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The effect of Nickel (Ni) doping on Zinc Oxide (ZnO) nanoparticles to photocatalytic activity Congo Red (CR) dye has been studied using the coprecipitation method. ZnO(1-x)Ni(x) with various concentrations of x=0 wt %, 5 wt %, 6 wt % and 7 wt % was prepared by sodium hydroxide as a precursor. For the characterization of Ni-doped ZnO nanoparticles, we used FTIR (Fourier transmission infrared) spectroscopy to investigate the functional group of the nanoparticles. The absorption of the samples was recorded in the range of 500 – 4000 cm. The bandgap energy of ZnO nanoparticles decreased with increasing Ni concentration. The photocatalytic experiment reveals that the percentage of degradation of Congo-Red in which the presence of Ni-doped ZnO (Ni 6%) in the solution increased significantly by 98.76% after irradiation at 45 minutes. The increase in the diameter of the inhibition zone along with the increase in the concentration of Ni-doped ZnO nanoparticles with varying concentrations of ZnO0.95Ni0.05, ZnO0.94Ni0.06, ZnO0.93-Ni0.07 with Staphylococcus aureus and Escherichia coli bacteria indicated the presence of significant antibacterial activity of Ni-doped ZnO nanoparticles. [ABSTRACT FROM AUTHOR]

Using the methods of XRF, XRD, and low-temperature adsorption-desorption of nitrogen, the physicochemical characteristics of granular LSX zeolites like in many cation-exchange forms were studied. A comparative analysis of their adsorption properties in static and dynamic modes with an industrial imported analogue was carried out. It is shown that the adsorption characteristics for nitrogen, CO2, water vapor and benzene of the synthesized granular LSX zeolite in the Li-form and the imported analogue are close. In this work proposed a method for synthesis of granular zeolite LSX in lithium form, involving synthesis of highly dispersed zeolite NaK-LSX; its blending and granulation with clay mineral from Troshkovsky region; drying in air atmosphere at T= 120-140 °C for 4-6 hours and calcining at 600-650 °C for 4-6 hours; treatment in a sodium hydroxide solution with a concentration of C(NaOH) = 70 g/l at 70 °C for 3 hours, followed by a three-fold ion exchange in a Lithium chloride solution. [ABSTRACT FROM AUTHOR]

Rice straw is a high potency agricultural waste that can be converted to biogas. The high lignin content of rice straw, which results in low biodegradability, still limits its utilization. This study sought to determine the effects of sodium hydroxide, an alkali pre-treatment, on the generation of biogas from rice straw. Sodium Hydroxide was diverse from 1%w, 3%w, 5%w, 7%w. Cow manure is also used in addition to rice straw to increase themethane concentration. The total weight of feedstock is 1 kg in 1:1 proportion. Sodium Hydroxide was varied from 1%w, 3%w, 5%w, 7% w. The rice straw was divided into 1 cm lengths and soaked in Sodium Hydroxide solution for 30 minutes. The amount of biogas produced was calculated using the water displacement method. The results showed that 5%w was the ideal concentration of sodium hydroxide solution, producing a 215 ml volume of biogas. The outcome reveals that rice straw lignin content can be significantly reduced with pre-treatment with sodium hydroxide solution. [ABSTRACT FROM AUTHOR]

Particle surface treatment is often used for particleboard production to improve adhesive adhesion. Several types of surface treatment are used, e.g. water immersion, cold plasma, and alkaline treatment. A 10% sodium hydroxide (NaOH) solution was used in this research. Scanning electron microscopy was performed to better understand the microstructure of the treated rape straw surface and glued joints. The use of sodium hydroxide leads to surface damage and the formation of microcrystals on the surface of the straw. Treatment with a 10% NaOH solution proved to be ineffective based on the resulting mechanical properties of the manufactured particleboards. [ABSTRACT FROM AUTHOR]

Fired bricks are widely used, which are energy-intensive, non-eco-friendly, and costly. Non-fired bricks with chemical stabilisers can be the alternative solution, which is a low-energy-intensive manufacturing product that cures at a low temperature and emits a lower amount of carbon dioxide. It is synthesised in the reaction of main raw materials, which are rich in alumina and silica, with second raw materials, which are a highly concentrated alkali activator solution. Clay can be the raw material for the synthesis of non-fired clay brick in sodium hydroxide solution and sodium silicate solution. Thus, this chemical stabilisation for manufacturing non-fired clay bricks is reviewed. As a result, the compressive strength and water absorption characteristics of the geopolymer brick are dependent on the Na2SiO3/NaOH ratio, water amount, curing temperature, and moulding pressure. As a step forward, the effect of organic content on making clay-based geopolymer brick would be investigated due to the presence of acid, which can impact the geopolymerisation process. Overall, optimal performance of non-fired clay bricks can be achieved by the optimum rate of the geopolymerisation process; formation of strong and dense cross-linking of the aluminosilicate gel microstructure; and high concentration of alkali solution. [ABSTRACT FROM AUTHOR]

Photocatalysis is a recently developed technique that may be used as a supplement or alternative to the current drinking water treatment procedure. Applications for photocatalysts include the treatment of wastewater, antifogging, sterilization, deodorization, antifouling, air purification, conservation and energy storage. The photocatalytic elimination of trace hazardous organic compounds in air and water has been the subject of several investigations; nonetheless, there are still certain concerns about their practical application. Nickel oxide (NiO) and Copper oxide (CuO) nanostructure has been prepared. Nanoparticles are essential to develop a wide range of impact industrial product. The characterization studies such as X-ray Diffraction (XRD), UV-Visible (UV-Vis), Fourier Transform Infrared (FTIR), Raman Spectroscopy and Scanning Electron Microscope (SEM) are used. It can be shown that the produced nanoparticles have significant photocatalytic activity in addition to having a great dispersion in dye solution. [ABSTRACT FROM AUTHOR]

Unplanned disposal of Industrial effluents in open lands is becoming a common practice in most developing regions, significantly impacting soil contamination. Alkali-contaminated soils witness behavioral changes based on the chemical concentration reaching the soil. Kaolinitic soils are more pronounced for their low swelling nature. Kaolinitic soils induce an unexpected swelling, which may not be observed with the changes in moisture content but due to chemical interactions. Alkali spills, leakages, and disposal of end solutions like caustic soda from industries into kaolinitic soil give rise to alkali-induced swelling. In the present work, a kaolinitic soil, i.e., red earth, is chosen for studying its behavioral changes by contaminating with the different concentrations of NaOH (0.1 N, 1 N, 4 N, and 8 N), which is alkaline in nature. The red earth mixed with NaOH solutions and different properties of soil are evaluated. The liquid limit and plasticity index values increased by a maximum percentage of 30.1 % and 33.19 % for red earth with 1 N NaOH compared to red earth with distilled water. In comparison with OMC and MDD values of red earth with distilled water, the OMC values of red earth with 1 N NaOH increased by 25%, and the MDD value decreased by 5.64 %. The UCS value increased by a maximum of 28 % with 4N NaOH. The red earth showed a maximum free swell of 19.15 % when inundated with 1 N NaOH, and the value dropped to 9.28 % with 8 N NaOH. [ABSTRACT FROM AUTHOR]

