Sodium Bicarbonate Concentration Research Articles

In situ effervescence reaction-assisted mechanochemical extraction of ganoderic acids from Ganoderma lucidum

The aim of this work was to develop a simple, green and low-consumption method for the extraction of ganoderic acids. An in situ effervescence reaction-assisted mechanochemical extraction method was proposed, and the effects of independent variations in terms of sodium bicarbonate concentration, milling time, and liquid/solid ratio (mL/g) were investigated by means of a response surface methodology (RSM) Box-Behnken design (BBD). The highest yields of ganoderic acids were achieved by grinding a Ganoderma lucidum sample with sodium bicarbonate (372.60 mg/g) and citric acid for 0.87 min with a water to material ratio of 10.58 mL. The linear calibration ranges were from 0.01–5 μg/mL for the six analytes and had good linearity with a correlation coefficient of determination higher than 0.9991. In addition, the obtained LODs of the six target analytes were 1.46 − 2.97 ng/mL, and the LOQs calculated as ten times the signal-to-noise ratio were 4.88 − 9.90 ng/mL. The proposed method was successfully applied to the Ganoderma lucidum samples.

Impact of influent deviations on polymer coagulant dose in warm lime softening of synthetic SAGD produced water

Warm lime softening is commonly used to reduce hardness, silica, and a small fraction of organic matter from steam-assisted gravity drainage (SAGD) produced water through the addition of lime, soda ash, MgO, coagulant and flocculant. We report a systematic study on the impact of solution chemistry on the epichlorohydrin-dimethylamine coagulant demand for the treatment of synthetic SAGD produced water. Concentrations of magnesium, calcium, sodium bicarbonate, clay (mimicking suspended solids), sodium metasilicate (representing silica), and humic acid (mimicking dissolved organic matter) were varied to study their impact on coagulant demand. The impact of the concentration of lime, soda ash, and MgO on coagulant demand was also studied. Within the studied concentration range, the coagulant dose increased linearly with increasing concentration of humic acid (Ycoagulant = 29 + 0.703XHA) and silica (Ycoagulant = 52 + 0.537Xsilica), and increased slightly with increasing concentration of lime and soda ash, but remained almost unchanged with increasing concentration of dissolved hardness, clay, or MgO. The observations were correlated to the understanding of the electrokinetic properties of CaCO3 and Mg(OH)2 particles in lime softening. The findings provide insights for evaluating onsite coagulant dose and optimizing the process.

Microwave-assisted Preparation of Cross-linked Gelatin-Paracetamol Matrices: Optimization Using the D-optimal Design

This study was conducted to assess the effect of microwave heating on the preparation of paracetamol cross-linked gelatin matrices by using the design of experiment (DoE) approach and explore the influence of the duration of microwave irradiation, the concentrations of crosslinker, and the amount of sodium bicarbonate (salt) on paracetamol release. These parameters were also compared with those of the matrices prepared via conventional heating. Twenty gel matrices were prepared with different durations of microwave irradiation, amounts of maize, and concentrations of sodium bicarbonate as suggested by Design Expert (DX®). The percentage drug release, the coefficient of variance (CV) in release, and the mean dissolution time (MDT) were the properties explored in the designed experimentation. Target responses were dependent on microwave irradiation time, cross-linker amount, and salt concentration. Classical and microwave heating did not demonstrate statistically significant difference in modifying the percentage of drug released from the matrices. However, the CVs of microwave-assisted formulations were lower than those of the gel matrices prepared via classical heating. Thus, microwave heating produced lesser variations in drug release. The optimized gel matrices demonstrated that the observed percentage of drug release, CV, and MDT were within the prediction interval generated by DX®. The release mechanism of the matrix formulations followed the Peppas-Korsmeyer anomalous transport model. The DoE-supported microwave-assisted approach could be applied to optimize the critical factors of drug release with less variation.

