LYOBANANA MESOPHASES COMPOSED BY A MIXTURE OF APOLAR
LYO-BANANA MESOPHASES COMPOSED BY A MIXTURE OF APOLAR SOLVENTS AND BENTSHAPED MOLECULES O. G. Martins 1, Y. Huang 2, A. Jákli 2, H. Sawade 2 e A. M. Figueiredo Neto 1 1 Instituto de Física, Universidade de São Paulo, Brazil 2 Liquid Crystal Institute, Kent State University, USA Complex Fluids Group University of São Paulo, Brazil
Molecules with the “form” of 1925 1996 Complex Fluids Group University of São Paulo, Brazil
Complex Fluids Group University of São Paulo, Brazil
B 1 phase of the “smectic type” Complex Fluids Group University of São Paulo, Brazil
Bi , with i from 1 to 7 1) With ferroelectric switching B 2 B 5 (symmetry C 2 v), smectic, with 2 D rectangular ordering in the layers 2) 2 D ordering B 1 smectic, with 2 D rectangular ordering in the layers B 7 structure not well determined [probably of the type 1) above] Complex Fluids Group University of São Paulo, Brazil
3) phases with intercalated molecules B 6 smectic , with tilted molecules 4) Crystalline phases B 3 and B 4 Complex Fluids Group University of São Paulo, Brazil
Complex Fluids Group University of São Paulo, Brazil xilene molecular mass: 108
B 7 phase in the temperature range from 90 to 133 o. C Smectic with spacing layer of 38. 5Å, and a complex in-layer structure. Helical filaments at the transition from the ISO phase. -“telephone-wire-like” texture Complex Fluids Group University of São Paulo, Brazil
xilene weaken the dipole interaction Complex Fluids Group University of São Paulo, Brazil
In São Paulo and Kent C 10 H 21 named C 10 C 14 H 29 named C 14 Cr B 2 68 o. C 118 o. C Complex Fluids Group University of São Paulo, Brazil ISO 127 o. C 140 o. C C 14 C 10
The solvent n – hexadecane: CH 3 – (CH 2)14 - CH 3 boiling point: 287 o. C density: 0. 77 g/cm 3 molecular weight: 226. 4 Doping (in weight %): 20 and 40 Complex Fluids Group University of São Paulo, Brazil
X Ray Diffraction Crystalline phase C 10 , T=22 o. C d C 14 , T=23 o. C b Complex Fluids Group University of São Paulo, Brazil 4. 4 Å 51. 4 Å
C 14 , T=23 o. C, 20 wt% B 3 phase, oriented d = 54. 7Å > d 0 wt% b = 4. 6Å b 0 wt% hexadecane Complex Fluids Group University of São Paulo, Brazil
C 14 , T=79 o. C, 20 wt% B 3 phase, non oriented d = 55. 6Å > d 0 wt% b = 4. 6Å b 0 wt% Complex Fluids Group University of São Paulo, Brazil
C 14 , T=23 o. C, 40 wt% C 14 , T=79 o. C, 40 wt% Complex Fluids Group University of São Paulo, Brazil
C 14 , T=80 o. C, 0 wt% B 2 phase Complex Fluids Group University of São Paulo, Brazil
C 14 , T=25 o. C, 20 wt% B 3 phase Complex Fluids Group University of São Paulo, Brazil
1) The doping with 20 and 40 wt % of hexadecane a) stabilized a B 3 phase b) destabilized the B 2 phase 2) The doping with xilene (p and m) a) Reduced the clearing point b) Reduced the transition enthalpy Complex Fluids Group University of São Paulo, Brazil
Complex Fluids Group University of São Paulo, Brazil
Complex Fluids Group University of São Paulo, Brazil
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