Calorimetric study of CdS nanoparticle formation in w/o microemulsions

The formation of CdS nanocrystals in ternary w/o microemulsions of sodium bis(2-ethylhexyl) solfosuccinate/water/isooctane and in quaternary w/o microemulsions of cetyltrimethylammonium bromide (CTAB)/n-pentanol/water/n-hexane was studied by calorimetric measurements. In order to gain information on the role played by the various factors governing the formation of nanoparticles, the enthalpy of formation of CdS nanocrystals in microemulsion was investigated as a function of W0, the molar ratio between water and surfactant and P0, the molar ratio between alcohol and surfactant. Different energetic states of CdS nanocrystals in microemulsions and in water and a dependence of them on the composition and nature of the microemulsive system are evidenced.