ones are obtained at low value (10%). A linear relationship was observed between the AlN lattice parameter "c" (perpendicular to the substrate surface) and the in-plane compressive stress. Applying an RF bias to the substrate leads to a (100) texture, and films become amorphous. Moreover, the film's compressive stress increases up to a value of 8GPa before decreasing slowly as the bias voltage increases.


2018 ◽  
Vol 3 (8) ◽  
pp. 56
Author(s):  
Amie Thant ◽  
Chaw Su Su Hmwe

In this study, the performance of different acid treated Myanmar Natural Clay (Mabisian) was conducted the pyrolysis of mixed plastic wastes, 40% high density polyethylene, 30% polypropylene, 25% low density polyethylene and 5% polystyrene. Mabisian clay was refluxed with different concentration of nitric acid (2M, 4M, 6M, 8M, 10M, 12M and 14M)  at 100ºC for 3hrs followed by calcination at 500ºC for 1hr. The physico-chemical characteristics of resulted leached clay were studied by X-Ray Fluoresence spectroscopy (XRF), X-Ray Diffraction (XRD) and Fourier Transformed Infrared Spectroscopy (FTIR). The pyrolytic oil was characterized by Gas Chromatography – mass spectopy (GC-MS). XRF and FTIR studies indicated that acid treatment under reflux condition lead to the removal of octahedral Al3+ cations along with other impurities.  The chemical treatment increased the Si/Al ratio.  The maximum liquid yield (75%) was obtained at 12 M nitric acid, 3hr reaction time and 100 º C reaction temperatures. In addition, the percent peak area of gasoline range hydrocarbon was obtained 55.6% at optimum condition. Thus, the treated clay can be used as promising as catalyst support.


2021 ◽  
Author(s):  
T. Shiyani ◽  
Indrani Banerjee ◽  
Santosh K. Mahapatra ◽  
Asim K Ray

Abstract Photoelectrochemical properties have been investigated for flexible ZnO/ITO/PET photoelectrodes. ZnO was spin coated on ITO/PET substrate with thickness of about 310 nm. The high crystalline structure of ZnO was studied using x-ray diffraction pattern. A value of 3.4 eV has been estimated for optical band gap from its absorption spectra. The flexible ZnO photoelectrode was demonstrated to generate photoelectrochemical current. Values of 1.022 and 0.714 were found to be for photo switching and photoresponsivity, respectively. ZnO/ITO/PET can be used as a substrate for making flexible hybrid PEC devices to generate solar power and solar fuels.


2020 ◽  
Vol 990 ◽  
pp. 149-154
Author(s):  
Nutchaporn Ngamthanacom ◽  
Napat Kaewtrakulchai ◽  
Weerawut Chaiwat ◽  
Laemthong Chuenchom ◽  
Masayoshi Fuji ◽  
...  

Waste lignin (WL) from the pulp mill and paper was studied for its potential application to prepare the nanoporous carbon with high porosity via carbonization assisted acid activation. The effect of acid activation such as HNO3, HCl, H2SO4, and H3PO4 on lignin transformation to nanoporous carbon investigated. The physicochemical properties of nanoporous carbon were comprehensively characterized through N2 sorption, Scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR), respectively. N2 sorption revealed that the condition using 5% vol of phosphoric acid activation at carbonization temperature of 700°C for 2 h exhibited the highly porous structure of carbon nanoparticles with a total pore volume of 0.035 cm3/g. With the properly selecting process variables of waste lignin development could be producing high porosity nanoporous carbon.


2012 ◽  
Vol 727-728 ◽  
pp. 1473-1478
Author(s):  
Mariaugusta Ferreira Mota ◽  
Fabricio Machado ◽  
Meiry Glaúcia Freire Rodrigues

This work presents an experimental study focusing on the preparation and characterization of modified natural green clay-mud with quaternary ammonium salts of chloride and alkyl dimethyl benzyl ammonium chloride (Dodigen) and dimethyl stearyl ammonium chloride (Praepagen). X ray Diffraction (XRD), infrared spectroscopy (IR) and expansion tests (adsorption capacity and Foster swelling) measurements were performed in order to evaluate the performance of the ion exchange reactions and the degree of affinity with oil products. It is observed an increasing in the XRD basal spacing of the modified clays (1.96 nm and 2.25 nm for Praepagen and Dodigen salts, respectively) in comparison to the observed value (1.56 nm) for the natural clay. The IR results showed that salts were successfully incorporated to natural clay structure. Based on the expansion tests the organoclays presented the best efficiency independent on the kind of solvent used in comparison with the natural clay performance.


