Small Amount Of Sodium Hydroxide Research Articles

Sodium Carbonate Pulping of Wheat Straw—An Alternative Fiber Source for Various Paper Applications

European paper mills are currently facing the question of whether recovered paper, their main raw material, will be available in sufficient quantities and an acceptable quality in the future. An alternative to recovered paper or wood fiber is the use of agricultural residues such as wheat straw. Sodium carbonate-based straw pulping processes have the advantage of not requiring recausticizing for chemical recovery, which reduces investment and operating costs. With the addition of oxygen, delignification can be significantly improved to provide pulps suitable for bleaching. This study compares the pulping of wheat straw using sodium carbonate, sodium carbonate + oxygen, and sodium carbonate + sodium hydroxide + oxygen. Pulping parameters such as temperature, retention time, and chemical charge were varied, and their influence on pulp properties was studied. The use of sodium carbonate alone produced pulps with high yields of up to 72% and comparably high burst and compressive strength. The addition of oxygen and small amounts of sodium hydroxide produced pulps with a high initial brightness of 42 %ISO and a low kappa number (18), still at high pulp yields of 62%. These pulps were two-stage bleached to achieve brightness levels of up to 73 %ISO.

Accelerating the reaction process of sodium carbonate-activated slag mixtures with the incorporation of a small addition of sodium hydroxide/sodium silicate

This paper investigates the possibility of accelerating the slowly progressive early reaction process of sodium carbonate-activated slag mixtures by adding a small amount of sodium hydroxide or sodium silicate to the sodium carbonate activator. The reaction process of sodium carbonate-activated slag mixtures was evaluated by isothermal calorimetry and ultrasonic wave technology. Test results showed that adding a small amount of sodium hydroxide or sodium silicate to the sodium carbonate activator significantly accelerated the reaction process, resulting in shortened setting times and enhanced mechanical properties. Only 1% Na2O contribution from sodium hydroxide addition can lead to a 2-d compressive strength of 20 MPa for sodium carbonate-activated slag mixtures. In addition, the 28 days compressive strength was significantly higher than the sole sodium carbonate activator. The addition of sodium hydroxide or sodium silicate also considerably influenced the rheological behavior of the sodium carbonate-activated slag mixture, enhancing the structural build-up rate and transforming the shear-thinning behavior to Bingham or shear-thickening behavior. A more well-packed microstructure was observed in the mixtures with the addition of sodium hydroxide; however, more micro-cracks were observed in the mixtures with a small incorporation of sodium silicate.

Production of nickel-rich LiNi0.89Co0.08Al0.03O2 cathode material for high capacity NCA/graphite secondary battery fabrication

Abstract Li-ion secondary battery is highly recommended as a power source to highly advanced battery electric vehicles. Among various types, the lithium nickel cobalt aluminum oxide (NCA) battery is considered suitable for high energy and power application. In this study, the NCA cathode material LiNi0.89Co0.08Al0.03O2 was produced via the oxalate co-precipitation technique to reduce the overall production cost and process complexity. Oxalic acid and a small amount of sodium hydroxide were used as the precipitant and pH regulator, respectively. Homogenous and loose metal oxalate precipitate formation was confirmed by X-ray diffraction (XRD), scanning electron microscopy, and Fourier-transform infrared spectroscopy analysis. XRD patterns of the as-obtained micron-sized NCA showed a well-layered hexagonal structure. The electrochemical properties of the cathode in the full cell were thoroughly examined. The specific discharge capacity of the as-obtained NCA in NCA/LiPF6/graphite at a current rate of 20 mA/g was 142 mAh/g. The as-prepared NCA sample had capacity retention of 80% after being charged and discharged at 0.1 A/g for 101 cycles. Scaling up of NCA production process to 2 kg per batch was conducted and evaluation of NCA product quality was performed by material characterization. Based on the overall results and considering the overall process, such an approach is expected to be developed and improved for future large-scale production purposes.

Development and research of the influence of the composition and concentration of activators on the strength of phosphorus slag binders

The paper discusses various ways of activating phosphorus slags by introducing additives for the development of phosphorus slag binders (PSB), replacing cement. Considering that pseudowollastonite is the main mineral of phosphorus slags and without activating components does not possess the binding properties necessary for the production of building materials based on them, we used compositions of small amounts of sodium hydroxide with alkali metal salts, the anions of which form poorly soluble compounds with calcium. When choosing activating components, scarce alkaline additives were replaced by waste from chemical plants, which allows a passing solution of their practical use and environmental problems. The strength at a sodium hydroxide content of 1–4 % after curing of slag samples of various batches was in the range of 50.0–70.0 MPa. Samples of binders of normal hardening at the age of 28 days with a sodium hydroxide content of 0.5; 1.0, 2 and 4 % had the strength of 20.3; 35.4; 45.6; 55.8 MPa, respectively. The effect of the combined presence of alkali and salt is especially noticeable for small amounts of sodium hydroxide. Binders containing a composition of cement with salts under normal conditions and after curing showed a slightly lower strength than in an alkaline medium. With a constant cement content (4 %), the strength indicators increase with an increase in the proportion of the salt additive, reaching at 4 % its maximum value. The effect of the nature of activators on pH was determined. The data obtained indicate the advantages of using PSB and various industrial wastes with a low content of alkaline compounds in the production

