Recent advances in applications of low-cost adsorbents for the removal of heavy metals from water: A critical review

Wood and composites cantilever beam structure has gained attention among researchers in the current years due to its universal structural applications, such as bridges, aeroplane wings, buildings, and transmission towers. However, when the structure is exposed to a constant loading for a very long time, it induces a structural collapse due to creep deformation. Therefore, it is essential to understand and identify the initial creep that can lead to structural collapse. In this study, wood and composite materials exhibit the same structural material morphology which performs as anisotropic material as it majorly contributes to failure. In this study, a state-of-the-art review of creep analysis and engineering design is carried out, with particular emphasis on the creep methodology of a cantilever beam. The existing theories and creep design approaches are grouped into two analysis methods, namely experimental and numerical approaches. To be more specific, the experimental works involved two main methods, namely load-based (conventional) and temperature-based (accelerated) techniques. Selected creep test on cantilever beam structure and coupon scale of wood and composite were highlighted and proposed as the building blocks for a prospective structural creep methodology. These aids build confidence in the underlying methods while guiding future work and areas, especially for long-term service of full-scale structure. At the end, the challenges of creep behaviour description accuracy and improvement on the strength criteria in engineering design were presented.

Woods and composites cantilever beam: A comprehensive review of experimental and numerical creep methodologies

Preparation of iminodiacetic acid-modified magnetic biochar by carbonization, magnetization and functional modification for Cd(II) removal in water

Core–shell nanoparticles are a unique class of nanostructured materials, which received significant attention in the last two decades owing to their exciting properties and a wide variety of applic...

Core–Shell Nanomaterials for Microwave Absorption and Electromagnetic Interference Shielding: A Review

Temperature dependence of creep and recovery behaviors of polymer composites filled with chemically reduced graphene oxide Part A Applied science and manufacturing

Heavy metal ions in waste water are known to affect human health, aquatic life and the overall ecosystem in adverse ways. Such pollutants need to be removed however, the technologies utilized for such removal is often expensive and is not easily accessible for all the people around the world. It has been found that chemically activated organic wastes from tomato and carrot can be utilized to remove toxic metal ions and organic pollutants from aqueous solution. To increase the efficiency of the adsorbent these were combined with activated polyethylene terephthalate (PET) to produce a composite adsorbent. This study describes the preparation of novel adsorbents from carrot, tomato and PET. The developed adsorbents were used for the removal of Co (II) from aqueous solutions. The synthesized adsorbent particles were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD), Field emission scanning electron microscope (FESEM), Electron dispersive x-ray (EDX) and thermogravimetric analysis (TGA). The effect of all the three adsorbents on the physicochemical properties of Co (II) adsorption was studied by varying different parameters such as contact time, adsorbent dose and pH. Kinetic behavior of the three adsorbents for the uptake of Co (II) were studied. The adsorption isotherms such as Langmuir and Freundlich isotherms were used to investigate the equilibrium behavior of the system. Langmuir model was best suited for the composite adsorbent with an adsorption capacity 312.50 mg/g.

A novel adsorbent from carrot, tomato and polyethylene terephthalate waste as a potential adsorbent for Co (II) from aqueous solution: Kinetic and equilibrium studies

Effects of temperature and load on the creep performance of CNT reinforced laminated glass fiber/epoxy composites

In the current era of high-strength, lightweight, and durable aircraft components, the need for carbon fiber-reinforced epoxy (CFRP) laminates is highly desired owing to their high specific strength and modulus, low coefficient of thermal expansion, and tunable properties that are unmatched by other materials. However, such components’ catastrophic failure occurs due to the interfacial defects and debonding, thereby reducing service life and economic viability. Therefore, there is a pressing need to enhance the mechanical properties of CFRPs through matrix and fiber modifications and introduce the components’ self-healing ability under a natural trigger. This study assessed the crucial role of “thermoreversible bonds” and graphene oxide (GO) “interconnects”, which worked in tandem toward significantly improving the mechanical properties and imparting self-healing properties in CFRP laminates. The laminates were fabricated with varying percentages of GO-modified epoxy matrix via vacuum-assisted resin transfer molding (VARTM) method. The carbon fibers were covalently modified with bis-maleimide (BMI) to establish a thermoreversible bond with GO at the fiber matrix interface to make interconnects. Flexural strength and interlaminar shear strength (ILSS) values for the optimized GO-modified epoxy laminates with BMI-deposited carbon fibers exhibited a significant increase of 30 and 47%, respectively. After a self-healing cycle triggered at 60 °C, they exhibited a recovery in their ILSS values up to 70%. These improvements are particularly useful for aircraft wings made up of CFRP laminates.

