10, is a linear curve for 4-NP reduction using AuNPs. It was observed that the increase in temperature helps the rate of reaction to increase. The activation energy was calculated from the slope of the straight line and was found to be 7.4 ± 1.34 k Cal/mol. The above results are of clear indication that catalysis usually takes place on the surface of the nanoparticles. 3.8 Catalytic reduction of potassium hexacyanoferrate (III) The electron transfer reaction between hexacyanoferrate (III) and sodium borohydride results in the formation of hexacyanoferrate (II) ion and dihydrogen borate ion and this reaction is strongly catalyzed by AuNPs.
The solvents DMF and methanol were distilled for purification. Other chemicals were used as obtained. 2.2 Preparation of polystyrene (PS) Polystyrene prepared by free radical polymerization of styrene monomer. Styrene (1 mole) was taken in a round bottom flask (RBF) fitted with a reflux condenser. DMF was used as a solvent and AIBN (0.5% w/w of total monomer) as free radical initiator .The reaction was carried out at 70±2° C for 6 hour with constant stirring.
2) Citrate reduction A very common, method for synthesizing silver nanoparticles is citrate reduction. It involves the reduction of silver nitrate, AgNO3, to colloidal silver using trisodium citrate, Na3C6H5O7 at high temperatures (~100 °C). Here, the citrate ion acts as reducing agent. This method is useful due to its relative ease and short reaction time. However, the silver particles formed may exhibit broad size distributions or form several different particle geometries simultaneously.
The pH level was frequently checked with the aid of pH indicator paper for fine coating thickness. Whenever the coating starts a drop of SDS surfactant was plunged into the Ni-P bath exactly on the coating zone. Simultaneously nano Sic was stirred well in the separate beaker using magnetic stirrer for 1 hour. Fine stirred nano Sic was injected on to the Ni-P bath using injector with uniform time interval. After coating of the first layer (nickel phosphorous) for
The reduction of ethyne occures in an exceedinglyn ammonical solution of chromous chloride or in a solution of chromous salts in H2SO4. The selective catalytic hydrogenation of ethyne to ethylene, that yield over supported Group eight metal catalyst, is of nice industrial importance within the manufacture of ethyne by thermal transformation of organic compound. HALOGENATION AND HYDROHALOGENATION Halogens add to the triple bond.Fecl3 catalyzes the addition of cl2 to ethyne to produce 1,1,2,2-tetrachloromethane that is intermediate within the production of the commercial solvents 1,2-dichloroethylene,trichloroethylene and perchloroethylene. ethyne will be chlorinated to 1,2 –dichloroethylene by directly using FeCl3 as a catalyst and a large excess ethyne trans-C2H2Cl2 is made from ethyne in solutions of CuCl2,CuCl and HCl. Br in solution or as a liquid adds to ethyne to create first 1,2-dibromoethylene and eventually tetrabromoethylene.
The purpose of this experiment was to learn about the electrophilic aromatic substitution reactions that take place on benzene, and how the presence of substituents in the ring affect the orientation of the incoming electrophile. Using acetanilide, as the starting material, glacial acetic acid, sulfuric acid, and nitric acid were mixed and stirred to produce p-nitroacetanilide. In a 125 mL Erlenmeyer flask, 3.305 g of acetanilide were allowed to mix with 5.0 mL of glacial acetic acid. This mixture was warmed in a hot plate with constantly stirring at a lukewarm temperature so as to avoid excess heating. If this happens, the mixture boils and it would be necessary to start the experiment all over again.
Then, 0.5 g of synthesized copolymer dissolved in DMSO was added to the chitosan solution and the constant stirring was continued for 2 h. About 0.5 mL of glutaraldehyde is added in to the mixture in order to increase the crosslinking efficiency. After the stipulated time, the mixture was evenly poured in the Teflon plate and dried at 60 °C for 24 h. Finally, the membranes were peeled off from the Teflon sheet and used for further characterizations and applications. Similarly, 0.6 wt%, 0.7 wt% and 0.8 wt% of chitosan–copolymer (CS-SFP) blend membranes were developed by the same procedure and named
The peak at 2083 cm-1 could be the presence of –CH stretch in the biomass (Clothup et al., 1990). After contacting with the metal solution , -COO shifted from 1404 to 1442 cm-1 suggesting the affinity of carboxyl group to metal ions. The peaks in the range 887-825 cm-1 represents amine group and H2PO4- and 478- 408 cm-1 are due to the presence of PO42- (El Nemr et al., 2011). The IR spectra obtained before and after metal binding shows that –CH3 group is involved in the biosorption of chromium. The shift from 1327 to 1381 cm-1 indicates that =CH3 group is one of the major functional group involved in chromium binding (Yang and Chen,
Cadmium sulfide is one of the more useful compounds for the application in solar cells and for the practical applications in electronics and photonics. The cadmium sulphide nanoparticles has the optical prpperty which will modify the confinement of charge carrier within the nanoparticles. The properties like physical and chemical property of cadmium sulphide nanoparticles are found to be size depended. CdS nanoparticles are synthesized by simple chemical precipitation reactions. Six different combinations of chemical reactions can be used for the synthesis CdS nanoparticles.
Benefits of Nanotechnology The use of nanotechnology has increased effectiveness in removing contaminants even at low concentrations. Specificity toward target contaminants has been increased. Nanotechnology has made removal of new contaminants possible. Contaminants that were previously impossible to remove could now be removed such as heavy metals. Nanotechnology has made things simples, helps to reduce the number of steps, materials and energy needed to purify water, making it easier to implement.