321 research outputs found
Novel biopolymer-based sustainable composites for food packaging applications: A narrative review
No full textIn the contemporary era of nutrition science, food industries are facing myriad challenges in assuring quality food with extended shelf life and long-term preservation. Biopolymer-based sustainable and biodegradable food packaging materials have helped the industries to meet these challenges. Additionally, these eco-friendly materials are also alleviating the environmental concerns associated with plastic-related pollution due to their excellent biodegradability, renewability, bioavailability, and non-toxicity. Herein, biopolymer-based food packaging materials and their composites, their biodegradation mechanisms, and the effect of nano-additives on the food packaging properties are presented. This review also elucidates ongoing research investigations for meeting current challenges by using these environmentally benign materials in food packaging applications. It is anticipated that the implementation of green technology could help in improving food quality and safety while reducing food loss and plastic waste, which will assist in achieving environmental sustainability goals.</p
Recent trends in recycling and reusing techniques of different plastic polymers and their composite materials
No full textThe rising environmental concerns caused by the excess use of synthetic materials have diverted the world's attention towards sustainable materials along with a circular economy approach using recycling routes. Nowadays, composite materials have been enormously utilized in different industrial sectors, thus, causing serious accumulation of plastic waste in the environment. The end-of-life (EOL) treatments for plastic composites are imperative as these materials cannot be easily disposed of. The recycling methodologies adopted for polymer composites have two major advantages. Firstly, recycling techniques control plastic composite waste consumption. Secondly, the energy required in the recycling of plastic composite materials is quite low, compared to conventional manufacturing techniques. In this review, we highlight some recent recycling and reusing techniques adopted for plastics and their composite materials. Among all the reported recycling techniques for polymer composites, thermal recycling is best suited for the recycling of carbon fibers (CFs) and glass fibers (GFs). Through thermal recycling, the properties of recycled materials can meet the properties of virgin materials and energy is significantly lower than chemical recycling. However, mechanical recycling requires very low energy for the recycling of composites as compared to the other recycling process. It was concluded that the composite materials consumption in different industries would only be justified when recycling and reusing of composites should be given equal consideration. Additionally, the recycling of polymer composites will boost the circular economy.</p
Recycling of wind turbine blades through modern recycling technologies: a road to zero waste
No full textWind is a clean, efficient, fastest-growing, renewable energy source, which is extensively applied for power generation. The expected design lifetime of a wind turbine lies between 20 to 25 years and requires decommissioning at its end-of-life (EOL) stage. In recent years, the global trend is shifted towards power generation through wind turbines and has globally increased the decommissioned wind turbine blades (WTBs). Compared to other components of wind turbines, it is not convenient to recycle the carbon/glass fiber-reinforced composite-based WTBs, due to their complicated nature and inhomogeneity. Additionally, it is extremely harmful to landfill or incinerate WTBs, as these strategies may result in severe health and environmental issues. Consequently, recycling of WTBs is a viable pathway for the renewable energy sector that ensures the sustainability of wind turbines. To date, only 80% - 85% of the wind turbine materials can be recycled but have potential to reach at 100 % through proper attention required on recovery of all wind turbine materials and adaptation of circular economy (CE) models. The motivation behind this review is to emphasize the importance of sustainable options to treat WTB wastes and minimize the utilization of conventional EOL approaches such as landfilling and incineration. This review also shed lights on the current research and development (R&D) projects, which are related to the adaption of various hybrid recycling technologies and CE models. Moreover, this review also highlights current challenges and future developments of WTB composites. It is concluded that consistent and collaborative efforts should be made by each of the individuals, such as researchers, policy makers, and legislative and industrialist stake holders to improve the viability and effectiveness of the wind energy.</p
4D bioprinting of smart polymers for biomedical applications: recent progress, challenges, and future perspectives