Rambutan can be potentially employed as sugar source during the production of curdlan by Agrobacterium sp. ATCC 31479. In this study, Agrobacterium sp. ATCC 31749 was grown in the production medium supplemented with 10%, 20% and 40% concentrations of Rambutan Juice as the sugar source. The curdlan was extracted via sodium hydroxide and acetic acid precipitation followed by Fourier transform infrared (FTIR) spectroscopy analysis. At 20% concentration of Rambutan Juice, the Agrobacterium sp. ATCC 31479 showed highest curdlan yield of 13.65 mg/mL. The optimization of curdlan production in bioreactor showed the highest curdlan yield was 6.2 mg/mL after 7 days. The results suggest rambutan could be employed as the alternative sugar source in microbial production of curdlan. [ABSTRACT FROM AUTHOR]

Excessive load is a significant factor contributing to building collapse during earthquakes. To mitigate this risk, lightweight and resilient materials are essential, and partition boards, commonly used for walls, offer a solution with their low mass. However, most current partition board materials are non-renewable, negatively impacting the environment. This study introduces an environmentally friendly partition board innovation that addresses these concerns. It utilizes waste bamboo fiber and locally available blood cockle shells, combined with basalt powder and water activated by alkali activators like sodium hydroxide (NaOH) and sodium silicate (Na2SiO3). These materials offer high quality, ease of production, and environmental sustainability. The research involved three composition variations, with evaluation based on physical properties, mechanical properties, and heat resistance. According to standards (SNI 03-2104-1991 and JIS A 5417-1992), the results classify this innovation as a high-quality, environmentally friendly, and renewable material. This innovation effectively addresses excessive load concerns while promoting environmental sustainability in construction. [ABSTRACT FROM AUTHOR]

For the import substitution of sodium sulfide, which is necessary for the industries of the republic, a new method and technological scheme, as well as the necessary equipment, have been developed. As a result, the cost of the products obtained has been reduced due to the available local cheap feedstock of sodium hydroxide and hydrogen sulfide, which is an impurity of the produced natural gas, and the simplification of the technological scheme of the equipment used. [ABSTRACT FROM AUTHOR]

Sodium hydroxide (NaOH) or known as caustic soda is a type of caustic metallic base that is available in liquid or solid form. Many industries highly require caustic soda as the main raw material or supporting materials such as the paper and pulp industry, soap and detergent industry, oil and gas industry, alumina processing, etc. National demand for sodium hydroxide reaches 987 million tons in the last year. To encourage increased production of caustic soda to support the chemical industry in Indonesia, a techno-economic analysis is required for the production of caustic soda to fulfill the supply. Therefore, in this study, the design of the NaOH plant process will be studied according to the product specifications and its economic analysis. The design of the caustic soda plant process has been developed based on membrane technology with a capacity of 100000 tons of product per year using SNI industrial salt raw materials. The product specification from this plant is 50% NaOH solution and HClO solution as byproduct. With this capacity, the estimated investment for the caustic soda plant is around US$ 44.45 million and its operational cost is around US$ 67.93 million per year. Using the current price of raw materials and products, the net present value (NPV) is US$ 206.58 million, the internal rate of return (IRR) is 40.75%, and its payout time (POT) is 4 years and 7 months. Based on these parameters, the design of the developed caustic soda plant was technically and economically feasible. [ABSTRACT FROM AUTHOR]

Recovery of rare earth element from acid mine drainage has been extensively explored worldwide as it can be potential alternative sources in the future. Malaysian acid mine drainage was previously considered as a liability to mining industry due to the environmental issue but found to be new potential asset for the country soon. The main objective of this work was to conduct a preliminary study on recovery process of rare earth element from Malaysian acid mine drainage. AMD is sampled from iron ore areas which containing significant amount of pyrite and contained 1.84 ppm of total rare earth elements, 61.71 ppm Fe, 49.53 ppm Al and 35.62 ppm Mn. The pH value of acid mine drainage was controlled in narrow-range by using sodium hydroxide solution to conduct selective precipitation process. Selective precipitation of acid mine drainage from pH range of raw sample till pH above 12 was conducted in this study. Further separation process of precipitated rare earth element was conducted via re-dissolution and oxalic acid precipitation process in this study. A simple process flow for recovery of Malaysia acid mine drainage was developed as baseline study in order to enhance the recovery efficiency in the future. [ABSTRACT FROM AUTHOR]

A study has been undertaken to investigate the possibility of producing foamed fly ash based geopolymer concrete by adopting the pre-formed foam method. Mixes with a density of 1000 kg/m3 were designed and produced. Molarity value, sand fineness, fly ash type, sodium silicate solution (SS)/ sodium hydroxide(SH) ratio and viscosity of sodium silicate solution (SS) were investigated as factors affecting the production of foamed geopolymer concrete. From the experimental work, among these several investigated factors; it was found that the viscosity of sodium silicate solution (SS) is the crucial factor affecting the production process i.e. producing mixes without the issue of solid materials segregation. In addition, it was noticed that the mix made with only sodium hydroxide(SH) as an activator was produced successfully without segregation issue. However, its strength was less than that of mix made with the combination of the sodium silicate solution (SS) and sodium hydroxide solution (SH) as activator by about 60%. The compressive strength of foamed geopolymer-based fly ash type F was greater than that of foamed geopolymer-based fly ash type C by about 118%. [ABSTRACT FROM AUTHOR]

In this work, NiO nanoparticles were produced at low temperatures via thermal decomposition of freeze-dried Ni(OH)2. Ni(OH)2 precursor was first synthesized from nickel chloride and sodium hydroxide solution using precipitation method then was freeze-dried to powder form. For comparison purposes, the precipitate was also dried using conventional oven. The resulting Ni(OH)2 precursors were then calcined at 200 °C and 350 °C to form NiO nanoparticles. Thermal decomposition of precursors was investigated using a thermogravimetric analyzer (TGA) while X-ray diffraction (XRD) and field-emission scanning electron microscopy with energy-dispersive X-ray spectrometry (FESEM-EDX) were employed to study the structural and morphological of the samples respectively. From the TGA result, the decomposition reaction of freeze-dried Ni(OH)2 to form NiO nanoparticles occurred at a very low-temperature range of 170 °C to 320 °C with 16% weight loss which is much lower compared to oven-dried sample. XRD result confirmed the formation of the cubic phase of NiO while the FESEM micrograph revealed the uniform spherical NiO nanoparticles with average particle size in the range of 17 to 19 nm. [ABSTRACT FROM AUTHOR]