Ultrasound-assisted hydration with sodium bicarbonate solution enhances hydration-cooking of pigeon pea

This work studied the effect of ultrasound power and sodium bicarbonate (NaHCO3) concentration during soaking process on the hydration and cooking kinetics of pigeon pea (Cajanus cajan). The pigeon pea grains were hydrated using 0, 1, 1.5, and 2% m/m NaHCO3 solutions without and with ultrasound assistance (17 W/L; 40 kHz and 43 W/L; 40 kHz) at 27 °C. Cooking process was studied using softening kinetics. Grains were cooked in boiling water and their softening was evaluated with a texturometer. Both hydration and softening kinetics were fitted to suitable models and their parameters were used for evaluating the effect of ultrasound power and salt concentration. Ultrasound accelerated hydration kinetics but did not affect the cooking process. Soaking in NaHCO3 solution, delayed hydration kinetics, but accelerated the softening kinetics. The synergetic effect of ultrasound (17 W/L) and NaHCO3 solution (1% m/m) accelerated both hydration and cooking kinetics by approximately 3 h. In fact, hydration is a long process, which requires more than 6 h, and cooking requires boiling temperature, which increases energy use and cost. Using ultrasound technology and adding sodium bicarbonate in soaking water can improve grain processing. Studying other grains and salts solutions on hydration-cooking process in the future is recommended.

Study on the combined effect of duct scale and SBC concentration on duct-vented methane-air explosion

A gas explosion is often vented to a safe location by means of a discharge duct. However, the presence of a discharge duct increases the explosion severity in the vessel, inducing a higher explosion overpressure compared to a simply vented vessel. To reduce the explosion overpressure in the vessel, an experimental study was performed to suppress the methane-air explosions in a 5 L vessel connected to a discharge duct of different scales (e.g., length and diameter) and with various sodium bicarbonate concentrations. The results show that the initial flame propagation process in the vessel was basically similar in the simply vented vessel and in the vessel vented through a discharge duct (i.e., ducted-vessel). In the middle and late stages of flame propagation in the vessel, the flame fragmentation was more pronounced for the ducted-vessel. Moreover, the degree of flame fragmentation in the vessel increased with the duct length. The flame structure in the vessel was more irregular for a larger vent coefficient (Kv = 9.75). The more pronounced quenching in the short duct (250 mm duct) is related to the high inhibition efficiency due to the leakage of a large amount of sodium bicarbonate (SBC) powder into the discharge duct while in the long duct (750 mm duct) the disturbance is due to the strong turbulence. The appropriate SBC concentration can transform the mechanism for the pressure rise in the vessel. At high powder concentrations the maximum pressure in the vessel is dictated by the flame reaching the vessel wall, while at low concentrations the maximum pressure is dominated by the pressure (i.e., burn-up) in the discharge duct. There is an approximately linear correlation between the maximum pressure and the average flame velocity in the discharge duct for a given powder concentration, and a linear relationship between the maximum pressures in the vessel and the duct independent of the SBC concentration. Through the analysis of the flame dynamics (e.g. flame morphology, flame propagation velocity and turbulence) and friction resistance induced by the varying duct scales, the suppression efficiency of SBC powder in the vessel is higher for a longer and narrower discharge duct.

A facile and sensitive video-analysis method for tracking floating lag-time and floating rate of gastro-retentive tablets

Floating effervescent tablets are designed to rapidly float in the gastric fluids by gas formation, after an initial lag-time. We developed here a method to characterise these dosage forms. Tablets were prepared containing various concentrations of hydroxypropyl methylcellulose (HPMC), dicalcium phosphate (DCP) and sodium bicarbonate (NB) as gelling agent, high-density model compound and gassing agent, respectively. Videos of the motion of tablets exposed to fluids for 6 h were recorded and then analysed to measure: i) tablet swelling; ii) floating kinetic until lag-time and iii) residual floating rate of the tablets over time. The developed technique was able to precisely track tablet motion and thus describe the floating performance of the dosage forms. Specifically, it was found that floating lag-time and floating fluctuations were influenced by the concentration of NB, more than DCP. Moreover, both swelling volume and residual floating rate over time were not affected by tablet composition, suggesting that density developments of the tablets were similar across formulations. Floating rate also remained constant over the test duration, which correlates well with previous findings on the floating force of HPMC/NB matrices. Overall, we showcase here a simple video-recording and -analysis technique to effectively characterise the performance of floating dosage forms.

