Dilatant effect enhancers for silica dispersions in poly(propylene glycols)
Marcin Orawiec , Marcin Kaczorowski , Gabriel Rokicki
AbstractShear thickening fluids have found many applications in energy damping materials such as sports guards and liquid body armors. Therefore, an additive which could tailor the dilatant properties of such fluids without significantly affecting other properties, especially zero shear viscosity, could significantly increase the versatility of protective materials based on shear thickening fluids. In this paper, poly(propylene glycols) (PPGs) diacetates are investigated as dilatant effect enhancers for nano-silica dispersions in poly(propylene glycols). The influence of the modifiers on rheological properties of the dispersion is studied and discussed. Additionally, FTIR and rheological properties measurements are conducted in order to determine relative interactions strength between hydroxyl groups of PPGs and silica and carbonyl groups of PPG diacetates. Our findings suggest that the relative attractive interaction strength in studied systems can be arranged in the following order: C=O - C=O < C=O - OH < OH - OH. Therefore, the addition of PPG diacetate hinders the attractive interactions between liquid and solid. We report that the addition of diacetates can lead both to enhancement and deterioration of dilatant effect depending on the concentration of the modifier and its chain length. Based on conducted measurements and literature data, mechanism explaining that phenomenon is suggested. As a result, we propose an easy to make and cheap dilatant effect enhancer for widely used shear thickening fluids which, when used in small amounts (1–2.5%), raises the viscosity jump drastically. Additionally, the presence of the modifier does not significantly affect the zero shear viscosity of the shear thickening fluid.
|Journal series||Journal of Colloid and Interface Science, ISSN 0021-9797, (A 30 pkt)|
|Publication size in sheets||0.5|
|Keywords in English||Shear thickening fluid; Nanosilica composite; Dilatant effect; Dilatant effect enhancement; Rheological properties modifier; Poly(propylene glycol)|
|Score|| = 30.0, 24-07-2018, ArticleFromJournal|
= 30.0, 24-07-2018, ArticleFromJournal
|Publication indicators||: 2016 = 4.233 (2) - 2016=3.988 (5)|
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