Complex fluids containing long polymer chains exhibit measurably large resistance to stretching or extensional flows, due to additional stresses generated by the extensional deformation of the underlying fluid microstructure. Understanding and quantifying the response of such elastic fluids to extensional flows is necessary for optimizing fluid composition for technological applications like in...

The behaviour of a cetylpyridinium chloride/sodium salicylate wormlike micellar system undergoing capillary breakup is investigated experimentally. The transient elongational flow induced in a thinning thread is used to study the apparent viscosity and effective relaxation time of the micellar network in extension. The sensitivity of the material response to initial conditions and deformation h...

Xanthan gum and scleroglucan, two rod-like polysaccharide hydrocolloids, are compared using a wide range of instrumental techniques methods: steady shear flow, small amplitude oscillatory shear, first normal stress difference, capillary break-up soft-contact tribology. The aqueous solutions these hydrocolloids with similar flow viscoelastic profile show marked differences in time apparent exten...

Abstract Filament stretching rheometry is a prominent experimental method to determine rheological properties in extensional flow whereby the separating plates extension rate. In literature, several correction factors that can compensate for errors introduced by shear contribution near have been and validated linear viscoelastic regime. this work, systematic analysis conducted if material-indep...

Extensional rheometry has only recently been developed into a commercially available tool with the introduction of the capillary breakup extensional rheometer (CaBER). CaBER is currently being used to measure the transient extensional viscosity evolution of mid to low-viscosity viscoelastic fluids. The elegance of capillary breakup extensional experiments lies in the simplicity of the procedure...

Cellulose derivatives containing associating hydrophobic groups along their hydrophilic backbone are used as rheology modifiers in the formulation of water-based spray paints, medicinal sprays, cosmetics and printable inks. Jetting and spraying applications of these materials involve progressive thinning and break-up of a fluid column or sheet into drops. Strong extensional kinematics develop i...

A viscous Newtonian fluid and two model polystyrene Boger fluids are used to investigate the evolution of free-surface instabilities during the debonding of two cylindrical parallel rigid surfaces. A filament stretching rheometer is used to separate the surfaces at an exponential rate and simultaneously measure the evolution in the axial force. The experimental configuration also allows for sim...