Assessment of morphological characteristics and physico-mechanical properties of geopolymer green foam lightweight aggregate formulated by microwave irradiation

This research work was as alkaline activator as well as foaming agent, however, small amount of sodium hydroxide (1%) and 1–2% sodium bicarbonate (NaHCO3) were also used. Nine types of green FLWA pellets were formulated by varying the proportions of foaming agent and sodium bicarbonate and all pellets were cured in instantaneous thermal irradiation of microwave oven for only 5 min. After foaming in microwave, characterization of porous green FLWAs were assessed; large pores (up to 7 mm) at cross section of pellet, expansion (up to 30%) and weight reduction (up to 30%) were observed with the increase in the amount of foaming agent, whereas apparent density reduced. Water absorption was slightly higher than the recommended ACI values due to internal porous structure of FLWA. However, high particle crushing strength (1.11 MPa) was observed for pellets with 54% foaming agent and 1% NaHCO3, therefore this optimized ratio of FLWA mix was selected for casting green lightweight concrete (LWC). Density, compressive strength, flexural strength, and sorpitivity were evaluated and it was observed that density was within acceptable range as specified by ACI for LWC. Flexural strength was also high (4.29 MPa) and showed strong potential to be used as panels of false ceiling for insulation. Sorpitivity results were also consistent with the performance of green FLWA. Therefore, adopted curing technique can be considered as rapid and sustainable solution for formulation of green FLWA and recommended to be applied at industrial scale for reducing dead load of structure.

Developing chlorine-based antiseptic by electrolysis

The use of Alcohol-based antiseptics is efficient and approved, however it has some limitations. This paper examined the possibility of using hypochlorite water as a chlorine-based antiseptic for handwashing in public buildings and healthcare facilities. The electrolysis method was used, which produces Hypochlorous acid (HOCl) from mixing drinking water with small amounts of sodium hydroxide. Hypochlorous acid is usually produced by blood cells to surround pathogens when the skin is cut and exposed to pathogens. The methods used were based on hydrolysing drinking water at a different salt concentration (from 0 up to saline water 0.9% NaCl) under the different power supply. The results showed that 0.005–0.01% hydrochloride water can be a perfect antiseptic that can kill most bacteria and pathogenies within 12 s. In one prototype set up one litter of the prepared solution needed the only 2 g of NaCl, 12 V and 3 amps' power. However, the pH value should be maintained to be around 5–6. The results also showed that the most efficient way was to produce the solution on-site. However, if stored properly it can be used for 7–10 days after production.

Production of biodiesel from castor oil using sub and supercritical ethanol: Effect of sodium hydroxide on the ethyl ester production

The biodiesel obtained by the reaction of castor oil with ethanol under sub and supercritical condition (200–350°C at endogenous pressure) using small amounts of sodium hydroxide (NaOH) as catalyst was studied. The influence of the operating variables such as temperature, reaction time, ethanol:oil molar ratio and catalyst concentration (when used) on the reaction yield was evaluated using a statistical design of experiments along with the surface response methodology for both the catalytic and non-catalytic processes. It was observed that using only 0.1% wt of NaOH for the catalytic process, amount smaller than the necessary to neutralize the castor oil, it was possible to obtain high yields. The maximum ethyl ester yield reached was 98.9% for the catalytic process and 56.2% for the non-catalytic process. Additionally, the reaction kinetic was determined and it was found that a pseudo first order model represents the overall reaction. Activation energies were calculated from the Arrhenius equation for both processes.

Synthesis and Properties of Lightweight Geopolymer using Ash from Thermal Power Plants

A lightweight inorganic polymer is obtained using ash from thermal power plants, metakaolinite and lightweight aggregate. This inorganic material is activated using small amounts of sodium hydroxide and sodium silicate solution. Processing parameters and various curing conditions, such as curing temperature, curing time and moisture, are investigated. Compressive strength, rate of water absorption and density of each sample were measured.

