A schlieren texture with six dark brushes emanating from a point and a closed inversion wall have been observed under polarizing optical microscope in nematic state of a thermotropic aromatic copolyester, which have n...A schlieren texture with six dark brushes emanating from a point and a closed inversion wall have been observed under polarizing optical microscope in nematic state of a thermotropic aromatic copolyester, which have not been reported so far in the field of liquid crystalline polymers (LCPs).展开更多
Rod-like molecules confined on a spherical surface can organize themselves into nematic liquid crystal phases. This can give rise to novel textures displayed on the surface, which has been observed in experiments. An ...Rod-like molecules confined on a spherical surface can organize themselves into nematic liquid crystal phases. This can give rise to novel textures displayed on the surface, which has been observed in experiments. An important theoretical question is how to find and predict these textures. Mathematically, a stable configuration of the nematic fluid corresponds to a local minimum in the free energy landscape. By applying Taylor expansion and Bingham approximation to a general molecular model, we obtain a closed-form tensor model, which gives a free energy form that is different from the classic Landau-de Gennes model. Based on the tensor model, we implement an efficient numerical algorithm to locate the local minimum of the free energy. Our model successfully predicts the splay, tennis-ball and rectangle textures. Among them, the tennis-ball configuration has the lowest free energy.展开更多
文摘A schlieren texture with six dark brushes emanating from a point and a closed inversion wall have been observed under polarizing optical microscope in nematic state of a thermotropic aromatic copolyester, which have not been reported so far in the field of liquid crystalline polymers (LCPs).
基金supported by National Natural Science Foundation of China(Grant Nos.21274005 and 50930003)
文摘Rod-like molecules confined on a spherical surface can organize themselves into nematic liquid crystal phases. This can give rise to novel textures displayed on the surface, which has been observed in experiments. An important theoretical question is how to find and predict these textures. Mathematically, a stable configuration of the nematic fluid corresponds to a local minimum in the free energy landscape. By applying Taylor expansion and Bingham approximation to a general molecular model, we obtain a closed-form tensor model, which gives a free energy form that is different from the classic Landau-de Gennes model. Based on the tensor model, we implement an efficient numerical algorithm to locate the local minimum of the free energy. Our model successfully predicts the splay, tennis-ball and rectangle textures. Among them, the tennis-ball configuration has the lowest free energy.
