Natural Biopolymer Research Articles

Extraction and Characterization of Chitosan from Eco-Green <i>Hermetia Illucens</i> for Application in Dentistry

Chitosan can be extracted from the hermetia illucens chitin. It has excellent biocompatibility, non-toxic, bioresorbable, anti-inflammatory and wound healing properties. It can be formed into a gel, granules, sheet/film, porous structure, or scaffold in dental medications. Hermetia illucens cocoons were collected and extracted from the by-product of organic waste management in Bandung City. The samples were dried in the oven at 105°C for 48h and grounded in the powder grinder and sieved. Demineralization proces were done by immersed samples in 1 M HCl for 6h. The powder then deproteinized using 1 M NaOH solution for 8h at 80 oC, filtrated, and washed with distilled water. Then, the samples were immersed in 1% KMnO4 solution for 1h, and cleaned the residue with an oxalic acid solution. Samples obtained were dried in the oven at 60 oC for 48h before deacetylated with deionized water. Characterization were done by Fourier Transform Infrared spectroscopy (FTIR), and Scanning Electron Microscope (SEM). IR spectra showed disctinctive OH bond at 3253.62 cm-1 and amide I band at 1616.98 cm-1. Degree of deacylated were calculated using infrared spectra data and resulting 77.372% indicating good character of chitosan. The result SEM were inducated typical pattern of chitosan. Further study is to fabricate the medical-grade chitosan for dental material. The chitosan from the hermetia illucens is a promising natural biopolymer for dental applications and organic waste management solutions.

Benchmarking La‐Based Perovskites as Bifunctional Cathodes For Primary and Rechargeable Zinc−Air Batteries with Biopolymer‐Based Electrolyte

AbstractState‐of‐the‐art perovskite‐based electrocatalysts for zinc−air batteries (ZABs) may include one or more Critical Raw Materials (CRMs) like Co, Ru, and rare earth elements, for oxygen reduction/evolution reactions. Under the warnings described by the CRMs Act in Europe, future research in this field must limit the use of these elements, find more sustainable formulations, and better design/integration strategies to trade off costs, supply, and performances. In this benchmarking study, three main perovskites, i. e., LaNiO3‐δ (LNO), LaMnO3+δ (LMO), and LaMn0.5Ni0.5O3 (LMNO), are studied as quasi‐CRM‐free benchmarks and integrated with a novel gel electrolyte from a natural biopolymer in primary and secondary ZABs. By comparing literature performances based on the number of total/active site CRMs for the first time, these reference perovskites showed Zn utilizations >90 % in primary ZABs, with LMO and LMNO approaching 94 % at 2 mA/cm2, the highest result in the field. In secondary ZABs, LMO demonstrated limited cyclability (62 cycles), while LMNO had a moderate number of cycles (117 cycles) and the highest round‐trip efficiency (54.3 %), while LNO presented the lowest charge potential (2.04 V) and longer cyclability (455 cycles). This work demonstrates encouraging performance with fewer CRMs and proper integration in more sustainable ZABs, opening the way to future CRM‐free perovskites.

Performance and Degradation of Nonwoven Mulches Made of Natural Fibres and PLA Polymer-Open Field Study.

The need for sustainable alternatives to conventional plastic mulches in agriculture has led to the development of various types of biodegradable mulches made from natural fibres and biopolymers to reduce environmental pollution and mitigate soil pollution caused by conventional plastic mulch usage. Degradation, impact on soil temperature and humidity, and weed suppression properties of needle-punched nonwoven mulches of different mass per unit area, made of jute, hemp, viscose, and PLA biopolymer, are investigated. Their biodegradation is determined by changes in the mulch properties (mass per unit area, thickness, air permeability, tensile properties, microscopic images, and FTIR analyses) during 300 days of exposure to the environmental conditions in the period from May 2022 to February 2023. The change in mass per unit area, thickness, air permeability, and tensile properties of nonwoven mulches did not show a tendency to degrade during exposure to environmental conditions. The microscopic and FTIR analysis showed the degradation of the fibres from the mulches during the exposure time to a certain extent. The environmental conditions influence the change in the dimensions of the mulches (shrinkage and expansion)-which impact periodically tested mass results per unit area-as well as their thickness and air permeability. The nonwoven mulches provide higher temperatures compared to bare soil, though not as high as those observed beneath traditional agricultural foil. When comparing the humidity in bare soil and soil covered by mulches during the plant growth period (June to October), it was found that soil humidity was higher beneath all mulches. The nonwoven mulches provide superior soil moisture retention compared to conventionally used agrofoil. Almost all nonwoven mulches effectively suppressed weed growth, except hemp mulches. The newly produced mulches have the potential to replace traditional agrofoil, offering improved conditions for plant growth, effective weed control, and faster degradation without causing harm to the environment.

