Search Results (756)

Heavy oil and extra-heavy oil represent mobility-limited petroleum resources because supramolecular associations of asphaltenes and resins, together with strong interfacial resistance, generate extremely high apparent viscosity. In recent years, nanotechnology has emerged as a promising approach for viscosity management and enhanced oil recovery (EOR). This review critically examines recent advances in nano-assisted viscosity reduction from a reservoir-operational perspective and organizes the literature into two field-relevant categories: metal-based and non-metal nano-systems. Metal-based nanoparticles (NPs) mainly promote catalytic aquathermolysis and related bond-cleavage and hydrogen-transfer reactions under hydrothermal conditions, enabling partial upgrading and persistent viscosity reduction during thermal recovery. In contrast, non-metal nano-systems—particularly silica- and graphene-oxide-derived materials—primarily operate through interfacial and structural regulation mechanisms at low or moderate temperatures. These effects include wettability alteration, interfacial-film stabilization, modification of asphaltene aggregation behavior, and the formation of dispersed-flow regimes such as Pickering-type emulsions that reduce apparent flow resistance in multiphase systems. Beyond summarizing nanomaterial types, this review emphasizes reservoir-scale considerations governing field applicability, including brine stability, NPs transport and retention in porous media, and formulation compatibility. Comparative analysis highlights the distinct operational windows of thermal catalytic nano-systems and cold-production nano-systems, providing a reservoir-oriented framework for designing nano-assisted viscosity-reduction technologies. Full article

Foam concrete and fiber-reinforced foam concrete are promising building materials for sustainable and energy-efficient construction. Improving the environmental performance of cellular composites through the use of industrial waste and additives based on them is highly relevant. This study intends to create a novel complex nanomodifying additive (CNA) from industrial waste and nanomaterials, alongside new eco-friendly foam concrete (FC) and fiber-reinforced foam concrete (FFC) mixes incorporating CNA and polypropylene fiber (PF). Experimental studies yielded the optimal CNA formulation and described a method for its preparation. The test results indicate that FC’s properties are enhanced by CNA. The properties were best in the FC that was modified with 10% CNA. The FC control composition was surpassed by a 25.5% increase in compressive strength and a 23.1% increase in flexural strength, with a 9.5% reduction in thermal conductivity. Dispersed PF reinforcement also positively impacts the properties of FFCs with CNA, and the combined modification of 10% CNA and 1.2% PF provides maximum increases in compressive and flexural strength, amounting to 43.1% and 102.2%, respectively, and a 16.9% reduction in thermal conductivity. A microstructural analysis of the cellular composites confirms the feasibility of the tested formulation solutions. The FFCs, when modified by CNA and PF, display a homogeneous cellular structure, and the interpore zones contain multiple clusters of calcium silicate hydrate. Using CNA in the production of FC and FFCs will reduce cement consumption and improve their environmental friendliness. Full article

Iron oxide nanoparticles have emerged as multifunctional compounds with prominent potential in cancer theranostics, particularly in photothermal therapy (PTT) and photodynamic therapy (PDT). Their unique electronic and crystal structures, such as the dispersion of Fe²⁺ and Fe³⁺ ions and d-orbital splitting, contribute to their magnetic and catalytic properties. In PTT, Fe₃O₄ nanoparticles exhibit moderate near-infrared (NIR) absorption and photothermal conversion efficiency, which can be enhanced through adjustments in particle size, surface modification, and combinations with other components. In PDT, Fe₃O₄ nanoparticles demonstrate intrinsic peroxidase-like catalytic activity, facilitating Fenton and photo-Fenton reactions that generate reactive oxygen species (ROS), including hydroxyl radicals (^•OH), thereby amplifying oxidative stress in cancer cells. These nanoparticles can also function as carriers for photosensitisers (PS), promoting targeted delivery and enhanced ROS generation. Multifunctional nanomaterials that integrate Fe₃O₄ with other therapeutic agents and targeting ligands have demonstrated synergistic antitumour effects through amplified photothermal, photodynamic, chemodynamic, and chemotherapeutic mechanisms. Despite certain drawbacks, such as relatively low NIR absorption and challenges in optimising delivery and light activation, ongoing improvements in Fe₃O₄-based nanoplatforms present significant potential for enhancing treatment outcomes and the precision of cancer therapy. This article systematically explores the synergistic role of Fe₃O₄ nanoparticles in PTT and PDT, encompassing their magnetic and catalytic characteristics. Additionally, it focuses on multifunctional hybrid nanoplatforms that combine Fe₃O₄ with targeting or imaging agents, highlighting their potential to enhance therapeutic precision. Full article

