7631-99-4 Usage
Chemical Properties
Different sources of media describe the Chemical Properties of 7631-99-4 differently. You can refer to the following data:
1. Colorless tripartite crystal or diamond crystals or white tiny crystal or powder. Odourless, taste salty, slightly bitter. Soluble in water and liquid ammonia, soluble in ethanol, methanol, slightly soluble in glycerol and acetone.
2. Sodium nitrate, NaNO3, also known as soda niter and Chile saltpeter, is a fire-hazardous, transparent, colorless and odorless crystalline solid. It is soluble in glycerol and water,decomposes when heated,and melts at 308°C (585 °F). Sodium nitrate is used in making nitric and sulfuric acids, in the manufacture of glass and pottery enamel, as a fertilizer, as a food preservative, in explosives, and as a welding flux.
3. Sodium nitrate, white solid, soluble, source in nature is Chile, in the fixation of atmospheric nitrogen HNO3 is frequently transformed by sodium carbonate into sodium nitrate, and the solution evaporated. Used (1) as an important nitrogenous fertilizer, (2) as a source of nitrate and HNO3, (3) in pyrotechnics, (4) in fluxes.
Uses
Different sources of media describe the Uses of 7631-99-4 differently. You can refer to the following data:
1. Sodium nitrate is one of the earliest nitrogen fertilizer, can be used for acid soil, especially suitable for root crops, such as sugar beet and radish. In the end of the 19th century to the early 20th century, Chile exploited sodium nitrate mining in large scale as nitrogen fertilizer for the world. Farmers in Xinjiang uygur autonomous region in China digged desert surface soil contain NaNO3 to plant grape fruits, and the fertilizer effect is remarkable.
Sodium nitrate can be used to make nitrate, picric acid, explosives, mineral raw materials, dyes, osmotic pressure regulator in medicine and other nitrogen compounds, it also can be used in glass, metallurgy, light industry and other industrial sectors.
In glass industry, it can be used for the production of various kinds of glass and its products of defoaming agent, decoloring agent, clarifying agent and oxidation solubilizer. Enamel industry uses it as oxidant, solubilizer, and to make enamel powder. Machinery industry uses it as metal cleaner, dispensing black metallic blue agent. Metallurgical industry uses it for steel and aluminum alloy heat treatment. Light industry uses it as combustion improver of cigarettes. Pharmaceutical industry uses it as a medium of penicillin.
It can be reduction by bacteria into sodium nitrite in meat, which results in color protection and bacteriostatic effect, and can be used as food color fixative in China.
It also can be used as decolorizing agent of molten caustic soda and analytical reagent.
2. Sodium Nitrate is the salt of nitric acid that functions as an antimi-
crobial agent and preservative. it is a naturally occurring substance
in spinach, beets, broccoli, and other vegetables. it consists of color-
less, odorless crystals or crystalline granules. it is moderately deli-
quescent in moist air and is readily soluble in water. it is used in
meat curing to develop and stabilize the pink color. see nitrate.
3. In manufacturing of HNO{3}, as a catalyst to manufacture H{2}SO{4}, in manufacturing of glass, enamel for pottery, sodium nitriteSodium nitrate is used in the production of fertilizers, nitric acid, pyrotechnics, smoke-bombs, glass and pottery enamels. In combination with boron trifluoride it forms an efficient reagent for nitration of aromatic compounds. Adsorption on alumina provides an environmentally benign aromatic nitrating agent. Further it finds use as food preservative and as a solid rocket propellant. It is also used as an electrolyte in a salt bridge, and as thermal storage medium in power generation systems.
4. manufacture of nitric acid and as catalyst in the manufacture of sulfuric acid. manufacture of sodium nitrite, glass, enamels for pottery; in matches; for improving burning properties of tobacco; pickling meats; as color fixative in meats. Clinical reagent (parasites). The technical grade is used as fertilizer.
Water Solubility
The dissolved grams per 100 ml of water at different temperature (oC):
73g/0oC; 80.8g/10oC; 87.6g/20oC; 94.9g/30oC; 102g/40oC; 122g/60oC; 148g/80oC; 180g/100oC .
