Abstract
The effect of Sodium pyrophosphate and polyethylene oxide on thermal diffusivity of Laponite RD colloidal suspension is studied with optical technique of Mach-Zehnder interferometer. Laponite RD is synthetic nano-crystalline colloid having a disk shaped monodispersed particle with radius 12.5 nm and edge thickness 1 nm. Aqueous Laponite suspension generally forms complex microstructure with and without addition of externally added salt. At low volume fraction and low concentration of externally added salt it forms dilute gel and at high concentration and high volume fractions, a disconnected Wigner glass. The appropriate concentrations of sodium pyrophosphate in the range of 5–25 mM and Polyethylene oxide (PEO) 0.5–1.5 wt% is mixed with 2–3 wt% Laponite RD suspension. The freshly prepared 10 days old Laponite RD suspension was stirred for half an hour before pouring in an octagonal test cell cavity. The top and bottom sides of octagonal cavity are attached to copper plates. Initially the suspension was kept at uniform temperature. Collimated laser light beam generated from He–Ne laser with 632.8 nm wavelengths is passed through the test cell in which Laponite suspension is kept. The initial alignment of the interferometer is in the infinite fringe setting mode, which is obtained by balancing the density of test cell filled with Laponite suspensions and reference cell filled with dextrose solution. Subsequently, there is step increase of temperature of top plate in the range of 1–3 °C. Refractive index variation through change in temperature of Laponite suspension leads to a well-defined interference pattern. The interferograms are then processed through fringe thinning procedure and are analyzed to obtain the time dependent temperature field varying with spacing of octagonal cavity. They are then compared with analytical solutions of the heat conduction diffusion equations. The comparison of least square fit of the experimental data with analytical solutions leads to estimation of thermal diffusivity. Interestingly even with very small concentration of sodium pyrophosphate, the Laponite RD suspension (around 2–3 wt%), shows a substantial reduction in thermal diffusivity values as compared to Laponite RD suspension. The aggregation rate of Laponite suspension as a function of pyrophosphate and polyethylene oxide concentrations are compared using static light scattering experiments from literature in order to interpret laser interferometric thermal diffusivity results.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Abbreviations
- T c :
-
Cold water bath temperature (K)
- T h :
-
Hot water bath temperature (K)
- α:
-
Thermal diffusivity (m2/s)
- H :
-
Height of cavity (m)
- y :
-
Spatial variation in cavity (m)
- t :
-
time interval (s)
- n :
-
Integer used in the analytical solution
- T :
-
Temperature at any instant (°C or K)
- S(τ, α):
-
Non-dimensional sensitivity coefficient
- τ:
-
Non-dimensional time
- L :
-
The length of test cell (m)
- \(\frac{dn}{dT}\) :
-
Variation of refractive index with temperature (K−1)
- λ :
-
Wavelength of light, nm
- Θ:
-
Non-dimensional temperature
- η:
-
Non-dimensional spacing
References
Assael, M.J., Chen, C.F., Metaxa, I.N., Wakeham, W.A.: Thermal conductivity of suspensions of carbon nanotubes in water. In: 15th Symposium on Thermo physical Properties, National Institute of Standards, University of Colorado, Boulder, USA, 2003
Bandyopadhyay, R., Liang, D., Harden, J.L., Leheny, R.: Slow dynamics, aging, and glass rheology in soft and living matter. J. Solid State communication 139, 589–598 (2006)
Bhandari, S.S., Muralidhar, K., Joshi, Y.M.: Enhanced thermal transport through a soft glassy nano-disk paste. PRE 87, 022301–022306 (2013)
Bhandari, S.S., Muralidhar, K., Joshi, Y.M.: Thermal diffusivity and viscosity of suspensions of disk-shaped nanoparticles. Ind. Engg. Chem. Res. 52, 15114–15123 (2013)
Bison, P.G., Marinetti, S., Mazzoldi, A., Grinzato, E., Bressan, C.: Cross comparison of thermal diffusivity measurements by thermal methods. Infrared Phys. Technol. 43, 127–132 (2002)
Eastman, J.A., Choi, S. U.S., Li, S., Thompson, L.J., Lee, S.: Enhanced thermal conductivity through the development of nanofluids. In: Materials Research Society Symposium—Proceedings, vol. 457, Materials Research Society, Pittsburgh, PA, USA, Boston, MA, USA, pp. 3–11 (1997)
Jabbari- Farouji, S., Tanaka, H., Wegdam, G.H., Bonn, D.: Multiple non ergodic disordered states in colloidal suspensions: a phase diagram. Phys. Rev. E 78(6), 061405–061410 (2008)
Joseph, S., Mishra, A., Mathew, S., Sharma, G., Soumya, A., Hadiya, V.M., Radhakrishnan, P., Nampoori, V.P.N.: Thermal diffusivity of Rhodamine 6G incorporated in silver nanofluid measured using mode-matched thermal lens technique. J. Optics Commun. 283, 313–317 (2010)
Joshi, Y.M., Reddy, G.R.K., Kulkarni, A.L., Kumar, N., Chhabra, R.P.: Rheological behavior of aqueous suspensions of laponite: new insights into the ageing phenomena. Proc. R. Soc. London A. 464, 469–489 (2008)
Laponite Technical Bulletin: laponite: structure, chemistry and relationship to natural clays. vol. L104-90-A, pp. 1–15 (1990)
Lee, S., Choi, S.U.S., Li, S., Eastman, J.A.: Measuring thermal conductivity of fluids containing oxide nanoparticle. J. Heat Transf. 121, 280–289 (1999)
Liu, M.-S., Lin, C.C.M., Huang, I.T., Wang, C.C.: Enhancement of thermal conductivity with carbon nanotube for nanofluids. Int. Commun. Heat Mass Transf. 32(9), 1202–1210 (2005)
Maxwell, J.C.: A treatise on electricity and magnetism, 2nd edn. Clarendon Press, Oxford, UK (1881)
Mongondry, P., Nicolai, T., Tassin, J.F.: Influence of pyrophosphate or Polyethyleneoxide on the aggregation and gelation of aqueous Laponite dispersion. J. Coll. Interf. Sci. 275, 191–196 (2004)
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2017 Springer India
About this paper
Cite this paper
Bhandari, S.S. (2017). Effect of Sodium Pyrophosphate and Polyethylene Oxide on Thermal Diffusivity of Laponite RD Colloidal Suspension. In: Saha, A., Das, D., Srivastava, R., Panigrahi, P., Muralidhar, K. (eds) Fluid Mechanics and Fluid Power – Contemporary Research. Lecture Notes in Mechanical Engineering. Springer, New Delhi. https://doi.org/10.1007/978-81-322-2743-4_22
Download citation
DOI: https://doi.org/10.1007/978-81-322-2743-4_22
Published:
Publisher Name: Springer, New Delhi
Print ISBN: 978-81-322-2741-0
Online ISBN: 978-81-322-2743-4
eBook Packages: EngineeringEngineering (R0)