10- Transfer the ester layer to a small dry test tube and dry the ester with anhydrous CaCl2 and stir for 10 min. 11- put it in a preweighed dry round bottom flask . 14- Determine the yield, refractive index, and % yield of ester. Conditions :- 1) This reaction is catalyzed by acid, Like Fischer esterification. 2) Usage of water in step (5):So that after Estrification is completed , any excess unreacted acetic anhydride is hydrolyzed.
This diluted solution will be used in the assay as duplicate samples. Then, 1.0mL of standard glycine solution containing (7.5mg/mL) was diluted to 100mL with water using a volumetric flask. This solution contains 1.0µmole/mL of glycine. 8 tubes were set up according to the following protocol and 2.0mL of ninhydrin reagent was then added to each of the 8 tubes and were placed in a boiling water bath for 20 minutes. After 20 minutes, the tubes from the bath was carefully removed, cooled in a beaker of cold water, then 8.0mL of 50% ethanol was added and mixed well.
In the round-bottom flask (100 mL), we placed p-aminobenzoic acid (1.2 g) and ethanol (12 mL). We swirled the mixture until the solid dissolved completely. We used Pasteur pipet to add concentrated sulfuric acid (1.0 mL) to the flask. We added boiling stone and assembled the reflux. Then, we did reflux for 75 minutes.
After the 30 minutes is done, the tests tubes are then immersed in a 100 degrees Celsius methanol water bath for 15 minutes. Once the samples become frozen, put in a lyophilizer at a temperature of -109 degrees Celsius. The samples are allowed to completely dry. After 6 hours remove from the lyophilizer. Acetonitrile at a PH of 7 (neutral) is added to each of the test tube samples.
Rose Bengal-(bis(aminoethyl)ethylene glycol) (2) from Rose Bengal disodium salt (1) The synthesis was done following procedure from . Rose Bengal Na+ salt (915 mg, 0.90 mmol) was dissolved in DMF (2ml) and DIPEA (0.312 ml, 1.80 mmol), HATU (308 mg, 0.81 mmol) were added. After activation for 15 min, the mixture was added to O-Bis-(aminoethyl)ethylene glycol trityl resin (309 mg, 0.31 mmol) preswollen in DMF for 2 hours. The coupling reaction wrapped in aluminum foil was allowed to proceed overnight on a nitrogen bubbler apparatus. The resulting red-burgundy coloured resin was filtered and washed well with DMF.
Preparation of Polyaniline Solution. To obtain polyaniline solution, prepare 0.12M aniline solution by adding 2 ml of aniline into 200 ml of 1 M sulfuric acid. Start with 98% purity sulfuric acid, 10.8784 ml of 98% sulfuric acid is added to 200 ml distilled water to obtain 1 M sulfuric acid. 0.12 M aniline solution can be created by adding 2 ml of aniline and 200 ml of 1 M sulfuric acid. Refrigerated the solution for a night to let the polyaniline solution form nanotube structure.
We then slowly added 25ml of chilled deionised water to the filtrate to initiate crystallization by using a measuring cylinder and a dropping pipette, once we had done this we left it for about 10 minutes to allow crystallization at room temperature. We then weighed a filter paper which we will use later in the experiment. We then collected the crystallized acetylsalicylic acid by vacuum filtration in a Buchner funnel and washed the product with a little ice-cold water. We then pre-weighed a clean, empty watch glass and labelled it with our initials and the date, we did this do we could easily identify that it was ours when we go to weigh it with the crystals on. We
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. After completion of the process it was cooled to room temperature and resultant polymer solution was poured in the large amount of methanol with stirring when polymer precipitated out. It was filtered and washed with methanol. The polymer was purified by repeated precipitation using methanol from solution in DMF and then it dried. 2.3 Preparation of PS
Repeat the experiment. The cola drinks were titrated using the following method: Prepare the beverage in a 250ml volumetric flask. Use a funnel to facilitate the process. Place the beaker on a hot plate so that it boils and place a watch glass on top to prevent the carbon dioxide from the atmosphere getting dissolved in the cola. Once the cola starts to boil, continue to boil it for another 10 minutes so that the carbon dioxide is removed.
2. Experimental 2.1. Catalyst preparation The CuMnOx catalyst was prepared by the co-precipitation method, the aqueous solution manganese acetate (Mn(CH3COO)2.4H2O) and copper (II) nitrate (Cu(NO3)2.2.5H2O) were premixed by stirring for 1 hour. After the proper mixing of the copper nitrate and manganese acetate solution, it was added to the aqueous KMnO4 solution by a burette under the stirring conditions. After dropped completely the copper manganese solution into the precipitant ageing for 2h, then filtered, washing several times with hot deionized water.