Calcium peroxide nanoparticles (CaO₂ NPs) have recently attracted increasing attention as oxygen-generating nanomaterials with potential biomedical applications. Their ability to release molecular oxygen and reactive oxygen species (ROS) in aqueous environments enables modulation of hypoxic and oxidative microenvironments, which play critical roles in infection control, tumor progression, and tissue regeneration. Despite growing interest in oxygen-releasing biomaterials, the literature specifically addressing CaO₂ nanomaterials remains comparatively limited and fragmented, particularly when compared with the extensive body of work on calcium oxide-based systems. This review provides a comprehensive overview of CaO₂ nanoparticles, focusing on synthesis strategies, physicochemical properties, and emerging biomedical applications. Conventional bottom-up synthesis routes based on calcium salts, calcium hydroxide, and calcium oxide are critically compared, highlighting the influence of reaction parameters and stabilizing agents on particle size, morphology, crystallinity, and colloidal stability. Surface modification strategies, including polyethylene glycol, polyvinylpyrrolidone, and hyaluronic acid, are also discussed for their role in improving nanoparticle stability, regulating decomposition kinetics, and enhancing biocompatibility. The mechanisms governing oxygen and ROS generation are analysed in relation to antibacterial activity, hypoxia alleviation in tumor microenvironments, and oxygen-supplying biomaterials for tissue engineering and wound healing. In addition, key challenges associated with oxidative stress responses are discussed. Finally, the review outlines current limitations and perspectives regarding the clinical translation of CaO₂-based nanotherapeutic systems. Overall, this work aims to consolidate the currently dispersed knowledge on CaO₂ nanoparticles and provide a critical framework to guide future research in oxygen-releasing nanomedicine. Full article

Nanocellulose materials (CNMs), encompassing cellulose nanocrystals (CNCs), cellulose nanofibrils (CNFs), and bacterial nanocellulose (BNC), have emerged as a versatile and sustainable class of bio-based nanomaterials with significant promise for applications in mechanical engineering. This review systematically examines the processing of nanocellulose via mechanical, chemical, and enzymatic routes, alongside surface modification strategies that enhance performance and address scalability challenges. A principal advantage of CNMs lies in their exceptional mechanical properties, including superior strength, stiffness, and toughness, which position them as high-performance, sustainable reinforcement agents for advanced composites. Beyond mechanical reinforcement, CNMs exhibit a suite of functional properties critical for engineering design, such as thermal stability, tunable conductivity, effective gas/moisture barrier performance, and improved tribological behavior. These characteristics enable their use in diverse high-value applications, including lightweight composites, protective coatings, energy storage devices, sensors, actuators, and intelligent material systems. Furthermore, the inherent renewability, biodegradability, and recyclability of nanocellulose align closely with the principles of a circular economy and green engineering. However, the successful integration of CNMs into mainstream manufacturing requires overcoming key challenges. These include the energy intensity of certain production processes, inherent moisture sensitivity, long-term stability under operational conditions, and compatibility with established industrial techniques. Life-cycle analyses reveal important environmental trade-offs that must be navigated. Overall, nanocellulose represents a renewable, multi-functional material platform whose unique combination of mechanical performance, functional versatility, and environmental benefits is poised to drive innovation in next-generation engineering materials. Full article