Identification Test
Nitrate test (IT-23) and sodium salt test (IT-28) are positive.
Content Analysis
GB 1891-86 method
Principle:
Boiling nitrate and nitrogen alloy (45A150; u5Zn) in strong alkaline solution results in releasing of hydrogen, which reduces nitrogen nitrate (or other nitrogen compounds) to ammonia. Absorption ammonia with excess sulfuric acid then titration with standard alkali solution.
Reagent and Solution :
Preparation of mixed indicating liquid: Dissolve 0.12 g of methyl red and 0.12 g of methylene blue in 100 ml 95% ethanol solution.
Nitrogen alloy is smashed to pass through a screen of 20 meshes, and the content of alloy can pass through a screen of 80 meshes should not exceed 20%.
Dissolve 14 g (Accurate to 0.0002 g) of fully blended sample in water with a beaker, then transfer into 500 ml volumetric flask, dilute to scale and shake to be a backup.
Use the distillation unit as shown. Draw 50 ml of 0.5 mol/L sulfuric acid solution using straw into 500 ml conical flask, then add 50 ml of water.
Draw 50 ml of prepared liquid sample through a straw into a 1000 ml flat-bottomed distillation flask, then add 7.5 g nitrogen alloy, and 150 ml of water along the wall of bottle. Join the distillation unit according to the figure, and make the tube 4 hit the end of the bottom of the bottle. Add 70 ml of sodium hydroxide solution (300 g/L solution) in distillation bottle 1 quickly, immediately insert rubber stopper, reaction after 20 min at room temperature, micro heat 10 min, then high temperature distillation. After boiling 50~60 min, and obtain about 270 ml of solution in bottle (residual liquid product is about a third of the initial volume), down the conical flask, leave the tip of the tube 4 out of the liquid level inside the conical flask solution, then wash pipe 4 with water, stop heating.
Blank experiment was carried out at the same time under the same conditions in addition to the water replacement of liquid sample.
In the formula, c-concentration of standard sodium hydroxide solution (0.5 mol/L)
Vo-Blank consumption volume of NaOH standard solution, ml;
V-Sample consumption volume of NaOH standard solution, ml;
m-The quality of sample, g;
z-water content measured by the standard, %;
z,-Sodium nitrite content measured by the standard, %;
0.08499-Millimoles quality of sodium nitrite, g;
1.232-The coefficient of sodium nitrite to sodium nitrate.
The difference between the two parallel determination results should not be greater than 0.3%. Take the arithmetic mean as the determination results of parallel determination results. The difference between the different laboratory determination results is not greater than 0.5%.
Notice: Before testing the sample, verification using replacement of potassium nitrate with the same method. Calculation method is as follows.
In the formula, G-The quality of the benchmark potassium nitrate, g;
0.10111-millimoles quality of potassium nitrate, g.
If several analysis results of potassium nitrate were between 99.95%~100.05%, the test equipment is regarded in good condition (at least to be between 99.80%~100.10%).
FAO/WHO method
Accurately weight 0.4 g of sample which has been dried at 105oC for 4 h into a 500 ral round bottom flask, then add 300 ml water. Add 3 g of Devardas alloy powder and 15 ml of 40% sodium hydroxide solution, join the splash ball and condenser on the flask. Stewing for 2h. Use a bottle containing50 ml of 0.1 mol/L sulfate acid to collect 250 ml of distillate, add three drops of methyl red-methylene blue test solution (TS-150), use 0~mol/L sodium hydroxide titration excess sulfuric acid. Blank experiment was carried out at the same time. Every mL0.1 mol/L equivalent to 8.5 mg sulfate sodium nitrate (NaNO3).
Toxicity
ADI 0~3.7 mg/kg (NO3-meter, but do not apply to the baby younger than 3 months FAO/WHO, 2001). LD50 1100～2000mg/kg (rats, through the mouth).
Accordance to the stipulations of GB 2760-86, it can be used in hair color agent and in meat products, the maximum amount is 0.5 g/kg; residues be calculated by sodium nitrite, meat canned must not exceed 0.05 g/kg, meat products shall not be more than 0.03 g/kg.