Chitosan-photocatalyst nanocomposite on polyethylene films as antimicrobial coating for food packaging

Chitosan (CS), an edible and non-toxic natural biopolymer, has been widely used in food preservation attributed to its intrinsic antimicrobial, biodegradable, and excellent film-forming properties. In this work, we report photocatalyst-loaded chitosan coating on commercial polyethylene (PE) film with enhanced antimicrobial properties for food packaging application. To improve the chemical stability of zinc oxide (ZnO) photocatalyst in acidic chitosan matrix, a thin layer (1–5 nm) of amorphous tin oxide (SnOx) was coated on ZnO nanoparticles. Consequently, the charge transfer efficiency of ZnO is improved and most of the surface defects are retained according to the studies of UV–Vis and fluorescence spectroscopy. The thin SnOx coating on ZnO was observed by high-resolution transmission electron microscopy (HRTEM) and its effects on crystallinity and particle size of ZnO were examined using X-ray diffraction (XRD) and particle sizer, respectively. The addition of ZnO@SnOx particles in chitosan coating increases water contact angle (WCA) and enhances thermal stability of chitosan coating. The antimicrobial activity of chitosan, ZnO-SnOx nanoparticles, and CS-ZnO@SnOx coated PE films were examined against both Gram-negative (E. coli, A. faecalis) and Gram-positive (S. aureus, B. subtilis) bacteria. Compared to the limited antimicrobial effects of chitosan, ZnO-SnOx demonstrates an improved inhibition effect on bacterial growth over 48 h period under light. For the CS-ZnO@SnOx nanocomposite coated PE films, no inhibition zone was observed due to the limitation of disc diffusion method. Meanwhile, there were no bacterial colonies found to develop on the film, rendering this CS nanocomposite coating a good candidate for food packaging applications.

Structure Dependent Electrochemical Behaviors of Hard Carbon Anode Materials Derived from Natural Polymer for Next-Generation Sodium Ion Battery.

Hard carbons are one of the most promising anode materials for next-generation sodium-ion batteries due to their high reversible capacity, long cycle life, and low cost. The advantage in terms of price of hard carbons can be further improved by using cheaper resources such as biomass waste as precursors. Lignin is one of the richest natural bio-polymer in the earth which can be obtained from woods. As the lignin has three-dimensional amorphous polymeric structure, it is considered as good precursor for producing carbonaceous materials under proper carbonization processes for energy storage devices. In this study, structural properties of lignin-derived hard carbons such as interlayer spacing, degree of disorder and surface defects are controlled. Specifically, lignin-derived hard carbons were synthesized at 1000 °C, 1250 °C, and 1500 °C, and it was confirmed that the structure gradually changed from a disordered structure to ordered structure through X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy. Hard carbons exhibit sloping regions at high voltage and plateau region at low voltage during the electrochemical processes for sodium ions. As the heat treatment temperature increases, the contribution to the overall reversible capacity of the sloping region decreases and the contribution of the plateau region increases. This trend confirms that it affects reversible capacity, rate-capability, and cycling stability, meaning that an understanding of structural properties and related electrochemical properties is necessary when developing hard carbon as a negative electrode material for sodium ion batteries.

Epoxy Resin-Based Materials Containing Natural Additives of Plant Origin Dedicated to Rail Transport.