In today’s environment, rapid, reliable, and accurate bacterial detection is essential for protecting public health while preserving and ensuring the safety of food, water, and agricultural and environmental systems. Over the years, electrochemical sensors have gained widespread attention as viable candidates due to their rapid response, high sensitivity and selectivity, adaptability and portability, and low manufacturing cost. This facilitates their integration into various sectors, including healthcare and diagnostic applications, food safety and agriculture, and water and environmental monitoring. While these achievements represent tremendous progress, some of the challenges that need to be overcome include stability, batch-to-batch reproducibility, manufacturability, performance reliability, and the lack of point-of-care (POC) implementation for the utilization of these sensors for real-sample bacterial analysis. However, in the future, it is expected that with continued efforts made towards improving durability, standardization, and manufacturability, electrochemical bacterial sensors will be pivotal to the advancement of efficient bacterial diagnostics across various fields. This review presents major developments in modern electrochemical sensing technologies, which include, but are not limited to: electrochemical sensor and biosensor surface modifications, nanomaterials, the integration of artificial intelligence (AI) and machine learning (ML), and the emergence of wearable systems, for bacterial detection and monitoring. Additionally, their utilization in the aforementioned sectors is discussed. The integration and sustained use of these advanced electrochemical sensors for bacterial detection and surveillance can significantly enhance global safety and public well-being. Full article

The rising demand for clean water has reinforced the importance of thin-film composite TFC polyamide membranes in desalination and wastewater treatment. While improvements often target the selective layer, these can sometimes reduce stability or selectivity. An alternative approach is to tailor the porous support, particularly through the incorporation of nanomaterials such as metal oxides, carbon-based nanomaterials, metal–organic frameworks (MOFs), zeolites, and cellulose-based materials, to improve overall membrane performance. The modification of membrane substrates through the incorporation of nanofillers has demonstrated notable advantages, including enhanced hydrophilicity, improved mechanical stability, and increased porosity. These improvements collectively contribute to higher permeability, reduced internal concentration polarization and enhanced separation performance in FO, NF, and RO applications. The review starts by clearly distinguishing substrate modification, in which nanomaterials are localized in the porous support, from interlayer modification, which involves constructing a distinct layer between the support and selective layer. This concise review highlights current developments in the nanomaterial-based support modification of polyamide TFC membranes; it summarizes nanomaterials selections, incorporation techniques, and resulting property changes. Current challenges and potential research opportunities are also discussed. Full article

Biopolymers such as chitosan are considered important candidates for water purification due to their non-toxicity, biodegradability, natural origin, biocompatibility, and potential for modification to provide additional capabilities, such as incorporating nanomaterials for magnetism to enable rapid separation or adding functional groups to enhance selectivity towards target adsorbates. This study investigated adsorption of Co (II), traced by Co-60 radionuclide, systematically evaluated in natural aquatic matrices selected according to water body type: seawater (Baltic Sea) and freshwater systems further distinguished as lentic (Lake Balsys) and lotic (Neris River) environments, using synthesized magnetite–chitosan nanocomposites (MCNs) with varying loadings of Fe₃O₄ (10–30 wt. %) nanoparticles providing different levels of magnetization. Comprehensive characterization (TEM, FTIR, AFM, XRD, and Mössbauer spectroscopy) confirmed successful integration of magnetite nanoparticles within the chitosan matrix and reproducible structural properties. An optimal magnetization of 11 emu/g was achieved at 20 wt. % Fe₃O₄, enabling rapid magnetic separation within <1 min without compromising sorption capacity. Adsorption isotherm models were applied to investigate the adsorption parameters, and sorption kinetics were studied, yielding a maximum adsorption capacity of 14.93 mg/g for MCN-10 in seawater and 11.95 mg/g for MCN-20 in freshwater with observed equilibrium within 120 min. These promising results indicate that the MCN is a suitable nanocomposite for the removal of Co (II) ions and the Co-60 radionuclide from aquatic media. Full article

Glassy carbon electrodes (GCEs) have gained increased attention for the sensitive electrochemical detection of heavy metals due to their excellent chemical stability, wide potential window, and good electrical conductivity. These characteristics make GCEs an effective platform for sensor development. In particular, nanomaterial-modified GCEs have emerged as a promising strategy, offering enhanced sensitivity, selectivity, and faster response compared to conventional analytical techniques. This review summarizes recent advances over the past five years in the use of GCEs modified with chemically synthesized nanoparticles for the simultaneous detection of multiple heavy metal ions, including cadmium, lead, mercury, and chromium. It also includes how quantum chemical methods have aided our understanding of these phenomena. Heavy metals pose significant environmental and public health risks, with well-documented neurological, cardiovascular, reproductive, and carcinogenic effects, highlighting the need for accurate and rapid monitoring methods. Regulatory limits established by organizations such as the World Health Organization and the Environmental Protection Agency further emphasize the demand for highly sensitive detection technologies. This review examines the fundamental properties of GCEs, common nanomaterial modification techniques, and their application in multi-ion detection systems. Key advantages such as cost-effectiveness, portability, and adaptability to diverse sample matrices are highlighted. Current challenges, including electrode fouling, selectivity, and matrix interference, are also addressed, along with future perspectives for improving GCE-based sensors for real-world environmental monitoring. Full article

