Sodium Hydroxide Concentration Research Articles

Production of Vanillin from Pumpkin Peels via Microbiological Fermentation using Aspergillus niger

Vanilla is the main natural flavouring agent used in industries such as pharmaceuticals, food, flavouring, and fragrance, in which vanillin is the major component. Vanillin (4-hydroxy-3-methoxybenzaldehyde) is a secondary metabolite of plants and the major organoleptic aroma component of natural vanilla. The vanillin compound can be produced using the following routes: direct vanilla bean extraction, chemical synthesis, and biotechnological processes (bio-vanilla production). Nowadays, the chemical synthesis method used for vanillin production has been rejected by the United States and European legislation, while plant-derived vanillin is expensive. The current study demonstrates vanillin production from pumpkin peels (Cucurbita moschata) by Aspergillus niger via one-step fermentation approach. This study implements different concentrations of sodium hydroxide (1.0 M and 2.0 M) during alkaline hydrolysis pretreatment and different feeding volumes of hydrolysates during the biotransformation processes of ferulic acid into vanillin, classified as small feeding volumes (SFV) and large feeding volumes (LFV). Detection and quantification analysis were carried out using high performance liquid chromatography (HPLC), resulting in vanillin yield of 0.49 mg/L (1.0 M SFV), 0.5 mg/L (1.0 M LFV), 0.33 mg/L (2.0 M SFV), 0.59 mg/L (2.0 M LFV). Analysis with ultraviolet-visible (UV-VIS) spectrophotometry using thiobarbituric acid as reagent was carried out as well, resulting in vanillin yield of 2.76 µg/ml (1.0 M SFV), 3.78 µg/ml (1.0 M LFV), 2.68 µg/ml (2.0 M SFV), 3.05 µg/ml (2.0 M LFV). In conclusion, pumpkin peels can be considered a great source of ferulic acid and Aspergillus niger was reported as an efficient fungus in converting ferulic acid to vanillic acid, which will then be transformed into vanillin.

Integrated Hemicellulose Extraction and Papermaking Fiber Production from Agro-Waste Biomass.

The present study deals with the valorization of corn stalks in an integrated processing strategy targeting two products: extracted hemicelluloses (HC) and papermaking fibers. Preliminary trials were conducted to assess the individual or the combined effects of biomass treatment on the quality of the obtained hemicelluloses and papermaking fibers. Depending on the hot alkaline extraction (HAE) conditions, the extracted HC had a xylan content between 44-63%. The xylan removal yield ranged between 19-35%. The recovery of HC from the extraction liquor and final black liquor was significantly affected by process conditions. The experimental approach continued with the study of HAE conditions on the obtained paper's mechanical properties. The optimization approach considered conserving paper strength properties while achieving an equilibrium with the highest possible HC extraction yield. The optimal values are sodium hydroxide concentration (1%), process time (33 min), and temperature (100 °C). The xylan content in the separated HC sample was ~55%. An extended extraction of HC from the resulting pulp under hot alkaline conditions with 5% NaOH was performed to prove the HC influence on paper strength. The xylan content in HC samples was 65%. The consequence of xylan content reduction in pulp leads to 30-50% mechanical strength loss.

Central composite design for optimization of kenaf-reinforced epoxy composite bonding performance

Kenaf fiber is gaining prominence because of its ability as a natural-based reinforced material in advanced composites. However, kenaf contains a hygroscopic natural waxy substance that covers the fiber layer, providing a low surface tension and preventing strong bonding with the polymer matrix. The goal of this study is to optimize the blending parameters of kenaf fiber-reinforced epoxy composites by alkali treatment concentration, length, and fiber-matrix loading using central composite design. The maximum tensile strength was obtained at 6.03 wt% of NaOH concentration, fiber loading of 26.02 wt%, and fiber length at 7.39 mm, which showed a strong correlation between experimental and predicted values. The analysis of variance function model indicated that fiber length, sodium hydroxide concentration, and fiber loading all play important roles in mechanical properties of composites. Based on the fracture surface observations, kenaf fiber composite strength was closely related to bonding at fiber-matrix interfaces. The most common failure modes in the samples were voids, matrix fracture, fiber breakage, weak bonding, and fiber pull-out.

