The influence of silica nanoparticles on the microstructure and rheology of the suspensions containing wax network

Suspensions with jammed networks are found in different products such as chocolate, peanut butter, margarine in foods, creams, ointments in pharmaceuticals and consumer goods. Organic molecules present in these suspensions act as structuring agents. Network formation during the congealing step mostly governs the textural and rheological properties of the end product. Different additives are used to refine these properties by altering crystal morphology. Nanoparticles with different surface characteristics are reported to impact rheology by changing crystallite shape, size and size distribution.

We observe the effect of silica nanoparticles (SNPs) on wax in oil suspension. SNPs are synthesized using the Stöber method and hydrophobized via attachment of long alkyl chains. The influence of SNPs on wax crystal number density, size, morphology and suspension rheology is studied. Variation of alkyl chain grafting density, concentration and size of SNPs is also investigated.