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The concern over agricultural waste disposal can be resolved by converting them into value-added products. Here, sustainable fruit coatings and films have been developed via. wealth from waste concept. The cellulose nanofibers (CNF) have been extracted from the waste onion skin. The isolated CNF has been characterised using scanning electron microscopy (SEM), transmission electron microscopy (TEM), optical microscopy (OM), dynamic light scattering (DLS) and solid-state 13C NMR spectroscopy. A combination of cellulose nanofiber (CNF) and nanocurcumin in polyvinyl alcohol (PVA) matrix has been used for the fabrication of coating over fresh mandarin oranges. The effect of nanocurcumin in PVA-CNF nanocomposite on the post-harvest maintenance of mandarin oranges has been investigated. The morphology of the prepared films is studied by SEM and atomic force microscopy (AFM). The quality of the orange fruits coated using the above formulation by dip coating method was analysed via. weight loss analysis, total soluble solid (TSS), pH, titrable acidity (TA) and antioxidant activities. It was found that the nanocurcumin incorporated PVA-CNF coating was effective in reducing mass loss and maintaining the physiochemical properties of oranges in comparison with other formulations. The developed method could be extended to use as food packaging films, which would be a sustainable solution for agricultural waste valorisation and plastic pollution. Through this research work, we propose an environment friendly approach for the preservation of fruits and vegetables.

Fiber-reinforced composites are among the recognized competing materials in various engineering applications. Ramie and pineapple leaf fibers are fascinating natural fibers due to their remarkable material properties. This research study aims to unveil the viability of hybridizing two kinds of lignocellulosic plant fiber fabrics in polymer composites. In this work, the hybrid composites were prepared with the aid of the hot compression technique. The mechanical, water-absorbing, and thickness swelling properties of ramie and pineapple leaf fiber fabric-reinforced polypropylene hybrid composites were identified. A comparison was made between non-hybrid and hybrid composites to demonstrate the hybridization effect. According to the findings, hybrid composites, particularly those containing ramie fiber as a skin layer, showed a prominent increase in mechanical strength. In comparison with non-hybrid pineapple leaf fabric-reinforced composites, the tensile, flexural, and Charpy impact strengths were enhanced by 52.10%, 18.78%, and 166.60%, respectively, when the outermost pineapple leaf fiber layers were superseded with ramie fabric. However, increasing the pineapple leaf fiber content reduced the water absorption and thickness swelling of the hybrid composites. Undeniably, these findings highlight the potential of hybrid composites to reach a balance in mechanical properties and water absorption while possessing eco-friendly characteristics.

Abstract A novel bio adsorbent was fabricated from turmeric, polyvinyl alcohol and carboxymethyl cellulose for MB dye removal. The physicochemical, antibacterial and biodegradable nature of the film was evaluated using scanning electron microscopy, optical microscopy, universal testing machine, water contact angle, thermogravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffraction, agar disc diffusion method and soil degradability. The inclusion of turmeric into PVA/CMC film improves the biodegradability, antibacterial activity and thermomechanical property of the films. PVA/CMC/TUR film displayed good MB adsorption capacity (qe: 6.27 mg/g) and maximum dye adsorption (R%; 83%) and was achieved at initial dye concentration of 10 mg/L with contact time 170 min at room temperature. The adsorption data of MB on PVA/CMC/TUR film was evaluated using four models Langmuir, Freundlich, Temkin and D-R isotherms. The different kinetic of adsorption (pseudo-first order, pseudo-second order and intraparticle diffusion model) was also applied for adsorption of MB on the films. The experimental result suggests that PVA/CMC/TUR films are an alternate cheap adsorbent for water treatment.

