Optical Properties of 4-Octyl-4'-Cyanobiphenyl Liquid-Crystalline Free-Standing Films

Abstract

The short-wavelength effects on the fluctuation-induced diamagnetism (FD) in bulk isotropic three-dimensional (3D) superconductors are taken into account by introducing in the Gaussian-Ginzburg-Landau approach different cut-off conditions. These calculations, which extend to the 3D case our previous results on layered superconductors, are then used to briefly analyse the FD data measured for the low-temperature superconducting alloy Pb-8 at.% In. These analyses confirm the adequacy of a total-energy cut-off for explaining, for low-temperature 3D superconductors also, the thermal fluctuation effects in the high-reduced-temperature region. These results thus provide further support to the recent proposal that, due to the localization energy, the size of the effective fluctuations cannot be appreciably smaller than the superconducting coherence length amplitude extrapolated to T = 0 K.

T10 Polyhedral Oligomeric Silsesquioxane-Based Shape Amphiphiles with Diverse Head Functionalities via “Click” Chemistry

“…However, many typical liquid crystal moieties (i.e., 4-cyano-4′-biphenyl) are also UV-attenuating which cannot be fully installed on the POSS head by thiol–ene modification of VPOSS-PS (only ∼30% vinyl groups were reacted when cyanobiphenyl thiol (CB-SH) was used, see Figure S4d). Herein, CuAAC was again used to do the complete head modification of (N 3 ) 9 POSS–PS with 4-cyano-4′-biphenyl-alkyne to develop shape amphiphiles with optical properties …”

“…Herein, CuAAC was again used to do the complete head modification of (N 3 ) 9 POSS−PS with 4-cyano-4′-biphenyl-alkyne to develop shape amphiphiles with optical properties. 55 Similar to (Fc) 9 POSS−PS, the macromolecular structure of (CB) 9 POSS−PS was again fully supported by 1 H NMR (the disappearance of chemical shift at δ 3.30 ppm, Figure 2d), 13 C NMR spectrum (the disappearance of chemical shift at δ 53.52 ppm, Figure S2d), and FT-IR spectrum (the disappearance of the vibrational band at ∼2100 cm −1 , Figure S3d). In addition, the SEC overlay (Figure 3) reveals a decreased retention volume of (CB) 9 POSS−PS relative to (N 3 ) 9 POSS−PS (M n = 8.1 kg/mol, PDI = 1.03, Table 1).…”