Orientational Ordering of Bipolar Nematic Droplets in a Stretched PVA Matrix

References

• Crawford , O. P. and Doane , J. W. 1992 . Condensed Matter News , 1 : 5 and references therein.
   Google Scholar
• Doane , J. W. 1991 . MRS Bulletin. , XVI : 22 and references therein.
   Web of Science ®Google Scholar
• Dubois-Violette , E. and Parodi , O. 1969 . J. de Phys. , C4 : 57
   Google Scholar
• Candau , S. , Le Roy , P. and Debeauvais , F. 1973 . Mol. Cryst. Liq. Cryst. , 23 : 283
   Web of Science ®Google Scholar
• Volovik , G. E. and Lavrentovich , O. D. 1983 . Zh. Eksp. Tear. Fiz. , 85 : 1997 [Sov. Phys. JETP, 58, 1159 (1983)].
   Google Scholar
• Williams , R. D. 1986 . J. Phys. A: Math. Gen. , 19 : 3211
   Google Scholar
• Drzaic , P. S. 1986 . J. Appl. Phys. , 60 : 2142
   Web of Science ®Google Scholar
• Koval'chuk , A. V. , Kurik , M. V. , Lavrentovich , O. D. and Sergan , V. V. 1988 . Zh. Eksp. Teor. Fiz. , 94 : 350 [Sov. Phys. JETP, 67, 1065 (1988)].
   Google Scholar
• Drzaic , P. S. 1988 . Mol. Cryst. Liq. Cryst. , 154 : 289
   Web of Science ®Google Scholar
• Drzaic , P. S. 1988 . Liq. Cryst. , 3 : 1453
   Web of Science ®Google Scholar
• Golemme , A. , Zumer , S. , Doane , J. W. and Neubert , M. E. 1988 . Phys. Rev. A. , 37 : 559
   PubMed Web of Science ®Google Scholar
• Doane , J. W. , Golemme , A. , West , J. L. , Whitehead , J. B. and Wu , B.-G. 1988 . Mol. Cryst. Liq. Cryst. , 165 : 511
   Web of Science ®Google Scholar
• Drzaic , P. S. and Muller , A. 1989 . Liq. Cryst. , 5 : 1467
   Web of Science ®Google Scholar
• Vilfan , I. , Vilfan , M. and Zumer , S. 1989 . Phys. Rev. A , 40 : 4724
   Web of Science ®Google Scholar
• Wu , B.-G. , Erdmann , J. H. and Doane , J. W. 1989 . Liq. Cryst. , 5 : 1453
   Web of Science ®Google Scholar
• Erdmann , J. H. , Zumer , S. and Doane , J. W. 1990 . Phys. Rev. Lett. , 64 : 1907
   PubMed Web of Science ®Google Scholar
• Kralj , S. , Zumer , S. and Allender , D. W. 1991 . Phys. Rev. A , 43 : 2943
   PubMed Web of Science ®Google Scholar
• Ondris-Crawford , R. , Boyko , E. P. , Wagner , B. W. , Erdmann , J. H. , Zumer , S. and Doane , J. W. 1991 . J. Appl. Phys. , 69 : 6380
   Web of Science ®Google Scholar
• Kralj , S. and Zumer , S. 1992 . Phys. Rev. A , 45 : 2461
   PubMed Web of Science ®Google Scholar
• Zumer , S. , Kralj , S. and Bejic , J. 1992 . Mol. Cryst. Liq. Cryst. , 212 : 163
   Web of Science ®Google Scholar
• Xu , F. , Kitzerow , H.-S. and Crocker , P. P. 1992 . Phys. Rev. A , 46 : 6535
   PubMed Web of Science ®Google Scholar
• Bodnar , V. G. , Lavrentovich , O. D. and Pergamenshchik , V. M. 1992 . Zh. Eksp. Teor. Fiz. , 101 : 111 [Sov. Phys. JETP, 74, 60 (1992)].
