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Title page for etd-0826116-150122


URN etd-0826116-150122 Statistics This thesis had been viewed 575 times. Download 0 times.
Author Chang-yi Guo
Author's Email Address No Public.
Department Chemical Engineering
Year 2015 Semester 2
Degree Master Type of Document Master's Thesis
Language English Page Count 54
Title Wide blue phase range observed in simple binary mixture systems containing biphenyl mesogens with 2-octyloxy tail
Keyword
  • racemic
  • blue phase
  • biphenyl
  • biphenyl
  • blue phase
  • racemic
  • Abstract Four series of simple and rodlike racemic biphenyl mesogens possessing 2-octyloxy tail and different substituents at inner-core position of phenyl ring were easily prepared. In general, cubic BPs can be induced by adding appropriate ratio of chiral additive S811 or ISO(6OBA)2 into these racemic biphenyl mesogens during the heating and cooling processes. Interestingly, BPIII (5-6 K) easily dominates in high chirality condition for the blending mixture composed of mono-substituted biphenyl mesogens and chiral dopant S811. In addition, formation temperature of BPIII is near room temperature (36°C) when compound C6OBiPhI-OH is blend with 35 wt% S811 during the cooling process. Stable BPs with more than 20 K present in the blending mixture system composed of chiral dopant ISO(6OBA)2 and no substituted biphenyl mesogens CnOBiPhI-H or difluoro substituted CnOBiPhI-FF. Notably, the widest temperature range of BP (~34 K) can be induced by adding only 10 wt% chiral dopant ISO(6OBA)2 with high HTP into the biphenyl compound C6OBiPhI-H. The properties of BPs were characterized by POM, DSC and reflection spectra. On the basis of our experimental results and molecular modeling, we demonstrated that the appearance and temperature range of BPs in this simple type of biphenyl mesogen with 2-octyloxy tail are affected by the molecular dipole moment and biaxiality.
    Advisor Committee
  • Chiung-cheng Huang - advisor
  • Hong-chou Lin - co-chair
  • I-jui Hsu - co-chair
  • Mei-ching Yu - co-chair
  • Files indicate in-campus access at 3 years and off-campus not accessible
    Date of Defense 2016-07-25 Date of Submission 2016-08-29


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