Search Results (557)

With the low-carbon transformation of the steel industry, using low-carbon raw materials is one of the important ways to achieve the “dual carbon” goals. Pellets have great physical and chemical properties as low-carbon furnace materials, which can significantly reduce blast furnace carbon emissions, exhibiting favorable overall environmental benefits. Increasing their proportion in the furnace is one of the important measures the steel industry can take to reduce carbon emissions. Binders play a critical role in the pelletizing process, and their properties directly influence pellet quality, thereby affecting the subsequent blast furnace smelting process. Compared with traditional bentonite, organic binders have become a potential alternative material due to their environmental friendliness, renewability, and ability to significantly reduce silica and alumina impurities in pellets while improving the iron grade. This work systematically elucidates the mechanism of organic binders, which primarily rely on the chemical adsorption of carboxyl groups and the hydrogen bonding of hydroxyl groups to enhance pellet strength, and then provides three typical examples of organic binders: lignosulfonate, carboxymethyl cellulose (CMC), and carboxymethyl starch (CMS). The common characteristic of these organic binders is that they are derived from renewable biomass through chemical modification, which is a derivative of biomass with renewable and abundant resources. However, the main problem with organic binders is that they burn and decompose at high temperatures. Current research has achieved technological breakthroughs in pellet quality by combining LD sludge, low-iron oxides, and nano-CaCO₃, including improved iron grade, reduced reduction swelling index (RSI), and enhanced preheating/roasting strength. Future studies should focus on optimizing the molecular structure of organic binders by increasing the degree of substitution of functional groups and the overall degree of polymerization. This approach aims to replace traditional bentonite while exploring applications of composite industrial solid wastes, effectively addressing the high-temperature strength loss issues in organic binders and providing strong support for the steel industry to achieve the green and low-carbon goals. Full article

Edible hydrogels are the central material class in 3D food printing because they reconcile two competing needs: (i) low resistance to flow under nozzle shear and (ii) fast recovery of elastic structure after deposition to preserve geometry. This review consolidates the recent years of progress on hydrogel formulations—gelatin, alginate, pectin, carrageenan, agar, starch-based gels, gellan, and cellulose derivatives, xanthan/konjac blends, protein–polysaccharide composites, and emulsion gels alongside a critical analysis of printing technologies relevant to food: extrusion, inkjet, binder jetting, and laser-based approaches. For each material, this review connects gelation triggers and compositional variables to rheology signatures that govern printability and then maps these to process windows and post-processing routes. This review consolidates a decision-oriented workflow for edible-hydrogel printability that links formulation variables, process parameters, and geometric fidelity through standardized test constructs (single line, bridge, thin wall) and rheology-anchored gates (e.g., yield stress and recovery). Building on these elements, a “printability map/window” is formalized to position inks within actionable operating regions, enabling recipe screening and process transfer. Compared with prior reviews, the emphasis is on decisions: what to measure, how to interpret it, and how to adjust inks and post-set enablers to meet target fidelity and texture. Reporting minima and a stability checklist are identified to close the loop from design to shelf. Full article

Waste materials have emerged as attractive low-cost feedstocks for adsorbent development in environmental remediation and materials engineering. Organic wastes are particularly rich in cellulose, hemicellulose, lignin, and pectin, which provide reactive oxygenated groups such as hydroxyls and carboxyls. While inorganic wastes offer stability, lower water retention makes them promising candidates. This study explores the functionalization of waste-derived organic and inorganic matrices using two amine-based agents: 3-aminopropyltrimethoxysilane (APTMS) and polyethylenimine (PEI). The materials were categorized as organic (orange peel, corn cob) or inorganic (silica gel, eggshell) and subjected to a pretreatment process involving drying, grinding, and sieving; inorganic substrates additionally underwent acid activation with citric acid. Surface modification was carried out in ethanolic (APTMS) or aqueous (PEI) media. To assess their suitability and processability as particulate sorbents, drying kinetics, physicochemical properties (FTIR, ζ-potential, pH, conductivity, Boehm titration), and flow characteristics (Carr and Hausner indices) were evaluated. The findings enable a comparative analysis of the functionalization efficiency and elucidate the relationship between substrate type (organic vs. inorganic) and its performance as a modified adsorbent. This approach advances the development of novel sorbent matrices for greenhouse gas mitigation while reinforcing circular economy principles through the valorization of low-cost, readily available waste materials. Full article

