The study investigated the thermophysical properties of suspensions containing Ni₃(μ₃-ppza)4Cl₂ metal string complex (MSC) microparticles in aqueous glycerol solutions. The results showed that the use of microparticles of monocrystalline metal string complexes Ni₃(μ₃-ppza)4Cl₂ and Ni₅(μ₅-pppmda)4Cl₂ leds to the highest thermal conductivity enhancements and a decrease in freezing point. A comparative analysis of thermal conductivity enhancements of suspensions with micro- and nanoparticles was also conducted. Compared to the base fluid, at 5% volume fraction Ni₃-water-glycerol showed a 72% increase in thermal conductivity, while Cu-water-glycerol and Ni5-water-glycerol showed enhancements of 53% and 47%, respectively. The study suggests that the higher stability of suspensions with MSC microparticles, due to the formation of hydrogen bonds between the organic fragments of particles and water molecules, thier lower density and the formation of particle assemblies, is responsible for the significant thermal conductivity enhancement compared to nanofluids. The colloidal structure of suspensions with MSC microparticles greatly affects their thermophysical properties. Keywords: nanofluid, microfluid, metal string complex, thermal conductivity, suspension.