A phytoreduction route for selective synthesis of highly stable Ag and Ag:AgCl hybrid nanocolloids

Ag and Ag:AgCl hybrid nanocolloids with excellent stability are selectively synthesized using a room-temperature, aqueous-phase and phyto-reduction approach. The extract of Vernonia anthelmintica (L.) wild seed acts as both a reducer and stabilizer. It also provides a slow-release chlorine resource for the formation of AgCl. A small amount of sodium hydroxide switches the products between Ag and Ag:AgCl nanocolloids. The introduction of NaOH can greatly enhance the reducing ability of organic reducing agents derived from the extract, e.g., phenolics, thus giving rise to complete reduction of AgCl into Ag. Meanwhile, phenolics and vernolic acid-derived carboxylate offer highly effective stabilization to the synthesized nanocolloids. Our approach represents a selective and green synthetic route for Ag-based nanomaterials, and the highly stable Ag and Ag:AgCl nanocolloids should have promising applications in various fields, such as biomedicine and sensors.

E204 エポキシ樹脂製ボンド磁石からのネオジムの回収(OS3 バイオマス・新燃料・環境技術)

Bond magnet, which is made of neodymium powder and epoxy resin, is widely used electric device. However, recovery and reuse of neodymium from the bond magnet is difficult, because neodymium magnet property deteriorate by high temperature treatment. In this work, liquefaction of the bond magnet was carried out in some solvents with small amount of sodium hydroxide at 200-220℃ for 180min. The bond magnet was almost completely liquefied in methylbenzylalcohol. These experimental results suggest that recovery of neodymium powder from the waste bond magnet is feasible by liquefaction at enough low temperature to give no influence to magnet property.

Preparation of surfactant-free vinyl polymers by conventional emulsion polymerization using hydrolysable emulsifiers

Emulsion polymerizations of several vinyl monomers, styrene, methyl methacrylate, butyl methacrylate, butyl acrylate, and vinyl acetate, in water using alkali–hydrolysable cationic surfactants with a betaine ester group (1-alkoxycarbonylmethyl)trimethylammonium chlorides, as emulsifiers were carried out and properties of the resulting latices and the polymers recovered by hydrolysis and salting out were investigated. There were little influences of the surfactants and monomers used here on the polymerizations, forming stable and monodisperse latices with a mean diameter of ca. 70 nm and giving a high molecular weight of polymers at high yields. All polymers were precipitated and recovered by adding a small amount of sodium hydroxide into the latex solutions contained little amount of ionic species. Solvent-cast films of the polymers were found to have surfaces as hydrophobic as those for the corresponding pure polymers prepared by bulk polymerization.

Synthesis and Characterization of Silver–Platinum Bimetallic Nanowires and Platinum Nanotubes

A galvanic replacement reaction was used to prepare silver–platinum bimetallic nanowires and platinum nanotubes. Silver nanowires, prepared by boiling aqueous silver nitrate with sodium citrate in the presence of small amount of sodium hydroxide, were used as the sacrificial template in the galvanic reaction to prepare silver–platinum bimetallic nanowires and ultimately hollow platinum nanotubes. The resulting nanomaterials are stable and can be isolated without core aggregation or decomposition. These new materials have been characterized by transmission electron microscopy, energy dispersive X-ray analysis, and inductively coupled plasma atomic emission spectroscopy.

Bleaching of Cotton Fabrics by Hydrogen Peroxide with Metallic Ion

In order to establish the bleaching method for cotton fabrics under the neutral or acid condition, the cotton fabrics were pretreated by iron(II) sulfate before subsequent hydrogen peroxide bleaching. The white index and tensile strength at break for yarns from bleached fabrics were measured and considered concerning the pretreated condition by iron(II) sulfate. It was revealed that the high white index attained, by contraries, tensile strength for yarns decreased ca. 20% by processing. However, an addition of a small amount of sodium hydroxide into bleaching bath enabled to depress a decrease of tensile strength for yarns. In addition, it was observed by ESR measurement that an amount of radicals increased when a small amount of NaOH was added into hydrogen peroxide solution in the presence of iron (II) sulfate.

Transition from brittle to ductile behavior of fly ash using PVA fibers

In this study, short polyvinyl alcohol (PVA) fibers are employed to improve the mechanical properties of brittle fly ash samples, which are solidified by a small amount of sodium hydroxide (NaOH) and by a hydrothermal hot-pressing process. The mechanical properties of the PVA fiber reinforced fly ash composites are evaluated by splitting tensile test. Several key factors such as fiber content, processing temperature, and processing duration are investigated. The effect of different types of fly ash (Class C vs. Class F) is also studied. The experimental results demonstrate that the addition of short PVA fibers can significantly improve the ductility of the fly ash composites. The optimum fiber volume content is estimated to be 1.0% with Class C fly ash.