Central Composite Design for the Development and Evaluation of Floating-mucoadhesive Tablets of Gliclazide

Background: Gliclazide assimilation rate from the gastrointestinal (GI) tract is slow and inconstant, which may be either due to poor dissolution or poor permeability of the drug across the GI membrane. Objective: The present investigation deals with the formulation of floating-mucoadhesive tablets of gliclazide for oral administration using the central composite design by direct compression technique, using HPMC K4M and Carbopol 934 as release controlling polymers and sodium bicarbonate as an effervescent agent. Methods: Central composite design was employed to quantify the effect of three factorsconcentration of HPMC K4M (X1), the concentration of Carbopol 934 (X2), and concentration of sodium bicarbonate (X3) on floating lag time, drug release and mucoadhesive time of the formulation. Results: The results revealed that floating lag time decreases with a rise in the concentration of sodium bicarbonate, drug release was highest at low levels of HPMC and Carbopol and mucoadhesive time was highest at a high level of Carbopol. Conclusion: The optimized batch (F-7) shows a mucoadhesive time of 23 minutes 27 seconds, floating lag time of 22 seconds and in vitro cumulative percentage of drug release 86.73 % in 10h. From the investigation, it can be summarized that the gastro-retentive drug delivery can be utilized to enhance bioavailability and gastric residence time of the drugs.

Prevention and Control of Hydrogen Sulphide Accidents in Mining Extremely Thick Coal Seam: A Case Study in Wudong Coal Mine

Hydrogen sulphide is a toxic gas often present in coal seams and seriously threatens the lives and health of underground workers in coal mines. In this study, we theoretically modelled hydrogen sulphide generation in extremely thick underground coal mines with the +575 level #45 coal seam of Wudong Coal Mine as an example and obtained the on-site hydrogen sulphide emission pattern and spatial distribution features by combining field measurements and computational fluid dynamics simulation. The results showed that hydrogen sulphide mainly exists in the coal porous system in an adsorbed state. Because hydrogen sulphide has a molecular weight greater than the average molecular weight of air molecules, its concentration decreases with the increase of altitude to the bottom plate. When mining the upper stratified coal stratum, it diffuses widely in the working space; while when mining the lower coal stratum, it mainly concentrates at the bottom of the working face. Based on these analyses, on-site treatments were carried out using mixtures with different concentrations of sodium carbonate and sodium bicarbonate. In addition, different combinations of catalysts as well as type A and type B wetting agents were also tested. Eventually, a neutral KXL-I absorbent was developed, and the process of preinjecting absorbent and spraying absorbent was designed. The results showed that the newly developed KXL-I absorbent has high hydrogen sulphide absorption ability and is suitable for use as an absorbent in Wudong Coal Mine; preinjecting and spraying the absorbent can effectively prevent hydrogen sulphide disasters in the +575 level #45 coal seam in Wudong Coal Mine with the optimal final concentration of 0.9% and the absorption rate of 87% at the shearer of 66.6% at the support. Overall, our study provides valuable information for the prevention and control of hydrogen sulphide disasters in coal mines.

