Effect of surfactant/water ratio and reagents’ concentration on sizedistribution of manganese carbonate nanoparticles synthesized bymicroemulsion mediated route

tIn this work nanoparticles of manganese carbonate were produced by microemulsion-mediated routeat room temperature, without any post-thermal treatment. All produced samples were characterizedby XRD and by TEM and obtained images were analyzed in order to evaluate particle size distribution,mean size and polydispersity (variance). The influence of water–surfactant molar ratio and concentrationof reagents were investigated in the range 5–7.5 and 0.25–1.0 M, respectively, according to factorialdesign. Significant effects on particle mean size and polydispersity were assessed by statistical analysis.Results showed that by increasing the water–surfactant molar ratio from 5 to 7.5, the average particlesize increased from less than 10 nm to around 100 nm, and the standard deviation increased from lessthan 5 nm to 35 nm. Statistical analysis put in evidence that water–surfactant molar ratio has significantpositive effect on both mean and variance of particle size. Concentration of reactants, in the investigatedrange, did not influence mean size of particles, while significant changes of variance were observed:passing from 0.25 to 1 M concentration, variances of particle size increased for w = 5 and for w = 6.25,while decreased for w = 7.5.