Infants younger than six months are particularly sensitive to nitrate, do not be used for baby food. HACSG (EC child protection group) suggestions restriction for infants and young children food.
Dust can irritate the lungs and skin. Sodium nitrate has the characteristic of reduction to sodium nitrite in body, often resulting in formation of denaturation of hemoglobin, drinking water containing 50~100 RNG/L sodium nitrate, denaturation of hemoglobin in the blood rise significantly. Workers operate the production must wear work clothes, protective masks, latex gloves and other labor insurance supplies, in case of dust suction and protect respiratory and skin. Production equipment should be closed and the workshop ventilation is good. Take a shower after work.
Utilization Limitation
GB 2760-1996: same as "17301," potassium nitrate.
The FAO/WHO (1984 mg/kg): cooked the ham, meat cooked pork shoulder, maximum amount 500; General cheese 50.
FDA, § 172.170 (2000 mg/kg): sodium nitrate total 500, 200 total sodium nitrite.
Production Method
Absorption method:
Bubble the exhaust derived from nitric acid production (contain NO + NO2 0.5%~1.5%) into the bottom of absorption tower, use soda solution with a relative density of 1.240~1.3 and temperature of 25~60 oC spraying from the top of the tower to absorption nitrous oxide in gas, and then obtain the neutralizer. Add neutralizing liquid and nitric acid into converter, sodium nitrite will transform into sodium nitrate, the conversion temperature is between 90~105 oC, stirring with air at the same time. Using soda solution to neutralize the free acid in converted solution, keeping the alkalinity below 0.3 g/L, in atmospheric evaporation to solution the boiling point of 123~123 oC, through cooling crystallization, centrifugal separation, drying, sodium nitrate is obtained.
Na2CO3+NO+NO2→2NaNO2+CO2↑
Na2CO3+2NO2→NaNO2+NaNO3+CO2↑
3NaNO2+2HNO3→3NaNO3+H2O+2NO↑
Nitrogen gas released from oxidation reaction process can be returned to nitric acid production system to make nitric acid.
Double decomposition method:
Mix 50%~52% of calcium nitrate, sodium sulfate and calcium nitrate solution cycle solution into a stirring reactor, reaction was conducted in the 50~55 oC under stirring for 3~4 h, filter the plaster through vacuum filter, and further filter to remove impurities, remove plaster after been washed with water, wash water merged with the filtrate, part of them return to diluted slurry reactor, and part of them been evaporation and concentration, through cooling crystallization, centrifugal separation and drying, sodium nitrate is obtained.
Ca(NO3)2+Na2SO4→2NaNO3+CaSO4↓
Direct extraction method:
The sodium nitrate ore is broken to a certain size, use fresh water or brine to spray heap leaching, then get a certain concentration of sodium nitrate brine, cooling to separate mirabilite, send brine to evaporation pans tan, until sodium nitrate alum (Na2SO4, NaNO3·H2O) crystal appeared, after filtering, the by-produc of sodium chloride brine continue insolation evaporation to get semi-finished products contained sodium nitrate alum. Melt the semi-finished product with a certain amount of brine (or crystallization mother liquor), after been filtered to remove impurities, filtrated the cooling crystallization, centrifugal separation, drying, sodium nitrate is obtained.
Conversion method:
Sodium nitrite concentration and dilute nitric acid mother liquor are sent into the tower, through steam heating and ventilation with compressed air mixing, then transform into sodium nitrate solution, add soda solution until slightly alkaline solution, then through purification, filtration, removal of arsenic and heavy metals, evaporation and concentration, cooling crystallization, centrifugal separation, drying, the food grade sodium nitrate is obtained.
3NaNO2+2HNO3→3NaNO3+H2O+2NO↑
Category
Oxidizing agent
Toxicity Grading
Poison.
Acute Toxicity
Oral-LD50 in rats: 1267 mg/kg. Static chamber-LD50 in mice: 175 mg/kg.
Explosive Dangerous Features
Explosive mixed with sulfur, phosphorus, charcoal and other flammable.