The presented study is focused on the modification of commercially available epoxy resin with flame retardants by means of using natural substances, including quercetin hydrate and potato starch. The main aim was to obtain environmentally friendly material dedicated to rail transport that is resistant to the aging process during exploitation but also more prone to biodegradation in environmental conditions after usage. Starch is a natural biopolymer that can be applied as a pro-ecological filler, which may contribute to degradation in environmental conditions, while quercetin hydrate is able to prevent a composite from premature degradation during exploitation. To determine the aging resistance of the prepared materials, the measurements of hardness, color, mechanical properties and surface free energy were performed before and after solar aging. To assess the mechanical properties of the composite material, one-directional tensile tests were performed for three directions (0, 90, 45 degrees referred to the plate edges). Moreover, the FT-IR spectra of pristine and aged materials were obtained to observe the changes in chemical structure. Furthermore, thermogravimetric analysis was conducted to achieve information about the impact of natural substances on the thermal resistance of the achieved composites.

Extraction and modification of cellulose from Artocarpus heterophyllus for biosorption of lead ion from aqueous solution as cost effective biosorbent

The heavy metals found in contaminated waters are dangerous for the environment and human health, so it is necessary to seek and apply techniques to remove these pollutants, using adsorption techniques with natural biopolymers as cost effective biosorbent. Since large amounts of Jackfruit (Artocarpus heterophyllus fruit) waste part are abandoned after the pulp used around Tepi areas, the possibility of developing value-added products from them is interesting innovation. In this work, cellulose fiber was extracted from Artocarpus heterophyllus fruit waste part and modified with Isopropyl alcohol groups to produce which were then used as Lead metal ion adsorbents. The modified cellulose was characterized by several techniques including Fourier transform infrared spectra (FTIR), scanning electron microscope (SEM), and thermogravimetric analysis (TGA). This modified cellulose was used as adsorbents for adsorption studies of heavy metal ions (Pb2+) within batch adsorption systems. A solution of lead ion (Pb2+) was used as artificial wastewater for the purpose of studying biosorption efficiencies. The biosorption efficiencies of modified cellulose were studied by using four adsorption parameters. The optimum biosorption of modified cellulose at 25 °C, were found to be 94.2%, 76.12%, 82.54%, and 90.13%, of Pb2+ for the adsorption parameter; biosorbent dosage, contact time, Pb (II) concentration, and pH respectively. The biosorption kinetics behaviour of modified cellulose for Pb2+ fitted well with a pseudo-second-order model with correlation coefficient of 0.9975. The biosorption isotherm behaviour was well described using the Langmuir biosorption isotherm model with higher correlation coefficient of 0.9935. The reusability and desorption study of modified cellulose shows that it can be reused 2 to 4 times and after 5th cycles the desorption was significantly decreased. This study showed that the modified cellulosic adsorbents made from (Artocarpus heterophyllus fruit) were able to efficiently adsorb metal ions from aqueous solution.

Sustainable natural biopolymers for biomedical applications

Biopolymers are materials specifically engineered to interact with biological systems. They can be derived from either natural or synthetic sources, depending on the biological resources used or the manufacturing process employed. Over recent decades, these materials have gained significant popularity within the medical field due to their remarkable attributes such as biodegradability, bioactivity, and compatibility with human tissue. One notable application is their use as scaffolds for bone regeneration. Biopolymers, being renewable biomaterials, provide opportunities for continuous manufacturing and technological progress across various industries. These biomaterials have demonstrated great promise in medical sectors, including nerve regeneration and the production of surgical devices. Additionally, their versatility extends to non-biomedical applications, like food packaging. This paper aims to provide a comprehensive overview of different biopolymers, elucidating their properties, showcasing their latest applications, and delving into the state-of-the-art manufacturing technologies used in their production. Special emphasis is placed on their suitability as bone tissue repair and regeneration scaffolds, owing to their unique properties, which render them an ideal choice for this specific application.