Short Sansevieria cylindrica fibre/polylactic acid composites (SCFP) were fabricated using a twin screw extruder followed by the hot press technique, with variations in fibre loadings of 10 wt%, 20 wt%, 30 wt% and 40 wt%. The thermal properties of SCFP were assessed through dynamic mechanical analysis (DMA), thermomechanical analysis (TMA), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Notably, the samples loaded with 40 wt% of fibre exhibited an increased storage modulus. In terms of loss modulus, the fibre-loaded samples displayed high values, indicating more heat is released during DMA experiment. Interestingly, the composite trend did not solely rely on increasing fibre loading, highlighting the intricate interplay between reinforcement and matrix crucial for determining viscoelastic properties across various temperatures. The TGA results revealed a decrease in inflection temperature with increasing fibre loadings, accompanied by a proportional rise in residues. The DSC thermograms indicated minimal differences in T _g , T _cc , and T _m values among composites with varying fibre loadings. However, neat PLA showed slightly higher values than the composites. On the other hand, reinforcing SCF into the PLA matrix promoted the crystallization of PLA by 1%–3% with the maximum degree of crystallinity of 25.4% obtained for 30 wt% of SCFP.

Plant fibers are increasingly used in fabricating polymer composite components useful in the automotive, construction, and aerospace industries. This surge in the usage of plant fibers in different industries is owing to the improved understanding of the toxicity of synthetic fibers. It is essential to point out that “Humans need earth, not earth needs humans” therefore policymakers and researchers are working on replacing traditional materials with green materials. Plant fibers are green materials with many advantages over synthetic materials, such as easy processing, reduction of CO2 emissions, biodegradable, recyclable, good thermomechanical properties, and better compatibility with human health. Therefore, plant fibers are extensively used as a modifier for polymers. The drawbacks of plant fibers are the presence of OH groups in their basic structure and the presence of amorphous components. Both these drawbacks can be reduced by chemically treating the fibers. Further coupling agents can be used to increase the compatibility between the fiber and polymer. It is reported that incorporating fibers (non-continuous or continuous), and fiber mats as a reinforcement for polymers improve the mechanical, thermal resistance, thermal conductivity, and surface properties. Accelerated aging studies also reported favourable results for the use of plant fiber-based composites for long-term outdoor applications. However, plant fibers have lower strength and are hydrophilic compared to synthetic fibers, more research is required to overcome fully these drawbacks. This review examines and discusses the fundamentals of plant fiber, its processing, drawbacks, recent research trends, composites properties, prospects, and potential applications.

Abstract 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.

Organic dyes are a severe threat to aquatic life. Most dyes are toxic, non-biodegradable, and likely carcinogenic. Dyes are usually removed from water via adsorption using adsorbents like wood, seaweed, algae, etc. However, traditional treatment methods are ineffective to an extent. Nanoparticles have emerged as excellent materials for dye removal due to their superb surface properties and chemical reactivity. Many different adsorbents are used today; one example is nanocomposites with embedded silver nanoparticles. In nanocomposites, silver nanoparticles embedded on graphene oxide sheets, carbon nanotubes, cellulose, orange peel, biopolymers, etc., are reported. The solid and hydrogel-based metallic and bimetallic silver nanoparticle-based nanocomposites are successful enough to degrade dyes. These nanocomposites had high reusability, stability, high surface area, tunable properties, selectivity, cost-effectiveness, excellent processability, and recyclability. For instance, AgNPS/alginate composites reported high reusability with recyclability up to 25 times. This article sheds light on the use of biopolymer composites with embedded Ag-NPs for effective dye removal. Various preparation methods as well as the kinetics of the reaction are also discussed.

In this work, graphene was used as a filler for banyan aerial root fibers reinforced epoxy composites at various compositions. The synergetic effect of graphene and banyan fibers, on the physical and mechanical characteristics of the epoxy thermoset, was studied. The mechanical tests, hardness, water absorption behavior and morphology of the composites were studied. Significant improvement in tensile strength, flexural strength, shore D hardness and substantial reduction in the percentage of water absorption was observed. This paper also discusses the ideal proportion of banyan fibers with graphene powder for the development of the improved epoxy composites. The optimum concentration of the composites was observed at 4% of graphene powder in the 40% banyan fiber-reinforced hybrid epoxy composites. From the results, it is proved that graphene combined with 40% banyan fiber-reinforced epoxy hybrid composites will efficiently improve the strength of the composites.