Study on physicochemical properties and morphology of surface-modified and raw Coccinia grandis natural fiber

The 21st century may well be termed the cellulosic century as bio-source materials such as natural fibers are fast replacing traditional man-made materials due to their aprimary advantage of being lightweight. As natural plant fibers are eco-friendly, they play a more prominent role than synthetic fibers in the manufacture of composite materials because of their superior environmental benefits. In light of their multiple advantageous benefits, the present research study focuses on the use of raw and chemically treated extractedCoccinia grandisfiber (CGF) in polymer composites. The tensile test is conducted on individual fibers with gauge lengths of 10 mm, 20 mm, 30 mm, 40 mm, and 50 mm cut from the raw CGF. The gauge length that exhibits a higher tensile strength of fiber was carried out Sodium bicarbonate (NaHCO3) surface-modified 5%, 10%, and 15% concentrations. The gauge length that exhibits the highest tensile strength of fiber is chosen for chemical surface modification with different concentrations (5%, 10%, and 15%) of Sodium bicarbonate (NaHCO3) solution. The chemical composition and morphology of both raw and surface-modified CGFs are examined using Fourier-Transform Infrared Spectroscopy (FTIR) technique. The physicochemical properties and the results of the morphological studies reveal that the surface-modified fiber has higher tensile strength values than the raw fiber. Based on the obtained results, it is recommended that surface-modified CGFs be used as reinforcement material in composite manufacturing for light load applications.

Cell size influences inorganic carbon acquisition in artificially selected phytoplankton.

Cell size influences the rate at which phytoplankton assimilate dissolved inorganic carbon (DIC), but it is unclear whether volume-specific carbon uptake should be greater in smaller or larger cells. On the one hand, Fick's Law predicts smaller cells to have a superior diffusive CO2 supply. On the other, larger cells may have greater scope to invest metabolic energy to upregulate active transport per unit area through CO2 -concentrating mechanisms (CCMs). Previous studies have focused on among-species comparisons, which complicates disentangling the role of cell size from other covarying traits. In this study, we investigated the DIC assimilation of the green alga Dunaliella tertiolecta after using artificial selection to evolve a 9.3-fold difference in cell volume. We compared CO2 affinity, external carbonic anhydrase (CAext ), isotopic signatures (δ13 C) and growth among size-selected lineages. Evolving cells to larger sizes led to an upregulation of CCMs that improved the DIC uptake of this species, with higher CO2 affinity, higher CAext and higher δ13 C. Larger cells also achieved faster growth and higher maximum biovolume densities. We showed that evolutionary shifts in cell size can alter the efficiency of DIC uptake systems to influence the fitness of a phytoplankton species.

The efficacy of sodium bicarbonate as an anaesthetic agent in Oreochromis macrochir juveniles

The ever increasing demand for fish and fishery products in Zambia has resulted in the culture of many tilapia species including greenhead tilapia (Oreochromis macrochir). This increase in aquaculture entails an increase in routine procedures being performed which require anaesthetizing fish to reduce stress. In this study, we examined the efficacy of sodium bicarbonate commonly known as ‘baking soda’ as an anaesthetic agent for greenhead tilapia juveniles (7.2 ± 1.10 g weight and 27.64 ± 4.44 mm length). The juvenile fish were subjected to different concentrations of baking soda namely 0 (control), 5, 10, 15, 20, 25 and 30 g/L of sodium bicarbonate solution. In each of these different concentrations of the anaesthetic agent, fish were bath-immersed. Generally, the time of induction decreased while the time of recovery from anaesthesia increased with an increase in sodium bicarbonate concentration. The time of induction and recovery depended significantly (p < 0.05) on the concentration of the anaesthetic agent. All the fish reached full anaesthesia in less than 4 min in higher concentrations (above i.e. 15 g/L) and no mortality occurred under any of the concentrations tested. The most optimal concentration leading to full anaesthesia in 4 min and recovery in less than 10 min was 20 g/L.

Application and optimization of a quantified kinetic formula to mineral carbonation of natural silicate samples

Mineral carbonation for global warming mitigation has attracted worldwide attention. The combination of mineral processing for primary metal recovery and mineral carbonation for carbon sequestration is an emerging field of study with the potential to minimize capital costs. A quantified kinetic formula of mineral carbonation was tested for application to various natural silicate samples. Our research confirms the optimized kinetic formula can be successfully applied to predict mineral carbonation of various natural silicate samples within absolute 4% precision. The kinetic factor is exponentially dependent on the activation energy of carbonation of natural silicate samples. The application of the kinetic formula is restricted to a mineral carbonation process under chemical reaction control. The successful application is not affected by mineral compositions, olivine content, mineral carbonation capacity, specific surface area, particle size distribution, temperature, CO2 partial pressure or concentration of sodium bicarbonate in solution. This quantified kinetic formula can predict mineral carbonation efficiency for an integrated process of mineral processing and mineral carbonation.