Polysaccharide nanocomposites in wastewater treatment: A review

In modern times, wastewater treatment is vital due to increased water contamination arising from pollutants such as nutrients, pathogens, heavy metals, and pharmaceutical residues. Polysaccharides (PSAs) are natural, renewable, and non-toxic biopolymers used in wastewater treatment in the field of gas separation, liquid filtration, adsorption processes, pervaporation, and proton exchange membranes. Since addition of nanoparticles to PSAs improves their sustainability and strength, nanocomposite PSAs has gained significant attention for wastewater treatment in the past decade. This review presents a comprehensive analysis of PSA-based nanocomposites used for efficient wastewater treatment, focusing on adsorption, photocatalysis, and membrane-based methods. It also discusses potential future applications, challenges, and opportunities in adsorption, filtration, and photocatalysis. Recently, PSAs have shown promise as adsorbents in biological-based systems, effectively removing heavy metals that could hinder microbial activity. Cellulose-mediated adsorbents have successfully removed various pollutants from wastewater, including heavy metals, dyes, oil, organic solvents, pesticides, and pharmaceutical residues. Thus, PSA nanocomposites would support biological processes in wastewater treatment plants. A major concern is the discharge of antibiotic wastes from pharmaceutical industries, posing significant environmental and health risks. PSA-mediated bio-adsorbents, like clay polymeric nanocomposite hydrogel beads, efficiently remove antibiotics from wastewater, ensuring water quality and ecosystem balance. The successful use of PSA-mediated bio-adsorbents in wastewater treatment depends on ongoing research to optimize their application and evaluate their potential environmental impacts. Implementing these eco-friendly adsorbents on a large scale holds great promise in significantly reducing water pollution, safeguarding ecosystems, and protecting human health.

A Facile One-Step Synthesis of Polystyrene/Cellulose (PS@MFC) Biocomposites for the Preparation of Hybrid Water-Absorbing Sponge Materials.

The elaboration of a low-cost and effective approach to synthesize hybrid composite materials based on the conventional thermoplastics and natural biopolymers is a sustainable alternative to the production of "traditional" plastics. Cellulose is one of the most abundant biopolymers. Its fibrils possess outstanding mechanical characteristics and, hence, attract considerable interest of researchers during recent decades. However, modification of the hydrophobic polymer matrix by cellulose fibrils is significantly complicated by the hydrophilic nature of the latter. In this study, we propose an effective and low-cost approach to the synthesis of polystyrene at the cellulose microfibrils composite material via the emulsion polymerization method. The obtained fibrous composite was comprehensively analyzed with FTIR spectroscopy, SEM, TGA, and DSC, and was further employed to produce sponge hybrid materials. We investigated the influence of the cellulose/polystyrene ratio on the density, porosity, pore volume, and water uptake of the obtained sponge materials. The sample containing 70 wt.% of cellulose demonstrated the best water absorption properties while preserving its shape, even after 24 h of floating on water. The produced sponge materials might be employed as sorption materials for the purification and desalination of waters of various origins, filtration, and collection of undesirable elements under specific industrial or natural conditions.

Biodegradable Packaging Based on Poly(vinyl Alcohol) and Carboxymethyl Cellulose Films Incorporated with Ascorbic Acid for Food Packaging Applications.

Petroleum-based plastics are used as packaging materials because of their low cost and high availability; however, continuous use of these nondegradable materials especially in the food industry has led to environmental pollution. The present study aimed to synthesize antibacterial and biodegradable films based on natural biopolymers carboxymethyl cellulose (CMC), poly(vinyl alcohol) (PVA), and ascorbic acid (AA) cross-linked in the presence of glutaraldehyde (GA). The films were synthesized in two different concentrations, 60PVA:40CMC:AA and 70PVA:30CMC:AA with a fixed amount of AA. Films with smooth texture and overall uniform thickness were obtained. Fourier transform infrared spectroscopy (FTIR) confirmed the cross-linking between the aldehyde group of GA and hydroxyl of PVA through detection of acetal and ether bridges. The synthesized films were thermally stable in the temperature range of 180-300 °C; however, 70PVA:30CMC:AA showed higher weight loss in this range as compared to the 60PVA:40CMC:AA film. Soil burial test demonstrated that the 60PVA:40CMC:AA film was more degradable (71% at day 15) as compared to the 70PVA:30CMC:AA film (65% at day 15). The films exhibited excellent antimicrobial activity against Gram-positive staphylococcus aureus(inhibition zone of 21 mm) and Gram-negative Escherichia coli (inhibition zone of 15 mm). In comparison, the 60PVA:40CMC:AA film showed better results in terms of high mechanical strength, uniform morphology, higher soil burial degradation, and lower water vapor transmission rate. Therefore, the prepared film could be used as a promising candidate in the food packaging industry.