In this work, NiO nanoparticles were produced at low temperatures via thermal decomposition of freeze-dried Ni(OH)2. Ni(OH)2 precursor was first synthesized from nickel chloride and sodium hydroxide solution using precipitation method then was freeze-dried to powder form. For comparison purposes, the precipitate was also dried using conventional oven. The resulting Ni(OH)2 precursors were then calcined at 200 °C and 350 °C to form NiO nanoparticles. Thermal decomposition of precursors was investigated using a thermogravimetric analyzer (TGA) while X-ray diffraction (XRD) and field-emission scanning electron microscopy with energy-dispersive X-ray spectrometry (FESEM-EDX) were employed to study the structural and morphological of the samples respectively. From the TGA result, the decomposition reaction of freeze-dried Ni(OH)2 to form NiO nanoparticles occurred at a very low-temperature range of 170 °C to 320 °C with 16% weight loss which is much lower compared to oven-dried sample. XRD result confirmed the formation of the cubic phase of NiO while the FESEM micrograph revealed the uniform spherical NiO nanoparticles with average particle size in the range of 17 to 19 nm. [ABSTRACT FROM AUTHOR]

Biofuels derived from biomass have been gaining more importance because it is renewable, easily available and biodegradable. Biodiesel obtained from vegetable oil are non-toxic, reduce emission and a promising alternative fuel for CI engine. Thus, present study relates the biodiesel used in this experimental work was prepared using mustard oil by transesterification process in which catalyst concentration (sodium hydroxide 3.5g, 4.5g, and 5.5g) was varied. Methyl esters obtained at different weight of catalyst showed different values such as viscosity and density was found to be 9.15 mm2/s and 876 kg/m3 in 3.5g of catalyst whereas 6.47 mm2/s and 814.4 kg/m3 in 5.5g of catalyst. The concentration of the catalyst and alcohol which affect the percentage of yield in the transesterification was studied and optimized, parameters such as viscosity, density, acid value and percentage of yield at different catalyst ratio was analysed. [ABSTRACT FROM AUTHOR]

Research on the utilization of natural fibres as sound absorption materials has shown tremendous growth across the globe. The capabilities of natural fibre as the replacement material for synthetic fibre sound absorbers have been proven by many researchers. However, due to several drawbacks, natural fibre needs to be treated, and alkaline pre-treatment using sodium hydroxide (NaOH) has become the most favourable method. The use of NaOH in the natural fibre pre-treatment varies depending on the type of natural fibre. This treatment leads to significant changes in the surface morphology as well as the physical characteristics of the fibre. This paper reviewed the usage of low and high NaOH concentrations during the pre-treatment of natural fibre. Their effects on the surface morphology, the diameter of the strand and sound absorption performance were observed and further discussed. Findings revealed that the differences in NaOH concentration and soaking duration during the pre-treatment affect not only the physical properties but also the sound absorption performance of natural fibre. NaOH pre-treatment using either low or high NaOH concentrations can eliminate most of the impurities such as the oil residue, waxes, and pectin from lignin, which is one of the outer structural layers of natural fibre. The use of higher NaOH concentration in the pre-treatment results in a much rougher surface on natural fibres and creates many micropores in palm-based fibres such as empty fruit bunches and coconut coir due to the elimination of silica bodies from the fibre. Increasing the surface roughness consequently increases the friction between sound waves and fibres, hence improving the sound absorption coefficient (SAC) values. Besides, higher NaOH concentrations also caused the diameter of the fibre to decrease, resulting in a thinner fibre. Hence, in the fabrication of any natural fiber composite, more fibre needs to be used in order to achieve the same volume, weight, thickness, and density of the composite. The use of more fibres results in a larger surface area and results in longer routes and more difficult airflow movement in the composite, which also allows more sound energy to be dissipated. Those factors improved the sound absorption performance of natural fibres as a sound absorber. [ABSTRACT FROM AUTHOR]

It is essential to reduce the environmental footprint of the construction industry. One approach to achieving this goal is to replace ordinary Portland cement (OPC) by alkali-activated cementitious materials such as ground granulated blast furnace slag (GGBS) and fly ash. This article presents the findings of an experimental study that evaluated water absorption characteristics, and initial/final setting times of mortar that uses alkali activated blend of GGBS and fly ash. It was found that the relationship between water absorption and square-root of time (t0.5) of mortar pore system for up to 6 hours of standard base immersion, is linear with high coefficient of correlation, for binders including alkali activated GGBS and fly ash. This is similar to the relationship that characterizes mortar with OPC binders. Sorptivity of mortar prepared with alkali activated GGBS binder decreased with increase in solution molarity as well as ratio of sodium silicate/sodium hydroxide at the age of 7 days. At the age of 28 days, GGBS-based mortar exhibited a decrease in strength of correlation between water absorption t0.5 in several mixes, when the molarity of NaOH activator is 12M or higher. The pattern persisted for GGBS-based mortar at the age of 90 days, but with more mixes experiencing decrease in strength of correlation (R2<0.98). Loss of linearity in GGBS-based mortar was attributed to shrinkage induced cracking. At the ages of 7 days and 28 days, mortar based on alkali activated 50% fly ash + 50% GGBS exhibited linear absorption relationship, except for high NaOH molarity of 16M, which indicates coarser mesh at higher solution alkalinity, along with shrinkage cracking. At the age of 90 days, mortars with 50% fly ash + 50% GGBS exhibited linear absorption relationship with high R2 value, indicating finer mesh, which was consistent in all NaOH molarities. Initial and final setting times were found to be strongly corrected to initial ratio of (Ca + Si)/Al established at mixing time. Setting time of mortar with high GGBS content (greater than 50%) was too short for many practical applications and a suitable retarder is necessary. [ABSTRACT FROM AUTHOR]

The heavy use of pineapple in a wide range of applications leads to the disposal problem of solid pineapple waste that is generated every year. In this study, an aqueous extract of pineapple wastes was utilized as a reduction agent for the fabrication of ZnO nanoparticles (ZnO NPs). The objective of this study is to reduce the high energy and chemical consumption during the synthesis of ZnO NPs. ZnO NPs were synthesized using extracts from pineapple peels and zinc acetate dihydrate. Sodium hydroxide was added to the mixture until it reaches the desired pH of 10. It was found that the reaction time and temperature have a significant influence on the size of ZnO NPs produced. The smallest crystallite size of the ZnO NPs was 22.18 nm which correlates the biggest surface area with reaction temperature at 60 °C and reaction time was 4 hours. Overall, this study demonstrated that pineapple waste has great potential to be used as a biological reduction agent in the green synthesis of ZnO NPs. [ABSTRACT FROM AUTHOR]