Currently, one of the major trends in the construction industry is the creation of structures with increased strength and durability. The solution is the use of nanomaterials as modifiers for cementitious composites. The aim of this study is to produce concretes with a variable structure modified with a combination of aluminum oxide (NA) and titanium oxide (NT) nanoparticles with improved properties. A variatropic structure is characterized by differences in properties across the cross-section of the material. Concretes were produced using vibration (V), centrifugation (C), and vibrocentrifugation (VC) technologies. Modification was carried out with NA particles from 0% to 4.0% in increments of 1.0% and NT from 0% to 2.0% in increments of 0.5% of the binder mass. Through experimental study, the impact of combined nanomodification on the compressive strength, water absorption, and frost resistance of concrete created with different technologies was investigated. The most effective modification dosages with NA and NT particles were determined to be 2% and 1%. The determination of concrete properties and the statistical processing of experimental results were carried out in accordance with the requirements of standardized methods. Compared to control samples, the maximum compressive strengths for V, C, and VC concretes were 12.4%, 17.5%, and 20.3% higher, reaching 48.9 MPa, 58.4 MPa, and 62.9 MPa, respectively. The lowest water absorptions for V, C, and VC concretes were 5.21%, 4.24%, and 3.76%, which are 18.5%, 24.4%, and 29.2% lower than those of the control samples. After a series of freeze–thaw cycles—6 for V, 8 for C, and 10 for VC—the losses in compressive strength and mass of the nanomodified composites were less than those of the control samples, indicating an increase in the frost resistance of concrete. The influence of concrete production technology on the effect of nanomodification with NA and NT particles was proven. Nanomodified C and VC concretes have improved physical and mechanical properties compared to V concretes. Nanomodified concretes with a variable structure have a more organized microstructure with a greater number of clusters of calcium silicate hydroxides. The resulting variable-structure concrete has improved properties and can be used to manufacture columns, piles, and transmission line supports. Full article

Although natural enzymes have a high catalytic activity as biocatalysts, they still face many limitations in practical applications, including high preparation and purification costs, poor environmental stability, and difficulties in recovery and reuse. Nanozymes are a class of synthetic nanomaterials with enzymatic catalytic properties. They are regarded as promising alternatives to natural enzymes due to their low cost, good stability, adjustable catalytic activity, and easy surface modification. Among many nanozyme materials, metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) have attracted much attention due to their high specific surface area, adjustable porosity, and stable framework structure. This review summarizes the latest research progress of nanozymes based on MOFs and COFs and reveals the catalytic properties of different enzymes (oxidase, peroxidase, catalase, glucose oxidase, superoxide dismutase, hydrolase) simulated by them. In addition, their potential applications in sensors and medical fields are discussed. Finally, this review discusses the current challenges and developments of organic framework-based nanozymes and provides suggestions for future research directions. Full article

