Asmare Tezera Admase

Polymer composites have become indispensable materials for advanced engineering applications due to their lightweight nature, tunable properties, and versatile processing capabilities. The incorporation of fillers particularly ceramic, carbon-based (including graphene and carbon nanotubes), and nanoclay fillers has emerged as an effective strategy to overcome the inherent limitations of polymer matrices and achieve multifunctional performance. This review provides a comprehensive overview of the role of these fillers in polymer composites, emphasizing dispersion behavior, interfacial interactions, and structure-property relationships. The effects of filler type, morphology, size, loading level, and hybridization on mechanical, thermal, thermo-chemical, and electro-mechanical properties are systematically discussed. Special attention is given to nanofiller distribution states agglomerated, intercalated, and exfoliated and their influence on load transfer, crack deflection, barrier performance, and functional enhancement. Processing routes & dispersion-control strategies, including melt blending, solution processing, in situ polymerization, and surface functionalization, are critically examined. The review further highlights synergistic effects of hybrid filler systems and current challenges related to dispersion, scalability, and cost. Future directions in sustainable, hybrid, and bio-based filler designs are also briefly discussed to guide the development of high-performance polymer composites.

Energy storage technologies have become increasingly essential in addressing the global transition toward renewable energy systems. The rapid global shift toward renewable energy has made efficient and reliable energy storage technologies (ESTs) essential for addressing the intermittency of solar, wind, and other clean energy sources. Recent research highlights significant advancements in battery chemistries, supercapacitors, hydrogen storage, and thermal energy systems; however, persistent challenges such as high manufacturing costs, limited cycle life, low energy density, and environmental impacts continue to hinder large-scale implementation. Despite the growing number of studies, there is a lack of integrated knowledge that systematically maps recent trends, material innovations, and application specific challenges. This review aims to bridge that gap by comprehensively analyzing advancements in energy storage technologies over the past decade, evaluating key performance indicators such as energy and power density, efficiency, and lifecycle sustainability. By synthesizing findings from peer-reviewed literatures this study identifies critical barriers and emerging strategies such as nanostructured materials, hybrid systems, and circular economy approaches that could redefine future energy storage landscapes. The conclusions underscore the urgent need for interdisciplinary research, material optimization, and cost-effective designs to accelerate the development and deployment of next-generation storage technologies.

Lignocellulosic biomass, particularly bamboo, has emerged as a promising renewable energy source for bioethanol production. However, the recalcitrant nature of bamboo's complex structure poses a challenge for efficient enzymatic hydrolysis. This study comparatively evaluated the impact of acidic and thermal pretreatment approaches on enhancing fermentable sugar yields from bamboo biomass. The results demonstrated that a maximum cellulose recovery of 76.48% was achieved with a 1.5% sulfuric acid concentration, 90°C temperature, and 70-minute treatment time. The pretreatment effectively increased cellulose content while decreasing hemicellulose and lignin fractions. Furthermore, the study elucidated the influence of acid concentration, temperature, and treatment duration on reducing sugar yields, highlighting the critical role of lignin removal for efficient hydrolysis. These findings provide valuable insights into optimizing bamboo biomass pretreatment for improved bioethanol production from this renewable and abundant lignocellulosic resource

This paper evaluates the performance of biopolymer-based antimicrobial packaging solutions which designed to enhance food safety and extend shelf life. The films were subjected to a range of physico-chemical and thermomechanical tests, including mechanical properties (tensile strength), moisture absorbency, biodegradability, water vapor permeability, and antimicrobial activity. Incorporating chitosan at various concentrations (6% w/w, 12% w/w, and 18% w/w) significantly improved the films’ ability to inhibit microbial growth. The highest reduction was observed at 12% chitosan, achieving a 70% reduction in Escherichia coli (1.0 × 10^⁶ CFU/mL to 3.0 × 10^⁵ CFU/mL) and a 55% reduction in Staphylococcus aureus (1.2 × 10^6 CFU/mL to 5.4 × 10^⁵ CFU/mL) (using Eq. 6). In contrast, at 18% chitosan, effectiveness declined, stabilizing at a 68% reduction for Staph. aureus (approximately 4.8 × 10^⁵ CFU/mL), indicating that higher concentrations may hinder antimicrobial penetration and promote bacterial aggregation. The inclusion of filler (clay particles) enhanced thermal stability and mechanical integrity. The films were formulated based on specific ratios of clay to starch-chitosan (1:1:6, 7:5:12, and 10:5:18 w/w) and plasticizer to starch-chitosan (5:1:6, 6:1:12, and 7:1:18 w/w). Comprehensive analyses, including TGA–DSC, tensile strength, barrier properties, moisture absorbency, biodegradability, and antibacterial activity against E. coli and Staph. aureus, were performed. The optimal film was identified with a clay-chitosan-plasticizer ratio of 7:2:5:12, achieving a mechanical strength of 4.96 ± 0.12 MPa, a water vapor transmission rate of 3.96 ± 0.12%, and a degradation rate of 44.76 ± 0.32%. These findings suggest that these antimicrobial films are promising packaging solutions for safer food products. Graphical abstracts