This study aims to develop a method for analyzing total ammonia levels in saliva using a card based on gas diffusion microfluidic paper-based analytical device (μPAD-Card). The total amount of ammonia in saliva can be an indicator of the oral microbiome status potentially correlates with gastric cancer problems, periodontal disease or to assess caries risk. The developed μPAD-Card contained 6 unit of detections, where each unit consisting of three rounded stack layers: sample layer (paper layer impregnated with sodium hydroxide solution), hydrophobic PTFE membrane layer for gas separation, and detection layer (paper layer impregnated with Caesalpinia sappan L extract). The six units were aligned on a transparent laminated film bag with hot lamination. The analysis process involved converting ammonium to ammonia gas in the sample layer, which then diffuses the ammonia gas through the gas permeable PTFE membrane to the detection layer, resulting in a color change in the natural acid-base indicator of Caesalpinia sappan L extract from yellow to purplish red due to changes in pH in the presence of ammonia. The colors formed on the detection layer were processed using Image J software to determine the RGB intensity. Operational and chemical conditions were optimized to achieve sensitivity and to test the selectivity and validity of the method. Optimum conditions were achieved under reaction time of 5 minutes, concentration of NaOH of 1 M, and concentration of the extract of 1 % w/v. The μPAD-Card method provided two linear regression equations of y = 0.2214x+33.759 (R2 = 0.9769) for total ammonia concentrations ranging from 0 mg/L to 40 mg/L, and y = 0.1091x+37.489 (R2 = 0.9831) for higher concentrations (40 mg/L to 100 mg/L) with respective LOD and LOQ values of 3.38 mg/L and 5.63 mg/L. The development of the μPAD-Card was successfully applied for the determination of ammonia levels in saliva samples. [ABSTRACT FROM AUTHOR]

Mix trials have been conducted in order to develop an effective GPC that provides maximal strength. By-products from industries such as calcined clay and GGBS (Ground Granulated Blast-Furnace Slag) can be used to substitute with cement for lowering carbon di-oxide (CO2) emissions and thereby reducing greenhouse gas emissions. Using the mentioned items reduces water demand in concrete and has practically nothing long-term impacts in concrete; therefore, these by-products may be efficiently employed in concrete manufacturing. GGBS and calcined clay were offered as substitutes for cement in the production of M30 geopolymer concrete. The Alkali concentrations of sodium hydroxide and sodium silicate were substituted with water for improved adhesion and mixing. The GGBS and Calcined geopolymer was made paste in this work using 10M sodium hydroxide solution. Bacterial concentration (105 CFU) of bacillus sphaericus bacteria was used during the mixing of concrete paste. Bacterial solution improved the mechanical properties of the geopolymer concrete. [ABSTRACT FROM AUTHOR]

Alkali activation of ground-granulated blast-furnace slag (GGBS) and calcined clay is a long-term solution for recycling industrial waste into geopolymer composites. The aim of this investigation is to develop ground granulated blast furnace slag (GGBS) and calcined clay based geopolymer mortar. Both GGBS and calcined clay are alumino silicates that are activated using alkaline activator. 8 M sodium hydroxide solutions are used to develop the alkaline activator. Consistency, setting time and compressive strength of geopolymer were investigated in respect to mixture proportioning and curing conditions at the age of 3, 7, 28 days. The percentage of calcined clay, GGBS, fines content and alkaline activator solution content were all examined process parameters. The experimental results showed that the consistency and setting time were enhanced with increased the percentage of calcined clay in geopolymer mortar. The maximum compressive strength is attained at 100% used of GGBS in mortar mix while increasing the percentage of calcined clay replaced with ggbs in the mortar mix compressive strength was reduced. [ABSTRACT FROM AUTHOR]

Tensile strength is an essential aspect of cement composites. The tensile strength of cement composites can be enhanced using various methods. Out of all the available methods, natural fibers improve the tensile resistance with a positive impact on the environment. Various natural fibers are in use, and they are chosen depending on availability. The present study aims to effectively use oil palm fibers extracted from palm oil trees. Palm oil industries are growing rapidly, and a vast amount of oil palm empty fruit bunch fibers are disposed of every day. The oil palm empty fruit bunch fibers can be used directly in cement composites or treated before usage for better performance. In the present study, the oil palm empty fruit bunch fibers (spikelet and stalk fibers) are treated with different sodium hydroxide (NaOH) solutions to improve their mechanical and durability properties. This study also focusses on the effect of treatment duration for different concentrations of sodium hydroxide solution. It was found that spikelet fibers treated using 5% NaOH solution with an immerse duration of 12 hours has improved the tensile resistance and water absorption properties compared to 3% and 10% concentrated NaOH solution. [ABSTRACT FROM AUTHOR]

The high demand for eco-friendly fibers as a reinforcement in composite materials applications has attracted the attention of researchers to develop new materials to replace the synthetic ones. Natural fibers have been used in materials composite due to its excellent properties and can be obtained from various resources but only several sources that have been widely and commercially used. Sansevieria plant is one of the natural fibers which has good thermal and mechanical properties. Researchers have been trying to investigate the performance of sansevieria fiber as a reinforcement material. The aims of this research were to extract cellulose fiber from sansevieria trifasciata plant and to study the effect of alkaline concentration on the chemical composition and the density of sansevieria fiber. The cellulose was extracted from sansevieria using sodium hydroxide solution at various concentrations during alkali treatment. The content of sansevieria fiber was determined using the Chesson-Datta method and confirmed the result by using FTIR characterizations. The density of sansevieria fiber was measured using a pycnometer. The highest yield value of sansevieria fiber was 84.2% and the lowest was 75.6%. The cellulose content was increasing as an increase in the sodium hydroxide concentrations during alkali treatment. The highest cellulose content of sansevieria fiber was 61.5% using a concentration of 17.5% sodium hydroxide. The decrease of non-cellulosic contents due to alkali treatment was confirmed through the FTIR spectrum. The density of sansevieria fiber was decreasing as an increase in sodium hydroxide concentrations during the alkali treatment process. The concentrations of sodium hydroxide solutions affect the yield, the chemical composition, and the density of sansevieria fiber. [ABSTRACT FROM AUTHOR]

Since the onset of the COVID-19 pandemic, soap has become an important ingredient because it can cleanse the body of bacteria or viruses. Therefore, the purpose of this study was to see how the addition of citronella oil affects the final product of trasparent soap. VCO, sodium hydroxide, stearate, glycerin, ethanol, sugar, cocoamide DEA, citric acid, and varying quantities of citronella oil, 0, 1 and 2 percent, are among the materials used to manufacture transparent soap. Citronella oil was obtained by extracting 125 g of lemongrass in 250 ml of ethanol under reflux for 3 hours and evaporating to separate the solvent from the citronella oil. The parameters of transparent soap measured were water content, free alkali, and pH. As a result, the optimum amount of citronella oil additive was 1%, the water content was 11, 0.04% free alkali, and the pH was 10.5. In addition, the quality of the resulting transparent soap meets the SNI standard for solid soap no. 3532-2016. The addition of citronella oil produces transparent soap, which has better anti-bacterial and fungal properties and a more fragrant smell when compared to transparent soap without citronella oil. [ABSTRACT FROM AUTHOR]

