Thermogravimetric analysis deposition

Multiwall carbon nanotubes (MWCNTs) have been synthesized by catalytic chemical vapor deposition (CCVD) of ethylene on several mesoporous aluminosilicates impregnated with iron. The aluminosilicates were synthesized by sol-gel method optimizing the Si/Al ratios from 6 to 80. The catalysts are characterized by nitrogen adsorption, X-ray diffraction, 27A1 NMR, thermogravimetric analysis (TGA) and infrared. The MWCNTs are characterized by TGA and transmission and scanning electron microscope. 

For this purpose, all three catalyst supports were initially synthesized by a chemical vapor deposition (CVD) process and thereafter, using a wet impregnation method, loaded with cobalt as the active component for FTS. The as-synthesized Co/nanocatalysts were then characterized by applying electron microscopic analysis as well as temperature-programmed desorption, chemi- and physisorption measurements, thermogravimetric analysis, and inductively coupled plasma... 

Amount of deposited material - Table 4 shows the deposited weight measured with thermogravimetric analysis (TGA) for the different carbon black types after polyacetylene deposition at 27 Pa monomer pressure, 250 W power, and 1 h treatment time. These values show that the most active carbon black is the fullerene soot EP-P434. 

Thermogravimetric analysis of the yellow salt (btaH)2H2[Fe(CN)6], deposited from K4[Fe(CN)6J/btaH solutions on acidification with HC1, reveals o-aminobenzonitrile to be the major organic product (226). 

The solids were characterized by X-ray diffraction using a Siemmens D-500 diffractometer equipped with a copper anode and a nickel filter. The deposition of carbon was studied by thermogravimetric analysis (TGA) using a Perkin-Elmer 1700 TGA analyzer. For the TGA runs the sample was heated at 10°C/min in air (2.0 1/h) from ambient temperature (20 C) to 850°C the procedure was repeated to eliminate Ae effect of adsorbed water. 

General. Commercially available polyimides were used (see Table I). Solvents were reagent grade or better and were used as received. 1-Methylpiperazine (Aldrich Chemical Co.) was > 99.9% pure. Lactic acid (Aldrich) was reduced to 50% by weight in water and refluxed for an hour to hydrolyze esters. IR spectra were recorded on a Perkin-Elmer Model 1430 spectrometer. Thermogravimetric analysis was done on a P-E System 4/TGS-2 instrument. Size exclusion chromatography was done on a Perkin-Elmer Series 3B equipped with the LC-75 spectrophotometric detector. The column set used consisted of P-E 0258-2134, 2133, and 2131 columns (pore sizes 103, 104, and 106 A, respectively). For electrophoretic deposition experiments, a TCR Power Supply (Electronic Measurement Systems Inc.) was used. Temperatures are reported in °C throughout. 

The thermal stability of polymers can be tested by thermogravimetric analysis (TGA). In this method, a sample of a few milligrams is deposited in a scale pan mounted on a furnace. TGA measurements can be done in isothermal mode by maintaining a certain temperature for a fixed period of time or in temperature cycling mode. Most often the data are obtained with a constant... 

The stability but also the catalytic activity of nickel-based perovskite was improved with a low amount of magnesium or rhodium in the structure. The solubility of Mg in the perovsldte structure is limited phases such as NiO and MgO are evidenced by XRD when >0.1 in LaNii Mg >,03 [24]. High catalytic activity was reached at 700 °C, with LaNio.9Mgo.1O3 under severe reaction conditions 10 mg of catalysts, CH4/CO2 50/50 ml/min without dilution gas. The CH4 and CO2 conversion were respectively equal to 57 and 67% and maintained during 15 h on stream even if carbon deposition was detected by thermogravimetric analysis at the end of the reaction (27 wt%). 

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