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Journal of the American Oil Chemists' Society

, Volume 31, Issue 12, pp 628–639 | Cite as

The microscopy of the liquid crystalline neat and middle phases of soaps and synthetic detergents

  • F. B. Rosevear
Article

Summary

The mesomorphic or “liquid crystalline” neat and middle phases encountered in aqueous systems of soaps and synthetic detergents differ considerably in plasticity. Nevertheless, in fundamental phase studies or the examination of commercial products and processes, identification of these two phases has hitherto been uncertain, particularly when they are mixed with each other or with other phases; even under the polarizing microscope, their identification has not been positive since, by the classical criteria for identifying mesomorphic phases, both are “smectic.”

The present work reveals additional criteria by which the two phases may be satisfactorily distinguished. In the first place, there are non-geometric textures exhibited by middle but not by neat. Conversely, there are planar textures exhibited by neat but not by middle. Furthermore there are important systematic differences even among the focal conic textures upon which the smectic nature of the two phases has previously been predicated.

While the microscopic method now makes possible the identification of phase mixtures, it serves also as a rapid method even where one-phase compositions are concerned.

This study is primarily descriptive in its present state of development, but the existence of systematic microscopic differences between these two nominally smectic phases, coupled with their well-known and pronounced difference in consistency, suggests a fundamental structural distinction between them.

Much of the present subject-matter applies also to such materials as certain wetting agents and dyes, as well as phosphatides and certain other biological substances.