Rice Bran Oil (RBO) is an oil derived from the outer layer of rice grains, which has many health benefits. However, it's has been recognized to be difficult to refine due to the high content of free fatty acid, unsaponifiable matters, and color. Therefore, the present study was conducted to evaluate the quality and oryzanol content during the crude RBO refining process. Crude RBO was obtained by the reflux method using n-hexane as a solvent, followed by the dewaxing process by cooling and filtering procedure. The degumming process was carried out by adding phosphoric acid 1.5%; 3% and 4.5% (v / v), respectively, and the deacidification process was performed by adding 4.5% (w / v) sodium hydroxide. The refined RBO quality was evaluated visually and the oryzanol content was determined by TLC-densitometry. The extraction process was yielded by 15.6 ± 0.01%. (w / w) of crude RBO. There was a loss of oil weight of 17.74%, 5.67%, and 10.27% after the process of dewaxing, degumming (phosphoric acid 1.5%, 3%, and 4.5%), and deacidification (NaOH 4.5%). TLC densitometry indicates the presence of compounds in crude RBO and RBO that have been degummed (phosphoric acid 1.5%, 3%, and 4.5%), but after deacidification (NaOH 4.5%), there was no oryzanol found. [ABSTRACT FROM AUTHOR]

The availability of abundant rubber seeds and not being used by the wider community is something that must be found a solution. Rubber seeds can be processed into biodiesel oil as alternative energy. Currently, renewable alternative energy is urgently needed as a substitute for non-renewable energy such as oil and coal. The purpose of this study was to determine the effect of variations in the mixture of methanol and caustic soda as a catalyst in rubber seed oil (Hevea brasiliensis). The tests carried out were droplet combustion to determine flashpoint, ignition delay time, burning rate, and visualization of fire at atmospheric pressure. Variations of the mixture (catalyst: methanol) used were: 0 gram : 0%; 0.25 grams : 10%; 0.5 grams: 20% and 0.75 grams: 30%. Variations of this mixture were prepared in 5 ml of rubber seed oil per sample. The addition of mixed variations affects droplet combustion where the flashpoint and ignition delay time increase continuously. The burning rate value decreased due to the length of time the burning occurred. The burning rate value also affects the height of the burning fire, this is indicated by the dominant yellow flame color. The increase in the percentage of the catalyst mixture with methanol causes a higher flame. Burning time caused by mixing caustic soda with rubber seed oil resulted in an increased in viscosity. [ABSTRACT FROM AUTHOR]

This research was conducted to determine the optimum conditions for the synthesis of sodium silicate from natural silica. Sodium silicate is a silicate compound that is widely used as a basic material in various industries. Characterization of the resulting sodium silicate was carried out using FTIR, XRD and SEM instruments. The basic material for the synthesis of sodium silicate is natural silica. Natural silica is activated first using 1 M HCl. Then the activated natural silica is reacted with NaOH to form sodium silicate. Characterization using XRF showed that the synthesis of sodium silicate was more effective at high temperatures. Determination of the optimum conditions for silica synthesis was carried out at a concentration of 4 M NaOH with variations in melting time (10, 20, 30, 40 and 50 minutes), as well as variations in melting temperature (300, 400, 500 and 600°C). Based on the research that has been done, the optimum condition for the synthesis of sodium silicate is the addition of 4 M NaOH concentration with a melting temperature of 400°C for 30 minutes. [ABSTRACT FROM AUTHOR]

Currently, the production of bioethanol based on oil palm empty fruit bunches (OPEFB) has been utilized to obtain high chemical content such as cellulose, hemicellulose, and lignin. However, it is not easy to produce bioethanol from lignocellulosic biomass waste; it needs to go through several stages of methods. For this reason, bioethanol production is focused on applying a simple method using sulfuric acid during the OPEFB pretreatment process and followed by the saccharification and co-fermentation (SScF) simultaneously. Based on these results, it was found that 6% sulfuric acid was the optimum concentration for the OPEFB pretreatment process. The effective recovery for xylose and acetic acid was 39.70% and 2.73 g/L, respectively. In addition, it was also found that the use of 10% sodium hydroxide was effective in increasing the purity of the cellulose residue by up to 30.65%. In this work, the best bioethanol yield was 42.42 g/L; this was obtained during the fermentation time of 48 hours. [ABSTRACT FROM AUTHOR]

In the manufacture of bioethanol made from lignocellulose, lignin content becomes the main inhibitor in the conversion of bioethanol. Cellulose is coated by lignin making it difficult to hydrolyzed into glucose. Therefore, pretreatment of lignocellulose raw materials is required. Pretreatment aims to separate the bond between lignin and cellulose (delignification), eliminate the content of hemicellulose and lignin, damage the crystalline structure of cellulose and increase the porosity of the material. The damage to the crystal structure results in cellulose easily decomposing into glucose. Furthermore, the sugar compounds will be fermented by microorganisms into ethanol. Control variables are the amount of rice husks (100 g), pH hydrolysis (4-5 hrs), while the research variable is the type of pretreatment solution (NaOH and NH4OH), soaking duration (1-7 hours), and the concentration of the pretreatment solution (3-17%). While observed parameter are changes in lignin and cellulose contents. The results showed that the higher the concentration of pretreatment solution, the smaller the remaining lignin obtained, and the greater the cellulose content obtained but the pretreatment with NH4OH resulted in greater content of cellulose compared to pretreatment with NaOH. This is because NH4OH solutions are more selective in eliminating lignin and do not dissolve β-cellulose and γ-cellulose. [ABSTRACT FROM AUTHOR]

Natural fiber composites are very environmentally friendly because they can be degraded naturally and also the price of natural fibers is cheaper than synthetic fibers. The importance of pre-treatment of the fiber because it can increase the mechanical strength of the fiber itself. One of the pretreatments for fiber is to perform an alkalization process, including soaking the fiber in a solution of Sodium Hydroxide (NaOH) and the concentration of NaOH affects the mechanical strength of the fiber. So this study aims to determine the effect of NaOH concentration on the alkalization process on the mechanical strength of rice straw fiber (RSF). The stages of this research were soaking RSF in NaOH solution with concentrations of 2%,3% and 4% for 60 minutes and without treatment, then washing with distilled water, drying at room temperature for 7-8 days, making a single fiber tensile test sample and testing and analysis of fiber morphology structure with Scanning Electron Microscope (SEM). The results showed that the effect of 4% NaOH treatment on rice straw showed a maximum tensile stress of 82.23 MPa, a strain value of 28.2% and an elastic modulus of 291 MPa. SEM results showed that at 4% concentration of alkali treatment, fiber surface roughness, tears and small holes on the RSF surface showed that impurities were removed including lignin, resulting in increased fiber absorption. This can facilitate the absorption of the matrix against the fiber in composite manufacturing applications. [ABSTRACT FROM AUTHOR]

