## 7 Conclusions
* The platinum-hydrocarbon nanofluids with hyperbranched polymer as initiator and stabilizer are very promising fuels having enhanced cracking behavior and endothermic ability for the heating/cooling in hypersonic aircraft. * The nanofluids containing palladium nanoplatelets can ameliorate the thermal performance of surface solar collectors by up to nearly 32%, whilst decreasing the required pumping power by 15%. * The palladium nanoparticles stabilized by long-chain alkyl-modified hyperbranched polyglycol present enhanced thermal conductivity and over time stability. * The incorporation of gold, silver, and palladium in polyethylene glycol showed improved light-to-heat conversion efficiencies. The large size spectrum of the silver nanoparticles enhanced their capability to absorb and convert a broader spectrum of sunlight wavelengths. The nanofluids were stable in time due to the interactions between the molecules of the nanoparticles and the polyethylene glycol molecules. * The gold-platinum nanofluids demonstrated to possess slightly lower thermal conductivity in reference to the gold nanofluids. This can be interpreted based on the hybrid metallic nanostructure, where the platinum having much lower thermal conductivity than gold will decrease the overall thermal conductivity of the bimetallic nanofluids. * The gold-palladium bimetallic nanofluids exhibit better photothermal conversion than that of monometallic gold or palladium nanofluids. * Further research works should be performed on the noble metal nanofluids with different formulations and extremely low concentrations to address the impact on the heat transfer capability and photothermal conversion efficiency of the systems incorporating such type of nanofluids, together with an accurate investment cost-benefits analysis. Conceptualization, J.P.; methodology, J.P. and A.M. ([PERSON]); software, [PERSON] ([PERSON]); validation, [PERSON] ([PERSON]) and A.M. ([PERSON]); formal analysis, [PERSON] ([PERSON]); investigation, J.P.; resources, A.M. ([PERSON]); data curation, J.P.; writing--original draft preparation, J.P.; writing--review and editing, J.P.; supervision, [PERSON] ([PERSON]) and [PERSON] ([PERSON]); project administration, [PERSON] ([PERSON]); funding acquisition, [PERSON] ([PERSON]). All authors have read and agreed to the published version of the manuscript. **Funding:** The authors are grateful to the Fundacao para a Ciencia e a Tecnologia (FCT), Avenida D. Carlos I, 126, 1249-074 Lisboa, Portugal, for partially financing the Project \"Estrategias interfaciais de arrefecimento para tecnologias de conversao com elevadas potencias de dissipacao\", Ref. PTDC/EMETED/7801/2020, [PERSON], Associacao do Instituto Superior Tecnico para a Investigacao e o Desenvolvimento (IST-ID). The author [PERSON] also acknowledges FCT for his PhD Fellowship Ref. 2021.05830.BD. **Institutional Review Board Statement:** Not applicable. **Informed Consent Statement:** Not applicable. **Data Availability Statement:** Data sharing not applicable. **Conflicts of Interest:** The authors declare no conflict of interest. **Abbreviations/Nomenclature**  
ACN  Acetonitrile  
B  Constant Rate of Heat Dissipation  
[Bmim]PF\({}_{6}\) 1-butyl-3-methylimidazolium hexafluorophosphate  
CHF  Critical Heat Flux  
CTAB  Cetyltrimethylammonium bromide  
EGMUDE  Triethysleeplycolmono-11-mercapquandecylethe  
ETOTAL  Total stored Energy  
E%  Photothermal Conversion Energy  
HTC  Heat Transfer Coefficient  
LSPR  Localized Surface Plasmon Resonance  
LAL  Laser Ablation in Liquids  
MWCNT  Muti-walled carbon nanotubes  
PBS  Polybutylene succinate  
PEG  Polyethylene glycol  
PVP  Polyvinylpyrrolidone  
SER  Stored Energy Ratio  
SH  Specific Heat  
TC  Thermal Conductivity  
TD  Thermal Diffusivity  
THF  Tetrahydrofuran  
TOAB  Tetraocylammonium bromide  
Liquid that integrates a nanofluid in which the incorporated  
Banew Fluid  nanoparticles are dispersed. Some examples of base fluids are water, ethylene glycol, and oil.