Three-dimensional (3D) bioprinting has become one of the most advanced and useful innovations that allows the creation of personalized macroscopic and microscopic constructs at different scales that match a patient’s anatomy. Intensive research efforts are currently underway to develop highly printable and biocompatible materials. Among the variety of bioprinting materials (i.e., biomaterial inks), naturally derived hydrogels have attracted great interest due to their beneficial properties in terms of biocompatibility, cost-effectiveness, and biodegradability. In this proceeding paper, we provide an overview of the formulation and use of three functional polysaccharides as ink-based hydrogels. First, 3D bioprinting is summarized as revolutionary technology that is able to create cell-laden structures layer by layer in a specific pattern that mimics native tissue and organs. Cellulose, chitosan, and lignin are presented below, followed by an overview of their applicability in 3D bioprinting, focusing on printability and the resulting printed 3D structures as illustrated in various published figures. In the same way, a comparative overview of 3D bioprinting applications is summarized. Finally, a section dedicated to comparisons, limitations, and crosslinking strategies is provided. It is worth noting that this proceedings paper provides a brief overview rather than a comprehensive review, as it is limited by page constraints and is based on the content of our poster presented at the 1st International Online Conference on Bioengineering. Full article

Water-developable photoresist was synthesized by introducing methacrylate groups into hydroxypropyl cellulose (HPC), a cellulose derivative, via substitution of hydroxyl groups. The material enabled micropatterning through ultraviolet (UV) exposure at a wavelength of 365 nm with an exposure dose of 450 mJ/cm². Line and dot micropatterns were formed on polypropylene substrates applying underlayer, achieving resolutions of 4.5 µm and 5.0 µm, respectively. The photoresist demonstrated superior etching resistance under CF₄ plasma compared to another water-soluble photo resist. Unlike conventional photoresists that require hazardous organic solvents, this water-developable photoresist offers an environmentally friendly alternative, reducing health risks and environmental impact in the electronics industry. Full article

Phosphorylated cellulose nanocrystals (P-CNCs) are a superior alternative to conventional sulfuric acid-derived CNCs because of their enhanced thermal and colloidal stability. However, further research is needed to understand the factors influencing their synthesis and properties for advanced material applications. In this study, P-CNCs were synthesized from bleached hardwood kraft pulp (BEKP) using a controlled hydrolysis method involving pretreatment with H₃PO₄ followed by reaction with metaphosphoric acid (HPO₃) and urea. To optimize the process, a full factorial design was employed to evaluate the effects of reaction time (60–90 min) and HPO₃ concentration (3–4 M). The P-CNCs were characterized using physicochemical, morphological, and thermal analyses. Surface charge densities ranged from 757 to 1993 mmol/kg, with exceptional colloidal stability, as evidenced by zeta potentials ranging from −30.17 to −67.40 mV. Statistical analysis showed that reaction time had a significant main effect on surface charge (p-value = 0.0022) and zeta potential (p-value = 0.0448), while a significant interaction between reaction time and HPO₃ concentration was observed when analyzing the surface charge (p-value = 0.0097), suggesting a combined effect of these factors on the surface modification of CNC. Crystallinity indices ranged from 63.6% to 71.3%, and the thermal stability exceeded that of the raw material. These findings contribute to a better understanding of the surface modification and stability of P-CNCs and support efforts to sustainably produce functional CNCs for advanced composite applications. Full article