No full text4D bioprinting is the next-generation additive manufacturing-based fabrication platform employed to construct intricate, adaptive, and dynamic soft and hard tissue structures as well as biomedical devices. It is achieved by using stimuli-responsive materials, especially shape memory polymers (SMPs) and hydrogels, which possess desirable biomechanical characteristics. In the last few years, numerous efforts have been made by 4D printing community to develop novel stimuli-responsive polymeric materials by considering their biomedical perspective. This review presents an up-to-date overview of 4D bioprinting technology incorporating bioprinting materials, functionalities of biomaterials as well as the focused approach towards different tissue engineering and regenerative medicine (TERM) applications. It includes bone, cardiac, neural, cartilage, drug delivery systems, and other high-value biomedical devices. This review also addresses current limitations and challenges in 4D bioprinting technology to provide a basis for foreseeable advancements for TERM applications that could be helpful for their successful utilization in clinical settings.</p
Investigation of tensile and flexural behavior of green composites along with their impact response at different energies
No full textGreen composites can reduce the use of synthetic fibers in many applications. The motivation behind the fabrication of green composites is their excellent biodegradability and recyclability. However, fundamental issues related to green composites are their inferior mechanical properties and the reinforcement’s hydrophilic nature. This paper presents the hand layup technique to produce green composites containing different ratios of synthetic fiber (E-glass) and natural fiber (Jute). The mechanical properties were characterized as per ASTM standards. The impact strength was also investigated for different impact energies. In addition to this, the numerical simulations using ABAQUS were performed. The experimental results for tensile and flexural results were compared and validated with finite element analysis (FEA) results. An error of nearly 4% was observed between the numerical and experimental results. The microscopic analysis of fractured tensile specimens indicated that more pull out of jute fabric in high jute weight percentage composites was the leading cause of its lower tensile strength.</p
Tensile strength evaluation of glass/jute fibers reinforced composites: An experimental and numerical approach
No full textPolymer-based composites have an exceptional perspective to replace traditional structural materials like steel and aluminium, owing to their low weight, high strength, and outstanding performance at elevated temperatures. However, the utilization of natural reinforcements for functional polymer composites is still in infancy. In this study, the tensile properties of natural and synthetic fiber-reinforced hybrid composites are reported. Glass-jute hybrid composites, prepared through hand layup technique, were used with different glass and jute fiber stacking sequences. The experimental results stipulate that the tensile properties of glass fiber reinforced polymer (GFRP) were merely affected at lower jute fiber concentration. The strength of composites consisting of single jute fabric lamina and four glass-fiber laminas were comparable with five-laminas GFRP composites. For validation of the experimental tensile testing results, a numerical simulation was also executed. Errors between experimental and numerical simulations were found for different stacking sequences due to non-uniformity in jute fiber diameter and the manufacturing process adopted for these hybrid composites. Fractographic analysis revealed the micro voids and adhesive failure at different joining layers of fibers as the primary cause of delamination.</p
3D printing of stimuli-responsive hydrogel materials: Literature review and emerging applications
No full textAdditive manufacturing (AM) aka three-dimensional (3D) printing has been a well-established and unparalleled technology, which is expanding the boundaries of materials science and is exhibiting an enormous potential to fabricate intricate geometries for healthcare, electronics, and construction sectors. In the contemporary era, the combination of AM technology and stimuli-responsive hydrogels (SRHs) helps to create dynamic and functional structures with extreme accuracy, which are capable of changing their shape, functional, or mechanical properties in response to environmental cues such as humidity, heat, light, pH, magnetic field, electric field, etc. 3D printing of SRHs permits the creation of on-demand dynamically controllable shapes with excellent control over various properties such as self-repair, self-assembly, multi-functionality, etc. These properties accelerate researchers to think of unthinkable applications. Additively manufactured objects have shown excellent potential in applications like tissue engineering, drug delivery, soft robots, sensors, and other biomedical devices. The current review provides recent progress in the 3D printing of SRHs, with more focus on their 3D printing techniques, stimuli mechanisms, shape-morphing behaviors, and their functional applications. Finally, current trends and future roadmap of additively manufactured smart structures for different applications have also been presented, which will be helpful for future research. This review holds great promise for providing fundamental knowledge about SRHs to fabricate structures for diverse applications