An innovative method for recycling vanadium and valuable materials from high-lime steel making slag disposal

A considerable amount (more than tens of millions of tons) of slag has been collected as discarded waste in the landfilled site of steelmaking company. Recovery of valuable metals and materials to the recycling of slag could be an urgent decision for solving this problem. To turn into usable products, slag leaching by hydrochloric acid reduces the slag weight by up to 50%. The leaching solution can be used to calcium sulfate and hydrochloric acid as byproducts. After Alkaline roasting at 900 °C, the remaining slag was leached in a sodium bicarbonate solution. The results showed that sodium bicarbonate concentration, temperature, and particle size of 80 g/l, 80 °C and − 53 μm, respectively, provided favorable conditions for vanadium recovery. High efficiency of leaching, along with a high concentration of vanadium, is urgent. So to increase the two criteria, leaching studies in higher solid to liquid ratio (0.4 g/ml) were carried out in two-stage countercurrent. Under the optimum condition, vanadium recovery, and vanadium concentration are more than 75% and 3.5 g/l, respectively. Moreover, based on proposed flow sheet vanadium pentoxide is the main product and the gypsum and fertilizer are the byproducts of the process.

Responses of seven strawberry cultivars to alkalinity stress under soilless culture system

Due to impact on the pH of growing medium, water alkalinity is the most important parameter determining water quality. Thus, to investigate the effect of sodium bicarbonate on strawberry, an experiment was carried out considering two factors including sodium bicarbonate at three levels (0, 15 and 30 mM) and seven strawberry cultivars (Albion, SanAndreas, Paros, Aromas, Diamante, QueenElisa, and Camarosa). Sodium bicarbonate increased the EC and pH of growing medium in all studied cultivars. The results showed that vegetative and reproductive growth, chlorophyll fluorescence parameters, and relative water content of leaves diminished with an increase in sodium bicarbonate concentration and Camarosa cultivar was more sensitive than other cultivars. The maximal quantum yield of PSII photochemistry (Fv/Fm), PI, Fv, Fm, Area, Fv/Fo, RC/ABS and (1-Vj)/Vj parameters declined in all cultivars with increasing sodium bicarbonate, especially in Camarosa cultivar. Fo parameter rose with increasing sodium bicarbonate, with the greatest increase being related to Camarosa cultivar at 30 mM sodium bicarbonate. The chemical/physical parameters of fruit diminished by bicarbonate, with the San Andreas and Diamante showing the highest and lowest fruit EC, pH, and TSS, respectively. Under stress conditions, Paros cultivar showed the minimum changes in fruit color parameters. The results showed that Paros and Camarosa are the most tolerant and sensitive cultivars to alkalinity stress, respectively. Also, chlorophyll fluorescence parameters, especially PI and Fo, are suitable indices for bicarbonate stress evaluation in strawberry cultivars and secondary alkalinity induced stress like salinity and drought stress may cause a change in PI and Fo.

Formulasi Granul Effervescent Ekstrak Pandan Laut (Pandanus tectorius Parkinson ex Du Roi) Sebagai Analgetik

Sea pandanus plants are plants that are spread along the coast in Indonesia. Pandan sea fruit itself has never been used by the community, so it becomes waste on the beach. The purpose of this study was to make a formulation of effervescent granules from ethanolic extracts of sea pandanus (Pandanus tectorius) which has analgesic activity. The effervescent granule formula consists of ethanol extracts of sea pandanus, sodium bicarbonate, citric acid, tartaric acid, mannitol, lactose, PVP, aerosils and orange dyes. The difference of the three formulas are the ratio of the concentration of sodium bicarbonate which is 25%, 30% and 35%, respectively. The results show that the best formula is formula I, which fulfills the organoleptic test requirements, water content, rest angle, real specific gravity test, incompressible density test, compressibility, disperse time and pH. The analgesic activity test results using siegmund method known analgesic activity of formula I as the best formula with a dose of 125 mg / kg BW and aspirin as a comparison with a dose of 65 mg / kg body weight gives an anlgetic effect with protective power is 83.68%.

