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Volumn 80, Issue 3, 2009, Pages

Dispersions of pyrogenic alumina in pentylcyanobiphenyl studied by deuteron NMR

Author keywords

[No Author keywords available]

Indexed keywords

AEROSIL DISPERSIONS; ALIGNMENT EFFECTS; ALKYLCYANOBIPHENYL; ANNEALING PROCESS; CYANOBIPHENYLS; DEUTERON NMR; DEUTERON NUCLEAR MAGNETIC RESONANCE; DIRECTOR CONFIGURATION; DISORDER EFFECT; DISORDER STRENGTH; HYDROPHILIC GEL; IN-FIELD; ISOTROPIC PHASE; ISOTROPIC-NEMATIC COEXISTENCES; NETWORK INTERACTION; NON-POLAR SURFACES; ORDER PARAMETER; ORIENTATIONAL ORDERS; ROBUST NETWORK; ZERO-FIELD COOLING;

EID: 70349780649     PISSN: 15393755     EISSN: 15502376     Source Type: Journal    
DOI: 10.1103/PhysRevE.80.031704     Document Type: Article
Times cited : (2)

References (45)
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    • For all the dispersions studied, the observed TIN is lower than that of the pure 5CB. Their values scatter about 0.4°C below the TIN of 5CB and within ranges of ±0.2°C and ±0.3°C for Alu C/5CB and Alu C 805/5CB, respectively. The more or less constant TIN values could be considered as indicating the presence of a shallow TIN minimum, which has been reported for aerosil/8CB dispersions with comparable void sizes. However, in view of the uncertainty in the measured TIN value (±0.20°C), we are reluctant to speculate relationships between Δ TIN and ρs values. We attribute the observed small variation of TIN with ρs to the limited range of void sizes covered in this study.
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    • As suggested by the strong temperature dependence of ZFC spectra of Alu C/5CB ρs =0.10g/ cm3, shown in Fig. 3 left column, almost all domains will become aligned when the sample temperature reaches the TIN (36°C), i.e., before performing the IFC procedure. Thus, the well-aligned IFC spectrum of the same sample (Fig. 6, left column, second spectrum from the bottom) cannot be taken as evidence that IFC procedure is more effective in producing aligned states at ρs =0.10g/ cm3.
    • As suggested by the strong temperature dependence of ZFC spectra of Alu C/5CB ρs =0.10g/ cm3, shown in Fig. 3 left column, almost all domains will become aligned when the sample temperature reaches the TIN (36°C), i.e., before performing the IFC procedure. Thus, the well-aligned IFC spectrum of the same sample (Fig. 6, left column, second spectrum from the bottom) cannot be taken as evidence that IFC procedure is more effective in producing aligned states at ρs =0.10g/ cm3.
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    • Spectra were monitored after an initial waiting period of ∼10min to verify that the two-phase system had reached thermal equilibrium at the selected temperature as indicated by the identical spectra being observed in successive recordings.
    • Spectra were monitored after an initial waiting period of ∼10min to verify that the two-phase system had reached thermal equilibrium at the selected temperature as indicated by the identical spectra being observed in successive recordings.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.