Results and discussion Reaction mechanism of the sol-gel process Monodisperse silica NPs can be prepared by hydrolysis and condensation of alkoxysilanes in a mixture containing alcohol, water, and catalyst. The chemical reactions describing the hydrolysis and condensation of TEOS and MTES are shown in Fig. 3. As shown in this figure, TEOS can be hydrolyzed and condensed to form SiO2 colloid particles in mixture of Methanol, NH4OH and H2O after being stirred for 1 h at room temperature. Similar to the results reported by Wang et al., the obtained inorganic silica (SiO2) colloid particles have active hydroxyl groups on their surfaces. When MTES is added into the SiO2 colloid sol, the ethoxy groups of MTES can be immediately hydrolyzed, generating …show more content…
It is generally accepted that the addition of inorganic NPs into the polymeric matrix improves the polymer’s mechanical properties (Nguyen et al., 2013). In this regard, the mechanical strength of fabricated membrane was examined in terms of stress and elongation at break. Data derived from mechanical testing are shown in Table 6. It can be seen that the synthesis of inorganic NPs on the surface and cross section of the PP hollow fiber membrane has increased the membrane rigidity. Enhancement in membrane rigidity is achieved by increasing the stress and decreasing the elongation. This must be due to the original property of inorganic materials and the re-enforcement effect of incorporated NPs in the membrane matrix (Ahsani and Yegani, 2015). The TGA analysis was carried out to further confirm the formation of PP composite membrane. Fig. 11 shows the weight loss curve obtained by TGA for the pure PP membrane and the modified membrane. From TGA curve, it can be seen that the thermal decomposition of composite membrane is higher than the pure PP membrane because of the existence of inorganic NPs on the membrane surface which had a higher thermal resistance. Other researchers observed a similar behavior for the incorporation of the fluorinated silica inorganic layer on the PEI membrane (Zhang and Wang,
The monomers will be transformed into colloidal solution which is known as sol. Sol is a colloidal suspension with solid particles in a liquid and they remain evenly dispersed throughout the solution. As for gel, it is an integrated network which varies from discrete particles to linked polymers. In this process, typical precursors are used preferably metal alkoxides. 3.2.2.2 Electrospinning
In order to separate KNO3 and CuSO4, which are both soluble in water, recrystallization was used. The reason the two components can be separated through recrystallization is because of the temperature dependence of solubility, KNO3 is much more soluble in hot water and insoluble in cold water while CuSO4 is only slightly more soluble in hot water. When the filtrate was heated the solution was saturated with KNO3 but when the system was cooled, the KNO3 became insoluble and pure crystals reformed while CuSO4 stayed dissolved in the
“Sanitol Tooth Powder, the powder that will reduce doctor visits each year” “Makes tooth brushing an enthusiastic habit” is a popular quote used by Sanitol Chemical company during the 1900s. From the moment, we first learn to brush our teeth, we are taught that we should always keep them clean and white. Sanitol tooth powder made this possible during the early 19th century. Having pearly white teeth is seen as an attractive quality to have. Therefore, Sanitol made various ads to display the beauty of having white teeth in their ads.
N-(1-Carboxymethyl-1H-tetrazol-5-yl)-hydrazinium nitrate (3). A solution of AgNO3 (0.10 g, 0.60 mmol) in distilled water (1.5 mL) was added dropwise in the dark to the solution of compound 2 (0.10 g, 0.60 mmol) in Deionized water (1.5 mL) under stirring. After 2-3 hour, the precipitate was filtered, and rinsed with 4 mL distilled water. The solvent was removed by rotary Evaporation to produce a white solid at 88% yield (0.10 g); N-(1-Carboxymethyl-1H-tetrazol-5-yl)-hydrazinium nitrate: Yield: 88%; yellow crystals;. IR (KBr): 3396, 3329, 3140, 3008, 1628, 1494, 1383 cm-1; UV (H2O): λmax = 293-296
Purpose and Techniques: This experiment has the aim to determine a chemical formula of hydrated compound, which ingrains cupper, chloride and water molecules in its structure. In order to find this hydrated compound, it is necessary to use the law of multiple proportions. In other word, finding the appropriate variables values to this compound (CxCly*zH2O). Additionally, two major steps are required to proceed the experiment.
1: Introduction to a hydrate. What is a hydrate? Why is it called a hydrate? A hydrate is a compound (usually crystalline) where water molecules are chemically bonded to another compound or an element. This is called a hydrate because the substance is hydrated.
