Recent advances in thermophysical properties of MXene and its hybrid nanofluid for thermal application: progress, opportunities, and challenges

Progress The present article offers a thorough review of MXene-based nanofluids, encompassing the basic synthesis methods for MXene and their application in thermal energy systems, specifically solar thermal collectors and PV/T systems. The production of MXene can take place as either a dry powder or a suspension. Consequently, while choosing the nanofluid preparation method using these components, the available alternatives can be reduced from two pathways to a single process. Moreover, the physical stability of the suspension, considered a critical factor that can significantly influence the thermophysical properties of MXene nanofluid, was examined concerning its formulation mechanism and assessment methods. Despite the existence of numerous sophisticated methods for assessing dispersion stability, it was determined that the photographic capturing technique is the most dependable due to its ability to provide real-time assessment of both short- and long-time dispersion stability for the combination with great precision. Nonetheless, this procedure is exceedingly time-consuming to execute, particularly when the described sample exhibits a high degree of stability. Opportunity Chemical procedures such as surfactants and physical techniques including ultrasonication, magnetic stirring, homogenization, and ball milling were examined to demonstrate their efficacy in enhancing particle dispersion within an unstable suspension. The conclusion drawn is that, in contrast to chemical methods, physical techniques for improving dispersion stability are superior for maintaining the optimal effective thermal conductivity of the nanofluid, with the homogenizer yielding the most favorable results among the available physical options. Challenges The stability of the suspensions often does not affect the mixture density or specific heat capacity; however, it does modify both the enhanced thermal conductivity and the efficient viscosity of the nanofluid. Both characteristics were shown to deteriorate progressively over time as a result of nanoparticle aggregation and sediment development. Numerous techniques were demonstrated to ascertain these two qualities (i.e., effective heat conductivity and effective viscosity), either by experimental approaches or through established connections. To yet, the scientific field has not succeeded in establishing a universal formula for both features; hence, the most dependable method remains experimental study. In the context of substituting traditional working fluids with MXene-based nanofluids in thermal applications (e.g., solar thermal collectors and PV/T systems), it has been demonstrated, at least in laboratory and pilot-scale studies, that these advanced fluids significantly enhance the overall performance of these systems. Consequently, they are considered as promising candidates for these industries, provided that their associated challenges are resolved and comprehensively understood. Recent investigations have shown that the concentration, size, and surface modification of MXene can substantially affect the thermal and rheological properties of the resultant nanofluids. For example, optimizing MXene content can promote heat conductivity, while appropriate surface functionalization can increase stability and inhibit sedimentation. Moreover, the investigation of hybrid nanofluids—combinations of MXene with other nanoparticles—offers a pathway to enhanced performance. Future Future study will likely concentrate on the scalability of MXene synthesis and functionalization, along with the examination of their long-term stability and performance in operational circumstances. The interaction between the physicochemical features of MXene and their performance in nanofluids requires additional investigation, especially with improved characterization techniques. The incorporation of MXenes into nanofluids indicates a significant advancement in materials science and engineering, with the potential to transform thermal management systems and energy applications. Ongoing interdisciplinary research will be essential for realizing the complete potential of MXene nanofluids and converting laboratory results into practical applications.