Structural Investigation of Carbosilane Liquid Crystalline Dendrimers
X-ray and neutron scattering investigations have been made on two series of liquid crystal dendrimers. The low generations (first to fourth) predominantly show smectic phases. The fifth generation shows a tendency to form columnar phases and two different types have been observed. The transition fro...
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Published in | The journal of physical chemistry. B Vol. 112; no. 51; pp. 16346 - 16356 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Chemical Society
25.12.2008
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Subjects | |
Online Access | Get full text |
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Summary: | X-ray and neutron scattering investigations have been made on two series of liquid crystal dendrimers. The low generations (first to fourth) predominantly show smectic phases. The fifth generation shows a tendency to form columnar phases and two different types have been observed. The transition from smectic to columnar has been explained in terms of the distance between the dendritic core and the mesogenic units. As the generation number is increased, the distance increases until it becomes greater than the maximum length of the flexible spacers causing a change in molecular shape and the formation of columnar phases. Although the materials are nearly monodisperse, the small variation in the number of mesogens per molecule gives rise to some subtle structural effects. Two coexisting structures have been observed over large temperature ranges in some materials and small angle neutron scattering indicates that there is some microphase segregation which is a reversible function of temperature. |
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Bibliography: | istex:250C112D7B637CA752EA6C8DA102381B45FD60B4 ark:/67375/TPS-Z8DB2ZT6-W ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1520-6106 1520-5207 |
DOI: | 10.1021/jp805769w |