| 摘要 |
We describe a reversible cycle phase change fluid, comprising: a polar working fluid; nanoparticles of a material having a density greater than 3000kg/m3; and a controllable gel; wherein said gel has a predominantly hydrophilic first phase having a first hydrophilicity and a predominantly hydrophobic second phase with a second, lower hydrophilicity, and is switchable between said phases by application of a phase change driver; wherein said gel coats said nanoparticles to a first thickness when the gel is in said first phase and is swollen by said polar working fluid, and wherein said gel coats said nanoparticles to a second, reduced thickness when in said second phase; wherein said coated nanoparticles form clusters with a first median nanoparticle number, or comprise individual unclustered nanoparticles, when the gel is in said first phase, and wherein said coated nanoparticles form clusters with a second larger median nanoparticle number when the gel is in said second phase. In embodiments aggregation of the nanoparticles into clusters is self-limiting, in particular because of electrical charges on the nanoparticles, such that in the second phase the clusters remain soluble within the liquid. |
