Characterization of novel natural cellulose fiber from Ficus macrocarpa bark for lightweight structural composite application and its effect on chemical treatment.

This study investigates Ficus Macrocarpa tree bark fibers (FMB) as a sustainable alternative reinforcement for polymer composites. The Industrial Revolution marked the evolution of polymer composites with synthetic material reinforcement, leading to environmental concerns. Natural fibers have recently gained prominence as efficient alternatives for polymer composites. Despite numerous natural fibers being considered, ensuring a sustainable raw material source remains crucial. In this study, fibers were extracted from FMB and subjected to alkali treatment to evaluate their impact on physical, chemical, and thermal properties. Initially, the extracted fibers measured 253.80 ± 15 µm in diameter, reduced to 223.27 ± 12 µm post-alkali treatment. Chemical analysis showed an increase in cellulose content to 59.7 wt%, a 23.34 % improvement over untreated fibers (48.4 wt%). The crystalline index for untreated and treated fibers measured 80.20 % and 84.75 %, respectively, with no noticeable changes in the cellulose phase. Additionally, the crystalline size increased to 3.21 nm. Thermogravimetric analysis demonstrated enhanced stability of treated fibers up to 378.87 °C, while the kinetic activation energy remained constant at 64.76 kJ/mol for both the treated and the untreated fibers. The alkali treatment further improved surface roughness to 39.26, confirmed by scanning electron microscopic images. These findings highlight the potential of cellulose fibers from Ficus Macrocarpa bark as a sustainable and environmentally friendly replacement for synthetic fibers in polymer composites. The enhanced physical properties and excellent thermal stability make them a promising choice for eco-conscious materials.

Extraction of nano-crystalline cellulose for development of aerogel: Structural, morphological and antibacterial analysis.

In the present decades, nanocellulose has been very popular in the field of nanotechnology and is receiving much attention from researchers because of its advantageous physicochemical properties, high aspect ratio, and high specific strength and modulus. The available non-eco-friendly conventional methods for the extraction of nano-crystalline cellulose (NCC) use highly concentrated chemicals and are time-consuming as well. The present adopted cost-effective method for the extraction of nano-crystalline cellulose involves minimum usage of chemicals and is environmentally friendly and relatively fast compared to other conventional methods. The nano-crystalline cellulose from sisal (NCC-S) fibers were extracted by steam explosion-assisted mild concentrated chemical treatments followed by mechanical grinding. The Dynamic light scattering (DLS) and Transmission electron microscopy (TEM) characterization confirmed the size of extracted NCC-S. A high aspect ratio was observed as 19.23, which signifies it could be a promising reinforcing material in developing nanocomposites for advanced applications. An increase in crystallinity and the removal of amorphous materials for NCC-S were confirmed by X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) analysis, respectively. Antibacterial study shows that NCC-S did not show any antibacterial properties against E. coli and S. aureus. The calculated yield of extracted nanocellulose was about 50 %. The aerogel with a porosity of 95.1 % and a density of 0.075 g/cm3 was prepared by vacuum freeze-drying method using extracted nanocellulose and chitosan. The cross-linking network structure and thermal stability of the aerogel were also confirmed by FTIR and TGA analysis respectively.

Waste chicken feather biofiller reinforced bioepoxy resin based biocomposites - A waste to wealth experimental approach.

Utilizing poultry wastes, particularly chicken feathers, in biopolymer composites is seen as an important aspect in lowering the environmental pollution and paving a new path to sustainability. The main objective of this experimental study is to develop polymer composites reinforced with waste chicken feather fillers and evaluate their physical, mechanical, and thermal characteristics. The composites were fabricated through an open mold casting process using bio epoxy (SR-33 Greenpoxy) as the matrix and chicken feather filler as a reinforcement in three distinct weight fractions (2.5, 5, and 7.5 wt%). To evaluate the effects of filler content on the mechanical properties of the fabricated bio-epoxy composites, they were subjected to tensile, flexural, impact, and hardness tests. The findings from the experimental studies demonstrated that the composites containing 2.5 wt% of chicken feather filler had improved mechanical properties, thermal stability, and crystallization behaviour. The thermal attributes of samples included a greater melting point, lower recrystallization temperature, higher glass transition temperature, and quicker crystallization rates. The Scanning Electron Microscope analysis of the fracture surface morphology of the biocomposites showed a better interfacial adhesion between the filler and matrix. It could be concluded from the results that the waste chicken feather can be used as potential filler reinforcements for begetting natural composites for various low- and medium-density structural and non-structural applications.

Lignocellulose based biofiller reinforced biopolymer composites from fruit peel wastes as natural pigment.