Linking processing to formulation in dynamic membranes of tunable pore size for lemon oil emulsions

Lemon oil is widely used for food flavoring purposes, but due to its low water solubility and tendency to oxidation, requires encapsulation in oil-in-water (O/W) emulsions. Therefore, this study assesses the use of two natural biopolymers and a tailor-made one to encapsulate lemon oil with a dynamic membrane of tunable pore size (DMTS). This emulsification system, consisting of an outer bed layer of silica beads sitting upon a metal microporous metallic membrane, overcomes the limitations of conventional emulsification membranes, such as low throughput, complex cleaning before reuse, fixed membrane thickness and pore size, and significative protein fouling. The effects of the DMTS characteristics on the droplet size distribution and emulsion productivity were studied. The results demonstrate that mono-dispersed emulsions can be obtained using dynamic membranes for all the biopolymers studied and the productivity can reach 1000 m3 m−2h−1 pointing out the suitability of this system for scale-up.

Nexus Advances Using Marine Biopolymeric Gel Material as a Photocatalyst for the Oxidation of Agricultural Wastewater Containing Insecticides.

The attention of the research community is focused not only on waste elimination, but also on waste valorization. The natural marine biopolymer gel substance chitosan, which can be derived from the waste substances of marine life, is a polymer-matrix-based nanocomposite. Chitosan attracts special attention due to its potential applications, especially in wastewater treatment. In this regard, magnetite-incorporated chitosan powders of nanometer scale were synthesized by a simple co-precipitation method to attain the dual functions of chitosan gel and magnetite. The synthesized magnetite-incorporated chitosan nanopowders were verified using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, a vibrating-sample magnetometer (VSM), a scanning electron microscope (SEM), and transmission electron microscopy (TEM) images, which showed that the synthesized magnetite-incorporated chitosan was nanosized. The superior application of such a material to offset the deterioration of the environment caused by insecticides is attained through a photocatalytic reaction. The experimental results verified the function of magnetite-incorporated chitosan, since it increased the composite-specific surface area, resulting in high methomyl molecule oxidation. Methomyl oxidation reached almost complete insecticide removal (99%) within only one hour of irradiance time. The optimal operational conditions were investigated, and the maximal removal rate occurred when the aqueous solution was at an acidic pH of 3.0. The reaction was affected by differing hydrogen peroxide and catalyst doses, and the optimized reagent was recorded at the levels of 40 and 400 mg/L of catalyst and hydrogen peroxide, respectively. Also, catalyst reusability was attained, confirming its sustainability, since it could be used for successive cycles. From the current investigation, it is proposed that magnetite-chitosan nanoparticles could serve as a promising photocatalyst for the elimination of insecticides from wastewater in a green manner.

Interspecies interactions determine growth dynamics of biopolymer-degrading populations in microbial communities.

Microbial communities perform essential ecosystem functions such as the remineralization of organic carbon that exists as biopolymers. The first step in mineralization is performed by biopolymer degraders, which harbor enzymes that can break down polymers into constituent oligo- or monomeric forms. The released nutrients not only allow degraders to grow, but also promote growth of cells that either consume the degradation products, i.e., exploiters, or consume metabolites released by the degraders or exploiters, i.e., scavengers. It is currently not clear how such remineralizing communities assemble at the microscale-how interactions between the different guilds influence their growth and spatial distribution, and hence the development and dynamics of the community. Here, we address this knowledge gap by studying marine microbial communities that grow on the abundant marine biopolymer alginate. We used batch growth assays and microfluidics coupled to time-lapse microscopy to quantitatively investigate growth and spatial distribution of single cells. We found that the presence of exploiters or scavengers alters the spatial distribution of degrader cells. In general, exploiters and scavengers-which we collectively refer to as cross-feeder cells-slowed down the growth of degrader cells. In addition, coexistence with cross-feeders altered the production of the extracellular enzymes that break down polymers by degrader cells. Our findings reveal that ecological interactions by nondegrading community members have a profound impact on the functions of microbial communities that remineralize carbon biopolymers in nature.