Abstract In the present work, we have developed a mesoporous silicalite-1 using CMC as a template for the removal of MB from aqueous solution. The synthesized silicalite-1 were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Energy-dispersive X-ray spectroscopy (EDAX) and N2 adsorption–desorption isotherm (BET). XRD and FT-IR analysis confirmed the formation of crystallinity and development of MFI structure in the mesoporous silicalite-1. The adsorption of MB dye on mesoporous silicalite-1 was conducted by batch adsorption method. The effect of various parameters such as adsorbent dosage, initial dye concentration, contact time and temperature on the dye uptake ability of silicalite-1 was investigated. The operating parameters for the maximum adsorption are silicalite-1 dosage (0.1 wt%), contact time (240 min), initial dye concentration (10 ppm) and temperature (30 ℃). The MB dye removal onto mesoporous silicalite-1 followed pseudo-second-order kinetic and Freundlich isotherm. The silicalite-1 exhibits 86% removal efficiency even after six adsorption–desorption cycle. Therefore, the developed mesoporous silicalite-1 is an effective eco-friendly adsorbent for MB dye removal from aqueous environment.

Biofillers based on cellulose, chitin, starch, and their composites have been topics of interest during the last few decades because of their eco-friendliness, low-cost, and good thermomechanical properties. The biofillers based on plant fibers are hydrophilic that reduce the compatibility with rubber matrix. In this manuscript, an effort has been made to review cellulose, chitin, and starch, focusing on their preparation and properties of natural rubber (NR) based composites reinforced with these fillers. The main characterization properties of NR based composites, such as mechanical, thermal, and biodegradability were discussed. The filler-NR interactions were also explored. The small size of the filler improved the physical interaction between the filler and matrix, and consequently, mechanical, thermal, sorption, crystallinity, and biodegradability of the biofillers/NR composites were found to be improved. Finally, the applications of NR-based composites reinforced with cellulose, chitin, and starch were reviewed in different areas such as medical, food packaging, footwear, sensors and water purification to study their practical uses.

Recently, considerable interest has been focused on developing greener and biodegradable materials due to growing environmental concerns. Owing to their low cost, biodegradability, and good mechanical properties, plant fibers have substituted synthetic fibers in the preparation of composites. However, the poor interfacial adhesion due to the hydrophilic nature and high-water absorption limits the use of plant fibers as a reinforcing agent in polymer matrices. The hydrophilic nature of the plant fibers can be overcome by chemical treatments. Cellulose the most abundant natural polymer obtained from sources such as plants, wood, and bacteria has gained wider attention these days. Different methods, such as mechanical, chemical, and chemical treatments in combination with mechanical treatments, have been adopted by researchers for the extraction of cellulose from plants, bacteria, algae, etc. Cellulose nanocrystals (CNC), cellulose nanofibrils (CNF), and microcrystalline cellulose (MCC) have been extracted and used for different applications such as food packaging, water purification, drug delivery, and in composites. In this review, updated information on the methods of isolation of nanocellulose, classification, characterization, and application of nanocellulose has been highlighted. The characteristics and the current status of cellulose-based fiber-reinforced polymer composites in the industry have also been discussed in detail.