The increasing demand for energy, reliance on fossil fuels, heightened environmental concerns, and the political commitments established in the Paris Climate Agreement drive the pursuit of new energy sources that are more sustainable and compatible with environmental protection. Biomass has emerged as a primary renewable energy resource, offering significant advantages in terms of its diversity, availability, and sustainability for meeting energy needs in heating, electricity generation, and biofuel production for transportation, among other applications. Various strategies have been explored for effectively utilizing biomass, ranging from biological to thermochemical conversion methods. Gasification is a thermochemical process recognized as one of the most effective methods for energy recovery from biomass, producing syngas primarily composed of hydrogen (H₂), carbon monoxide (CO), and methane (CH₄). Currently, various parameters influencing the yield of product gas and the performance of the gasifier have garnered significant attention from researchers. This paper aims to review the theory and process of biomass gasification, including the different types of gasifiers. It compiles key operational and performance parameters of the gasification process, as well as their influence on gasification conditions and products. This approach seeks to provide a comprehensive overview of hydrogen-rich syngas production based on current technologies and industrial/commercialization pathways.

The increasing demand for sustainable materials has propelled research into biomass-derived adhesives as eco-friendly alternatives to traditional synthetic options. This chapter investigates the enhancement of physicochemical and thermomechanical properties of bio-based adhesives, highlighting their applications across diverse industries, including medical devices, construction, automotive, wood and wood-based panels, and packaging. Bio-adhesives, sourced from renewable materials such as lignin, tannins, and proteins, offer advantages like biodegradability and non-toxicity. However, challenges such as low water resistance, bonding strength, and thermal stability persist. Recent advancements, including the incorporation of nanofillers and cross-linking agents, have shown promise in overcoming these limitations, significantly improving adhesive performance. In medical applications, bio-adhesives must be biocompatible and biodegradable to facilitate wound healing without harmful effects. In construction and automotive sectors, they provide sustainable bonding solutions for lightweight materials, enhancing structural integrity under various environmental conditions. The packaging industry is also benefiting from bio-adhesives derived from proteins like whey and casein, which improve barrier properties while remaining renewable. Despite their potential, the commercialization of biomass-derived adhesives faces challenges such as higher production costs and variable performance. Ongoing research aims to address these issues through physicochemical modifications and the development of standardized testing methods. This chapter underscores the transformative potential of bio-based adhesives, emphasizing their role in promoting sustainability while meeting the rigorous demands of various applications. Ultimately, enhancing the properties of these adhesives can contribute significantly to a more sustainable future in material science.

In construction engineering, there is currently a strong emphasis on finding construction materials, mainly the binder which plays a crucial role, that meet multiple criteria, including sustainability, cost-effectiveness, durability, and reduced environmental impact. However, there is a growing interest in exploring alternatives to traditional binders to address the limitations associated with their production and use. One such alternative is the use of naturally occurring materials like clay. Clay deposits are abundant and widely available, making them a sustainable resource for construction applications. Moreover, clay contains significant amounts of silica and alumina, which are key components for inducing pozzolanic reactions that contribute to the strength and durability of concrete. In recent studies, nanoclays (NCs) have emerged as a promising addition to construction materials as supplementary cementitious materials. These nanoparticles possess unique properties that can enhance the performance of concrete. Nanoclays significantly improve the compressive strength, sustainability, and durability of concrete structures. The high surface area and reactivity of nanoclays facilitate better bonding between cement particles, resulting in enhanced mechanical properties. This chapter aims to discuss the state of the art on performance enhancements of building materials that employ different types of nanoclays in place of conventional binders and the future trends.