Hybrid green bionanocomposites based on chitosan/starch/gelatin and metallic nanoparticles for biological applications

Multicomponent composites based on natural biopolymers: chitosan, starch and gelatin in two different ratios (0.5:1:1 and 1:1:1) were in situ crosslinked by intermolecular interactions and used as matrices for zinc oxide and magnetite fillers. The bionanocomposite films have been evaluated by spectral and microscopy methods: Fourier-Transform Infrared spectrometry (FT-IR), Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) confirming the electrostatic and hydrogen bonding interactions between the components of the polymeric matrices and the inorganic fillers and the crosslinking process. AFM and SEM images showed a compact, non-porous and homogenous morphology of the hybrid films, proving a good miscibility of the blends. At lower concentrations of embedded filler, the composites were less hardened and more ductile due to the interaction with the polymeric matrix. Increased amounts of inorganic NPs led to the reduced mechanical properties of the prepared materials and increased thermal stability. The bionanocomposites revealed a similar behavior of the dielectric constant with frequency and increased values at higher temperatures. The wettability of the films' surface and the values of the water sorption capacity revealed a slight hydrophilicity of the bionanocomposites as compared with the initial matrices. The biocompatibility, evaluated by means of the surface free energy components and the interfacial tension with blood, and the hemolysis analysis demonstrated that the bionanocomposites possess a low risk of thrombosis, being promising materials for in vivo biomedical applications.

In Situ Synthesis of Doped Bio-Graphenes as Effective Metal-Free Catalysts in Removal of Antibiotics: Effect of Natural Precursor on Doping, Morphology, and Catalytic Activity.

Wastewater contaminated with antibiotics is a major environmental challenge. The oxidation process is one of the most common and effective ways to remove these pollutants. The use of metal-free, green, and inexpensive catalysts can be a good alternative to metal-containing photocatalysts in environmental applications. We developed here the green synthesis of bio-graphenes by using natural precursors (Xanthan, Chitosan, Boswellia, Tragacanth). The use of these precursors can act as templates to create 3D doped graphene structures with special morphology. Also, this method is a simple method for in situ synthesis of doped graphenes. The elements present in the natural biopolymers (N) and other elements in the natural composition (P, S) are easily placed in the graphene structure and improve the catalytic activity due to the structural defects, surface charges, increased electron transfers, and high absorption. The results have shown that the hollow cubic Chitosan-derived graphene has shown the best performance due to the doping of N, S, and P. The Boswellia-derived graphene shows the highest surface area but a lower catalytic performance, which indicates the more effective role of doping in the catalytic activity. In this mechanism, O2 dissolved in water absorbs onto the positively charged C adjacent to N dopants to create oxygenated radicals, which enables the degradation of antibiotic molecules. Light irradiation increases the amount of radicals and rate of antibiotic removal.

Dyeing Improvement and Stability of Antibacterial Properties in Chitosan-Modified Cotton and Polyamide 6,6 Fabrics.

Cotton and polyamide 6,6 fabrics coated with chitosan, a natural biopolymer, have been tested against two different bacteria strains: Staphylococcus aureus as Gram-positive bacterium and Escherichia coli as Gram-negative bacterium. Using the ASTM standard method (Standard Test Method for Determining the Antimicrobial Activity of Antimicrobial Agents Under Dynamic Contact Conditions) for antibacterial testing, the treated fabrics is contacted for 1 h with the bacterial inoculum, the present study aims to investigate the possibility to reach interesting results considering shorter contact times. Moreover, the antibacterial activity of chitosan-treated fibers dyed with a natural dye, Carmine Red, was evaluated since chitosan has an interesting property that favors the attachment of the dye to the fiber (cross-linking ability). Finally, fabric samples were tested after washing cycles to verify the resistance of the dye and if the antibacterial property was maintained.