Finding the empirical formula for hydrated copper sulfate using calculations to find the amount of each element present in the copper ion, sulfate ion, and water while also comparing the empirical formula to a literature value. Christian Cooper Alexis Powers CHM1210-18M/Gregory Bowers 11-5-15 Purpose: To begin, there are several different goals, techniques, and claims to note in the experiment involving hydrated copper sulfate. The overall goal of this experiment is to find the empirical formula and compare it with a literature value. Yet, in finding the empirical formula of hydrated copper sulfate, there are several process for it to get through, like finding the percentages of copper, water, and finally sulfate.
Next, we turned our attention to the effect of oxidants. When various oxidants such as TBHP, K2S2O8, and DDQ were scrutinized (Table 1, entry 13-15), and TBHP (1 equiv) had the beneficial effect to give the best yield (Table 1, 75%; entry 13). However, the yield lowered when the amount of TBHP was decreased. The reaction did not proceed at all in the presence of other nano-particles, such as ZrO2, Fe3O4, NiO and in some copper salts CuBr2, CuCl2, (Table 1, entries
To the solution of methanol (50 ml) and KOH (1.1eq), carbon disulphide (1.1eq) was added slowly at room temperature. To the reaction mass, 2-aminophenol (1.eq) was added with stirring. The reaction mass was refluxed for 6 hr on water bath. Completion of the reaction was monitored by TLC. The reaction mixture was poured to a beaker containing ice cold water and acidified with glacial acetic acid (pH 6).
The results do not support the hypothesis that a higher surface area to volume ratio would result in sulphuric acid being diffused into the agar cubes in the shortest amount of time. This is evident in the results as the exact opposite to what was predicted occurred. Instead of the smallest cube with the largest surface area to volume ratio of 1cm3 having the quickest diffusion rate, it conversely took the longest at 0.092 cm3 per second, whilst the 2cm3 cube with 0.0384 cm3 per second took the least amount of time. This directly refutes the hypothesis. There was also no consistent trend evident in the results.
However, addition of HCl to the aqueous ionic solutions regenerates non-ionic substances which are only soluble in the organic layer. Materials • 2M diethyl ether • Saturated NaCl solution • Saturated aqueous solution of Sodium bicarbonate • Distilled water • Pasteur pipette • Anhydrous Calcium Chloride pellets • 3M aqueous NaOH • Litmus paper • Boiling stick • Source of heat • Water bath
Therefore, sucrose is able to dissolve in water. However Paraffin wax, Silicon dioxide and Tin, were insoluble in water,because they do not have a charge for electrons to flow and carry electrons. Paraffin wax was insoluble in water, because Paraffin is a non-polar, water is a polar solvent, therefore they can not attract because like cannot dissolve like. Silicon dioxide was insoluble in water, because the vast network of covalent bonds is much stronger than the water-water interactions , therefore the water is not able to break down the molecule to form aqueous ions in water. This results in there being no possible attractions between water molecules with silicon and oxygen, leaving it as insoluble .
Purpose This experiment is to determine the concentration of the solute copper sulfate pentahydrate, and the unknown solution, by passing different wavelengths of light through each solution. Procedure Weigh out approximately 5g of copper sulfate pentahydrate. Record the mass and place the solute into a 50 mL volumetric flask. Fill half of the flask with distilled water, add the stopper for the flask, and lightly shake the flask, until the copper sulfate pentahydrate fully dissolved.
One of the possible systematic error that may occur in this experiment is that the hydrated (II) ammonium sulfate is contaminated as the iron (II) salt was left uncovered. The iron (II) salt was prepared by the lab assistant and the salt was left at the table uncovered for students to scoop the desired amount of salt they want. The iron (II) salt might be contaminated by dust particles and even saliva. This would cause the standard iron (II) solution to have less iron (II) salt in it and this means that less potassium permanganate solution is needed to titrate the iron (II) solution. This is a systematic error because the iron (II) solution used throughout the experiment.
The former can be heated and shaped and are used in the modern world many times, containing everything from children's toys to toilet seats. Because they can be melted down and reshaped, thermoplastics are usually recycled. Thermoset plastics can only be heated and shaped once, after which the molecular changes mean they are “cured,” retaining their shape and strength even when they are subjected to intense heat and the pressure. Thermoset plastics plays a vital part in our modern world.