Stability and Morphological Characteristics of Lipid - Magnetite Suspensions

Abstract

The study of stability of lipid-magnetite suspensions (LMS) was carried out using photometry and electronic microscopy. All suspensions are rather stable in time. The best results in stability were demonstrated by suspensions with ratio Fe3O4 :SAS=0,02:0,35 g or 0,04 mass %:0,70 mass % and 0,025:0,35 g or 0,05 mass %:0,70 mass %. The sizes of magnetite particles from SAS were determined as – <d>~76 nm. It was established, that with time (0–48,0 hours) and growth of wave length (210–1000 nm) is observed the gradual increase of transmission coefficient from 25 % (210 nm) to 71,9 % (1000 nm) at 0 hours of suspension ageing; from 27,5 % (210 nm) to 81,2 % (1000 nm) at maximal time of suspension ageing (48 hours). There parameters of LMS were determined: concentration of particles – N=1,43∙1012 cm-3, in 48 hours concentration decreased by 20 % (N=1,19∙1012 cm-3); r=38 nm, n=1,48, κ=0,01. The function of particles distribution by sizes is rather narrow and symmetric that certifies the system of synthesized nanoparticles as homogenous with low degree of polydispersity. Ultraviolet spectrums of LMS and their components were fixed and analyzed. Comparison of transmission spectrums of suspensions with different degree of dilution testifies to the chemical identity of samples. There were studied kinetic dependencies of transmission coefficient for suspensions with different magnetite concentration (Fegen ), on which base was calculated the effective radius of particles of stabilized magnetite: 76–168 nm. The mean radius of particles in lipid suspension of magnetite without stabilizer (reff)=400 nm. Visually LMS manifested the high aggregative stability with high sedimentation time 48 hours. It was established, that LMS can be used as biologically active and feed additives with complex effect: manifest antioxidant activity, are the source of easily assimilated iron, improve quality and increase storage terms of fat-containing products. Thus, introduction of LMS in foodstuff improves its quality, nutritive and biological value.