   Google Scholar
• Hermel , H. and Seeboth , A. 1992 . J. Appl. Polym. Sci. , 46 : 143
   Web of Science ®Google Scholar
• Aphonin , O. A. , Panina , Yu. V. , Pravdin , A. B. and Yakovlev , D. A. 1993 . Liq. Cryst. , 15 : 395
   Web of Science ®Google Scholar
• Kelly , J. R. and Palffy-Muhoray , P. 1994 . Mol. Cryst. Liq. Cryst. , 243 : 11
   Web of Science ®Google Scholar
• Crawford , G. P. , Polak , R. D. , Scharkovski , A. , Chien , L.-C. , Doane , J. W. and Zumer , S. 1994 . J. Appl. Phys. , 75 : 1968
   Web of Science ®Google Scholar
• Xu , F. , Kitzerow , H.-S. and Crooker , P. P. 1994 . Phys. Rev. E. , 49 : 3061
   Web of Science ®Google Scholar
• West , J. L. , Doane , J. W. and Zumer , S. 1987 . US Patent 4 , 685 : 771
   Google Scholar
• Doane , J. W. , Chidichimo , G. and Zumer , S. 1987 . US Patent 4 , 688 : 900
   Google Scholar
• Heinhold , I. and Gaede , K. W. 1964 . Ingeniur statistic , Springer Verlag, Munchen, Wien .
   Google Scholar
• Havens , J. R. , Leong , D. B. and Reimer , K. B. 1990 . Mol. Cryst. Liq. Cryst. , 178 : 89
   Web of Science ®Google Scholar
• For the affine transformation of the matrix dimensions, a radius vector terminating at the point x, y, z on the surface of the undeformed droplet cavity terminates at pxx, pyy, pzz on the surfacee of the deformed ellipsoid, where px = p, py = p−A, and pz = p−B are the ratios of the stretched and unstretched dimensions of the sample, respectively, in the Cartesian coordinate system X YZ with the X axis parallel to the stretch direction and the Z axis normal to the film plane. A and B are constants, satisfying the condition for a constant film volume A + B = 1 (i. e., pxpypz = 1) and, for our samples, having the values A ≈ 0.55, B ≈ 0.45. Considering such a deformation, it is easy to obtain the Equation (5) and show that l = p1+A
   Google Scholar
• We have not related the observed peculiarites to the droplet sizes (i. e., the droplet size distribution function was not taken into account) since the number of droplets per histogram bin (in average about of 20) was too small to reliably detect such a correlation. To solve the problem, each bin should contain no less than hundreds of droplets that requires the automated sample inspection instead of the mannual statistical treatment used in this work.
   Google Scholar
• A unique rest orientation for the bipolar nematic droplet in an unstretched PVA film has been originally found by Drzaic7 who has observed that the droplet returns to its initial state after the external electric field is removed and also after heating the nematic to the isotropic state and then cooling back to the nematic. The main driving force for this preferred orientation was ascribed to the droplet shape anisotropy: each droplet was postulated to have an irregular shape and therefore the droplet director prefers to orient along the greatest dimension of the droplet cavity where the elastic deformation energy is minimized. Although an alternative view that the rest configuration is defined by a preferred alignment direction imposed by the polymer wall was not ruled out, it was reckoned as a secondary in importance to the shape anisotropy of the droplet.10
   Google Scholar
• Ushakov , S. N. 1960 . Poliviniloviy spirt i ego proizvodnye , Moscow-Leningrad : Izd. AN SSSR .
   Google Scholar
• Stein , R. S. 1971 . J. Polym. Sci., Pt. C , 32 : 45 in references therein.
   Google Scholar
• Geary , J. M. , Good by , J. W. , Kmetz , A. R. and Patel , J. S. 1987 . J. Appl. Phys. , 62 : 4100
   Web of Science ®Google Scholar
• The crystallite sizes commonly range from a few tens of Angstroms up to several hundred Angstroms36 (usually 300 A); therefore, they are not seen with an optical microscope. In some cases, crystallites can be spontaneously organized into spherulites, which range in size from 1 μm to millimeters. However, microscope observations have shown that the PVA/glycerol matrix used in this study was devoid of spherulite structures.
   Google Scholar
• Crawford , S. M. and Kolsky , H. 1951 . Proc. Royal Phys. Soc. , B64 : 119
   Web of Science ®Google Scholar
• Ji , Y. , Kelly , J. R. and West , J. L. 1993 . Liq. Cryst. , 14 : 1885
   Web of Science ®Google Scholar