Determine the Optimal Parameters for Biogas Production from Common Reed (Phragmites australis)

A series of batch assays have been conducted to investigate the optimal factors that can be adopted to improve the anaerobic digestion (AD) performance of Phragmites australis and increase biogas production. The assays were carried out using 125 mL microcosm reactors with a working volume of 80 mL and incubated at mesophilic conditions (37 ± 1ºC). The effect of particle size (10, 5, 2, and < 1 mm) and alkaline pre-treatment of P. australis using various concentrations of sodium hydroxide (0.5, 1, 2, and 4%) on biogas production was examined. Furthermore, the best pre-treatment incubation time (12, 24, 48, 72, 96, and 120 h) and the optimal inoculum to substrate ratio (ISR: 4:1, 2:1, 1:1, 1:2 and 1:4) were also assessed. The results revealed that the highest biogas production from P. australis was achieved at particle size < 1 mm (27.97 ± 0.07 and 16.67 ± 0.09 mL/g VS added, for pre-treated and untreated P. australis respectively); 2% and 4% NaOH concentration for pre-treatment (70.01 ± 3.75 and 76.14 ± 2.62 mL/g VS added, respectively); pre-treatment incubation time of 72, 96, and 120 h (71.18 ± 1.79, 72.46 ± 1.08, and 73.78 ± 1.87 mL/g VS added, respectively); and ISR of 1:2 for pre-treated P. australis (78.21 ± 0.36 mL/g VS added) and ISR 1:4 for untreated P. australis (28.93 ± 1.55 mL/g VS added). Determining optimal parameters in this work would guide further development of process configurations, such as continuous AD systems.

Recycling Ash and Slag Waste from Thermal Power Plants to Produce Foamed Geopolymers

Ash and slag waste (ASW) from coal combustion creates significant environmental and economic challenges. A promising method of ASW recycling is alkali activation with geopolymer material formation. This study investigates the influence of activating solution components (sodium hydroxide and sodium silicate) on the formation of porous geopolymers using ASW of different origins. The sodium hydroxide content of 0–4 wt.% and the sodium silicate content of 17–25 wt.% were studied. An increase in sodium hydroxide resulted in decreased density, but it adversely affected the strength. An increase in sodium silicate led to a compromised porous structure with relatively high density and compressive strength. An optimal composition, S19N3, comprising 3 wt.% of sodium hydroxide and 19 wt.% of sodium silicate obtained porous geopolymers with uniformly distributed 1.4–2 mm pores and a corresponding density of 335 kg/m3, a compressive strength of 0.55 MPa, a porosity value of 85.6%, and a thermal conductivity value of 0.075 W/(m·K). A mechanism for porous geopolymer formation was developed, including the interaction of alkaline components with ASW and a foaming agent, foaming, curing, and densification. The mechanism was examined using ASW from the Severodvinsk CHPP-1. This study allows for the optimization of geopolymer mixtures with various waste sources and the utilization of waste materials in the construction industry.

Pipette-Free and Fully Integrated Paper Device Employing DNA Extraction, Isothermal Amplification, and Carmoisine-Based Colorimetric Detection for Determining Infectious Pathogens.

A pipette-free and fully integrated device that can be used to accurately recognize the presence of infectious pathogens is an important and useful tool in point-of-care testing, particularly when aiming to decrease the unpredictable threats posed by disease outbreak. In this study, a paper device is developed to integrate the three main processes required for detecting infectious pathogens, including DNA extraction, loop-mediated isothermal amplification (LAMP), and detection. All key reagents, including sodium dodecyl sulfate (SDS), NaOH, LAMP reagents, and carmoisine, are placed on the paper device. The paper device is operated simply via sliding and folding without using any bulky equipment, and the results can be directly observed by the naked eye. The optimized concentrations of sodium dodecyl sulfate (SDS), sodium hydroxide (NaOH), and carmoisine were found to be 0.1%, 0.1 M, and 0.5 mg/mL, respectively. The paper device was used to detect Enterococcus faecium at concentrations as low as 102 CFU/mL within 60 min. Also, E. faecium spiked in milk was successfully detected using the paper device, demonstrating the feasible application in real sample analysis.