Recent advances in 3D-printed polylactide and polycaprolactone-based biomaterials for tissue engineering applications
No full textThe three-dimensional printing (3DP) also known as the additive manufacturing (AM), a novel and futuristic technology that facilitates the printing of multiscale, biomimetic, intricate cytoarchitecture, function-structure hierarchy, multi-cellular tissues in the complicated micro-environment, patient-specific scaffolds, and medical devices. There is an increasing demand for developing 3D-printed products that can be utilized for organ transplantations due to the organ shortage. Nowadays, the 3DP has gained considerable interest in the tissue engineering (TE) field. Polylactide (PLA) and polycaprolactone (PCL) are exemplary biomaterials with excellent physicochemical properties and biocompatibility, which have drawn notable attraction in tissue regeneration. Herein, the recent advancements in the PLA and PCL biodegradable polymer-based composites as well as their reinforcement with hydrogels and bio-ceramics scaffolds manufactured through 3DP are systematically summarized and the applications of bone, cardiac, neural, vascularized and skin tissue regeneration are thoroughly elucidated. The interaction between implanted biodegradable polymers, in-vivo and in-vitro testing models for possible evaluation of degradation and biological properties are also illustrated. The final section of this review incorporates the current challenges and future opportunities in the 3DP of PCL- and PLA-based composites that will prove helpful for biomedical engineers to fulfill the demands of the clinical field
3D/4D printing of cellulose nanocrystals-based biomaterials: Additives for sustainable applications
No full textCellulose nanocrystals (CNCs) have gained significant attraction from both industrial and academic sectors, thanks to their biodegradability, non-toxicity, and renewability with remarkable mechanical characteristics. Desirable mechanical characteristics of CNCs include high stiffness, high strength, excellent flexibility, and large surface-to-volume ratio. Additionally, the mechanical properties of CNCs can be tailored through chemical modifications for high-end applications including tissue engineering, actuating, and biomedical. Modern manufacturing methods including 3D/4D printing are highly advantageous for developing sophisticated and intricate geometries. This review highlights the major developments of additive manufactured CNCs, which promote sustainable solutions across a wide range of applications. Additionally, this contribution also presents current challenges and future research directions of CNC-based composites developed through 3D/4D printing techniques for myriad engineering sectors including tissue engineering, wound healing, wearable electronics, robotics, and anti-counterfeiting applications. Overall, this review will greatly help research scientists from chemistry, materials, biomedicine, and other disciplines to comprehend the underlying principles, mechanical properties, and applications of additively manufactured CNC-based structures.</p
Biopolymeric sustainable materials and their emerging applications
No full textAdvancements in polymer science and engineering have helped the scientific community to shift its attention towards the use of environmentally benign materials for reducing the environmental impact of conventional synthetic plastics. Biopolymers are environmentally benign, chemically versatile, sustainable, biocompatible, biodegradable, inherently functional, and ecofriendly materials that exhibit tremendous potential for a wide range of applications including food, electronics, agriculture, textile, biomedical, and cosmetics. This review also inspires the researchers toward more consumption of biopolymer-based composite materials as an alternative to synthetic composite materials. Herein, an overview of the latest knowledge of different natural- and synthetic-based biodegradable polymers and their fiber-reinforced composites is presented. The review discusses different degradation mechanisms of biopolymer-based composites as well as their sustainability aspects. This review also elucidates current challenges, future opportunities, and emerging applications of biopolymeric sustainable composites in numerous engineering fields. Finally, this review proposes biopolymeric sustainable materials as a propitious solution to the contemporary environmental crisis
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