The research included preparing activated carbon from apricot seeds. Activated carbon in this way was distinguished by its good quality in terms of its high surface area and Its pH is neutral. Activation was carried out using varying proportions of sodium hydroxide. Physical and chemical tests were performed.. Physical and chemical tests have been carried out for the prepared samples, including determination of low density, low ash content, iodine number (I.N), external surface area measurement by adsorption of methylene blue dye from its aqueous solution, ash content and moisture measurement. [ABSTRACT FROM AUTHOR]

Converting empty fruit bunch (EFB) fibers into a solid fuel through briquetting process has been actively explored due to its potential as renewable energy fuel. However, briquetting process required the addition of a binder as a solution in upgrading the briquette properties. In this study, carbonized EFB fibers was blended with different type of organic and inorganic binders at composition of EFB fibers to binders solution (water/binder) with ratio of 100:110/20. Organic binders used are tapioca starch and corn starch, while calcium hydroxide and sodium hydroxide represent inorganic binders. Blended materials were then manually compressed in a cylindrical mould for 10 minutes. The compressive strength, proximate properties and combustion characteristics were investigated to evaluate the effects of different types of binder on the briquette properties. Results showed that carbonized EFB briquette blended with tapioca starch had the best physical and chemical properties compared to others. Furthermore, the combustion rate of these briquette generate heating value up to 23.62 MJ/kg which indicate it has potential to be applied as good solid fuel and later to produce gas with less tar content. It was also observed that the type of binder influenced the combustion characteristics of the carbonized EFB briquette. [ABSTRACT FROM AUTHOR]

This study includes the preparation of multi-walled carbon nanotubes (MWCNTs) by hydrothermal method at temperature about 200 ͦ C. The starting materials are ferrocene and sulfur with sodium hydroxide as a reducing agent. The purification process of prepared MWCNT is carried out by using nitric and sulfuric acids as long as hydrogen peroxide and acetone. The structural and optical properties of MWCNTs are investigated by the FT-IR, TEM, XRD and UV-VIS characterization techniques. The d-spacing is 3.42 Ǻ from XRD, the bandgap about 4eV to 3.7eV from optical calculation, the average ID and OD are respectively, 34nm and 52nm from TEM measurements with the length of (0.7-1)µm. [ABSTRACT FROM AUTHOR]

This paper presents the compressive strength of zeolite-based geopolymer paste produced with various alkali to zeolite (A/Z) ratio of 0.4-0.7; and curing temperature (60°C and 80°C for 24 h) with sodium hydroxide (Na0H) molarity of 8 M. Specimens were tested for compressive strength after 28 days in ambient temperature. The test results showed that A/Z and curing temperature significantly influenced the compressive strength values. The optimum compressive strength was achieved with A/Z ratio of 0.5 and cured at 60° which is about 18.34 MPa. The zeolite-based geopolymer paste prepare in this study can be used for structural components from compressive strength viewpoint. [ABSTRACT FROM AUTHOR]

Synthesis of dansyl aziridine has been conducted. The aim of this study is to synthesize a fluorescent compound that would play an important role in chemical sensor, in which this compound is a dansyl aziridine. The target compound was prepared by reacting dansyl chloride with an aziridine available in solution, which is produced previously from the reaction of 2-Aminoethyl hydrogen sulfate with Sodium hydroxide. The product of the synthesis was analyzed with NMR Spectrophotometer to assess the NMR spectra and determined the melting point as well as conducted elemental analysis. Based on the results of characterizations of the product compared to the references, it is apparent that dansyl aziridine has been successfully synthesized giving 71% as a yellow solid. [ABSTRACT FROM AUTHOR]

The Bi-Zn binary system was investigated using wet chemical synthesis. Obtained results were applied to knowledge for lead-free solder materials with low melting elements as Bi and Zn. This synthesis between salts of elements and sodium hydroxides was used to prepare the solders. Different analysis was used for investigation of the system. Quantity of Bi and Zn were determined in the mixtures. The samples were synthesized at two pH ranges. With stoichometri quantity sodium hydroxides and after that with sodium hydroxides 10 percent less. [ABSTRACT FROM AUTHOR]

In this work we analyze the production of chlorine and caustic soda by the method of diaphragm electrolysis. The production of chlorine, hydrogen and electrolytic alkali is a dangerous process, accompanied by unfavorable conditions in the working area, and the raw materials and the resulting products are toxic to people, so it is necessary to exclude the influence of the human factor on the production process. In the existing management system, much attention is paid not only to the regulation of technological parameters, but also to the management of quality indicators of the control process, technical and economic efficiency. To get better products, it is necessary to improve the process control algorithms. In this regard, to optimize the process, the article presents the development of a mathematical model of an automated control system for the production of diaphragm electrolysis. The output variables are the current output, the NaOH concentration, the volume fraction of Cl2 in electrolytic chlorine, the volume fraction of H2 in electrolytic chlorine, the volume fraction of H2 in electrolytic hydrogen, and the volume fraction of O2 in electrolytic hydrogen. [ABSTRACT FROM AUTHOR]

In process fluids extracted from oil-bearing horizons, a significant amount of corrosion-hazardous components, such as salt ions, dissolved gases, mechanical impurities and microorganisms, often cause the destruction of oil and gas equipment. The greatest danger to low-alloy steel is acid gases - carbon dioxide and hydrogen sulfide. The simultaneous presence of carbon dioxide and hydrogen sulfide in the water-oil emulsion leads to the development of local corrosion processes due to the formation of soluble corrosion products - iron hydrogencarbonate. Therefore, one way to prevent the development of electrochemical corrosion is to neutralize the acidic components of the process medium. Alkaline solutions, including sodium hydroxide, are used as neutralizer of acid components of oil. As a result of the neutralization reaction, salts are formed. The presence of sodium salts in oil can cause disruption of the process of its further processing due to contamination of the obtained oil products and catalysts. Therefore, application of the method of non-reactive neutralization of acidic components of the process medium of oilfields is an urgent task. As neutralizer of acidic components of process medium of oilfields it is proposed to use catholyte - solution saturated with hydroxide ions. The research work considers the principles of forming protective corrosion-resistant films on the surface of low-alloyed steel in the presence of catholyte. Comparative evaluation of corrosion resistance of iron hydroxide films in the model of produced water obtained on low- alloy steel A 516-55 in.solutions of sodium hydroxide and catholyte is shown. The study made it possible to establish the influence of catholyte on the kinetics of corrosion processes, and also revealed the dependence of the corrosion rate of low- alloy steel on the concentration of added sodium hydroxide or catholyte reagents at various pH values. Microscopic studies have shown that in the presence of catholyte, a thinner (plastic) film is formed, which has high corrosion resistance and has a protective effect. [ABSTRACT FROM AUTHOR]