Effect of NaOH-based deproteinisation on chemical and biological properties of Moina sp. chitosan

Chitosan is a biopolymer which is isolated from the crustacean exoskeleton of Moina sp. with particular antibacterial properties. Alkali-sodium hydroxide deproteinisation has a huge role in ensuring the chitosan quality by removing protein to enhance its dispersivity. Modification of sodium hydroxide (NaOH) concentration by 3N and 6N was performed in this study to observe the effect on chemical and biological characteristics of chitosan. The highest concentration treatment of 6N NaOH exhibited the best composition of protein, fat, and ash by 6.09%, 3.77% and 0.9%, respectively. The deacetylation degree of chitosan treated with 3N NaOH depicted the highest solubility of 73.25% compared to the solubility of 6N NaOH by 61.06%. The antibacterial activity of Moina sp. chitosan was considered as having a weak and fluctuated activity by different concentrations of NaOH. The 6N NaOH treatment chitosan showed the best antibacterial activity against the grampositive bacterial strain of Staphylococcus aureus with the widest inhibition zone diameter of 4.34±0.55 mm, while the 3N NaOH treatment chitosan showed the best antibacterial activity against the gram-negative bacterial strain of Escherichia coli with widest inhibition zone diameter of 4.47±0.78 mm.

The Effect of Different Concentration of NaOH on Mechanical Properties of Allium sativum L. Peels Thin Sheet Paper

Allium sativum L. peels were used as raw material to obtain cellulosic pulps for paper making. The peels were treated with sodium hydroxide at different concentrations (5%, 12.5%, and 20%) before the paper production. The sheets were measured for weight and thickness and evaluated for tensile, tear and bursting strength. The chemical compositions of the peels were analysed. The results indicated that the peels are suitable for papermaking due to the appropriate contents of cellulose (37.22%), hemicellulose (35.21%) and lignin (9.96%) values. The colour of the sheets varies from dark to light brown when the amount of sodium hydroxide solution was increased. It was estimated that the weight of peels was in the range of 5.0 - 6.5 % of garlic clove. All the sheet samples have uniform weight and thickness. The results showed that increasing sodium hydroxide concentration from 5% to 20% decreased tensile and bursting strength, except tearing strength. Two kinds of microscopic observations showed that peels treated with the highest sodium hydroxide concentration had a fine and thin layer of binder within the fibres. The sheets appear to be transparent with due to a decrease in the tensile and bursting strength except for the tear strength.&#x0D;

Real-time signal processing via chemical reactions for a microfluidic molecular communication system

Signal processing over the molecular domain is critical for analysing, modifying, and synthesising chemical signals in molecular communication systems. However, the lack of chemical signal processing blocks and the wide use of electronic devices to process electrical signals in existing molecular communication platforms can hardly meet the biocompatible, non-invasive, and size-miniaturised requirements of applications in various fields, e.g., medicine, biology, and environment sciences. To tackle this, here we design and construct a liquid-based microfluidic molecular communication platform for performing chemical concentration signal processing and digital signal transmission over distances. By specifically designing chemical reactions and microfluidic geometry, the transmitter of our platform is capable of shaping the emitted signals, and the receiver is able to threshold, amplify, and detect the chemical signals after propagation. By encoding bit information into the concentration of sodium hydroxide, we demonstrate that our platform can achieve molecular signal modulation and demodulation functionalities, and reliably transmit text messages over long distances. This platform is further optimised to maximise data rate while minimising communication error. The presented methodology for real-time chemical signal processing can enable the implementation of signal processing units in biological settings and then unleash its potential for interdisciplinary applications.