Flammability Hazard Characteristics
Decompose to generate oxygen when been heated; flammable when encounter organic matter, reducing agent, charcoal, sulfur and phosphorus; combustion produces toxic nitrogen oxides smoke.
Transportation and Storing Characteristics
Ventilated warehouse; light discharge; keep separate from sulfur, phosphorus, organic matter, reducing agent and charcoal tinder.
Extinguishing Agent
Fog water and sand.
Physical properties
Colorless crystalline solid; saline taste; trigonal, and rhombohedrals structure; density 2.257g/cm3; refractive index 1.587 (trigonal) and 1.336 (rhombohedral); melts at 308°C; decomposes at 380°C; specific conductance 95 μmhos/cm at 300°C; viscosity 2.85 centipoise at 317°C; very soluble in water 92.1 g/100 mL at 25°C and 180 g/100 mL at 100°C; very soluble in liquid ammonia; soluble in alcohol.
Occurrence
There are several natural deposits of sodium nitrate in various parts of the world, including Chile, Mexico, Egypt, and the United States. The most important application of sodium nitrate is its use as a fertilizer in agriculture. It is an effective fertilizer for cotton, tobacco, and vegetable crops. Its agricultural applications, however, have dwindled considerably in recent years because of the growth of ammonium nitrate and other fertilizers.Another major use of sodium nitrate is in manufacturing explosives. It is a component of many types of dynamites and water-based slurry type blasting explosives. Sodium nitrate also is used in making charcoal briquettes. Sodium nitrate is used as an oxidizing and fluxing agent in manufacturing vitreous glass, fiberglass, porcelain, and enamels. Other uses are in the heat-treatment baths for alloys and metals, as a food preservative, in curing meats, and in preparing various salts.
Production Methods
Sodium nitrate is recovered from natural deposits. One such process, known as the Guggenheim nitrate process, is briefly outlined below: The ore is crushed. Sodium nitrate is leached from the ore by extraction with a brine solution at 40°C. The brine for leaching is made up of an aqueous solution of magnesium sulfate, MgSO3, and calcium sulfate, CaSO3. The caliche variety of Chilean ore contains mostly sodium nitrate and sodium chloride as the main saline components, along with limestone, clays, sand, lime, and inert volcanic rocks. Sodium nitrate usually occurs in this ore as a double salt with sodium sulfate NaNO3?Na2SO3?H3O. This double salt, which is sparingly soluble in water, is broken down by magnesium in leaching brine solution, thus releasing more sodium nitrate into the extract. Sodium nitrate finally is recovered from the leachate brine by fractional crystallization.Brines of other compositions have been used to extract sodium nitrate from its ores. Many such processes, including the Shanks process practiced in the past to produce sodium nitrate, are now obsolete.
Definition
ChEBI: The inorganic nitrate salt of sodium.
General Description
A white crystalline solid. Noncombustible but accelerates the burning of combustible materials. If large quantities are involved in fire or the combustible material is finely divided an explosion may result. May explode under prolonged exposure to heat or fire. Toxic oxides of nitrogen are produced in fires. Used in solid propellants, explosives, fertilizers, and for many other uses.
Air & Water Reactions
Soluble in water.
Reactivity Profile
A mixture of Sodium nitrate and sodium hypophosphite constitute a powerful explosive [Mellor 8, Supp. 1:154 1964]. Sodium nitrate and aluminum powder mixtures have been reported to be explosive,[Fire, 1935, 28, 30]. The nitrate appears to be incompatible with barium thiocyanate, antimony, arsenic trioxide/iron(II) sulfate, boron phosphide, calcium-sodium alloy, magnesium, metal amidosulfates, metal cyanides, powdered charcoal, peroxyformic acid, phenol/trifluoroacetic acid, sodium, sodium nitrite/sodium sulfide, sodium phosphinate, sodium thiosulfate, tris( cyclopentadienyl)cerium, and even wood [Bretherick 5th ed., 1995].
Hazard
Fire risk near organic materials, ignites on
friction and explodes when shocked or heated to
1000F (537C). Toxic by ingestion; content in cured
meats, fish, and other food products restricted.