Pure Copper oxide (CuO) and different mol% Manganese (Mn) substituted CuO nanoparticles were produced utilizing the chemical precipitation technique using copper chloride and sodium hydroxide. X-ray diffraction (XRD), Fourier transform infrared (FTIR), and Energy dispersive X-ray (EDAX) spectroscopy were used to analyze the crystallite size, functional groups and elemental composition of the synthesized samples. The average crystallite size was derived from XRD data. The results show that the crystalline size of Mn doped CuO reduced as compared to the pure CuO. The XRD patterns showed that the prepared CuO samples exhibits monoclinic crystalline structure. The SEM image suggested that the particles are more agglomerated with the addition of Mn in CuO. The composition of elements present in the sample was investigated by EDAX analysis. The bands at different modes are observed by the FTIR spectrum. Antimicrobial activity taken against E.Coli and Streptococcus oralis and zone of inhibition was observed. [ABSTRACT FROM AUTHOR]

The building industry produces brick waste, which is not using efficiently enough. Instead of looking for the use of such waste materials, we draw on non-renewable resources, burden the environment, and all this is very expensive. This work focuses on the recycling of such waste, specifically on the ceramic powder generated in the production of brick blocks. The main aim is to assess its applicability in the field of alkali-activated materials. Several alkali-activated composite mixtures were designed and prepared. The influence of the amount of added sodium hydroxide is the independent variable under this study. The effect of varying silicate modulus on initial and final setting time, characterization of pore structure, bulk density, matrix density, open porosity, compressive strength and flexural strength was investigated. Based on the presented observation, this alternative binder sufficiently meets applicability requirements and proves comparable performance to the Portland cement. Thus, it can be concluded that waste ceramic can be used as an environmentally friendly substitution for conventional materials. [ABSTRACT FROM AUTHOR]

Lithium ion batteries (LIBs) is currently the most promising energy storage device for technologies such as cellphones, gadgets, and electrical vehicles. Nowadays, LiCoO2 (LCO) type cells is still used due to its excellent performance even with high amount of cobalt. To reduce the overall production cost, a simple process with high scalability is proposed. In this study, a kilogram of LiCoO2 cathode materials were produced using room temperature cobalt crystallization of cobaltous solution. The effect of precipitating agents such as sodium hydroxide, oxalic acid and soda ash towards the material characteristics were deeply investigated. As obtained powders and products were characterized using XRD, FTIR, and SEM. Cobalt hydroxide, cobalt oxalate and cobalt carbonate were successfully synthesized based on XRD and FTIR study. Layered structure of LiCoO2 powders is confirmed by XRD study. SEM images of LCO products show a unique grape-like morphology with micron-sized secondary particles. Based on charge-discharge characteristics, the highest initial discharge capacity of 121 mAh/g is obtained by LCO from cobalt hydroxide with capacity retention of 24% after cycled for 230 cycles using 1C-2C-4C-8C-16C-30C current rates. [ABSTRACT FROM AUTHOR]

This paper covers thermodynamic studies of sulfide-alkaline leaching of antimony from sulfide Au-Sb concentrates have been carried out. Sulfide alkaline leaching were chosen as the best method of dissolving antimony among other hydro and pyrometallurgical ways. The Pourbaix diagram for Sb-S-H2O, S-H2O and Au-S-H2O systems have been studied. The dissolution features of antimony and gold in sulfide-alkaline solutions have been analyzed. Conditions for efficient sulfide-alkaline leaching process, ensuring high antimony extraction along with minimization of losses of gold in the solutions were determined: Eh from -0.8 to -0.6 V at pH no less than 13, temperature – 50 °C, Sb:S molar concentration ratio = 1:3. Extensive laboratory experiments on sulfide-alkaline leaching were provided. Following parameters are recommended: L/S = 4.5:1; sodium sulfide concentration – 61 g/L; sodium hydroxide concentration – 16.5 g/L have confirmed a high antimony recovery rate into solution – 97.6%. Thereby the gold recovery into the cake of 96.9 % has been achieved. [ABSTRACT FROM AUTHOR]

The method of electrodialysis of aqueous solutions of natural sodium sulfate (mirabilite) was used to obtain solutions of sodium hydroxide and sulfuric acid with the ultimate goal of isolating solid NaOH. Optimization of the process parameters (concentration of components, temperature, circulation rate of solutions) made it possible to achieve a unit energy consumption of 3.4 kWh/kg for NaOH. Carrying out the electrodialysis at a current of 1.1–2.7 A and a voltage of 30 V made it possible to achieve an alkali concentration of about 70 g/l and an acid concentration of 36 g/l. It was found that the optimal final concentration for NaOH solution is 14–16 wt%. The unit energy consumption for production of 1 kg NaOH strongly depends on the duration of electrodialysis; optimal time is about 5–6 hours at voltage of 30 V. It was shown that sodium chloride, which is often used as a wash solution, can be replaced with Na2SO4 in the wash solution in order to avoid unwanted chlorine formation. The purity of the target product – sodium hydroxide solution – was controlled during electrodialysis processes; for the electro-electrodialysis process, a base produced in the cathode compartment contains less than 1 wt% of sodium sulfate. A comparison of the efficiency of electrodialyzers of various designs using ion-exchange and bipolar membranes was carried out. The use of the lower-cost monopolar membranes in contrast to bipolar membranes made it possible to achieve higher concentrations of NaOH and H2SO4, but a high level of unit energy consumption is a disadvantage – 6.7 kWh/kg for NaOH. [ABSTRACT FROM AUTHOR]

The demand of tissue papers is increasing with the population increase. This will definitely increase the need of wood fibers as the main raw material. However, due to the wood shortages, there have been many attempts to use non- wood fibers as substitutes for papermaking. In Indonesia, corn production has gradually increased for the last 5 years, hence it also has an impact on the raising in the amount of corn husk waste. Corn husk has a high cellulose content which suitable to be used as a raw material for tissue papermaking. In this experiment, soda pulping process was conducted to remove out lignin. The resulting tissue paper will be added with additives that have antimicrobial properties of chitosan and mangosteen peel for the purpose of increasing the tensile strength or absorption of water. The aim of this research is to study the effect of depending variables (temperature and NaOH concentration) on chemical composition (cellulose and lignin content), and physical properties including water absorption and tensile strength.The research was started with the initial process of removing the lignin content in the pulp by pretreating delignification using the sodium hydroxide (NaOH) process with several variations in concentration (4–10%), and temperature (60–90°C) for 1.5 hours. To obtain tissue with a good physical condition, it has been influenced by the optimum chemical composition containing high cellulose and low lignin content, high tensile strength and water absorption. The optimum conditions for tissue paper in this study were at 90°C and 4% of NaOH concentration. The next step will be to vary the composition of the additive in order to obtain the effect of physical properties (tensile strength and water absorption). [ABSTRACT FROM AUTHOR]