Formulation and Evaluation of Floating Polymeric Nanoparticles of Linagliptin in Capsules

Objectives: Linagliptin is a BCS class III drug used in treatment of diabetes. In the present study floating polymeric nanoparticles of linagliptin are formulated to increase the residence time of drug in stomach by controlling drug delivery over a prolonged period of time and to increase permeability by nanosized particles, there by bioavailability can be increased. Methods: Polymeric nanoparticles were prepared by desolvation and ion gelation method. The prepared polymeric nanoparticles were evaluated for entrapment efficiency, drug content, percentage yield, diffusion studies and dissolution studies. Results: Among various formulations, GF2 formulation by ion gelation method, CF5 by desolvation (continuous addition) method and IF1 by desolation (intermittent addition) method have shown % drug release of 91.8±0.50%, 92.8±0.33% and 91.5±31% in 210min respectively. GF2 was considered as the optimized formulation based on its high entrapment efficiency of 88.6±1.09%, cumulative amount permeated of 997.0±2.15μg/cm2 for 4hrs, Zeta potential (-20.3mV), particle size (396 nm) and SEM (spherical and smooth surface). The GF2 formulation was converted into floating drug delivery system with sodium bicarbonate and different concentration of ethyl cellulose, HPMC E15M. GF2 (1:2 ratio of drug:ethyl cellulose) was optimized as it showed prolonged drug release by retaining drug through mucosa of goat with % drug release (53.1±0.50 % at 5.5 hrs) in comparison with pure drug (99.8±0.19% at 1 hr) and it was stable as per ICH guidelines. Conclusion: Hence the drug release has been retarded, permeation has been enhanced and residence time of drug in the stomach has been extended by floating polymeric nanoparticles. Key words: Floating Drug Delivery, Nanoparticles, Polymeric Nanoparticles, Desolvation Method, Ion Gelation Method, Linagliptin.

Effects of different fish sizes, temperatures and concentration levels of sodium bicarbonate on anaesthesia in Mozambique tilapia (Oreochromis mossambicus)

This study was conducted to determine the effects of different fish sizes, temperatures, and concentration levels of sodium bicarbonate (baking soda) in Mozambique tilapia (Oreochromis mossambicus). Three different body size classes of Mozambique tilapia; (i) small (0.92 ± 0.00 g, 3.4.21 ± 0.11 cm), (ii) medium (12.35 ± 2.71 g, 9.87 ± 1.23 cm), (iii) large (47.24 ± 3.12 g, 13.92 ± 2.61 cm) were subjected to three concentrations of sodium bicarbonate (30, 45, 60 g L−1) at 24, 28, or 32 °C, each replicated three times. The anaesthetic induction and recovery times were monitored at each treatment combination in five litres glass aquaria. Sodium bicarbonate proved to possess anaesthetic capacity for Mozambique tilapia, and its anaesthetic induction time was significantly affected by the concentration, water temperature, and fish size (P < .05). The induction time decreased with increase in temperature and sodium bicarbonate concentration, but increased with fish body size. Moreover, fish size and sodium bicarbonate concentration had a significant effect on the recovery time (P < .05). Inversely, anaesthetic recovery time increased with decrease in sodium bicarbonate concentration and temperature for all fish sizes; recovery time increased significantly with increased fish size (P < .05). No mortality was recorded during the anaesthetic induction and recovery time or within three days post recovery. This study indicates that, sodium bicarbonate is effective as anaesthetic in Mozambique tilapia at 45 and 60 g L−1 concentrations at all tested fish sizes and water temperature. Therefore, sodium bicarbonate is recommended as a satisfactory anaesthesia that can be used at all levels of aquaculture to improve fish welfare.