Keywords

Synthetic Detergent Middle Phase Positive Unit Neat Soap Potassium Oleate 

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References

  1. 1.
    Bernal, J. D., and Crowfoot, D., Trans. Faraday Soc.,29, 1042–3 (1933).Google Scholar
  2. 2.
    Bragg, W. H., Trans. Faraday Soc.,29, 1056–60 (1933).CrossRefGoogle Scholar
  3. 3.
    Bragg, W. H., Proc. Roy. Inst. Gt. Brit.,28, 57–93 (1934); see Plates I, II.Google Scholar
  4. 4.
    Bragg, W. H.,ibid., Plates I and II, Figures 6, 7 and 8.Google Scholar
  5. 5.
    Cameron, J.,Soaps and Candles, p. 102, Blakiston, Phila. (1888).Google Scholar
  6. 6.
    de Bretteville, A. Jr., and McBain, J. W., J. Chem. Phys.,11, 426–9 (1943).CrossRefGoogle Scholar
  7. 7.
    Dervichian, D. G., Trans. Faraday Soc.,42B, 180–7 (1946), espec. 183.CrossRefGoogle Scholar
  8. 8.
    Doscher, T. M., and Vold, R. D., J. Coll. Sci.,1, 299–312 (1946).CrossRefGoogle Scholar
  9. 9.
    Doscher, T. M., and Vold, R. D., J. Phys. & Colloid Chem.,52, 97–109 (1948).CrossRefGoogle Scholar
  10. 10.
    Ferguson, R. H.,et al., unpublished work in this laboratory, beginning 1932.Google Scholar
  11. 11.
    Ferguson, R. H., and Richardson, A. S., Ind. Eng. Chem.,24, 1329–36 (1932).CrossRefGoogle Scholar
  12. 12.
    Friedel, G., Ann. de physique,18, 300–304 (1922); see Plates 4 and 5 at end of volume. (More briefly in Ref. 16.)Google Scholar
  13. 13.
    Friedel, G.,ibid., 304–327; see Plates 6–10, 14, 16 at end of volume. Friedel terms a region based on a single ellipse and its corresponding hyperbola a “focal domain.”Google Scholar
  14. 14.
    Friedel, G.,ibid., 324–7; also Plates 11 and 18.Google Scholar
  15. 15.
    Friedel, G.,ibid., 328 ff.Google Scholar
  16. 16.
    Friedel, G., in Alexander’sColloid Chemistry, vol. I, pp. 107–8, Chem. Catalog Co., N. Y. (1926).Google Scholar
  17. 17.
    Friedel, G.,ibid.. Planar areas with sheets not parallel to the surface of the preparation, being derived ordinarily from sizeable single crystals, are rare in soaps.Google Scholar
  18. 18.
    Friedel, G., Z. Krist.,79, 9 (1931).Google Scholar
  19. 19.
    Hartshorne, N. H., and Stuart, A.,Crystals and the Polarizing Microscope, 2nd ed., Arnold, London (1950), chap. IX, espec. pp. 331–41.Google Scholar
  20. 20.
    Hermann, C., Z. Krist.,79, 186–221 (1931).Google Scholar
  21. 21.
    Hyde, A. J., Nature,170, 234 (1952).CrossRefGoogle Scholar
  22. 22.
    Lascaray, L., in Hefter-Schönfeld,Fette u. Fettprodukte, vol. IV, pp. 122, 125–7, 179 ff., Springer, Vienna (1939).Google Scholar
  23. 23.
    Lascaray, L.,ibid., pp. 122, 125.Google Scholar
  24. 24.
    Lascaray, L.,ibid., pp. 125, 181.Google Scholar
  25. 25.
    Lawrence, A. S. C., J. Roy. Microscop. Soc.58, 30–48 (1938); see Figure 3.CrossRefGoogle Scholar
  26. 26.
    Lehmann, O.,Flüssige Kristalle, Engelmann, Leipzig (1904): Photogr. 6 of Plate 1, Photogr. 1 of Plate 2.Google Scholar
  27. 27.
    Lehmann, O., ibid., Photogr. 6 and 7 of Plate 9.Google Scholar
  28. 28.
    Lehmann, O., ibid., Plates 3–5.Google Scholar
  29. 29.
    Lehman, O., Z physik., Chem.,4, 462–72 (1889).Google Scholar
  30. 30.
    Lehmann, O., Wied. Ann.,56, 771–88 (1895).CrossRefGoogle Scholar
  31. 31.
    Lewkowitsch, J.,Chem. Technol. ... Oils, Fats and Waxes, 5th ed., vol. III, Macmillan, London (1915), p. 304.Google Scholar
  32. 32.
    Maclennan, K., J. Soc. Chem. Ind.,42, 393T-401T (1923), Figures 6 and 8; while the specific compositions of these are not given, the captions and accompanying text indicate that they must be neat soaps.CrossRefGoogle Scholar
  33. 33.
    Maclennan, K.,ibid., Figures 20, 21.CrossRefGoogle Scholar
  34. 34.
    McBain J. W., Nature,115,805–7 (1925); 2.5 Nw (37.5%) potassium laurate (in water) 45°C. Original photomicrograph of composition later shown to be middle soap (42).CrossRefGoogle Scholar