Alkali-activated geopolymer materials prepared from coal gangue and municipal solid waste incineration byproducts

Coal gangue and municipal solid waste incineration byproducts (fly ash and bottom ash) are considered as solid and hazardous waste, respectively, and the accumulation of these wastes leads to significant environmental issues. Coal gangue is rich in Si and Al but lacks of Ca, making it challenging to create alkali-activated cementitious materials with good mechanical performances. Fly ash and bottom ash are abundant in Ca. The feasibility of using fly ash and bottom ash as calcium sources for preparing alkali-activated coal gangue-based geopolymers is investigated in the present work. The unconfined compressive strength (UCS) test and microscopic tests (XRD, FTIR, TGA, SEM and ICP-OES) are conducted to study the strength and reaction mechanism of coal gangue and fly ash/bottom ash (CGFA/BA) geopolymers. The results show that the strength of CGFA/BA geopolymers initially increases and then decreases with an increase in fly ash and bottom ash content, and the optimal dosage of fly ash and bottom ash is 15% and 30%, respectively. The liquid-solid ratio and alkali solution (NaOH/Na2SiO3) ratio have a significant influence on the strength of the CGFA/BA geopolymers and the optimal alkali solution ratio is 25:75, while the liquid-solid ratio of 0.45 and 0.60 is recommended for CGFA and CGBA geopolymers, respectively. The CGFA geopolymer with 15% fly ash, 25:75 alkali solution ratio, 0.45 liquid–solid ratio and 8 mol/L sodium hydroxide concentration obtains the highest UCS of 30.28 Mpa. The heavy metal immobilization efficiency (IE) of the CGFA geopolymer is better than that of the CGBA geopolymer. The IE of heavy metals of the CGFA geopolymer is larger than 84.66% and that of the CGFA geopolymer is larger than 55.95%. In the CGFA geopolymer, the IE is Hg>Pb>Zn>Cd>Cr>Ba, while in the CGBA geopolymer, the IE is Hg>Cd>Ba>Cr>Zn>Pb.

Efficient production of low molecular weight lignin from eucalyptus wood through methanol-alkali system

With the high phenolic hydroxyl content and excellent bioactivity, low molecular weight lignin (LMW-Lignin) holds tremendous potential for various applications in energy storage and antibacterial materials. However, conventional sources of lignin currently available are characterized by large molecular weights, and many of their active functional groups remain unreleased, limiting their exploitation for potential applications. In this study, we investigated the inhibition effect of methanol on the recondensation of lignin fragments under a hydrothermal system of methanol/sodium hydroxide, using eucalyptus wood flour as the raw material. Our findings revealed that, in the hydrothermal alkaline system,·OCH3 free radicals formed from methanol can effectively target and react with the active sites (Cα and Cβ) on the dissolved lignin side chains, resulting in the formation of stable methoxyl structures and preventing the formation of C-C bonds and polycondensation of dissolved lignin. Optimized conditions, including 20% CH3OH (methanol content), 14% NaOH (sodium hydroxide content), and a reaction temperature of 160 ℃, led to a weight-average molecular weight of 1478 for the lignin product, with a yield of 62.90%.

Cobalt nanoparticle synthesis through the mechanochemical and chemical reduction method as a highly active and reusable catalyst for H2 production via sodium borohydride hydrolysis process

The process of hydrolysis of sodium borohydride is a new and clean method for the production of hydrogen. In this study, cobalt nanoparticles were synthesized by the mechanochemical and chemical reduction methods, and their catalytic performance was compared. The effect of using different cobalt precursors and reducing agents was investigated for the sample prepared via the chemical reduction method. The results showed that the cobalt catalysts synthesized through the chemical reduction method possessed better catalytic performance. Also, the sample prepared using cobalt nitrate and sodium borohydride had a higher hydrogen generation rate (HGR), which was equal to 3272.7 ml min−1g−1. The kinetics of the cobalt catalyst in the process have also been investigated, revealing that the rate of hydrogen production is dependent on the concentrations of sodium borohydride and sodium hydroxide, the catalyst dosage, and the process temperature. The crystal size of this catalyst was 21.6 nm with spherical agglomerated particles. The BET area of the best sample and its activation energy was equal to 11.18 m2g-1 and 22.3 kJmol-1, respectively. This catalyst was also stable in successive cycles.