Health Hazard
INGESTION: Dizziness, abdominal cramps, vomiting, bloody diarrhea, weakness, convulsions, and collapse. Small repeated doses may cause headache and mental impairment.
Flammability and Explosibility
Nonflammable
Agricultural Uses
Sodium nitrate is the oldest known nitrogenous fertilizer.
It is a white, shiny crystal available in nature as Chilean
saltpeter or Chilean nitrate.
Sodium nitrate is manufactured by two methods. In
the first, known as the Guggenheim method, the
fertilizer is extracted from a mined product, called
caliche, mined mostly in Chile; hence the name (Chilean
saltpeter or Chilean nitrate). The caliche is dissolved in
warm water and then cooled to 0°C to produce sodium
nitrate crystals, which are circulated through heat
exchangers. The circulation keeps the crystals
suspended, to finally form pellets. Caliche mined in
Chile, contains sodium nitrate (8 to 20%), potassium and
magnesium nitrates and salts like borates, sulphates and
chlorides. Approximately, one ton of sodium nitrate of
99% purity is obtained from 10 tons of caliche. Sodium
nitrate is shipped in airtight containers. The pellets are
also coated to impart free-flowing characteristics.
Sodium nitrate is also manufactured from nitric acid
and soda ash, using salt and oyster shells. Nitric acid is
reacted with soda ash forming sodium nitrate solution.
Most water is removed by evaporation and the rest is heated to a high temperature and sprayed through
nozzles. Sodium nitrate solidifies as pellets while coming
through the nozzles.
Sodium nitrate fertilizer is water-soluble. It contains
16% nitrogen and about 26% sodium. Plants absorb most
of the nitrogen in a nitrate form and sodium nitrate is a
commonly preferred fertilizer, although the nitrogen
content of sodium nitrate is lesser than that in many other
inorganic nitrogen fertilizers. Sodium nitrate has a
neutralizing effect on soil acidity because of its inherent
basic residual effect. Its neutralizing value is 0.82 kg of
calcium carbonate equivalent to 0.45 kg of sodium
nitrate.
The field crops which benefit most from sodium
nitrate application are sugar beet and cotton. If applied
excessively, sodium nitrate can damage the soil structure
by reducing the flocculation. But normal applications of
100 to 200 kg of fertilizer/hectare/year do not affect the
soil structure.
Safety Profile
Human poison by ingestion. Poison by intravenous route.Questionable carcinogen with experimental tumorigenic data. Human mutation data reported. A powerful oxidizer. It will iqte with heat or friction. Explodes when heated to over 1000°F, or when mixed with cyanides, sodium hypophosphte, boron phosphide. Forms explosive mixtures with aluminum powder, antimony powder, barium thiocyanate, metal amidosulfates, sodium, sodium phosphinate, sodium thiosulfate, sulfur + charcoal (gunpowder). Potentially violent reaction or ignition when mixed with bitumen, organic matter, calcium-shcon alloy, jute + magnesium chloride, magnesium, metal cyanides, nonmetals, peroxyformic acid, phenol + trifluoroacetic acid. Incompatible with acetic anhydride, barium thocyanate, wood. A dangerous disaster hazard. Experimental reproductive effects. When heated to decomposition it emits toxic fumes of NOx and Na2O. See also NITRATES.
Purification Methods
Crystallise NaNO3 from hot water (0.6mL/g) by cooling to 0o, or from a concentrated aqueous solution by adding MeOH. Dry it under a vacuum at 140o. After two recrystallisations, technical grade sodium nitrate had K, Mg, B, Fe Al, and Li at 100, 29, 0.6, 0.4, 0.2 and 0.2 ppm respectively. (See KNO3.)
Check Digit Verification of cas no
The CAS Registry Mumber 7631-99-4 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 7,6,3 and 1 respectively; the second part has 2 digits, 9 and 9 respectively.
Calculate Digit Verification of CAS Registry Number 7631-99:
(6*7)+(5*6)+(4*3)+(3*1)+(2*9)+(1*9)=114
114 % 10 = 4
So 7631-99-4 is a valid CAS Registry Number.