In this study, the utilization of mangosteen and durian peel wastes as bio-filler and natural pigment in biopolymer of polybutyrate adipate terephthalate (PBAT) were examined. The related research work of hybridization of both mangosteen and durian peels reinforced in biopolymer as cellulose-based bio fillers and natural pigment is rarely studied. The content variation of mangosteen powder and durian powder ranged from 0 to 30 wt% with an increment of 10. The influence of mangosteen and durian powders reinforced in PBAT on color change, morphological, chemical composition, mechanical, thermal, and rheological properties were determined. Mangosteen peel and durian peel provided dark appearance for the green composites without pre-burn of these fruit peels. It can be concluded that mangosteen peel and durian peel can be used as bio pigment and natural reinforcement material in biopolymer matrix which can reduce massive waste of mangosteen and durian peel and add value to these wastes. These black biopolymer composites can be used in applications of eco-friendly food packaging and medicine zipper packaging. The overall mechanical properties, thermal stability, and dark color of mangosteen/PBAT composites were greater than those of durian/PBAT composites. However, durian/PBAT composites presented greater thermal and rheological properties than mangosteen/PBAT composites.

Statistical approach on the inter-yarn friction behavior of the dual-phase STF/ρ-Aramid impregnated fabrics via factorial design and 3D-RSM.

Shear thickening fluids (STFs) refer to non-Newtonian fluids of the dilatant variety, wherein their viscosity experiences a significant surge with an escalation in the shear rate. In this investigative work, the friction behavior between yarns (pull-out) and absorption of static and kinetic energy during the phenomenon of friction between yarns in STFs are performed by monophase (MP-STF) adding nano SiO2 and dual-phase (MP-STF) adding carbon nanotubes. The ρ-Aramid fabrics were reinforced via the "foulard process", and carried out on MP-STF, and DP-STF/ρ-Aramid-impregnated fabrics to evaluate and compare with the enhancement in interfacial friction properties between yarns. The results showed that DP-STF has more significant than MP-STF and MP-STF in ultimate load, kinetic shear stress, static shear stress, and friction energy level effects. The DP-STF exhibits various friction enhancement mechanisms at the yarn interface, leading to higher absorption of static and kinetic energy related to interfacial friction, as indicated by the results obtained. Furthermore, the DP-STF/ρ-Aramid impregnated fabrics exhibited ultimate load (22.23 ± 0.522 N), kinetic shear stress (35.73 ± 0.850 MPa*100), static shear stress (36.28 ± 0.900 MPa*100), and friction energy level (610.33 ± 0.250). Increased ultimate load (581.7% and 180.7%), kinetic shear stress (621.4% and 174.6%), static shear stress (550.5% and 159.1%), and friction energy level (680.2 and 186.7%) compared to WT-STF and MP-STF, respectively. The current discoveries hold immense potential for various applications in the fields of engineering and smart material technologies. These applications span a multiplicity of industries, including sports products, medical advancements, space technology, as well as protective and shielding products.

Recent advancements in lignocellulose biomass-based carbon fiber: Synthesis, properties, and applications.

A growing need to reduce the global carbon footprint has prompted all sectors to make significant efforts in this direction. For example, there has been much focus on green carbon fiber sustainability. For example, it was found that the polyaromatic heteropolymer lignin might act as an intermediary in synthesising carbon fiber. Biomass is seen as a potential carbon accommodated solid natural sources that protects the nature and has a big overall supply and widespread distribution. With growing environmental concern in recent years, biomass has gained appeal as a raw material for production of carbon fibers. Especially, the positives of lignin material include its reasonable budget, sustainability, and higher carbon content, which makes it a dominating precursor. This review has examined a variety of bio precursors that help produce lignin and have higher lignin concentrations. In addition, there has been much research on plant sources, lignin types, factors affecting carbon fiber synthesis, spinning methods, stabilization, carbonization, and activation the characterisation techniques used for the lignin carbon fiber to comprehend the structure and features. In addition, an overview of the applications that use lignin carbon fiber has been provided.

Sensitive Non-Enzymatic Glucose Electrochemical Sensor Based on Electrochemically Synthesized PANI/Bimetallic Oxide Composite.

The development of a sensitive glucose monitoring system is highly important to protect human lives as high blood-glucose level-related diseases continue to rise globally. In this study, a glucose sensor based on polyaniline-bimetallic oxide (PANI-MnBaO2) was reported. PANI-MnBaO2 was electrochemically synthesized on the glassy carbon electrode (GCE) surface. The as-prepared PANI-MnBaO2 was characterized by field emission scanning electron microscopy, Fourier transform infrared spectroscopy, energy dispersive X-ray spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. Glucose sensing on PANI-MnBaO2 is based on the electrocatalytic oxidation of glucose to the glucolactone, which gives oxidation current. The oxidation potential for glucose was 0.83 V, with a limit of detection of 0.06 µM in the linear and in the concentration range of 0.05 µM-1.6 mM. The generated current densities displayed excellent stability in terms of repeatability and reproducibility with fast response. The development of a sensitive glucose sensor as obtained in the current study would ensure human health safety and protection through timely and accurate glucose detection and monitoring.

Polymer composites from natural fibers and recycled waste surgical masks during COVID-19 pandemic.