In this work, we have developed super tough ternary polymer blends and composites composed of polystyrene (PS), low-density polyethylene (LDPE), polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SEBS) and exfoliated graphene nanoplatelets (xGnP). A 50/50 composition of PS and LDPE was selected for making the binary blend. The addition of xGnP in the binary blend reduces the tensile strength, elongation at break and tensile toughness considerably due to the unfavorable interactions existing between PS, LDPE, and xGnP. On the other hand, the mechanical properties of PS/LDPE binary blends are considerably improved by the addition of SEBS at the expense of modulus. The best results were obtained for a 33/33/33 (PS/LDPE/SEBS) composition. Further, different concentrations of xGnP were incorporated in the ternary blend with 33/33/33 composition. Interestingly, the composites show a significant improvement in mechanical properties especially for 2.91 wt% xGnP modified ternary blend. The DMA studies revealed that the stress with in the ternary composites are minimum when compared with binary blends and their composites. The variation in the phase morphology of the binary blends by the addition of SEBS and xGnP is responsible for the dramatic changes in mechanical and viscoelastic properties. This study validates large improvement in mechanical properties of the PS/LDPE polymer blends by the careful selection of SEBS and xGnP. Keywords: Polystyrene, Low-density polyethylene, Polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene, Exfoliated graphene nanoplatelets, Toughened plastics

This article presents a comprehensive review on the recent development of graphene and its derivatives in the design and engineering of smart sensors, actuators and soft robotics. Comparing with traditional materials used in the fabrication of sensors and actuators, graphene and its derivatives obviously improved the sensitivity and selectivity of the devices due to their unique properties stemmed from graphene. In this article, we summarized mechanisms, design and engineering, and development of different graphene-based sensors actuators and soft robotics. We also selectively discussed on different techniques and methodologies to improve the performance of graphene-based sensors actuators and soft robotics, especially sensitivity and selectivity. To yield significant improvement and extend the field of applications, scientists have to improve the production of high-quality graphene, enhance the interface and interaction between graphene and other materials, develop multi-functional sensors or actuators, and finally achieve industrial production. Finally, the current challenges, prospective and potential soft robot application of various graphene-based sensors and actuators have been highlighted in detail.

Epoxy resins as important organic matrices, thanks to their chemical structure and the possibility of modification, have unique properties, which contribute to the fact that these materials have been used in many composite industries for many years. Epoxy resins are repeatedly used in exacting applications due to their exquisite mechanical properties, thermal stability, scratch resistance, and chemical resistance. Moreover, epoxy materials also have really strong resistance to solvents, chemical attacks, and climatic aging. The presented features confirm the fact that there is a constant interest of scientists in the modification of resins and understanding its mechanisms, as well as in the development of these materials to obtain systems with the required properties. Most of the recent studies in the literature are focused on green fillers such as post-agricultural waste powder (cashew nuts powder, coconut shell powder, rice husks, date seed), grass fiber (bamboo fibers), bast/leaf fiber (hemp fibers, banana bark fibers, pineapple leaf), and other natural fibers (waste tea fibers, palm ash) as reinforcement for epoxy resins rather than traditional non-biodegradable fillers due to their sustainability, low cost, wide availability, and the use of waste, which is environmentally friendly. Furthermore, the advantages of natural fillers over traditional fillers are acceptable specific strength and modulus, lightweight, and good biodegradability, which is very desirable nowadays. Therefore, the development and progress of “green products” based on epoxy resin and natural fillers as reinforcements have been increasing. Many uses of natural plant-derived fillers include many plant wastes, such as banana bark, coconut shell, and waste peanut shell, can be found in the literature. Partially biodegradable polymers obtained by using natural fillers and epoxy polymers can successfully reduce the undesirable epoxy and synthetic fiber waste. Additionally, partially biopolymers based on epoxy resins, which will be presented in the paper, are more useful than commercial polymers due to the low cost and improved good thermomechanical properties.

