Rheological Characterisation

Rheology is the study of the flow of matter. The name derives from the Greek word rheo which means to flow . A solid will usually respond to a force by deforming and storing energy elastically. A liquid, however, will flow and dissipate energy 

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A number of peculiar properties are displayed, including rheology characterised by viscoelasticity. Viscosities are far higher than that of either bulk phase this is a result of the large amount of energy required to deform the network of thin films of the continuous phase. A yield stress is observed, below which HIPEs behave as elastic solids and will not flow. Resistance to flow occurs from the inability of compressed droplets to easily slip past each other. Above the... 

Kavanagh, G. M. and Ross-Murphy, S. B. 1998. Rheological characterisation of polymer gels. Prog. Polym. Sci. 23 533-562. 

Loret, C., Meunier, V, Frith, W. J., and Fiyer, P. J. 2004. Rheological characterisation of the gelation behaviour of maltodextrin aqueous solutions. Carbohydr. Polym. 57 (2) 153-163. 

De Kee, D. Turcotte, G. Code, R.K. Rheological characterisation of time-dependent foodstuffs. In Rheology Volume 3 Applications Astarita, G., Marrucci, G., Nicolais, L., Eds. Plenum Press New York, 1980 609-614. 

Ross-Murphy, S.B. Rheological characterisation of gels, /. Texture Stud., 26, 391,1995. 

Lupi, F.R. et al, A rheological characterisation of an olive oil/fatty alcohols organogel. Food Research International, 2013. 51(2) 510-517. 

G.P. Andrews, S.P. Gorman, D.S. Jones, Rheological characterisation of primary and binary interactive bioadhesive gels composed of cellulose derivatives designed as ophthalmic viscosurgical devices. Biomaterials 26 (5) (2005) 571-580. 

Taylor, C., Pearson, J.P., Draget, K.I., Dettmarc, P.W., Smidsrpd, O. Rheological characterisation of mixed gels of mucin and alginate. Caibohydr. Polym. 59, 189-195 (2005)... 

Talukdar, M.M. Vinckier, I. Moldenaers, P. Kinget, R. Rheological characterisation of xanthan gum and hydroxypropy I methyl cellulose with respect to controlled-release drug delivery. J. Pharm. Sci., 85(5) 537-540, 1996. 

The rheological characterisation of non-Newtonian fluids is widely acknowledged to be far from straightforward. In some non-Newtonian systems, such as concentrated suspensions, rheological measurements may be complicated by non-linear, dispersive, dissipative and thixotropic mechanical properties and the rheometrical challenges posed by these features may be compoimded by an apparent yield stress. 

The residue obtained from this test method may also be subjected to further rheological characterisation tests. 

This technique is used principally for the rheological characterisation of polymers and measurement of the dielectric constant. The technique measures changes in the properties of a polymer as it is subjected to a periodic electric field. This produces quantitative data, which can be used to determine the capacitive and conductive nature of a material. Molecular relaxations can be characterised and flow and cure of resins can be monitored. 

Tang YF, Du YM, Hu XW et al (2007) Rheological characterisation of a novel thermosensitive chitosan/poly(vinyl alcohol) blend hydrogel. Carbohydr Polym 67 491-499... 

Mesomo M, Silva ME, Boni G, PadUha FF, Mazutti M, Mossi A, et al. Xanthan gum produced by Xanthomonas campestris from cheese whey production optimisation and rheological characterisation.J... 

Rogers, T., 1989. Rheological characterisation of anisotropic materials. Composites 20,21-27. 

This technique is used principally for the rheological characterisation of polymers (Sections 18.1.3 and 18.1.4) and measurement of dielectric constant (Section 18.2). In the field of thermal and mechanical stability it has also found application in the fields of resin cure kinetics and resin cure monitoring. 

Morris, E.R. (1989) Polysaccharide solution properties origin, rheological characterisation and implications for food systems. In MiUane, R.P., BeMiUer, J.N. and Chandrasekaran, R. (eds), Frontiers in Carbohydrate Research- 1, Elsevier Applied Science, London, pp. 132-163. 

Heywood, N. I. 1991. Rheological characterisation of non-settling slurries. In Slurry Handling, Edited by N. P. Brown and N. I. Heywood. New York Elsevier Applied Sciences. 

Data is provided on the complete rheological characterisation, relative to steady-state shear stress and first and second normal stress differences as a function of shear rate, as well as the complementary oscillatory data, see figxires 13 and 14. The measured extensional properties are also available, see figure 15 [7]. 

Datta S, Naskar K, Bhardwaj YK, Sabharwal S (2011) A study on dynamic rheological characterisation of electron beam crosslinked high vinyl styrene butadiene styrene block copolymer. Polym Bull 66 637-647... 

The majority of foods show viscoelastic properties. This means that these foods react, when exposed to apphed force, by both the elastic component (which behave as in sohds) and the viscous component (which behaves as in hquids). The rheological characterisation of these materials, in addition to flow curves, requires knowledge of other parameters, complex (dynamic) modulus G, which is related to the elastic component of the material (storage modulus G ) and the viscous component of the material (loss modulus G") by the fohowing equation = (G + G" ). With the so-called... 

Chenite A, Busehmann M, Wang D, Ch ut C, Kandani N (2001) Rheological characterisation of thermogelling chitosan/glycerol-phosphate solutions. Carbohydr Polym 46 39... 

Durairaj, R., Ramesh, S., Mallik, S., Seman, A. Ekere, N.N. (2009b). Rheological Characterisation and Printing Performance of Sn/ Ag/ Cu Solder Paste. Materials and Design, Vol. 30, pp. 3812-3818. 

The final choice of the grades for injection moulding from different equivalent grades available may be made from the injection pressure versus injection time curve for different grades. The material that offers the lowest injection time at minimum injection pressure would be a candidate for the final choice. In blown film applications, screw speed, power required, and head pressure estimation based on rheological characterisation may be useful. 

Hickey, C., Bickerton, S., 2013. Cure kinetics and rheology characterisation and modelling of ambient temperature curing epoxy resins for resin infiisionA ARTM and wet la3mp applications. Journal of Materials Science 48, 690—701. 

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