The crucial role of face masks is highlighted in our day-to-day life during the COVID-19 pandemic. Polypropylene (PP)-based disposable face masks are widely used to hold back viral transmission. The discarded masks can create a huge burden of contamination on the environment. The purpose of this work is to recycle and reuse discarded masks to reduce environmental pollution. A simple and innovative technique to recycle surgical masks into composites of higher mechanical strength and antimicrobial properties is explored to reuse in packaging materials and cutleries. The surgical masks composed of PP fibers are recycled to use as a matrix material to reinforce with sisal and hemp fibers. The hot compression molding technique is used to sandwich the PP masks with natural fibers. The tensile strength of the composites is remarkably increased by 197% and 305% for sisal fiber composites and hemp fiber composites, respectively. The tensile elongation also increased to 574% for sisal fiber composites. The resulting composites exhibit notable antimicrobial properties against Staphylococcus aureus, a pathogen responsible for common staphylococcal food poisoning. The composites are found to be suitable to use as food contact cutleries and packaging materials.

Bioepoxy based hybrid composites from nano-fillers of chicken feather and lignocellulose Ceiba Pentandra.

In this work, fillers of waste chicken feather and abundantly available lignocellulose Ceiba Pentandra bark fibers were used as reinforcement with Biopoxy matrix to produce the sustainable composites. The aim of this work was to evaluate the mechanical, thermal, dimensional stability, and morphological performance of waste chicken feather fiber/Ceiba Pentandra bark fiber filler as potential reinforcement in carbon fabric-layered bioepoxy hybrid composites intended for engineering applications. These composites were prepared by a simple, low cost and user-friendly fabrication methods. The mechanical (tensile, flexural, impact, hardness), dimensional stability, thermal stability, and morphological properties of composites were characterized. The Ceiba Pentandra bark fiber filler-reinforced carbon fabric-layered bioepoxy hybrid composites display better mechanical performance compared to chicken feather fiber/Ceiba Pentandra bark fiber reinforced carbon fabrics layered bioepoxy hybrid composites. The Scanning electron micrographs indicated that the composites exhibited good adhesion at the interface of the reinforcement material and matrix system. The thermogravimetric studies revealed that the composites possess multiple degradation steps, however, they are stable up to 300 °C. The thermos-mechanical studies showed good dimensional stability of the composites. Both studied composites display better thermal and mechanical performance compared to neat bioepoxy or non-bioepoxy thermosets and are suitable for semi-structural applications.

A Comprehensive Review on Natural Fibers: Technological and Socio-Economical Aspects.

Asian countries have abundant resources of natural fibers, but unfortunately, they have not been optimally utilized. The facts showed that from 2014 to 2020, there was a shortfall in meeting national demand of over USD 2.75 million per year. Therefore, in order to develop the utilization and improve the economic potential as well as the sustainability of natural fibers, a comprehensive review is required. The study aimed to demonstrate the availability, technological processing, and socio-economical aspects of natural fibers. Although many studies have been conducted on this material, it is necessary to revisit their potential from those perspectives to maximize their use. The renewability and biodegradability of natural fiber are part of the fascinating properties that lead to their prospective use in automotive, aerospace industries, structural and building constructions, bio packaging, textiles, biomedical applications, and military vehicles. To increase the range of applications, relevant technologies in conjunction with social approaches are very important. Hence, in the future, the utilization can be expanded in many fields by considering the basic characteristics and appropriate technologies of the natural fibers. Selecting the most prospective natural fiber for creating national products can be assisted by providing an integrated management system from a digitalized information on potential and related technological approaches. To make it happens, collaborations between stakeholders from the national R&D agency, the government as policy maker, and academic institutions to develop national bioproducts based on domestic innovation in order to move the circular economy forward are essential.

Recycling of sisal fiber reinforced polypropylene and polylactic acid composites: Thermo-mechanical properties, morphology, and water absorption behavior.

The effect of recycling on the thermo-mechanical and water absorption behavior of polypropylene (PP)/sisal fiber and polylactic acid (PLA)/sisal fiber composites were studied. The PP-based non-biodegradable composites and PLA-based biodegradable composites were recycled for four times. The effect of recycling was determined by examining the morphology, thermo-mechanical properties, and water absorption behavior and the obtained results were compared. The results showed that the incorporation of sisal fibers in the PP and PLA matrix enhances the tensile modulus and percentage crystallinity of the composites. The tensile strength and modulus of the sisal fiber reinforced PP composites were not affected with recycling. Even though the tensile properties of PLA and PLA/sisal fiber reinforced composites are superior to PP and PP/sisal fiber composites, the PLA-based composites show a dramatic decrease in tensile strength and modulus after the first recycling due to the degradation of the polymer. The thermal stability of the PP/sisal fiber composites was not affected by the repeated recycling process. On the other hand, the PLA-based composites with higher sisal fiber content show a bit lower thermal stability after recycling. The PP-based composites show fluctuations in percentage crystallinity with recycling. On the other hand, a remarkable increase in percentage crystallinity for PLA and PLA-based composites was observed with increasing recycling times. Water diffusion study divulges that the diffusion of water into the polymer composites was reduced with recycling, irrespective of the polymer matrix.