Use of biochar co-mediated chitosan mesopores to encapsulate alkane and improve thermal properties

Biopolymer‑carbonaceous composites, progress, and adsorptive mitigation of water pollutants

Chitin is the second most abundant natural biopolymer, which is composed of N-acetyl glucosamine units linked by β-(1 → 4) Chitosan is an N-deacetylated product of chitin. Properties of chitosan and chitin, such as biocompatibility, non-toxic nature, and biodegradability, make them successful alternatives for energy and environmental applications. However, their low mechanical properties, small surface area, reduced thermal properties, and greater pore volume restrict the potential for adsorption applications. Multiple investigations have demonstrated that these flaws can be prevented by fabricating chitosan and chitin with carbon-based composites. This review presents a comprehensive analysis of the fabrication of chitosan/chitin carbon-based materials. Furthermore, this review examines the prevalent technologies of functionalizing chitosan/chitin biopolymers and applications of chitin and chitosan as well as chitosan/chitin carbon-based composites, in various environmental fields (mitigating diverse water contaminants and developing biosensors). Also, the subsequent regeneration and reuse of adsorbents were also discussed. Finally, we summarize a concise overview of the difficulties and potential opportunities associated with the utilization of chitosan/chitin carbon-based composites as adsorbents to remove water contaminants.

Innovative building materials by upcycling clothing waste into thermal energy storage matrix with phase change materials

The current volume of clothing waste reached 115 million tons in 2021 and is projected to increase to approximately 150 million tons by 2030. This significant surge in clothing waste has prompted heightened discussions regarding environmentally friendly recycling methods. Clothing presents complex properties, posing substantial challenges to recycling and usually resulting in environmental pollution when disposed. In this study, our recycling approach capitalizes on the differing melting points of textiles. This transformation was achieved through a physical process that included an opening procedure and high temperature heat compression. Textile materials exhibit exceptional thermal properties. Through experimentation on 50 g fiber specimens, thermal conductivities similar to commercial insulation materials were observed, registering an average of 0.0592 W/m·K at 20 °C and 0.06053 W/m·K at 40 °C. This study explores the impregnation of phase change materials (PCMs) into clothing waste-based specimens, equipping them with heat storage capabilities. During the experimental phase, we employed three distinct types of PCMs to evaluate their thermal properties and heat storage capacities in relation to their respective melting temperatures. Through thermal properties analysis, we determined the latent heat capacity of each specimen, ranging from a minimum of 6.63 J/g to a maximum of 75.81 J/g. Our observations indicated a reduction in peak temperature and time-leg effects attributable to the use of PCMs for surface heat flow. This research underscores the superior thermal performance of construction and building materials derived from clothing waste, enhanced by the integration of PCMs, when compared to traditional materials and other waste-derived alternatives.

Bio-Based Polymers for Environmentally Friendly Phase Change Materials

Phase change materials (PCMs) have received increasing attention in recent years as they enable the storage of thermal energy in the form of sensible and latent heat, and they are used in advanced technical solutions for the conservation of sustainable and waste energy. Importantly, most of the currently applied PCMs are produced from non-renewable sources and their carbon footprint is associated with some environmental impact. However, novel PCMs can also be designed and fabricated using green materials without or with a slight impact on the environment. In this work, the current state of knowledge on the bio-based polymers in PCM applications is described. Bio-based polymers can be applied as phase-change materials, as well as for PCMs encapsulation and shape stabilization, such as cellulose and its derivatives, chitosan, lignin, gelatin, and starch. Vast attention has been paid to evaluation of properties of the final PCMs and their application potential in various sectors. Novel strategies for improving their thermal energy storage characteristics, as well as to impart multifunctional features, have been presented. It is also discussed how bio-based polymers can extend in future the potential of new environmentally-safe PCMs in various industrial fields.

Advances in Biocarbon and Soft Material Assembly for Enthalpy Storage: Fundamentals, Mechanisms, and Multimodal Applications

High-value-added biomass materials like biocarbon are being actively pursued integrating them with soft materials in a broad range of advanced renewable energy technologies owing to their advantages, such as lightweight, relatively low-cost, diverse structural engineering applications, and high energy storage potential. Consequently, the hybrid integration of soft and biomass-derived materials shall store energy to mitigate intermittency issues, primarily through enthalpy storage during phase change. This paper introduces the recent advances in the development of natural biomaterial-derived carbon materials in soft material assembly and its applications in multidirectional renewable energy storage. Various emerging biocarbon materials (biochar, carbon fiber, graphene, nanoporous carbon nanosheets (2D), and carbon aerogel) with intrinsic structures and engineered designs for enhanced enthalpy storage and multimodal applications are discussed. The fundamental design approaches, working mechanisms, and feature applications, such as including thermal management and electromagnetic interference shielding, sensors, flexible electronics and transparent nanopaper, and environmental applications of biocarbon-based soft material composites are highlighted. Furthermore, the challenges and potential opportunities of biocarbon-based composites are identified, and prospects in biomaterial-based soft materials composites are presented.