Improving the quality of barbecued culled-dairy-goat meat by marination with plant juices and sodium bicarbonate.

Meat from dairy goats is less tender than that from meat goats since generally they are of an older age when culled. The objective of this study was to improve the quality of barbecued culled-dairy-goat by using juices (ginger and pineapple) and sodium bicarbonate (SB). The optimum time (30, 60, 90min) for marinating the goat meat with ginger and pineapple juices was evaluated. Then, the optimum levels of SB (0, 1, 3, 5%) and the optimum marinating procedure for the application of SB was studied. The results showed that the ginger-marinated samples had a lower cooking loss than the pineapple-marinated samples. The optimum time for marinating the samples with plant juices was 60min indicated by the lower hardness and chewiness as compared to those of the samples marinated with plant juices for 30 and 90min. The cooking loss and L* values of the marinated samples significantly decreased with increasing concentrations of SB. The lowest hardness were observed in the samples marinated with pineapple juice containing 3% SB and ginger juice containing 5% SB. The samples marinated with pineapple juice for 60min and then marinated with a barbecue sauce containing 3% SB for 60min had a lower cooking loss and hardness as well as higher scores for all sensory attributes compared to the non-juice-marinated meat with SB and the ginger-marinated meat. The results indicate that pineapple juice and SB (3%) can improve the quality of culled dairy-goat-meat, and in particular its texture.

Effect of chemical treatment on impact strength and dynamic thermal properties of Jute/PLA composites

The Untreated jute fiber reinforced composite (UTJFRC) and treated jute fiber reinforced composite (TJFRC) have been fabricated using compression molding processes. For chemical treatment of jute fiber mat sodium bicarbonate (NaHCO3) is used. The solution used for treatment has maintained pH of range 7–8 which show the ecofriendly treatment nature of sodium bicarbonate. Jute fiber mats were treated at three different concentration of sodium bicarbonate at 10, 20 and 30% for 4 h of treatment time. The prepared sample were characterized by dynamic mechanical thermal analysis (DMTA) and Izod impact test. All sample were cut according to ASTM standard to measure izod impact strength on impact tester. The composite sample which were treated at 10% concentration appear high impact strength. Even for dynamic mechanical properties treated jute fiber mat 20% concentration achieved maximum storage and loss modulus values. Even the glass transition temperature (Tg) is maximum shift for 20% concentration treated sample of jute/PLA composites. The improvement in properties because of good interfacial adhesion of jute and PLA achieved by sodium bicarbonate treatment of natural fiber.

Parametric study of sisal-epoxy resin composite treated in sodium bicarbonate solution using Taguchi orthogonal array

The sisal-fibre reinforced epoxy composite is fabricated with hand layup method using Taguchi L9 orthogonal array. The novelty of the present investigation is treatment of fibres with sodium bicarbonate, which is economical and eco-friendly as compared to other alkaline treatments like sodium hydroxide, isocyanate triazine in development of epoxy composite. The controlled process parameters viz. fibre length (mm), fibre content (wt%), and concentration of sodium bicarbonate (wt% by vol.) is considered in maximising the output response characteristic, i.e., tensile strength (Mpa). The average output response characteristic is measured as per ASTM D638 at defined set of experimentation condition. Moreover, variation in output response characteristics is predicted through ANOVA and significant effect of individual process parameters are identified. The statistical analysis exhibits that the fibre length is the most significant parameter in maximising the output response followed by sodium bicarbonate concentration, and fibre content. It is also observed that the maximum average tensile strength is achieved 79.93 Mpa with 6 mm fibre length, 20 wt% fibre content, and 10 wt% by vol. sodium bicarbonate in development of sisal-fibre reinforced epoxy composite.