In the 2D WAXD fiber pattern of polymer 4 (Fig. 3), there are three low-angle
diffractions on the equator. The diffractions have a scattering vector ratio of 1:3
1/2
:4
1/2
,
indicating a 2D hexagonal packing. The three diffractions can be assigned as 100, 110,
and 200 diffractions of the Col h phase.
PMPCS (polymer 5 with n = 1 in Chart 1) is a frequently used MJLCP. Figure 4
shows the 2D WAXD pattern of a fiber sample of PMPCS with a relatively high MW
(Ye et al. 2004). The X-ray beam was parallel to the fiber direction. The result
indicates a local sixfold symmetry of the lateral packing of the PMPCS rods.
Because no higher-order diffractions are observed, the order of the LC phase is not
long-range and is between those of the Col n and Col h phases. The LC phase is
assigned as hexatic columnar nematic (Col hn ).
Fig. 3 2D WAXD pattern of
an oriented fiber of polymer 4.
(Reprinted with permission of
the American Chemical
Society (Tu et al. 2000) and
Royal Society of Chemistry
(Chen et al. 2010))
Fig. 4 Geometry of experimental setup in the 2D WAXD experiment with the X-ray incident beam
parallel to the fiber axis (a) and 2D WAXD fiber pattern of the sample (b). (Reprinted with
permission of the American Chemical Society (Ye et al. 2004) and the Royal Society of Chemistry
(Chen et al. 2010))
34
Z. Shen
diffractions on the equator. The diffractions have a scattering vector ratio of 1:3
1/2
:4
1/2
,
indicating a 2D hexagonal packing. The three diffractions can be assigned as 100, 110,
and 200 diffractions of the Col h phase.
PMPCS (polymer 5 with n = 1 in Chart 1) is a frequently used MJLCP. Figure 4
shows the 2D WAXD pattern of a fiber sample of PMPCS with a relatively high MW
(Ye et al. 2004). The X-ray beam was parallel to the fiber direction. The result
indicates a local sixfold symmetry of the lateral packing of the PMPCS rods.
Because no higher-order diffractions are observed, the order of the LC phase is not
long-range and is between those of the Col n and Col h phases. The LC phase is
assigned as hexatic columnar nematic (Col hn ).
Fig. 3 2D WAXD pattern of
an oriented fiber of polymer 4.
(Reprinted with permission of
the American Chemical
Society (Tu et al. 2000) and
Royal Society of Chemistry
(Chen et al. 2010))
Fig. 4 Geometry of experimental setup in the 2D WAXD experiment with the X-ray incident beam
parallel to the fiber axis (a) and 2D WAXD fiber pattern of the sample (b). (Reprinted with
permission of the American Chemical Society (Ye et al. 2004) and the Royal Society of Chemistry
(Chen et al. 2010))
34
Z. Shen