Функционально-технологические свойства сухих рыборастительных концентратов

The studies of the functional and technological properties of dry fish-vegetable concentrates (DFVC) justifing the technology of their use in food products are presented in the article. The important functional and technological properties that determine the consistency of products obtained by using dry concentrates are the degree of swell-ing and the kinematic viscosity of the mixtures. The samples for the study were dry fish vegetable concentrates from Sardinella (S. maderensis) based on minced fish fillet, minced fish fillet with carrots, minced fish fillet with corn flour and minced fish fillet with powdered okra. We studied the process of swelling of dry fish vegetable concentrate samples. According to the type of kinetic curves it was found that dry fish vegetables are characterized by limited swelling, which ends with the absorption of the solvent by natural biopolymers. In the course of the experiment it was found that the highest degree of swelling in dry fish vegetable concentrate was with okra (180%), the smallest – in dry concentrate from minced fish without herbal additives (140%). The degree of swelling of samples of dry fish and vegetable concentrate with okra and cornmeal is higher than that of dry fish vegetable concentrate with carrots. The highest kinematic viscosity was observed in solutions of DFVC with corn flour (3.03 mm2/s and okra (2.86 mm2/s), the lowest in the control sample without vegetable ingredients (2.21 mm2/s). Thus dry fish concentrates with okra and cornmeal are recommended for use in the preparation of sauces, pureed soups and molded culinary products.

The impact of using natural waste biopolymer cement on the properties of traditional/fibrous concrete

The naturally occurring wastes contain a large number of active groups. In this study, shrimp shell wastes were modified chemically to form chitosan. When mixing concrete with a natural polymer the result revealed a synergistic impact on the characteristics and functionality of the concrete structure. The formed chitosan was characterized by Fourier-Transform Infrared Spectroscopy (FT-IR), Thermogravimetric Analysis (TGA), X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). Five concrete mixes were designed to achieve the study objective. For certain concrete mixes, admixtures such as a natural polymer (chitosan), and chemical (superplasticizer) were added with 0.05% by weight of the cement content. Those admixtures were added to study their behavior on the characteristics of the concrete mixes, and then compare test results with control concrete mixes. Also, the purpose of the experiment was expanded to study the impact of adding the admixtures to fibrous concrete, as this fibrous concrete faces interlocking due to steel fiber's presence in the fresh concrete mixture. The results indicated that concrete-embedded chitosan exhibited significant enhancement in the mechanical properties. Further, the surface shape of concrete was characterized by the presence of chitosan crystallites which spread and filled the spaces in the chitosan structure. Also, it’s noted that chitosan can delay the rate of cement hydration to a small value, which may help in hot weathering concrete.

Green nanocomposite synthesis and application: Electrochemically exfoliated graphene-modified biopolymer as an effective clay swelling inhibitor for water-based drilling muds

The expansion of shale formations causing wellbore instability is a costly challenge in drilling operations. To address this issue, researchers have explored the potential of graphene as a shale swelling inhibitor and fluid loss controller. However, the practical application of graphene has been hindered by settling and limited dispersion in drilling muds. In this study, we present a promising solution using low-cost graphene prepared through simple electrochemical exfoliation of graphite. The resulting graphene was further combined with a natural biopolymer to create a nanocomposite. The nanocomposite, known as electrochemically exfoliated graphene-modified Gum Arabic (GrO-ArG), was evaluated as a fluid loss controller and shale swelling inhibitor in water-based drilling muds. To assess its inhibition potential, linear swelling and capillary suction timer tests were employed using different concentrations of the nanocomposite. Additionally, the performance of the drilling mud was examined through rheology and fluid loss tests. The experimental outcomes revealed that modified graphene showed strong dispersion in the water compared to graphene with minimum settling with time. The modified graphene showed stable dispersion in different pH and salinity solutions. GrO-ArG prominently reduced the linear swelling of bentonite clay (Na-Ben). It was observed that the decline in linear swelling was the function of the concentration of GrO-ArG, such as 1 wt% of ArG-GrO-A and ArG-GrO-B reduced the linear swelling by 37.8% and 43.9% correspondingly as compared to deionized water. The zeta potential measurement confirms the adsorption of GrO-ArG with the Na-Ben. The addition of GrO-ArG also revealed a prominent decrease in fluid loss. After the addition of ArG-GrO-A and ArG-GrO-B, the fluid loss declined from 11.3 mL to 8.2 mL and 7.1 mL respectively. A decrease in shear stress was also observed due to the addition of GrO-ArG in the drilling mud. From the experimental findings, it can be inferred that GrO-ArG is a strong candidate that might serve as an alternate green clay swelling inhibitor and fluid loss controller for water-based drilling muds.