1996 ◽  
Vol 441 ◽  
Author(s):  
N. Sukidi ◽  
N. Dietz ◽  
U. Rossow ◽  
K. J. Bachmann

AbstractIn this contribution we report on the real-time monitoring of low temperature growth of epitaxial GaxIn1-xP/GaP heterostructures on Si(100) by pulse chemical beam epitaxy, using tertiary butylphosphine (TBP), triethylgallium (TEG), and trimethylindium (TMI) as source materials. Both step-graded and continuously graded heterostructures have been investigated. The composition of the GaxIn1-xP epilayers has been analyzed by various techniques including X-ray diffraction, Rutherford backscattering, Auger, and Raman spectroscopy. Good correlation has been found between X-ray diffraction, RBS, and Vegard's law compositional analysis. We used Ppolarized Reflectance Spectroscopy (PRS) and Laser Light Scattering (LLS) to monitor the growth rate and surface morphology during growth. The information gained by these techniques has been utilized in the improvement of the surface preconditioning as well as to optimize the initial heteroepitaxial nucleation and overgrowth process. We studied the optical response to the compositional changes in the surface reaction layer (SRL) during the exposure of the surface to either sequential or synchronous pulses of TEG and TMI. The cross sectional TEM analysis indicates that the synchronous exposure results in an abrupt GaxIn1-xP/GaP interface while the sequential exposure does not which may suggest a compositionally graded interlayer formation. For heteroepitaxial GaxIn1-xP films on Si, a buffer layer of GaP is found to be necessary for optimum uniformity of the GaxIn1-xP layer. The selective growth of GaxIn1-xP on Si(001) is accessed.


2015 ◽  
Vol 1784 ◽  
Author(s):  
Sandra Dias ◽  
S. B. Krupanidhi

ABSTRACTWe report the synthesis of Cu2SnS3 (CTS) nanostructures and its incorporation into an inorganic-organic hybrid device to enhance the photoresponse under AM 1.5 G solar illumination. The nanostructures were structurally and optically characterized. From X-ray diffraction (XRD) and Transmission electron microscopy (TEM) the CTS nanocrystals were found to be tetragonal. Flower like structures of CTS were obtained as seen from Scanning electron microscopy (SEM). A band gap of 1.4 eV was obtained from absorption studies. Two devices have been studied, P3HT: PCBM = 1: 1 and CTS: P3HT: PCBM = 8:1:1. The photocurrent increased from a value of 2.33 mA at dark to 2.5 mA for the P3HT-PCBM blend to 3.36 mA for CTS: P3HT: PCBM = 8:1:1 device. The responsivity, sensitivity, external quantum efficiency and specific detectivity increased from 18.81 mA/W, 1.07, 4.25% and 6.88 × 108 Jones respectively for P3HT:PCBM sample to 189.97 mA/W, 1.44, 42.9% and 6.95 × 109 Jones for CTS: P3HT: PCBM = 8:1:1 sample at 1V bias and 1 Sun illumination intensity. The time dependent photoresponse was stable over different ON-OFF cycles. From the fit to the rise and decay curves, the rise and decay time constants were obtained.


2015 ◽  
Vol 659 ◽  
pp. 127-131
Author(s):  
Usanee Malee ◽  
Sakdiphon Thiansem

The scientific process was used to explain characterization and physical properties of the clay sample close to the ancient Nan kiln site. These samples were obtained from JQA, FQB, PQC and NQD. X-ray diffraction (XRD) and X-ray fluorescence (XRF) technique were used to determine the chemical composition and phase transformation before and after fired at 800-1250 °C. XRF result was confirmed that all clay samples mainly contained SiO2(>80 wt. %) XRD pattern indicated that quartz was the majority of phase in the all of them. High amount of Fe2O3(>1.6 wt. %) was related to the red-brown tone color. The clay sample could be fired up to 1280 °C without wrapping behavior; it was found that FQB clay had the highest firing resistance due to the maximum quartz content.


Sign in / Sign up

Export Citation Format

Share Document