Synthesis of 3-buten-1-ol from 1,4-butanediol over ZrO 2 catalyst

Dehydration of 1,4-butanediol was investigated over ZrO 2 at temperatures of 325–375 °C. Modification of ZrO 2 with a small amount of sodium hydroxide greatly enhanced the selectivity to 3-buten-1-ol. Temperature-programmed desorption of adsorbed NH 3 and CO 2 elucidated acidity and basicity of the catalysts, respectively. The number of acidic sites on the ZrO 2 decreased with increasing Na content, and disappeared at Na content of 1.0 mol%, whereas the number of basic sites increased with increasing Na content. In the relationship between Na content and the selectivity to products, selectivities to tetrahydrofuran and γ-butyrolactone simply increased with the number of acidic and basic sites, respectively. However, the selectivity to 3-buten-1-ol was maximized at an appropriate Na content. 3-Butan-1-ol is possibly formed by acid–base-concerted catalysis of monoclinic ZrO 2 in the dehydration of 1,4-butanediol.

New building materials from fly ash-based lightweight inorganic polymer

A lightweight inorganic polymer is produced from Class F fly ash, metakaolinite and lightweight aggregate. This inorganic material is activated using small amounts of sodium hydroxide and sodium silicate solution. Processing parameters including the amounts of chemical activator and various curing conditions, such as curing temperature, curing time and moisture, are investigated. Compressive strength, water absorption rate and oven-dry density of each sample are measured and compared against the specifications of ASTM C90.

Size-Controlling Synthesis of Narrowly Distributed Particles of Methylsilsesquioxane Derivatives

Emulsion polymerization was used to prepare methylsilsesquioxane derivatives with an average particle size of 0.2−5.0 μm and various topological morphologies. Particles with an average particle size of 0.2−2.0 μm were prepared by emulsion polymerization using close to the critical micelle concentration of a nonionic emulsifier and a small amount of sodium hydroxide as a catalyst, whereas particles with an average particle size of 2.0−5.0 μm were obtained by suspension polymerization using a small amount of sodium hydroxide as a catalyst. Aggregation between the obtained particle colloids was not observed with the addition of an anionic emulsifier to the colloid solution at the earliest point in particle growth. A nonionic or cationic emulsifier was not effective, since the adsorption or diffusion of anionic emulsifier onto the particle colloids was accelerated due to the plus ζ potential of their surfaces.

A facile preparation of spherical methylsilsesquioxane particles by emulsion polymerization

Spherical methylsilsesquioxane particles with an average diameter of 0.3–1.0 μm were prepared by an emulsion polymerization technique using a non-ionic emulsifier and a small amount of sodium hydroxide as a catalyst. Aggregation of the particles was not observed at critical micelle concentration.

An unusual mechanism of airbag injury

An airbag mounted within the steering column of a car is an increasingly common safety feature in new motor vehicles sold in the UK. Together with the three-point lap-shoulder seatbelt it improves the level of protection for the driver in the event of a frontal collision. An airbag is intended to be a supplemental. It is triggered by a frontal impact within 30 degrees of each side of the head-on position, when an electronic crash sensor detects a sudden deceleration from a speed of over approximately 20 miles/h (32 km/h). If the sensor's crash conditions are satisfied then the inflator is fired. This is a pyrotechnic device containing sodium azide which on ignition produces a large volume of nitrogen gas, which then inflates the airbag up to a volume of 40 l (Eurobag design) or 70 l (full size) within 50 ms. The 'leading edge velocity' of the bag during deployment is between 46 and 184 mph but should be zero at the time of contact with a normally positioned driver. Evidence is accumulating to demonstrate that, with the airbag, overall mortality and serious injuries have been reduced, but there has been a new spectrum of injuries as a result of its deployment. Thermal injuries from the hot gases generated during firing, a chemical keratitis produced by the talcum or corn starch used to lubricate the neoprene surface or by a small amount of sodium hydroxide during sodium azide combustion, and the shearing forces produced by the 'punch out' of the bag are now well described, although uncommon. A case is reported in which the collision dynamics resulted in the driver being in close proximity to the steering column at the time of the bag's deployment.

The contact charge transfer absorption spectrum of dimethylsulphoxide with oxygen

Dimethylsulphoxide (DMSO) produces a strong ultraviolet contact charge transfer (CCT) absorption band with oxygen (O 2) with an intensity directly proportional to the partial pressure of the applied O 2 and the mole percentages of DMSO in a DMSO/acetonitrile solvent mixture. The CCT absorption spectrum is similar to, but much weaker than, that of the superoxide (O 2 −) ion in DMSO. Superoxide ions are also produced by adding a small amount of sodium hydroxide (NaOH) to DMSO. Electron spin resonance spectroscopy confirms the presence of O 2 − ions in a 5 mmol dm −3 NaOH, 1% (v/v) water in DMSO solution but no spectrum is observed in an oxygenated DMSO solution at 77 K.