Organic phase change materials (PCMs) have been used and studied for many years. In this work, we focus on an industrially available PCM—polyethylene waxes (PEW) modified with seven types of carbon black (CB) exhibiting different properties. Carbon black (CB) was selected as a more cost-effective modifier compared to carbon nanomaterials, as it is easier to implement industrially and capable of converting and storing thermal energy. The experiments were designed to evaluate the thermal properties and photothermal conversion efficiency of PCMs modified with different grades of carbon black. The influence of carbon black on selected PCM properties was investigated using differential scanning calorimetry (DSC), thermogravimetric analysis (TG), scanning electron microscopy (SEM), and laser flash analysis (LFA). Furthermore, the photothermal conversion capability was evaluated. The results indicate that modification with carbon black decreases the phase transition enthalpy for most formulations, with reductions ranging from 8 to 12% for 1 wt.% CB to 10–15% for 2.5 wt.% CB. At the same time, an improvement in the thermal conductivity of PCMs modified with carbon black was observed, with the best performance achieved for N234 carbon black, showing an increase of approximately 17–18% in the 25–55 °C temperature range. The ratio of the heat of solidification to the heat of melting (Qs/Qm) for most samples was approximately 0.90–0.98, indicating excellent thermal cycling stability. The highest photothermal conversion efficiency was observed for samples modified with N234 and N330; these materials exhibited the greatest temperature rise, reaching approximately 135 °C in about 15 min, due to enhanced light absorption of PCMs by carbon black. Overall, the results confirm that PEW/CB systems demonstrate a good balance between absorption, heat generation, and controlled phase-change behavior, making them promising candidates for solar–thermal energy storage and conversion applications. Full article

The growing environmental impact of petroleum-based plastics has intensified research into sustainable, biodegradable alternatives for food packaging. Among bio-derived polymers, carboxymethyl cellulose (CMC) has attracted increasing attention due to its abundance, non-toxicity, biodegradability, and excellent film-forming ability. Nevertheless, the intrinsic hydrophilicity and limited mechanical strength of neat CMC restrict its direct application in packaging systems. This review provides a comprehensive and critical overview of recent strategies developed between 2015 and 2025 to enhance the performance of CMC-based films for food packaging applications. Emphasis is placed on physical and chemical modification routes, including polymer blending, polyelectrolyte complex formation, incorporation of functional fillers and nanomaterials, and ionic or covalent crosslinking approaches. The influence of these strategies on key functional properties, such as mechanical behavior, water barrier performance, antimicrobial and antioxidant activity, is systematically discussed. Particular attention is given to CMC-rich systems, enabling meaningful comparison across studies. By highlighting structure–property relationships and identifying current limitations, this review aims to provide guidance for the rational design of advanced CMC-based materials as viable, eco-friendly alternatives to conventional plastic packaging. Full article

Kraft paper, commonly known as brown paper, has been widely used in the preservation of various food products and is increasingly explored in the development of active packaging materials with antimicrobial functionality by incorporating metal nanoparticles. This study aimed to comparatively investigate the surface modification of Kraft paper with silver nanoparticles (AgNPs) using dip-coating and drop-casting techniques. AgNPs were produced via green synthesis and incorporated onto the surface of Kraft paper samples. The modified samples were characterized using physicochemical techniques, including atomic force microscopy (AFM), Raman spectroscopy and light microscopy, as well as nanomechanical characterization via force spectroscopy. The antimicrobial activity of the modified papers was assessed using the disk diffusion method. The results demonstrated that the modification techniques resulted in distinct surface characteristics. Samples treated with the drop-casting method exhibited the highest AgNP surface loading; however, this was accompanied by pronounced surface heterogeneity and a tendency toward reduced load-bearing capacity. Overall, the findings indicate that the choice of deposition technique plays a key role in controlling nanoparticle distribution and surface properties. Within the limitations of the techniques evaluated, the incorporation of nanomaterials with potential antimicrobial activity into Kraft paper may offer opportunities for the development of active food packaging, although further optimization is required. Full article

Squid ink has recently garnered considerable attention as a natural melanin source for the development of biocompatible nanomaterials. Although numerous studies have explored the biological and therapeutic applications of squid ink, the fabrication and modification strategies for squid ink-derived nanoparticles (SINPs) have yet to be comprehensively reviewed. This paper provides an integrated overview of current extraction, purification, and functionalization strategies for SINPs, with a particular focus on how functionalization approaches modulate their physicochemical characteristics and biological behaviors. The review begins by outlining the natural mechanisms of melanin formation and summarizing common extraction methods—including centrifugation, ultrasonication, and dialysis. Subsequently, various surface modification and hybridization techniques—including polymer coating, incorporation of metallic elements (e.g., Se and Fe), and loading of photosensitizers—are compared in terms of their contributions to functional enhancement. Finally, the challenges of reproducibility, batch-to-batch variability, and scalable manufacturing are discussed, outlining future directions for the development of squid ink-derived nanomaterials into standardized biomedical platforms. Full article