Plant protein hydrogel as a delivery system of curcumin: Characterization and in vitro release Kinetics

In recent years, non-animal protein sources have led many consumers to eat plant-based alternatives. The Green gram protein is more biocompatible, highly sustainable and safer than animal proteins. Nutraceuticals have drawbacks such as poor water solubility, chemical instability at neutral and alkaline pH, auto-oxidation and poor absorption. Hydrogels are used to enhance the efficiency of these bioactive compounds. In this study, Green gram protein hydrogel enriched with curcumin was prepared. Protein was extracted from Green gram seeds using alkaline extraction and acid precipitation. Curcumin was extracted from turmeric using a Soxhlet Apparatus. A hydrogel was prepared using a sodium hydroxide concentration of 0.5 M to efficiently encapsulate curcumin and was characterized. The physicochemical properties of green gram protein hydrogels were evaluated by entrapment efficiency, swelling degree, FTIR, XRD, DSC, SEM, in vitro release and free radical scavenging assessment method. The encapsulation efficiency was 89.02 ± 0.56% respectively. The successful incorporation of curcumin in the hydrogel was confirmed by FTIR analysis. The surface properties of hydrogels were investigated using the SEM technique. The synthesized hydrogels are highly porous in nature and form cross linked structures. Moreover, hydrogels have a high swelling capacity. The swelling behaviour was due to the presence of hydrogen bonding interaction with the aqueous media. The hydrogel possesses a hydrophilic character when investigated by the contact angle. The contact angle of curcumin-loaded green gram hydrogel was increased by 9 °. The inhibition zone of 30 ± 03 mm was effective against E. coli. bacteria. The antioxidant property of the hydrogel gets increased by 50.46% after the addition of curcumin. Slow release of curcumin from hydrogel was studied using UV–vis Spectroscopy and it was inferred that it follows Korsmeyer-Peppas Kinetics model. The hydrogel was applied to tomato and apple as a coating. Generally, the results emphasised the potential use of Green gram protein hydrogel as a coating on fruits and vegetables.

NaOH-Activated Natural Glauconite for Low-Cost Adsorption of Congo Red Dye

To explore the adsorption of Congo red (CR) dye from textile effluent, natural clay glauconite was employed as a sustainable and inexpensive adsorbent. The effects of varying concentrations of sodium hydroxide (NaOH) on glauconite alteration were examined. Furthermore, this research focuses on the optimal NaOH concentration that improves removal efficiency and adsorption capacity. Thus, four NaOH solutions of concentrations ranging from 1 M to 4 M were used to activate glauconite raw (GL), indicated as GLACT1M, GLACT2M, GLACT3M, and GLACT4M. These samples were characterized using different analysis tools. The effects of starting concentration, adsorption time, adsorbent dosage, pH, temperature, and reusability on removal efficacy were all investigated. The data show that the CR removal efficiency increases with modification up to a 2 M NaOH activation, beyond which it begins to decrease. At 25 °C and pH 7, the CR removal efficiencies were ~77%, 72%, 80%, 34.5%, and 30.5% by GL, GLACT1M, GLACT2M, GLACT3M, and GLACT4M, respectively. Batch experiments were performed to explore both the kinetics and isotherms of CR adsorption to determine the impact of different experimental conditions accurately. Moreover, isotherm interpretations demonstrated that the Freundlich isotherm closely matches the experimental results. The pseudo-second-order model clearly explains the obtained results (R2 = 0.998) from 5 to 25 ppm for GL, GLACT1M, GLACT2M, and GLACT3M, but GLACT4 is expressed by the Elovich model from 20 to 25 ppm. The reusability investigation revealed that the reusability of adsorbents could be achieved efficiently. The findings suggest that glauconite and its NaOH-activated forms can be employed as natural and affordable adsorbents for removing CR from textile effluent.

Evaluating the role of magnesium aluminate nano spinel in phase composition, meso-porosity, compressive strength, and drying shrinkage of alkali-activated slag

The effect of nano magnesium aluminate (MA) spinel on the performance of blast-furnace slag with low NaOH content (3 wt%) was explored for the first time in the present work. Two different temperatures (500 and 800 °C) were applied to prepare nano spinel with different degrees of crystallinity. The impact of nano MA spinel crystallinity and content on phase composition, microstructure, compressive strength, meso-porosity, and drying shrinkage of alkali-activated slag (AAS) was evaluated. The results showed that nano spinel prepared at 500 °C (MA500) reduced the drying shrinkage and increased the compressive strength of AAS significantly, while MA800 showed a lower effect. The activated mixtures containing 0.5 wt% nano spinel demonstrated the highest performance regardless of nano spinel type. Adding nano spinel induced the formation of a hydrotalcite phase and enhanced the incorporation of Al inside calcium silicate hydrate, resulting in a substantial improvement in the performance of AAS. Nano spinel achieved the concept of “sustainability”, which strongly contributes to producing high-performance materials with low carbon footprint by utilizing low sodium hydroxide content.