The growing demand for sustainable alternatives to petroleum-based plastics has driven interest in bio-based packaging derived from renewable plant biomass. Cellulose, the most abundant biopolymer on Earth, provides high tensile strength, water resistance, and biodegradability, making it a key raw material for eco-friendly packaging. However, its extraction and processing are hindered by lignin, a complex polymer that adds structural rigidity but reduces cellulose accessibility. Recent research has identified plant microRNAs (miRNAs) as powerful post-transcriptional regulators capable of modifying cell wall composition by simultaneously targeting multiple genes involved in lignin biosynthesis, cellulose synthesis, and secondary cell wall formation. By fine-tuning specific miRNAs, it is possible to increase cellulose yield, reduce lignin content, and enhance overall biomass productivity without severely compromising plant growth or stress tolerance. This review summarizes the roles of major plant miRNAs in biomass regulation and outlines biotechnological strategies such as transgenic overexpression, target mimicry, artificial miRNAs (amiRNAs), and CRISPR-based editing for improving bio-based packaging feedstocks. Harnessing miRNA-mediated gene regulation offers a promising pathway toward producing high-quality biomass with optimized cellulose–lignin ratios, enabling more efficient, cost-effective, and sustainable packaging material production. Full article

Cellulose nanocrystals (CNCs), derived from renewable cellulose sources, have emerged as a versatile class of nanomaterial with exceptional mechanical strength, tuneable surface chemistry and inherent biocompatibility. In the scenario of contemporary commercial hydrogel products, which are expensive and rely on synthetic materials, the sustainable origin and unique physicochemical properties have positioned CNCs as promising sustainable functional building blocks for next-generation hydrogels in biomedical applications. Over the past decade, CNC-based hydrogels have gained momentum as soft biomaterials capable of interacting with diverse tissue types, predominantly demonstrated through in vitro cell line studies. This review critically examines the current landscape of research on biomedical applications of CNC-based hydrogels, focusing on their biomedical utility across 22 systematically screened studies. It revealed applications spanning around bone and cartilage tissue engineering, wound healing, medical implants and sensors, and drug delivery. We highlight the predominance of microcrystalline cellulose as the CNC source and sulfuric acid hydrolysis as the preferred extraction method, with several studies incorporating surface modifications to enhance functionality. Despite growing interest, there remains a lack of data for transitioning towards human clinical studies and commercialisation. Hence, this review highlights the pressing need for scalable, sustainable, and affordable CNC-based hydrogel systems that can democratise access to advanced biomedical technologies. Full article

This paper proposes the use of quantitative methods for the characterization of tissues by linking, into a single approach, ideas coming from the spectral analysis methods commonly used to determine the attenuation coefficient with the envelope statistics formulation. Initially, the Homodyned K-distribution model used to fit data obtained from ultrasound signal envelopes was reviewed, and the necessary equations to further derive the attenuation coefficient from this model were developed. To test and discuss the performance of these methods, experimental work was conducted in phantoms. To this end, a series of tissue-mimicking materials composed of poly-vinyl alcohol (PVA) loaded with different particles (aluminium, alumina, cellulose) at varying concentrations were manufactured. A single-channel scanning system was employed to analyse these samples. It was verified that quantitative images obtained from the attenuation coefficient and from the scatterer clustering μ parameter (associated with scatterer concentration) effectively discriminate materials exhibiting similar echo envelope patterns, enhancing the information obtained in comparison with the conventional analysis based on B-scans. Additionally, the implementation of quantitative bi-parametric imaging mappings based on both the μ parameter and the attenuation coefficient, as a means to rapidly visualize results and identify areas characterized by specific acoustic features, was also proposed. Full article

