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  • 1 Department of Chemistry, Centre of Advanced Study, Banaras Hindu University, Varanasi 221 005, India
  • 2 Department of Chemistry, Butwal Multiple Campus, Tribhuvan University, Butwal, Nepal
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Abstract

The phase diagram of 1,4-dibromobenzene (DBB) with pyrogallol (PG) shows the formation of a monotectic and a eutectic alloys at 0.12 and 0.99 mol fractions of DBB, respectively. The phase equilibrium shows the large miscibility gap region with the upper consolute temperature 159.0 °C at 0.55 mol fraction of DBB. Growth kinetics of pure compounds and their monotectic and eutectic at different undercooling (ΔT) obey Hillig–Turnbull's equation: v = uT)n. Thermodynamic parameters such as enthalpy of mixing, entropy of fusion, interfacial energy, roughness parameters and excess thermodynamic functions were computed based on enthalpy of fusion values obtained from DSC studies. The Cahn wetting condition is applicable for monotectic alloy. The optical microphotographs of binary alloys show lamellar and dendritic features.

  • 1.

    Majumdar, B, Chattopadhyay, K. 1996. The Rayleigh instability and the origin of rows of droplets in the monotectic microstructure of zinc-bismuth alloys. Met Trans A. 27 A 20532057.

    • Search Google Scholar
    • Export Citation
  • 2.

    Chang, TC, Hsu, YT, Hon, MH, Wang, MC. 2003. Enhancement of the wettability and solder joint reliability at the Sn–9Zn–0.5Ag lead-free solder alloy–Cu interface by Ag precoating. J Alloys Compd. 360:217224 .

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 3.

    Lin, L, Rui, T, Xueshan, X. 2008. Development of bulk metallic glasses based on the Dy-Al binary eutectic composition. J Rare Earths. 26 6 813816 .

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 4.

    Rice, JW, Fu, J, Suuberg, EM. 2010. Anthracene + pyrene solid mixtures: eutectic and azeotropic character. J Chem Eng Data. 55:35983605 .

  • 5.

    Rai, US, Rai, RN. 1998. Physical chemistry of organic eutectics. J Therm Anal Calorim. 53:883893 .

  • 6.

    Gupta, P, Agrawal, T, Das, SS, Singh, NB. 2011. Solvent free reactions, reactions of nitrophenols in 8-hydroxyquinoline–benzoic acid eutectic melt. J Therm Anal Calorim. 104:11671176 .

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 7.

    Dwivedi, Y, Kant, S, Rai, SB, Rai, RN. 2011. Synthesis, physicochemical and optical characterization of novel fluorescing complex: o-phenylenediamine-benzoin. J Fluoresc. 21:12551263 .

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 8.

    Chen, YP, Tang, M, Kuo, JC. 2005. Solid–liquid equilibria for binary mixtures of N-phenylacetamide with 4-aminoacetophenone, 3-hydroxyacetophe-none and 4-hydroxyacetophenone. Fluid Phase Equilib. 232:182188 .

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 9.

    Ji, HZ, Meng, XC, Zhao, HK. 2010. Solid + liquid) equilibrium of (4-chloro-2-benzofuran-1,3-dione + 5-chloro-2-benzofuran-1,3-dione. J Chem Eng Data. 55:25902593 .

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 10.

    Sturz, L, Witusiewicz, VT, Hecht, U, Rex, S. 2004. Organic alloy systems suitable for the investigation of regular binary and ternary eutectic growth. J Cryst Growth. 270:273282 .

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 11.

    Rai, US, Pandey, P. 2004. Some physicochemical studies on binary organic eutectic and monotectic alloys: p-dibromobenzene-m-aminophenol system. Mater Lett. 58:29432948 .

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 12.

    Rai, RN, Reddi, RSB. 2009. Thermal, solid–liquid equilibrium, crystallization, and microstructural studies of organic monotectic alloy: 4,4′-Dibromobiphenyl–succinonitrile. Thermochim Acta. 496:1317 .

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 13.

    Hillig, WB, Turnbull, D. 1956. Theory of crystal growth in undercooled pure liquids. J Chem Phys. 24:914 .

  • 14.

    Winegard WC . An introduction to solidification of metals. London: Institute of Metals Monograph; 1969 29: 67.

  • 15.

    Rai, US, Rai, RN. 1999. Physical chemistry of organic eutectic and monotectic: hexamethylbenzene-succinonitrile system. Chem Mater. 11:30313036 .

  • 16.

    Ratke, L, Diefenbach, S. 1995. Liquid immiscible alloys. Mater Sci Eng. R15:263347.

  • 17.

    Singh, NB, Rai, US, Singh, OP. 1985. Chemistry of eutectic and monotectic; phenanthrene-succinonitrile system. J Cryst Growth. 71:353360 .

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 18.

    Reddi, RSB, Kumar, SVSA, Rai, US, Rai, RN. 2012. Thermal, physicochemical and microstructural studies of binary organic eutectic systems. J Therm Anal Calorim. 107:377385 .

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 19.

    Hunt, JD, Jackson, KA. 1966. Binary eutectic solidification. Trans Met Soc AIME. 236:843852.