A facile approach to prepare bionanocomposites of poly(butylene adipate-co-terephthalate) (PBAT) is reported in this paper. The effect of different wt% of hemp/Sihemp, carbon nanofiber (CNF) and silver nanoparticle (Ag-NPs) on the density, water absorption, melting and crystallization behavior, thermal stability, mechanical properties and morphology was investigated. The density of the composites was reduced except for Ag-NPs reinforced nanocomposites while diffusion coefficient and maximum water absorption were decreased for Sihemp reinforced composites making it a suitable material to replace conventional polymers. Significant improvement in tensile strength (TS) and tensile modulus (TM) was observed for the PBAT/Sihemp composites. For CNF and Ag-NPs reinforced nanocomposites, mechanical properties were retained at lower filler concentration. But as the concentration increased, there was a tendency for the nanofillers to agglomerate, which resulted in a reduction in mechanical properties.

The increase in awareness of the damage caused by synthetic materials on the environment has led to the development of eco-friendly materials. The researchers have shown a lot of interest in developing such materials which can replace the synthetic materials. As a result, there is an increase in demand for commercial use of the natural fiber-based composites in recent years for various industrial sectors. Natural fibers are sustainable materials which are easily available in nature and have advantages like low-cost, lightweight, renewability, biodegradability, and high specific properties. The sustainability of the natural fiber-based composite materials has led to upsurge its applications in various manufacturing sectors. In this paper, we have reviewed the different sources of natural fibers, their properties, modification of natural fibers, the effect of treatments on natural fibers, etc. We also summarize the major applications of natural fibers and their effective use as reinforcement for polymer composite materials.

Effects of blend composition and compatibilizer concentration on the thermal degradation and crystallization characteristics of polyolefin blends are reported. Phase morphology and therefore, blend composition played a crucial role in the thermal degradation behaviour of the blends. Although compatibilization significantly improved the thermal stability of the blends, melting and crystallization parameters of the polymers were only marginally affected. Compatibilized blends with co-continuous morphology exhibited a type of “co-degradation” and “co-crystallization”.

Epoxy-based biocomposites are a good alternative for metals in lightweight applications. This research has been focused on the effect of accelerated weathering on the mechanical, thermal, contact angle, and water absorption behavior of neat epoxy, individual kenaf and sisal, and kenaf/sisal hybrid epoxy composites. The composite was fabricated by hand layup method. Among the various composites studied, sisal/kenaf/sisal hybrid epoxy composites showed the best properties and retained the thermo-mechanical properties with the lowest water absorption properties even after the weathering test. Thus, composites with hybridized kenaf and sisal with sisal outer layer are encouraging semistructural materials in outdoor applications.

Ionic liquids are promising candidates with huge potential in combination with thermosetting polymers. However, the behavior of ionic liquid modified epoxy system towards outdoor environmental conditions are seldom reported. Therefore, it is interesting to study the effect of accelerated weathering on ionic liquid modified bioepoxy blends. In this work, bio-based epoxy resin and 1-Butyl-3-methylimidazolium chloride (BMIM[Cl]) ionic liquid blends were prepared by melt mixing method. The concentration of ionic liquid used was 0, 5, 10, 20, and 30 phr. The miscibility, morphology, thermo-mechanical, and surface hydrophilicity of the ionic liquid modified bioepoxy blends were studied before and after the accelerated weathering test. The miscibility of the blends was studied by Fourier transform infrared spectroscopy (FTIR). The FTIR results demonstrate the presence of charge transfer complexation reaction between ionic liquid and bioepoxy resin. The tensile strength and modulus were reduced while the elongation at break is increased with the addition of ionic liquid. On the other hand, the glass transition temperature and thermal stability of the bioepoxy blends were reduced with the addition of ionic liquid. The contact angle value increases with the incorporation of up to 10 phr ionic liquid, this is followed by a decrease. The interaction between the ionic liquid and bioepoxy resin has vanished after the weathering test. The elongation at break was reduced dramatically after the weathering test, especially for 20 and 30 phr blends. The thermal stability of the weathered samples is similar to that of the samples before weathering. While the T _g values of the blends are stable with respect to neat bioepoxy resin. On the other hand, the contact angle value of the bioepoxy blends increased after the weathering test due to the increased surface roughness after weathering.