InChI:InChI=1/NO3.Na/c2-1(3)4;/q-1;+1
7631-99-4Relevant articles and documents
Single-crystal hexagonal disks and rings of ZnO: Low-temperature, large-scale synthesis and growth mechanism
Li, Feng,Ding, Yong,Gao, Puxian,Xin, Xinquan,Wang, Zhong L.
, p. 5238 - 5242 (2004)
Solution-phase synthesis of single-crystal ZnO disks and rings was achieved in high yield at low temperature (70-90°C) by using an anionic surfactant as a template. The reaction can be controlled by means of the growth temperature and the molar ratio of reagents to favor formation of disks or rings. A growth mechanism is proposed on the basis of structural information provided by SEM and TEM.
The state of ruthenium in nitrite-nitrate nitric acid solutions as probed by NMR
Emel'yanov,Fedotov
, p. 1811 - 1819 (2006)
The state of ruthenium in nitric acid solutions treated with sodium nitrite has been studied by 14N, 15N, 17O, and 99Ru NMR. In the acidity range 2.7-0.12 mol/L, the dominating ruthenium species are the [RuNO(NO
NaIn(CrO4)2·2H2O, the first indium(III) member of the kroehnkite family
Kolitsch, Uwe
, p. i35-i37 (2006)
Sodium indium(III) chromate(VI) dihydrate, NaIn(CrO4) 2·2H2O, synthesized from an aqueous solution at room temperature, is the first indium(III) member of the large family of compounds with kroehnkite [Na2CuII(S VIO4)2·2H2O]-type chains. The crystal structure is based on infinite octahedral-tetrahedral [In(CrO 4)2(H2O)2]- chains along [010], linked via charge-balancing Na+ cations. The slightly distorted InO4(H2O)2 octahedra are characterized by a mean In - O distance of 2.125 A. The CrO4 tetrahedra are strongly distorted (mean Cr - O = 1.641 A). The Na atom shows an octahedral coordination, unprecedented among compounds with kroehnkite-type chains. The NaO6 octahedra share opposite edges with the InO4(H2O)2 octahedra to form infinite [001] chains. The hydrogen bonds are of medium strength. NaIn(CrO 4)2·2H2O belongs to the structural type F2 in the classification of Fleck, Kolitsch & Hertweck [Z. Kristallogr. (2002), 217, 435-443], and is isotypic with KAl(CrO4) 2·2H2O and MFe(CrO4)2· 2H2O (M = K, Tl or NH4). All atoms are in special positions except one O atom.
The effects of synthesis pH and hydrothermal treatment on the formation of zinc aluminum hydrotalcites
Kloprogge, J. Theo,Hickey, Leisel,Frost, Ray L.
, p. 4047 - 4057 (2004)
Zn/Al hydrotalcites were synthesized by coprecipitation at increasing pH from 6.0 to 14.0, followed by hydrothermal treatment at 150°C for 7 days. The materials were characterized by X-ray diffraction (XRD), STEM, inductively coupled plasma-atomic emission spectroscopy (ICP-AES), thermal analysis, infrared spectroscopy and Raman spectroscopy. The XRD analysis for the samples prepared between pH 9.0 and 12.0 showed a pattern typical of hydrotalcite, with a c-axis distance of ～22.6 A. STEM showed that the pH of preparation affected the stability of the hydrotalcite and that instability, observed at pH 9.0, favored the formation of mixed phases when treated hydrothermally. It was also shown that treatment of a stable starting material increased the crystallinity and resulted in the formation of hexagonal plate-shaped particles. ICP-AES and thermal analysis showed that the Zn/Al ratio and thermal stability increased with pH. Thermal analysis showed three major weight losses corresponding to the loss of interparticle water, interlayer water and dehydroxylation of the hydroxide layers and decarbonization of the interlayer region.
A "green chemistry" approach to the synthesis of rare-earth aluminates: Perovskite-type LaAlO3 nanoparticles in molten nitrates
Mendoza-Mendoza, Esmeralda,Montemayor, Sagrario M.,Escalante-Garcia, Jose I.,Fuentes, Antonio F.