Parameters Synthesis of Na-Magadiite Materials for Water Treatment and Removal of Basic Blue-41: Properties and Single-Batch Design Adsorber

Na-magadiite materials were prepared from a gel containing a silica source, sodium hydroxide, and water via hydrothermal treatment at different temperatures (130 °C to 170 °C) and periods of time (1 day to 10 days). In this study, four silica sources were selected (fumed silica, colloidal silica, Ludox HS-40%, and Ludox AS-40%). Variable conditions such as sodium hydroxide and water contents were explored at a specific temperature and reaction time. The obtained materials were characterized by using X-ray diffraction (XRD), thermogravimetry differential thermal analysis TG-DTA, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), Fourier Transform Infrared spectroscopy (FTIR), solid 29Si magic angle spinning magnetic nuclear resonance (MAS MNR, and nitrogen adsorption isotherms. A pure Na-magadiite phase was obtained from the four silica sources at a synthesis temperature of 150 °C after a period of one to two days with a characteristic basal spacing of 1.54 nm. At a longer reaction time of 3 days and a higher temperature of 170 °C, Na-kenyaite with a basal spacing of 2.01 nm was achieved, in addition to a quartz phase. The content of water or sodium hydroxide in the gel affected the nature of the prepared phases. A cauliflower-like morphology was obtained from colloidal silica sources, while a different morphology was achieved using solid fumed silica. The 29Si solid NMR confirmed the presence of Q3 and Q4 silicon sites in the Na-magadiite materials. The optimal Na-magadiite materials at 150 °C for 2 days were assessed for their ability to remove Basic Blue-41 dye from artificially contaminated aqueous solution. The Langmuir equation was used to estimate the maximum removal capacity. A maximum removal capacity of 219 mg/g was achieved using Na-magadiite prepared from a Ludox-HS40% silica source, and a maximum removal capacity of 167 mg/g was observed for Na-magadiite prepared from fumed silica. Basic Blue-4’s removal percentage was enhanced at basic pH levels (8 to 10) to a maximum of 95%. These materials could be regenerated for seven cycles of reuse with a reduction of 27 to 40% of the original values. Therefore, Na-magadiite materials are promising and efficient removal agents for the removal of Basic Blue-41 from effluents.

Effect of thermal pretreatment on the two-stage extraction of aluminum, sulfur and potassium from a fine-quartz bearing alunite

The extraction of aluminum, sulfur, and potassium from an alunite ore (Ghazvin, Iran) was studied by roasting followed by two-stage alkaline leaching. In the roasting stage, the effects of several key parameters including temperature (520 to 620 °C), reaction time (30–150 min), particle size (0.075 to 10 mm), and furnace medium (with and without diesel fuel and with charcoal) were investigated on the leachability of sulfur and potassium by sodium carbonate and of aluminum by sodium hydroxide. The first leaching stage was carried out with sodium carbonate at a pulp density of 20% (w/w), a reaction time of 4 h, a particle size of less than 75 µm, a temperature of 95 °C and a ratio of sodium carbonate to alunite of 1.5:1. The highest extractions of sulfur and potassium (99.9 % for both elements) were obtained with the ore roasted at 620 °C, a particle size of 3 mm, and a roasting time of 90 min. The extractions were significantly increased by increasing the temperature and roasting time. The second stage of leaching was conducted at the temperature of 95 °C, leaching time of 6 h and the sodium hydroxide concentration of 5 M at 15 % pulp density. The highest aluminum extraction (95.3 %) was obtained by reductive roasting with charcoal at a temperature of 570 °C, a roasting time of 30 min, and a particle size of less than 3 mm. For potassium and sulfur extraction, increasing the roasting temperature, reaction time and diesel fuel addition (above 3%) resulted in a decrease in aluminum extraction, which was attributed to the conversion of the alumina phase to a stable phase. The results of this study show that alunite ore could be an interesting alternative for alumina production.