  35. 35.
    McBain, J. W., Proc. Roy. Inst. Gt. Brit.,1925, 579–84, Figure 2: 3 Nw (42%) potassium laurate.Google Scholar
  36. 36.
    McBain, J. W., in Alexander’sColloid Chemistry, vol. I, pp. 137–64, Chem. Catalog Co., N. Y. (1926).Google Scholar
  37. 37.
    McBain, J. W., J. Chem. Ed.,6, 2115–27 (1929), Figure 21: reprinting of photo from Ref. 34; Figure 20: 3 Nw (42%) potassium laurate.CrossRefGoogle Scholar
  38. 38.
    McBain, J. W.,ibid., Figure 22: 2.5 Nw (37.5%) potassium laurate, anisotropic liquid phase separating from isotropic melt at unspecified temperature.CrossRefGoogle Scholar
  39. 39.
    McBain, J. W.,ibid., Figure 12.CrossRefGoogle Scholar
  40. 40.
    McBain, J. W., and Elford, W. J., J. Chem. Soc.,1926, 421–38.Google Scholar
  41. 41.
    McBain, J. W., and Elford, W. J.,ibid., Photographs I and III: 9 Nw (74%) and 25 Nw (89%) potassium oleate in water. These two photographs, along with a statement that 4 Nw (56%) potassium oleate separates from isotropic liquid at 240°C. as “batonnets,” appear to constitute the total original evidence for the smectic nature of neat soap.Google Scholar
  42. 42.
    McBain, J. W., and Field, M. C., J. Phys. Chem.,30, 1545–63 (1926).CrossRefGoogle Scholar
  43. 43.
    McBain, J. W., and Langdon, G. M., J. Chem. Soc.,1925, 852–70.Google Scholar
  44. 44.
    McBain, J. W., Lazarus, L. H., and Pitter, A. V., Z. physik. Chem.,A147, 87–117 (1930).Google Scholar
  45. 45.
    McBain, J. W., and Lee, W. W., Oil & Soap,20, 17–25 (1943).CrossRefGoogle Scholar
  46. 46.
    McBain, J. W., Vold, M. J., and Porter, J. L., Ind. Eng. Chem.,33, 1049–55 (1941).CrossRefGoogle Scholar
  47. 47.
    McBain, J. W., Vold, R. D., and Frick, M., J. Phys. Chem.,44, 1013–24 (1940).CrossRefGoogle Scholar
  48. 48.
    McBain, J. W., Vold, R. D., and Vold, M. J., J. Am. Chem. Soc.,60, 1866–9 (1938).CrossRefGoogle Scholar
  49. 49.
    McBain, J. W., and Watts, O., J. Rheol.,3, 437–60 (1932). Figure 2: reprinting of photo from Ref. 34.CrossRefGoogle Scholar
  50. 50.
    Nordsieck, H., Rosevear, F. B., and Ferguson, R. H., J. Chem. Phys.,16, 175–80 (1948).CrossRefGoogle Scholar
  51. 51.
    Rinne, F., Trans. Faraday Soc.,29, 1016–32 (1933); Figure 2 of Plate I.CrossRefGoogle Scholar
  52. 52.
    Rosevear, F. B., Am. Mineral.,32, 693–4 (1947).Google Scholar
  53. 53.
    Vold, M. J., J. Am. Chem. Soc.,63, 1427–32 (1941).CrossRefGoogle Scholar
  54. 54.
    Vold, R. D., J. Phys. Chem.,43, 1213–31 (1939).CrossRefGoogle Scholar
  55. 55.
    Vold, R. D.,ibid., a) Figure 8: 36% sodium oleate, 80°C.; b) Figure 9: 36% sodium oleate, 115°C.CrossRefGoogle Scholar
  56. 56.
    Vold, R. D.,ibid., Figure 11: 56% sodium oleate at 90°C.CrossRefGoogle Scholar
  57. 57.
    Vold, R. D.,ibid., Figures 10, 12, 13, 14.CrossRefGoogle Scholar
  58. 58.
    Vold, R. D., Soap Sanit. Chemicals,16, 31–37 (1940).Google Scholar
  59. 59.
    Vold, R. D., and Ferguson, R. H., J. Am. Chem. Soc.,60, 6066–76 (1938).CrossRefGoogle Scholar
  60. 60.
    Vold, R. D., Reivere, R., and McBain, J. W., J. Am. Chem. Soc.,63, 1293–6 (1941).CrossRefGoogle Scholar
  61. 61.
    Vold, R. D., Rosevear, F. B., and Ferguson, R. H., Oil & Soap,16, 48–51 (1939).CrossRefGoogle Scholar
  62. 62.
    Vold, R. D., and Vold, M. J., J. Am. Chem. Soc.,61, 808–16 (1939).CrossRefGoogle Scholar
  63. 63.
    Vold, R. D., and Vold, M. J., in Alexander’sColloid Chemistry, vol. V, pp. 266–80, espec. Figure 5, Reinhold Publ. Corp., N. Y. (1944).Google Scholar
  64. 64.
    Vold, R. D., and Vold, M. J., J. Phys. & Colloid Chem.,52, 1424–44 (1948).CrossRefGoogle Scholar

Copyright information

© AOCS Press 1954

Authors and Affiliations

  • F. B. Rosevear
    • 1
  1. 1.Miami Valley LaboratoriesThe Procter and Gamble CompanyCincinnati

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