Cellulose aerogel is a promising thermal insulation material with terrific thermal insulation and environmental friendliness. However, the intrinsic flammability of polysaccharide molecules and dependence on freeze-drying have limited its application in flame-retardant and thermal management systems. Here, we develop a flame-retardant biomass aerogel based on a dual-network matrix of bacterial cellulose and sodium alginate. This innovative material enables high-efficiency and low-cost preparation via ambient pressure drying technology (only ~3.5% volume shrinkage), while achieving flame retardancy by introducing an inorganic nanosheet microstructure within a polymer matrix. The resulting dual-network flame-retardant cellulose aerogel demonstrates thermal performance superior to that of most polymer foams and conventional cellulose aerogels, featuring an ultra-low thermal conductivity of ~0.04 W m⁻¹ K⁻¹ and a high limiting oxygen index (LOI) of ~69%. This research provides a novel strategy for simultaneous flame-retardant modification and energy-efficient manufacturing of biomass-derived aerogels. Full article

The safe and efficient capture of CO₂ in confined environments such as coal mine goafs remains a significant challenge, posing both environmental and safety risks. To address this issue, this study developed a novel biomass-based aerogel adsorbent using CNF-C and CS through sol–gel synthesis and freeze-drying. A series of composite aerogels with varying mass ratios were systematically characterized by SEM, BET, FTIR, and TG-DSC to analyze their microstructure, specific surface area, pore characteristics, chemical properties, and thermal stability. A constant temperature and humidity experimental setup was specially designed to explore the effects of various temperatures, humidity, and material ratios on CO₂ adsorption performance. FTIR analysis confirmed that -NH₂ served as the primary adsorption site, with its density increasing with higher chitosan content. The 1:3 ratio exhibited the optimal specific surface area (7.05 m²/g) and thermal stability, withstanding temperatures up to 350.0 °C, while the 1:1 ratio demonstrated the highest porosity (80.74%). Adsorption experiments indicated that 35.0 °C and 50% humidity were the optimal conditions, under which the 1:2 ratio biomass aerogel achieved an 18% increase in CO₂ adsorption capacity compared to room temperature. The sample with a 1:1 high cellulose ratio is primarily dominated by physical adsorption, making its performance susceptible to environmental fluctuations. The sample with a 1:3 high chitosan ratio is predominantly governed by chemical adsorption, exhibiting more stable adsorption characteristics. The 1:2 ratio achieved the best balance under 35.0 °C and 50% humidity. The biomass aerogel synergistically combined physical barriers from its three-dimensional network structure and chemical adsorption via active functional groups, enabling efficient CO₂ capture and stable sequestration. This study demonstrates the feasibility of biomass-derived aerogels for CO₂ adsorption under complex conditions and provides new insights into the design of sustainable materials for environmental remediation and carbon reduction applications. Full article

In a world where the negative consequences of natural resources’ overexploitation for the environment are increasingly evident, repurposing waste to obtain high-value goods becomes essential. This study proposes the isolation of cellulose nanofibers from the bacterial cellulose (BC) membrane that results as a by-product during the fermentation of Kombucha tea by chemical treatment with sodium hydroxide (NaOH), sodium hypochlorite (NaClO), hydrogen peroxide (H₂O₂), sulfuric acid (H₂SO₄) or citric acid, followed by mechanical fibrillation via high-speed homogenization and microfluidization. Treatments with NaOH, NaClO, and H₂O₂ were effective in the purification of Kombucha-derived BC, while H₂SO₄ and citric acid exhibited a rather weak cleaning action, as revealed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Besides their cleaning effect, the applied chemical pretreatments had an important effect on the degree of fibrillation attained, as indicated by the scanning electron microscopy images. This study proposes simple and effective routes to obtain bacterial cellulose nanofibers from an inexpensive and abundant source, commonly regarded as a waste material, which can be further applied in medical and packaging applications as reinforcing agents, adsorbent materials, or scaffolds. Full article

