2.7. Sol-Gel Method
The sol–gel method allows the synthesis of TiO2 nanoparticles with different morphologies like sheets, tubes, particles, wires, rods, mesoporous and aerogels. The sol–gel method is also used due to the easy technique, low price, the purity of oxides obtained and the lower synthesis temperatures.
The raw materials and methodologies differ according to the type of nanoparticles required finally. 97 % % titanium tetra iso propoxide (TTIP) has been utilized by several studies as a starting material.
Titanium isopropoxide and acetic acid were added in in a 1:1 molar ratio along with a non-ionic surfactant in 2-propanol. An opalescent homogeneous gel was obtained which was aged and peptized and finally underwent hydrothermal
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(Shinen et al)
Several other studies utilized tetra isopropyl titanate (TIPT). TIPT was mixed with methanol and ethanol and refluxed, followed by a drop wise addition of distilled water. The mixture was filtered, dried and calcined to obtain white crystalline powder of Nano TiO2.. In a parallel study, TIPT was added to hydrogen peroxide, followed by addition of n-hexane and agar agar. After filtration, washing and calcination, nanoparticles were obtained. (Kale et al, 2012)
Some methods involved use of dimethyl acetamide (DMAC). TiO2 sol was prepared using DMAC as solvent to which tributyl tin (TBT) was added. Glacial acetic acid was added to control pH. The gel was heated to obtain TiO2 powders. (Zhang et al, 2016)
A variation of the sol-gel method was utilized in a study, where dibutyl phthalate and ethyl alcohol was mixed with hydrochloric acid and de-ionized water, and dried. A muffle furnace was utilized. (Liu et al, 2014)
Another study used 1% TiO2 and trisodium citrate followed by stirring and drying to obtain titania nanoparticles. (M. Hema et al, 2013) In a similar study, the initial sol gel consisted of Iron (III) Chloride 6-Hydrate, C12H28O4Ti (Tetraisopropyl orthotitanate), ethanol, citrate acid and C5H8O2 (Acetyl acetone). (Nasralla et. al.,
Solid triphenylmethanol (0.200 g, 0.768 mmol) and sulfuric acid (2 mL) were added to a reaction tube, which was then ground using a glass rod until it dissolved and turned a dark orange color. The mixture was then added dropwise via a glass pipette into another reaction tube containing methanol (1 mL). An extra amount of methanol (2 mL) was used to transfer the rest of the contents of the first reaction tube. Formation of crystals was facilitated by scratching the side of the tube and adding additional methanol until the color changed to an off-white color. The contents of the tube were then vacuum filtered with water and the resulting crude product was weighed and then recrystallized using hot methanol to form triphenylmethyl methyl ether (0.051 g, 0.186 mmol, 24.2%). The melting point was 81 – 83˚
This process is then repeated. In the second trial, the Mg ribbon did not completely dissolve and the results were thrown out. The third trial (referred to as the second in the following analysis due to the exclusion of the previous one) was successful, and measurements can be seen below. We then moved onto the second reaction using magnesium oxide and hydrochloric acid in the fume hood. We measured 200.1 mL of HCl and placed it in the calorimeter, and an initial temperature reading was taken.
Procedure: Anisole (0.35mL, 0.0378mol) was obtained and placed in a pre-weighed 25 mL round bottom flask, along with 2.5 mL of glacial acetic acid and a magnetic stir bar. Then the reaction apparatus was assembled, the dry tube was charged with conc. sodium bi sulfate, the 25 mL round bottom was attached to the apparatus, and 5 mL of Br2/HBr mixture was obtained and placed in the round bottom. The reaction took place for 20 minutes. An orange liquid was obtained and placed in a 125 mL Erlenmeyer flask along with 25 mL of water and 2.5 mL of conc. Sodium bisulfate soln. The solution was then placed in an ice bath to precipitate and then the solid product was filter in a Buchner funnel. These crystals were then re-dissolved minimum amount of hot solvent (heptane) and recrystallized. Once a dry product was obtained, a melting point was established (2,4-Dibromoanisol mp 55-58 C) and percent yield was established (52%).
