As starting materials, Mg (NO3)2·6H2O, and Fe (NO3)3. 9H2O were used to prepare MgFe2O4 MNPs. Firstly, 0.2 g of the tragacanth gum (TG) was dissolved in 40 ml of deionized water and stirred for 80 min at 70 °C to achieve a clear tragacanth gel (TG) solution. After that, the stoichiometric mixtures of the mentioned materials were added to the TG solution and the container was moved to a sand bath. The temperature of the sand bath was fixed at 80 °C and stirring was continued for 12 h to obtain a brown color resin. The final product was calcined at 600 °C in air for 4 h to obtain MgFe2O4 MNPs. 2.3 Preparation of MgFe2O4@Al2O3 MNPs At first, 0.2 g of the tragacanth gum (TG) was dissolved in 40 ml of deionized water and stirred for 80 min at 70 …show more content…
In this regard, 0.03 g of ferrite sample was dispersed in 50 ml solution of dye. The solutes on samples were taken out from the reaction medium at regular time periods. The MgFe2O4@Al2O3 MNPs were segregated from solution using magnetic force and the absorbance change at a maximum wavelength (λ max) of dyes (522 nm for RR195 and 486 nm for RO122) was followed by UV–Vis spectrophotometer (Analytical Jena-Specord 205). The effect of MgFe2O4@Al2O3 dosage on the degradation of photocatalytic dye was studied by contacting 50 ml of dye solution (20 mg/L for RR195 and RO122) at room temperature for 1 h. Different amounts of MgFe2O4@Al2O3 (0.01, 0.02, 0.03 and 0.04 g) were applied. The effect of initial dye concentration on the photocatalytic dye degradation was investigated. The MgFe2O4@Al2O3 (0.03 g) was added to 50 ml of different dye concentrations (5, 10, 15 and 20 mg/L for RR195) and (5, 10, 20 and 30 mg/L for RO122). The effect of visible light irradiation on the photocatalytic dye degradation was studied. The photocatalytic degradation performance of the process was defined as % Degradation = (A0 − A)/A0 × 100, where A0 is the initial absorbance and A is the final absorbance, at λ max = 522 nm for RR195 and λ max = 486 nm for
This paper describes the methods used in the identification, investigation of properties, and synthesis of an unknown compound. The compound was identified as calcium nitrate by a variety of tests. When the compound was received, it was already known to be one of twelve possible ionic compounds. The flame test identified the presence of the calcium anion in the compound. The compound tested positive for the nitrate cation using the iron sulfate test. At this point it was hypothesized that the compound was calcium nitrate. Reactivity tests and quantitative analysis comparing the unknown compound with calcium nitrate supported this hypothesis. Synthesis reactions were then carried out and analyzed.
Aim: To classify unknown substances according to their structure type and to observe how the structure of materials affects their uses.
Mg: Mg2+(aq) + 2NH3(aq) + 2H2O(l) < ==> Mg(OH)2(s) + 2NH4+(aq), which is white gelatinous
The most common fluorine minerals are fluorite, fluorspar and cryolite (Fluorine). Fluorine is also the 13th most common element in the Earth’s crust (Fluorine). There is 950 mg/L of fluorine in the earth’s crust (Periodic). Fluorine is also in seawater. Around 2,400 tons of fluorine gas and 4,700,000 tons of fluorite are produced each year (Periodic). Fluorine production areas are primarily in Canada, United States, United Kingdom, Russia, Mexico and Italy (Periodic). Fluorine is most commonly combined with sodium to form sodium fluoride (NaF) to put into toothpaste (Periodic). A very interesting fact about fluorine is that it is added to city water supplies in the proportion of about one part per million to help prevent tooth decay (The Element). Hydrofluoric acid is used to etch glass, including most of the glass that is used in light bulbs (The Element). You cannot purchase straight fluorine due to it being highly
pH is one of the most important factors influencing removal efficiency of many chemical and biological reactions (19). Removal efficiency by the nano-catalyst with exposure to UV radiation was reported as 99.14%, while in the absence of nano-catalyst was 86.72%. The greatest removal rate was reported at pH=11 in the presence of the nano-catalyst as much as 90 mg/L, owing to the high concentration of hydroxyl radical in the solution (20) (p<0.05). These radicals play an important role in oxidizing organic contaminants (21).The advanced oxidation processes are based on hydroxyl radicals, causing oxidation and removal of contaminants (19, 20). pH has an important impact on contaminant molecules, the surface charge of nano-catalysts, and the mechanism of the degree of production of hydroxyl radicals (22).
This experiment was used to demonstrate the preparation of luminol and its chemiluminescence. After luminol was synthesized by the condensation of 3-nitrophthalic acid with hydrazine, which produces 3-nitrophthalhydrazine and is reduced using sodium hydrosulfite to yield luminol, the chemical luminescent properties could be observed. Reacting luminol with potassium ferricyanide, the oxidizing agent, and hydrogen peroxide displays this chemiluminescent reaction.
