Shape-memory polymer nanocomposites (SMPNCs) have emerged as a transformative class of smart materials, combining the versatility of shape-memory polymers (SMPs) with the enhanced properties imparted by nanostructures. Integrating these nanofillers, this review explores the pivotal role of SMPNCs in addressing critical limitations of traditional SMPs, including low tensile strength, restricted actuation modes, and limited recovery stress. It comprehensively examines the integration of nanofillers, such as nanoparticles, nanotubes, and nanofibers, which augment mechanical robustness, thermal conductivity, and shape-recovery performance. It also consolidates foundational knowledge of SMPNCs, covering the principles of the shape-memory phenomenon, fabrication techniques, shape-recovery mechanisms, modeling approaches, and actuation methods, with an emphasis on the structural parameters of nanofillers and their interactions with polymer matrices. Additionally, the transformative real-world applications of SMPNCs are also highlighted, including their roles in minimally invasive medical devices, adaptive automotive systems, 4D printing, wearable electronics, and soft robotics. By providing a systematic overview of SMPNC development and applications, this review aims to serve as a comprehensive resource for scientists, engineers, and practitioners, offering a detailed roadmap for advancing smart materials and unlocking the vast potential of SMPNCs across various industries in the future.

The integration of polymer coatings with metal and metal oxide nanoparticles represents a significant advancement in nanotechnology, enhancing the stability, biocompatibility, and functional versatility of these materials. These enhanced properties make polymer-coated nanoparticles key components in a wide range of applications, including biomedicine, catalysis, environmental remediation, electronics, and energy storage. The unique combination of polymeric materials with metal and metal oxide cores results in hybrid structures with superior performance characteristics, making them highly desirable for various technological innovations. Polymer-coated metal and metal oxide nanoparticles can be synthesized through various methods, such as grafting to, grafting from, grafting through, in situ techniques, and layer-by-layer assembly, each offering distinct control over nanoparticle size, shape, and surface functionality. The distinctive contribution of this review lies in its systematic comparison of polymer-coating synthesis approaches for different metal and metal oxide nanoparticles, revealing how variations in polymer architecture and surface chemistry govern their stability, functionality, and application performance. The aim of this paper is to provide a comprehensive overview of the current state of research on polymer-coated nanoparticles, including metals such as gold, silver, copper, platinum, and palladium, as well as metal oxides like iron oxide, titanium dioxide, zinc oxide, and aluminum oxide. This review highlights their design strategies, synthesis methods, characterization approaches, and diverse emerging applications, including biomedicine (e.g., targeted drug delivery, gene delivery, bone tissue regeneration, imaging, antimicrobials, and therapeutic interventions), environmental remediation (e.g., antibacterials and sensors), catalysis, electronics, and energy conversion.

Magnetic iron oxide nanoparticles (MIONPs) represent a versatile magnetic nanoparticle (NP) system with considerable, yet underexplored, potential in diverse applications, particularly in emerging biomedical fields such as magnetic resonance imaging, magnetic hyperthermia, targeted drug delivery, and biosensing. The successful translation of MIONPs into these applications requires reproducible synthesis methods and precise control over particle uniformity in terms of size, shape, and composition. However, reproducibility in nanoparticle synthesis remains a persistent challenge, limiting the ability of researchers to replicate results and integrate MIONPs into application-oriented studies. In recent years, substantial efforts have been directed toward elucidating synthesis mechanisms and improving both reproducibility and particle uniformity, enabling notable advances in the biomedical deployment of MIONPs. This review summarizes progress in the synthesis of MIONPs, with emphasis on three widely employed precursors: iron oleate, iron acetylacetonate, and iron pentacarbonyl. The discussion focuses on key findings in NP synthesis, relevant chemical aspects, and the magnetic properties of MIONPs, which are critical for optimizing their functional performance. By consolidating recent advances, this review aims to provide a reliable framework for the preparation of high-quality MIONPs and to support their effective use in specific biomedical applications.

Recent advancements in nanotechnology and materials science have enabled the development of magnetic photocatalysts with improved efficiency, stability, and reusability, offering a promising approach for wastewater treatment. The integration of magnetic nanoparticles (MNPs) into photocatalytic processes has gained significant attention as a sustainable method for addressing emerging pollutants—such as antibiotics and pharmaceutical compounds—which pose environmental and public health risks, including the proliferation of antibiotic resistance. Surface modification techniques, specifically applied to MNPs, are employed to enhance their photocatalytic performance by improving surface reactivity, reducing nanoparticle agglomeration, and increasing photocatalytic activity under both visible and ultraviolet (UV) light irradiation. These modifications also facilitate the selective adsorption and degradation of target contaminants. Importantly, the modified nanoparticles retain their magnetic properties, allowing for facile separation and reuse in multiple treatment cycles via external magnetic fields. This review provides a comprehensive overview of recent developments in surface-modified MNPs for wastewater treatment, with a focus on their physicochemical properties, surface modification strategies, and effectiveness in the removal of antibiotics from aqueous environments. Furthermore, the review discusses advantages over conventional treatment methods, current limitations, and future research directions, emphasizing the potential of this technology for sustainable and efficient water purification.

Fine-tuning the superparamagnetic (SPM) properties of iron oxide nanoparticles (NPs) through precise control over size, shape, and assembly into superclusters is essential for advanced biomedical and electronic applications. We first analyzed the size-dependent magnetic properties of FeO@Fe₃O₄ core/shell NPs in both spherical and cubic shapes prepared via the thermal decomposition of iron(III) oleate. The detailed analyses of structure, composition, and crystallinity confirmed the presence of both FeO and Fe₃O₄ phases and the formation of the core/shell structure, with an increasing FeO/Fe₃O₄ phase ratio correlated with larger particle size. Overall, the SPM properties of these core/shell NPs were maintained, although saturation magnetization and varied with size, shape, and FeO/Fe₃O₄ ratio. Notably, iron oxide nanocubes exhibited enhanced saturation magnetization compared to their spherical counterparts. Next, we introduced a unique strategy to enhance and fine-tune the SPM properties of FeO@Fe₃O₄ NPs by assembling them into supercluster particles to promote interparticle interaction. By controlling the size and shape of the primary nanocrystals, we demonstrated the creation of SPM superclusters of consistent sizes, including the 150 and 240 nm superclusters reported here, which exhibit different SPM behaviors. Our research presents a synthetic strategy for optimizing the SPM properties of iron oxide NPs and their superclusters across a wide range of magnetically driven applications, especially useful for biomedical technologies.