Furthermore, when phosphoric acid was added during the experimental process, the solution was turned into bright orange. The purpose for pouring the reaction mixture into sodium acetate solution is to raise the PH value and precipitate the product. In addition water and sodium bicarbonate solution is used in this reaction in order to remove the remaining acid from the organic layer. The organic layer also must be dried over anhydrous magnesium sulfate. The product was looked like red-brown solid when evaporator was used in order to remove the solvent.
surfactants. They are made up of two amphiphilic moieties connected at the level of the head
In this lab, iron filings and copper sulfate pentahydrate were chemically reacted to produce iron sulfate and copper.
Society of Environmental Toxicology and Chemistry. (2013). SETAC/Rachel Carson Award - Society of environmental toxicology and chemistry. Retrieved from Society of Environmental Toxicology and Chemistry: http://www.setac.org/?SETACAwardSRachel
Michael P. Broadribb, C. (2006). Institution of Chemical Engineers . Retrieved July 26, 2010, from IChemE: http://cms.icheme.org/mainwebsite/resources/document/lpb192pg003.pdf
Titanium dioxide, also known as Titanium (IV) oxide or titania, is the naturally occurring oxide of titanium, chemical formula TiO2. When used as a pigment, it is called titanium white, Pigment White 6, or CI 77891. Generally it is sourced from ilminite, rutile and anatase. It has a wide range of applications, from paint to sunscreen to food colouring.
The Olefins II Unit makes hydrocarbons from naphtha or natural gas using furnaces. After distillation, the p...
The procedure for this experiment can be found in Inorganic Chemistry Lab Manual prepared by Dr. Virgil Payne.
Neutralization Experiment AIM:- To investigate how heat is given out in neutralizing sodium hydroxide (NaOH) using different concentrations of Hydrochloric Acid. Background Information:- Substances that neutralize acids are called alkalis. An acid is a substance that forms hydrogen ions (H+ ) when placed in water. It can also be described as a proton donor as it provides H+ ions. An example of an acid is hydrochloric acid (HCl), Sulphuric acid (H2SO4) etc.
Although Solar Energy is a flexible source of where energy could be directly or indirectly converted into forms of energy, it’s still not perfect. With its inefficiency, scientists are trying to find alternative solution to store solar cells for as long as possible. The main process of capturing solar energy happens at the nanoscale. With solar cells, it gets more efficient the tinier it gets. The converting rate of solar energy is equally price competitive as fossil fuel, with a dollar per watt of solar energy. With the help of nanotechnology, it could help raise solar energy conversion efficiency and help lower costs making it the ultimate method of raw energy conversion. To make sure the process of generating energy is kept at a low cost and energy output...
Thermal properties of material (Tg, Tm, Td) are those properties that response to temperature. They can be studied by thermal analysis techniques including DSC, TGA, DTA and dielectric thermal analysis. The nanometer-sized of inorganic particles incorporated into the polymer matrix can improve thermal stability by acting as a superior thermal insulator and as a mass transport barrier to the volatile products generated during decomposition [117]. Khanna et al. [57] reported the thermal (TGA) analysis of the PVA/Ag nanocomposite. They observed that the decomposition profile starting at about 330 ◦C and continuing till about 430 ◦C. They also found the PVA/Ag nanocomposites have higher thermal stability than the PVA alone. Mbhele et al. [99] also observed that that the pure PVA starts decomposing at about 280 ◦C and
Živković, Snežana; Takić, Ljiljana; Živković, Nenad UNAPREĐENJE EKOLOŠKIH PERFORMANSI PRIMENOM STANDARDA ISO 14001 - STUDIJA SLUČAJ.. Chemical Industry & Chemical Engineering Quarterly. 2013, Vol. 19 Issue 4, p541-552. 12p. DOI: 10.2298/CICEQ120513088Z. ,