, p. 1276 - 1283 (2012)
Perovskite-type LaAlO3 nanoparticles have been prepared by a facile, rapid, and environmentally friendly molten salts method using alkali metal nitrates as low-temperature fluxes. Starting from hydrated lanthanum and aluminum nitrates and alkali metal hydroxides, the proposed methodology consists briefly of two steps: a mechanically induced metathesis reaction followed by short firing at temperatures above nitrates melting points. The purpose of the first is twofold: on the one hand to generate in situ the alkali metal nitrate flux and on the other hand, to obtain a La and Al-containing precursor material suitable for the synthesis of bulk LaAlO3 nanoparticles in molten nitrates. Different alkali metal nitrates and eutectic mixtures were used to analyze the influence of melt basicity in the reaction outcome. Single phase LaAlO3 was obtained directly, without any purification step when using three molten media: LiNO3, NaNO3, and their mixture; using KNO3 as flux either alone or as part of eutectic compositions, prevents complete conversion, and the title material is obtained mixed with additional crystalline phases such as lanthanum hydroxinitrates and carbonates. As-prepared LaAlO3 powders are composed of loosely agglomerated nanoparticles with very fine crystallite size (32-45 nm). The present method reduces considerably previously reported synthesis time/temperatures for this material.
The synthesis of apatites with an organophosphate and in nonaqueous media
Sternlieb, Mitchell P.,Brown, Heather M.,Schaeffer Jr., Charles D.,Yoder, Claude H.
, p. 729 - 732 (2009)
The syntheses of barium, cadmium, calcium, lead, and strontium apatites were performed in anhydrous polar organic solvents such as DMSO, anisole, pyridine, glacial acetic acid, ethanol, methanol, and DMF. Reactions took place under anhydrous conditions at
Electrochemical response of nitrite and nitric oxide on graphene oxide nanoparticles doped with Prussian blue (PB) and Fe2O3 nanoparticles
Adekunle, Abolanle S.,Lebogang, Seonyane,Gwala, Portia L.,Tsele, Tebogo P.,Olasunkanmi, Lukman O.,Esther, Fayemi O.,Boikanyo, Diseko,Mphuthi, Ntsoaki,Oyekunle, John A. O.,Ogunfowokan, Aderemi O.,Ebenso, Eno E.
, p. 27759 - 27774 (2015)
Electrocatalytic behaviour of graphene oxide (GO), iron(iii) oxide (Fe2O3) and Prussian blue (PB) nanoparticles and their nanocomposite towards nitrite (NO2-) and nitric oxide (NO) oxidation in neutral and acidic media respectively was investigated on a platinum (Pt) modified electrode. Successful synthesis of these nano materials was confirmed using microscopic and spectroscopic techniques. Successful modification of the electrode was confirmed using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results showed that the Pt-GO-Fe2O3 and Pt-GO-PB nanocomposite modified electrodes gave a faster electron transfer process in both a 5 mM Ferri/Ferro ([Fe(CN)6]3-/4-) redox probe and 0.1 M phosphate buffer solution (PBS). The Pt-GO-Fe2O3 and Pt-GO-PB electrodes also gave an enhanced NO2- and NO oxidation current compared with bare Pt and the other electrodes studied. Electrocatalytic oxidation of the analyte occurred through a simple diffusion process but were characterized with some level of adsorption. Tafel slopes b of 468.4, 305.2 mV dec-1 (NO2-, NO); and 311.5, 277.2 mV dec-1 (NO2-, NO) were obtained for the analyte at the Pt-GO-Fe2O3 and Pt-GO-PB electrode respectively. The Pt-GO-Fe2O3 limit of detection and sensitivity in NO2- and NO are 6.60 μM (0.0084 μA μM-1) and 13.04 μM (0.0160 μA μM-1) respectively, while those of the Pt-GO-PB electrode are 16.58 μM (0.0093 μA μM-1) and 16.50 μM (0.0091 μA μM-1). The LoD compared favourably with literature reported values. Pt-GO-Fe2O3 gave a better performance to NO2- and NO electrooxidation, good resistance to electrode fouling, a higher catalytic rate constant and lower limit of detection. The adsorption equilibrium constant β and the standard free energy change ΔG0 due to adsorption are 10.29 × 103 M-1 (-22.89 kJ mol-1) and 3.26 × 103 M-1 (-20.04 kJ mol-1) for nitrite and nitric oxide respectively at the Pt-GO-Fe2O3 electrode. An interference study has also been reported. The fabricated sensors are easy to prepare, cost effective and can be applied for real sample analysis of nitrite and nitric oxide in food, water, biological and environmental samples.