Fly ash is the residue from burning coal in industrial furnaces which is hazardous and toxic waste. Fly ash accumulates will be a problem for living things and the environment. One of the efforts to utilize fly ash as a geopolymer product. Geopolymer products need an activator, that is reactive when it reacts with water. In this study, a solid activator made from fly ash containing silica and sodium hydroxide. Making this solid activator by calcination. Fly ash is added with sodium hydroxide which is then calcined at 400 °C, 500 °C, and 650 °C for 2 hours. Then the solid activator is crushed and sieved. The analysis carried out is XRF to determine the chemical composition of fly ash and XRD to determine the crystallinity and mineral content of the fly ash and solid activator in several temperature variations. The results showed that fly ash from Muara Enim, South Sumatra was class F fly ash which mostly contains CaO (8.562%), SiO2 (45.324%), Al2O3 (23.967%), and Fe2O3 (12.998%). Solid activator is good for solid activator of geopolymer products, namely at a calcination temperature of 500 °C because of the higher conversion of active minerals (sodium silicate) in solid activator that is 39.5%. [ABSTRACT FROM AUTHOR]

The TiO2 nanotubes are believed to be useful in various types of applications such as catalyst support for fuel cells and act as a photocatalyst for degradation of organic contaminant in wastewater. There are several ways to synthesize TiO2 nanotubes however, the convenient way is by using the hydrothermal method. Modification of the TiO2 nanotubes is predicted to enhance the properties of the nanotubes. In this work, the effect of different hydrothermal temperatures and times on the structural and morphology of TiO2 nanotubes were observed. Besides, the TiO2 nanotubes were further functionalized with sulfonic acid and their structure and morphology were also observed. The TiO2 nanotubes were first synthesized by mixing the TiO2 nanoparticles with sodium hydroxide and placed in a Teflon-lined stainless steel autoclave with the desired temperature and duration. The suspension was then washed with hydrochloric acid and distilled water and then subsequently centrifuged to obtain a solid. The solid was dried and annealed at high temperatures to remove any impurities present in the sample. The samples were then subjected to analysis using FESEM equipped with EDX. Functionalization of the TiO2 nanotubes was done by two steps which are coupling reactions followed by in situ oxidation. FESEM images proved that the sample with hydrothermal temperature and time of 200°C and 48 hours had successfully transformed into nanotubes. EDX analysis shows that the elements present in all the samples were mainly titanium, carbon, oxygen and sodium. Besides, the FTIR analysis shows that the peak of sulfonic acid was seen at the FTIR spectra. This proves that the functionalization of TiO2 nanotubes with sulfonic acid was successfully done. [ABSTRACT FROM AUTHOR]

Blend film is a thin layer made of biomaterial. One of the ingredients commonly used as blend film is chitosan. In the manufacture of blend films, chitosan can be used as a basic component of film manufacture. Chitosan has magnificent features due to its biodegradable and biocompatible and non-toxicity, but unfortunately chitosan is fragile material and generally insoluble in water. Poly Lactic Acid (PLA) and Glycerol was added to improve the characteristics of the film. The purpose of this study was to get the optimum ratio between chitosan and PLA, and get the characteristics of blend film from chitosan-PLA blended. The study was conducted in three step processes: (1) chitosan preparation, which was derived by deacetylation of chitin in the sodium hydroxide solution 50% w/w (2) PLA preparation, which was performed by direct polycondensation mechanism and (3) synthesis chitosan-PLA blend film. Blend film formation that was used the concentration ratio of chitosan: PLA (2:0 to 2:2 w/w), concentration of glycerol 0.03% v/v of chitosan solution, and drying temperature 70 °C for 10 hours. The analysis shows that the more percent of PLA added will decrease the value of tensile strength and elongation at break. The more percent of PLA added will increase the permeability of the film. The results showed that the best combination of chitosan: PLA concentration was on the ratio 2:0.4 of chitosan: PLA with the value of tensile strength and elongation of break of the film were 23.74 MPa and 14.82%. [ABSTRACT FROM AUTHOR]

This study was conducted to analyze the physical properties of cassava starch crosslinked with sodium trimetaphosphate (STMP) and used sodium hydroxide as a catalyst. The effect of crosslinker and catalyst (Starch/STMP/Catalyst) on thermal analysis, morphology, and structure crystal were investigated. The physical properties of native and modified cassava starch were also comparatively studied. Modified cassava starch was produced by adding different amounts of sodium trimetaphosphate (0.125, 0.25, and 0.5 % w/w) and catalyst of sodium hydroxide (0.5 and 1.0% w/w) into a reactor in water bath hotplate at 70 °C and 300 rpm for an hour. There are different diffraction patterns between the native cassava starch (NCS) and crosslink cassava starch (CLCS) samples. The sample of CLCS 1 (B); CLCS 2 (C) presented small new peaks in the regions of 32°, 38° and 41° (2θ), which may be related to changes in a three-dimensional network of the chains. It was indicated that the crosslinking process occurred successfully. The native cassava starch sample showed a smooth surface with rounded and bell shape granules. The samples CLCS presented loss of grain format, distorted and wrinkled surfaces with some rupture to the granules. [ABSTRACT FROM AUTHOR]

Zeolite was prepared from coal fly ash with sodium hydroxide in different concentration ratios at 550 °C with activation time of 12 hours by direct hydrothermal method. It was characterized by XRF,SEM, XRD and FTIR. Batch studies were conducted to study the effect of contact time, pH, amount of adsorbent, adsorbate concentration and temperature. The results revealed that the removal of Safranin dye was strongly pH dependent and maximum dye removal was observed at equilibrium pH of 9.0, optimum adsorbent dose and contact time were found to be 5 g/l and 180 minutes respectively. It was found that adsorption increased with increase in temperature thereby showing the process exothermic in nature. The experimental data were analyzed by Langmuir, Freundlich, Temkin and Dubnin isotherm models. The maximum removal of safranin dye was found to be 97.14% at 25 °C. The mechanism of adsorption was also investigated using kinetic models pseudo-first-order, pseudo-second-order, Elovich and Intra particle diffusion. [ABSTRACT FROM AUTHOR]