Solvent was evaporated to yield brownish orange powder solid (.170g, 77.3%); (mp: 310°C-313°C ); 1H NMR (60 MHz, DMSO) δ 6.2 (s, 4H), 6.5 (s, 2H), 7.7 (d, 1H), 7.8 (m, 1H), 7.9 (m, 1H), 8 (d, 1H); 1H NMR (400 MHz, DMSO) δ 6.6 (s, 4H), 6.7 (s, 2H), 7.3 (d, 1H), 7.7 (t, 1H), 7.8 (t, 1H), 8 (d, 1H), 10.2 (s, 2H); UV/Vis λmax 498.6
Products that contain sodium fluoride (NaF) as the active ingredient also need to have sufficient detergent to prevent the fluoride ions from reacting with the silica abrasives forming insoluble fluorosilicates (Carey, 2014). There is a large effort to develop reliable methods of measurement of available fluoride. The difficulty in achieving the analytical methods is related to the large variety of ingredients used in toothpaste products and the different forms of fluoride delivered during tooth brushing (Carey, 2014). There are three categories of fluoride form toothpaste during tooth brushing: free ionic fluoride which has the ability to react with tooth structure, interfere with microbial metabolism, absorb to the oral mucosa, and has anticaries efficacy; profluoride compounds that are delivered or precipitate in the oral cavity during brushing, release ionic fluoride over time, and contribute to anticaries efficacy; and unavailable fluoride compounds that do not release fluoride ions, are either spat out or swallowed, and have no anticaries efficacy (Carey, 2014). Monofluorophosphate is an example of a profluoride compound that is hydrolyzed to release ionic fluoride through salivary enzyme action (Carey, 2014). The total and potentially available fluoride can be
The samples were synthesized from a synthesis solution by dissolving 7.98 g sodium hydroxide pellets (A.R) and 11.01, 8.01, 6.79, 2.73, 1.64, 0.9 g of aluminum sulphate, aluminum chloride, aluminum isopropoxide, sodium aluminate, alumina and aluminum metal (Aldrich), respectively in 69.5 g deionized water in a beaker. The mixtures in the beaker were thoroughly mixed and a 50 g Ludox AS30 colloidal silica (Aldrich) was slowly added to the above solution under stirring at high speed. The molar composition of the resulting synthesis gel was 12Na2O: 100SiO2:2Al2O3: 500H2O. Prior to being transferred to a Teflon-lined stainless steel autoclave, the above synthesis solution was aged for 20 hr at room temperature and then hydrothermally treated
In this article, a study was conducted comparing various fluoride toothpastes and gels that are combined with different agents to enhance the uptake of fluoride without having to increase the dosage of fluoride (Schemehorn, DiMarino, & Movahed, 2014, p.58). The various fluoride combinations included amorphous calcium phosphate (ACP), tri-calcium phosphate (TCP), and casein-phosphopeptide-amorphous calcium phosphate (CPP-ACP). This study was conducted on incipient lesions to see which combination had the best fluoride uptake and
Synthesis of OA-Ag NPs: For the preparation of OA-stabilized Ag NPs [39], silver trifluoroacetate (0.4 g), OA (3.5 mL), and isoamyl ether (30 mL) were mixed in a 250 mL three-neck flask under argon. The mixture was heated at 160 °C for 30 min then cooled to room temperature by removing the heat source. The purification process was performed four times using excess polar solvent (ethanol) and centrifugation. The precipitated OA-Ag NPs were dispersed in
For decades, fluoride has been held in high regard by the dental community as an important mineral that is absorbed into and strengthens tooth enamel, thereby helping to prevent decay of tooth structures.
Fluoride is a trace element that possess many beneficial effects on skeletal and dental health. It prevents tooth decay by providing resistance against acids, supporting remineralization, and hindering the process of bacteria being able to produce. Another function is blocking osteoporosis from forming, and minimizes bone demineralization. Supplements can be developed from fluoride and provide protection for teeth to give them extra support. However, there is a certain amount that must be taken, failure in exceeding the minimum cause the mottling of teeth.
3.3 g of the iron (III) chloride were placed into a 250 mL conical flask. Around 25 mL distilled water were added into it and the solution was stirred by using a magnetic stirrer with a moderately large stirrer bar to dissolve it. A solution of acetylacetone was prepared by adding 3.9 mL of acetylacetone in 10 mL of methanol in a small beaker. Magnetic stirrer was used to keep the FeCl3 solution strongly stirred, the acetylacetone solution was added to it carefully over a period of 15 minutes. The mixture was turned dark red. A solution of sodium acetate was prepared by adding 5.1 g of it in 15 mL of distilled water. Over 5 minutes, the sodium acetate solution was added slowly and carefully to the red mixture. A red solid was appeared appear
18F-fludeoxyglucose Chemical Structure: - Formulation: - 18F-FDG is synthesized by electrophilic fluorination with 18F2. Carrier free dissolved 18F-fluoride (18F-) ions in water is produced by proton bombardment of 18O-enriched water which causes a (n-p) reaction in 18O. 18F- is then separated from the aqueous solvent by trapping it on an ion-exchange column. It is then eluted with an acetonitrile solution of 2,2,2-cryptand and potassium carbonate and evaporated to give [(crypt-222) K]+ 18F-. In the above reaction, intermediate (2) produced is treated with mannose triflate (1) which gives fluorinated deoxyglucose (3) by SN2 reaction by displacing the triflate group by fluoride anion.