Efficient thermal management is critical in high-performance electronics, nuclear reactors, and renewable energy systems, where excessive heat generation can degrade performance and compromise safety. This review explores the advancements in nanofluids flow boiling and convective heat transfer in microchannels over the past decade. Fundamental factors affecting heat transfer performance, including nanoparticle properties, microchannel geometries, and flow conditions, were highlighted. Key insights into bubble formation and flow dynamics are provided, with high-speed imaging and advanced microscopy techniques offering a detailed understanding of these phenomena. Nanofluids have demonstrated significant enhancements in heat transfer coefficient (HTC) and critical heat flux (CHF), with select formulations yielding up to a 49% increase in CHF over conventional coolants. Despite promising advancements, several challenges persist, such as nanoparticle stability, clogging and fouling, and variability in HTC and CHF. Further, pressure drop and pumping power requirements, along with environmental and health concerns, pose significant obstacles to practical implementation. Future research should focus on optimizing nanoparticle formulations, improving microchannel design, and developing robust modeling techniques to predict system performance. Also, environmental concerns relating to nanofluid synthesis, disposal, and ecological footprint necessitate further investigation. Future research should focus on optimizing nanofluid formulations, integrating artificial intelligence-driven predictive models, and developing eco-friendly nanofluid alternatives. By consolidating experimental findings, theoretical insights, and bibliometric trends, this review provides a valuable resource for researchers and engineers seeking to advance next-generation thermal management solutions in high-performance and sustainable energy applications. Overall, this review underscores nanofluids' potential to revolutionize thermal management in high-performance computing, power electronics, and renewable energy systems while also highlighting the need for continued research to overcome existing challenges and fully realize this technology's benefits.

The increasing integration of nanoparticles into laboratory studies and consumables, such as filters, pipette tips, test kits, and coatings, has raised critical concerns about their environmental sustainability, occupational safety, and end-of-life disposal. This review provides a comprehensive examination of the life cycle impacts of nanoparticle-based laboratory products, covering stages from synthesis and in-lab use to waste generation and disposal. Drawing upon ISO 14040/44 life cycle assessment (LCA) frameworks, we highlight methodological challenges in evaluating nano-enabled systems, including data gaps, toxicity uncertainties, boundary selection, and the influence of intrinsic nanoparticle properties (e.g., size, shape, and surface coating) on fate and impact modeling. We assess the environmental burden of nanoparticle synthesis methods, energy inputs, and hazardous byproducts, and explore their property-dependent transformation in laboratory waste streams. Comparative LCA analyses of nano-enabled versus conventional lab consumables reveal performance trade-offs with substantial implications for environmental policy and green lab practices. Furthermore, this review situates LCA within the emerging Safe and Sustainable by Design (SSbD) framework, emphasizing its role in guiding early-stage material innovation, risk prevention, and circularity strategies for nanotechnology. The review also evaluates regulatory responses and proposes safety and circular economy recommendations tailored for laboratories, manufacturers, and policymakers. By connecting LCA with nanowaste management, physicochemical risk factors, and SSbD-guided sustainability principles, this work establishes a foundational platform for safer, more sustainable adoption of nanomaterials in research environments. These findings are particularly relevant as nano-enabled products proliferate across biomedical, energy, environmental, and analytical laboratory domains. Graphical Abstract