Degradation behavior of polycarbonate during melt processing with an aqueous solution of sodium hydroxide

In this study, we aimed to enhance the reactivity of polycarbonate (PC) with the epoxy group of styrene-co-glycidyl methacrylate copolymer (SGMA) by introducing aqueous solutions of sodium hydroxide during the melt processing of PC. This approach led to the generation of hydroxyl groups at the ends of PC molecules, facilitating the formation of PC-SGMA copolymer. The effectiveness of this method in improving the compatibility of PC and styrene-acrylonitrile (SAN) blends was successfully confirmed through blending experiments with SAN and SGMA. Additionally, we investigated the impact of alkali-promoted hydrolysis on the rheological properties of PC, apart from the functionalization of PC end groups. Our findings revealed that an increase in the concentration of sodium hydroxide resulted in a decrease in the complex viscosity of PC. However, beyond a certain concentration level, the viscosity exhibited an upward trend. Furthermore, when constructing van Gurp-Palmen plots for the modified PC, we observed a significant deviation in curve shape compared to pure PC or water-modified PC. This observation suggests that changes in the microstructure occur during the degradation process due to the interaction between PC molecules and sodium ions.

Optimal Conditions for Alkaline Delignification Process in Cellulose Isolation from Sengon Wood Sawdust

Sengon wood sawdust (SWS) is a solid waste of the wood industry with the potential as a source of cellulose and can increase its economic value. However, cellulose in plants is tightly bound to lignin which is called lignocellulose therefore needs to be delignified before utilization. In this study, we determined the optimum conditions for delignification from sengon wood sawdust cellulose (SWSC). Optimization variables were determined with the parameter of obtained hemicellulose, cellulose, and lignin content. The optimization of SWSC delignification was then carried out using the factorial design by analyzing the effect of sodium hydroxide (NaOH) concentration (2% - 10%) and ratio (SWS : NaOH solution) (1:10 – 1:80) on hemicellulose, cellulose, and lignin content. Optimal conditions were obtained at 2% NaOH (1:19.20) with concentrations of 8.01% hemicellulose, 52.49% cellulose, and 22.2% lignin. One sample T-test analysis of predictive and research values of hemicellulose, cellulose, and lignin showed insignificant results (P&gt;0.05) which means that the optimization equation proved valid to determine the optimum conditions for cellulose delignification of sengon wood sawdust. FT-IR analysis, SEM imaging, and particle size distribution (PSA profile) showed that the cellulose produced under these conditions has similar characteristics to the standard of Avicel® PH 102.

Enset Fiber-Reinforced Polylactic Acid-Based Biocomposites for High-Performance Application

In recent years, there has been growing interest in using plant fibers to reinforce materials in modern manufacturing. This study focuses on the development of a novel biocomposite made from an enset fiber (EF) and polylactic acid (PLA) matrix using compression molding at a hot-pressing temperature of 170 °C and pressure of 7 MPa for 7 min. Before preparing the biocomposites, the fibers were chemically modified with different concentrations of sodium hydroxide (NaOH) and cut into shorter fibers with a 40 mm average length in size. Then, the extent of modifications on the mechanical properties, dynamic mechanical behavior, morphology, and water absorption were investigated. The tensile, flexural, and Charpy impact tests were carried out to evaluate the mechanical properties of the samples as per ASTM standards. Moreover, dynamic mechanical analysis (DMA) and the water absorbency of the biocomposites were investigated, and the results were graphically shown and explained. The results indicate that the biocomposite treated with 5% NaOH exhibited significant improvements in tensile strength, flexural strength, and impact strength compared to the untreated composite. The tensile modulus and flexural modulus of 5% NaOH-modified enset fiber biocomposite were also enhanced by 55.8% and 70.3% compared to untreated enset fiber biocomposite. The highest tensile strength, flexural strength, and impact strength found for the PLA composite reinforced by EF treated with 5% w/v NaOH solution were 20.16 MPa, 30.21 MPa, and 12.02 kJ/m2, respectively. In general, the modification of natural fibers improves adhesion at the interface and therefore decreases the water absorption and improves the dynamic mechanical properties of biocomposites.