Morphology control and large piezoresponse of hydrothermally synthesized lead-free piezoelectric (Bi0.5Na0.5)TiO3 nanofibres
Ghasemian, Mohammad Bagher,Lin, Qianru,Adabifiroozjaei, Esmaeil,Wang, Feifei,Chu, Dewei,Wang, Danyang
, p. 15020 - 15026 (2017/03/17)
Lead-free piezoelectric bismuth sodium titanate (BNT) nanostructures were synthesised using a low-temperature hydrothermal technique. It is found that the phase and morphology of the products are strongly dependent on the composition and concentration of the precursors, as well as the processing conditions. Through optimising the synthesis parameters, well-crystallized BNT nanofibers with 150-200 nm diameters and ～5 μm length were obtained. The BNT fibres show a pure perovskite phase with (011) orientation along the length direction. A piezoelectric constant of d33 = ～15 pm V-1 in the diameter direction was observed for these BNT nanofibers.
A highly selective and simultaneous determination of ascorbic acid, uric acid and nitrite based on a novel poly-N-acetyl-l-methionine (poly-NALM) thin film
Kannan, Ayyadurai,Sivanesan, Arumugam,Kalaivani, Govindasamy,Manivel, Arumugam,Sevvel, Ranganathan
, p. 96898 - 96907 (2016/10/25)
This paper demonstrates the facile fabrication of an N-acetyl-l-methionine (NALM) polymer film on a glassy carbon electrode (GCE) by an electropolymerization technique. Atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and electrochemical techniques such as cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to characterize the modified electrode. This poly-NALM/GCE not only exhibits strong electrocatalytic activity towards the oxidation of ascorbic acid (AA), uric acid (UA) and nitrite with a shift in oxidation potential towards the less positive side, but also enhances peak current responses at physiological pH (7.2) conditions. Further, the overlapped anodic voltammetric peaks of the three analytes on a bare GC electrode were well-resolved into their independent oxidation peaks at the poly-NALM/GC modified electrode with a peak separation of 160 and 590 mV for AA-UA and UA-nitrite, respectively. Under the optimal experimental conditions, the anodic peak currents of AA, UA and nitrite increased linearly within the concentration ranges 10-1000 μM, 1-600 μM and 1-500 μM with correlation coefficients of 0.990, 0.996 and 0.994, respectively. The detection limits are 0.97, 0.34 and 0.75 μM for AA, UA and nitrite ion, respectively (S/N = 3). The modified electrode was successfully utilized to determine AA, UA and nitrite ion simultaneously in real samples such as human urine and tap water samples.
BDO a harmless treatment method for organic waste
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Paragraph 0023; 0024; 0025, (2017/02/24)
The invention discloses a method for innocent treatment of a BDO organic wastewater. The method comprises the following steps: firstly, carrying out dealcoholizing treatment on the BDO organic wastewater to obtain a normal butanol product, rectifying tower overhead distillate and a water enriching layer; carrying out further rectifying extraction on the rectifying tower overhead distillate to obtain an oily mixture at the tower bottom; combusting the oily mixture in a conduction oil heating furnace so as to heat conduction oil; and dissolving the combustion waste residues with and mixing with nitric acid, so as to prepare sodium nitrate. According to the method disclosed by the invention, the BDO organic wastewater is processed to obtain an alcohol product and sodium nitrate, and meanwhile, tar with a high heat value is fully utilized, thus innocent treatment of pollutants is achieved; the whole method has the advantages that the steps are simple, conditions are easy to control, the product yield is high, all obtained products are good in purity, equipment investment is low, the production cost is low, and energy consumption is low. The method has economic and social significance on the aspects of improvement of the production additional value, reduction of environmental pollution and the like.
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