Abstract Titanium Di-boride (TiB2) nano particle was prepared using sol-gel and carbothermal reduction method. The effect of temperature, solvent and precursor ratio on the synthesis of TiB2 was studied after the synthesis of TiB2. Earlier work which was done on to synthesize TiB2 via this process has given the optimum result at 15000C carbothermal reduction temp. and Titanium : boron : carbon precursor ratio should be 1 : 2 : 5 ; aim was/is to reduce the temp. of carbothermal reduction reaction and using low cost precursor for the source of boron(B) and carbon(C) and also to get nano size particle but previously via this process only 3-5µm particle range has been obtained.
2. Materials and methods 2.1. Materials Analytical grade Fe(NO3)3.9H2O, Na2SO4, NaHCO3, and H2SO4 were obtained from Merck. Reagents such as pluronic acid P123, hydrochloric acid and tetraethylorthosilicate (TEOS) were collected from the Sigma Aldrich and Rhodamine B was purchased from Loba Chemie chemical company. These reagents and dyes were directly used without further purification.
A third peak with an integration of 3 was upfield of the benzene proton peaks. This peak corresponds to the protons of the methyl component of the ether substituent. Normally methyl protons would show up further upfield but the presence of the highly electronegative oxygen atom lead to increased deshielding of the protons. Carbon NMR showed six peaks the most deshielded carbon falling at a PPM of about 162. The most upfield of the carbons was at a PPM of 48 and belonged to the methyl carbon at the end of the ether substituent.
The 1H NMR spectra confirmed the synthesis of the alkyd resins. The characteristic peaks at = 7.2-7.3 ppm are for the proton for –CH- of the glycerol moiety . It was observed due to the deshielding effect of the anhydride group acquiring the aromatic ring, which are absent in the 1H NMR spectra of oils. The peaks at = 7.4-7.8 ppm are observed for the aromatic protons of phthalic anhydride-containing
Experimental procedure Chemicals Acid-functionalized multiwall carbon nanotubes (MWCNT–COOH, 30-50 nm in Outside diameter and length of approximately 20-30 nm, purity>95%) were purchased from US Research Nanomaterials, Inc. NaOH (97%), Fe(NO3)3.9H2O (99%) and Mn(NO3)2.4H2O (≥ 98.5 %) were supplied by Merck Chemicals Ltd (Gauteng, South Africa). Cationic yellow 40 (C20H20ClN3O2, molar mass 369 and ) and Direct Red 16 (C26H17N5Na2O8S2, molar mass 637.55 and ), as adsorbate were purchased from Alvan Sabet Companies (Iran). All the chemicals were used without further treatment. Deionized water was also used for all solution preparation. Preparation of MnFe2O4/MWCNT–COOH nanocomposite The composite used in this study were also synthesized by hydrothermal
2. Experimental method 2.1 Synthesis of PbSe and PbSe: Nd nanoparticles Neodymium doped PbSe samples (Pb1-xNdxSe) with x=0, 0.05, 0.10 at pH 5 were prepared by wet chemical precipitation technique, adding hydrazine hydrate as the precipitating agent at room temperature. Freshly prepared aqueous solution and analytical grade lead nitrate (Pb(NO3)2), neodymium oxide (Nd2O3) and selenium dioxide (SeO2) were used as precursor materials. Initially, 2 g of lead nitrate and 0.555 g selenium dioxide were separately dissolved in 60 ml of double distilled water in three neck flask and stirred for 30 min. Conversion of neodymium oxide into nitrate by adding 2N nitric acid in a water bath is used as dopant precursor.
The typical commercial bath for nitriding consists of NaCN, NaCO3 and NaCNO mixture of 60-70% . The bath used in liquid pressure nitriding operates with a cyanate content of 15 to 20% and cyanide content of 30 to 35%. The liquid bath initially aged at a selective time temperature for combination to increase the cyanates content and then parts are immersed in the liquid for further processing. Salt bath nitrided components exhibit excellent sliding and running in properties as well as greater wear resistance. This nitriding improves wear resistance, lubricity, fatigue strength and corrosion resistance as a result of the presence of iron nitride compounds formed at the surface in integration to a zone of diffused nitrogen in solid solution with the base metal adjacent to the compound layer.
The extracted organic layer was steam bathed to vaporize light petroleum which has low boiling point at 30-40˚C. Chromic acid is a more commonly used reagent for the oxidation of alcohols, it is a suspected carcinogen and generates hazardous waste. In green chemistry, innocuous chemical such as hypochlorous acid, HOCl will be used in oxidation, as to reduce the harmful waste. Green chemistry is the name given to modifications implemented in chemical manufacturing processes that ensure a safer and cleaner
Then, Fe(NO3)3·9H2O (0.5mol) was added to above solution and was kept at 80 °C for 12h under reflux. The obtained red-brown solid was filtered and washed for three times with methanol and DMF, then dried in air. The as-prepared photocatalyst was characterized by SEM (VP-1450), EDX (type
In the first step, the synthesis was carried out in a batch reactor by a mixture of polyol and HDB at a heating rate of 10 oC/min to 75 oC/min by stirring at 100 rpm and 4 kgf/cm2 of pressure in order to form an NCO-terminated prepolymer. At 75 oC, a sample of prepolymer was taken out of the reactor and placed in a high density polyethylene bottle for cooling. In the second step, the resulting mixture in the reactor