Thermoreversible Bonds and Graphene Oxide Additives Enhance the Flexural and Interlaminar Shear Strength of Self-Healing Epoxy/Carbon Fiber Laminates

The rapid advancement in wireless technology has become both a boon and a curse for mankind. With the development of sophisticated electronics that serve to ease our day-to-day work, the emergence of electromagnetic waves from individual components interfere with each other and harm our physical as well as mental well-being. In this scenario, epoxy-based composites are emerging to be a state-of-the-art electromagnetic interference (EMI) shielding alternative to conventional materials such as metals. Their lightweight structure and improved mechanical properties render epoxy composites extremely efficient for structural applications. Reinforcements in the form of particles/fabrics are widely used in this regard. The present review deals with the various advancements in the field of modifications of epoxy composites to develop EMI shielding materials. Primary focus has been given on the development of lightweight epoxy modified composites through carbonaceous reinforcements either in the form of particles or fiber mats. Synthesis of hybrid nanoparticles in an epoxy matrix to account for both reflection and absorption losses has also been detailed in this review. Subsequently, we present an outlook on which the direction of future research work can be carried out. Cartoon depicting the outlook of various reinforcements that have been used in the last few years in constructing epoxy composites for EMI shielding applications.

Lightweight Epoxy-Based Composites for EMI Shielding Applications

The incorporation of nano fillers in Fibre reinforced polymer (FRP) composites has been a source of experimentation for researchers. Addition of nano fillers has been found to improve mechanical, thermal as well as electrical properties of Glass fibre reinforced polymer (GFRP) composites. The in-plane mechanical properties of GFRP composite are mainly controlled by fibers and therefore exhibit good values. However, composite exhibits poor through-thickness properties, in which the matrix and interface are the dominant factors. Therefore, it is conducive to modify the matrix through dispersion of nano fillers. Creep is defined as the plastic deformation experienced by a material for a temperature at constant stress over a prolonged period of time. Determination of Master Curve using time-temperature superposition principle is conducive for predicting the lifetime of materials involved in naval and structural applications. This is because such materials remain in service for a prolonged time period before failure which is difficult to be kept marked. However, the failure analysis can be extrapolated from its behaviour in a shorter time at an elevated temperature as is done in master creep analysis. The present research work dealt with time-temperature analysis of 0.1% SiO2-based GFRP composites fabricated through hand-layup method. Composition of 0.1% for SiO2nano fillers with respect to the weight of the fibers was observed to provide optimized flexural properties. Time and temperature dependence of flexural properties of GFRP composites with and without nano SiO2 was determined by conducting 3-point bend flexural creep tests over a range of temperature. Stepwise isothermal creep tests from room temperature (30°C) to the glass transition temperature Tg (120°C) were performed with an alternative creep/relaxation period of 1 hour at each temperature. A constant stress of 40MPa was applied during the creep tests. The time-temperature superposition principle was followed while determining the Master Curve and cumulative damage law. The purpose of a Master Curve was to determine the variation of compliance with respect to increase in time and temperature of the specimen. The shift factors at any reference temperature were determined by Arrhenius activation energy method at a far lower temperature than Tg (Glass transition temperature) and by manual shift method at a temperature near Tg (Glass transition temperature).

https://iopscience.iop.org/article/10.1088/1757-899X/338/1/012020/pdf

Poulami Banerjee

Papers

A novel adsorbent from carrot, tomato and polyethylene terephthalate waste as a potential adsorbent for Co (II) from aqueous solution: Kinetic and equilibrium studies

Effects of temperature and load on the creep performance of CNT reinforced laminated glass fiber/epoxy composites

Thermoreversible Bonds and Graphene Oxide Additives Enhance the Flexural and Interlaminar Shear Strength of Self-Healing Epoxy/Carbon Fiber Laminates

Lightweight Epoxy-Based Composites for EMI Shielding Applications

Lifetime Prediction of Nano-Silica based Glass Fibre/Epoxy composite by Time Temperature Superposition Principle