Anthropomorphic CT phantoms are essential training tools for interventional radiology. Given the high technical demands and stringent safety requirements in this field, realistic CT phantoms are vital simulation tools that support effective hands-on training, procedural planning, and risk mitigation. However, commercially available phantom geometries are limited in their scope. This study investigates the use of polyvinyl alcohol (PVA) to fabricate customizable training phantoms. PVA, a non-toxic material, can be processed into PVA cryogels (PVA-C) with tissue-like mechanical properties. We modified PVA-C (10 wt.% PVA) by incorporating various additives to adjust X-ray attenuation and achieve Hounsfield units (HUs) similar to different soft tissues. HU values were measured at X-ray tube voltages of 70, 120, and 150 kV. The inclusion of barium sulfate (e.g., U = 120 kV; 0.1–2 wt.%: 33.29 ± 5.45–323.72 ± 12.64 HU) and iohexol (e.g., U = 120 kV; 0.1–2 wt.%: 26.05 ± 4.74–161.99 ± 5.69 HU) significantly increased HU values. Iohexol produced more homogeneous HU distributions than barium sulfate and cellulose derivatives, with the latter having air gaps and inconsistencies. The tested formulations encompassed a wide range of soft tissue densities, with HU values varying significantly across the energy range (p < 0.001). While cellulose derivatives showed variable HU modulation, their primary role appears to be in modifying phantom texture and morphology rather than precise attenuation control. In conclusion, PVA-C demonstrates strong potential for use in interventional radiology training phantoms. Further studies may enhance phantom realism by replicating tissue textures, for example, through the incorporation of cellulose-based substances. Full article

Industrial wastewater pollution has reached acute levels in the environment; consequently, scientists are developing new sustainable treatment methods. Lignocellulosic biomass (LB) stands as a promising raw material because it originates from agricultural waste, forestry residues, and energy crop production. This review examines the application of nanomaterials derived from lignocellulosic resources in wastewater management, highlighting their distinctive physical and chemical properties, including a large surface area, adjustable porosity structure, and multifunctional group capability. The collection of nanomaterials incorporating cellulose nanocrystals (CNCs) with lignin nanoparticles, as well as biochar and carbon-based nanostructures, demonstrates high effectiveness in extracting heavy metals, dyes, and organic pollutants through adsorption, membrane filtration, and catalysis mechanisms. Nanomaterials have benefited from recent analytical breakthroughs that improve both their manufacturing potential and eco-friendly character through hybrid catalysis methods and functionalization procedures. This review demonstrates the ability of nanomaterials to simultaneously turn waste into valuable product while cleaning up the environment through their connection to circular bioeconomic principles and the United Nations Sustainable Development Goals (SDGs). This review addresses hurdles related to feedstock variability, production costs, and lifecycle impacts, demonstrating the capability of lignocellulosic nanomaterials to transform wastewater treatment operations while sustaining global sustainability. Full article

The conversion of cellulosic biomass into renewable chemicals can serve as a sustainable resource for levulinic acid (LA) production. LA yield is significantly influenced by reaction temperature, reaction time, substrate concentration, active sites, catalyst amount, catalyst porosity, and durability. Beyond the features of the catalyst, such as acidity, porosity, functional groups, and catalytic efficiency, the contact between the solid acid catalyst and the solid substrate is of vital importance. Solid-based catalysts show remarkable catalytic activity for cellulose-derived LA production, thanks to the incorporation of functional groups. For a solid carbon-based catalyst to be effective, a synergistic interaction between the binding domain (functional groups capable of anchoring cellulose to the catalyst surface, such as chloride groups, COOH, or OH) and the hydrolysis domain (due to their ability to cleave glycosidic bonds, such as in SO₃H) is essential. As a relatively new market niche, carbon-based catalyst supports are projected to reach a market value of nearly USD 125 million by 2030. This review aims to highlight the advantages and limitations of carbon-based materials compared to conventional catalysts (including metal oxides or supported noble metals, among others) in features like catalytic activity, thermal stability, and cost, examine recent advancements in catalyst development, and identify key challenges and future research directions to enable more efficient, sustainable, and scalable processes for LA production. The novelty of this review lies in its focus on carbon-based catalysts for LA production, emphasizing their physical and chemical characteristics. Full article