Limits...
Enhanced magnetic-field-induced optical properties of nanostructured magnetic fluids by doping nematic liquid crystals.

Wang X, Pu S, Ji H, Yu G - Nanoscale Res Lett (2012)

Bottom Line: The figure of merit of optical properties weighs the birefringence and extinction of the materials and is more appropriate to evaluate their optical properties.In addition, the enhancement of Q value increases monotonously with the magnetic field and becomes remarkable when the applied magnetic field is beyond 50 mT.The maximum relative enhanced value of QR exceeds 6.8% in our experiments.

View Article: PubMed Central - HTML - PubMed

Affiliation: College of Science, University of Shanghai for Science and Technology, Shanghai, 200093, China. shenglipu@gmail.com.

ABSTRACT
Ferronematic materials composed of 4-cyano-4'-pentylbiphenyl nematic liquid crystal and oil-based Fe3O4 magnetic fluid were prepared using ultrasonic agitation. The birefringence (Δn) and figure of merit of optical properties (Q = Δn/α, where α is the extinction coefficient) of pure magnetic fluids and the as-prepared ferronematic materials were examined and compared. The figure of merit of optical properties weighs the birefringence and extinction of the materials and is more appropriate to evaluate their optical properties. Similar magnetic-field- and magnetic-particle-concentration-dependent properties of birefringence and figure of merit of optical properties were obtained for the pure magnetic fluids and the ferronematic materials. For the ferronematic materials, the values of Q increase with the volume fractions of nematic liquid crystal under certain fixed field strength and are larger than those of their corresponding pure magnetic fluids at high field region. In addition, the enhancement of Q value increases monotonously with the magnetic field and becomes remarkable when the applied magnetic field is beyond 50 mT. The maximum relative enhanced value of QR exceeds 6.8% in our experiments. The results of this work may conduce to extend the pragmatic applications of nanostructured magnetic fluids in optical field.

No MeSH data available.


Related in: MedlinePlus

Birefringence of samples with different volume fractions of 5CB as a function of magnetic induction. The magnetic particle volume fraction is fixed.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3475033&req=5

Figure 3: Birefringence of samples with different volume fractions of 5CB as a function of magnetic induction. The magnetic particle volume fraction is fixed.

Mentions: To further investigate the influence of 5CB concentration on the birefringence of ferronematic samples, the birefringence of samples MF-5CB, MF-5CB(2), MF-5CB(3), and MF-5CB(4) is also measured, and the experimental results are shown in Figure 3. Table 3 shows that all the ferronematic samples have the same volume fraction of magnetic particles (0.50%) but have different 5CB volume fractions. The Δn-B curves for different samples in Figure 3 almost overlap with each other, which mean that only the magnetic particle concentration is crucial to the birefringence of the samples, and 5CB concentration has no influence on the birefringence of the samples.


Enhanced magnetic-field-induced optical properties of nanostructured magnetic fluids by doping nematic liquid crystals.

Wang X, Pu S, Ji H, Yu G - Nanoscale Res Lett (2012)

Birefringence of samples with different volume fractions of 5CB as a function of magnetic induction. The magnetic particle volume fraction is fixed.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3475033&req=5

Figure 3: Birefringence of samples with different volume fractions of 5CB as a function of magnetic induction. The magnetic particle volume fraction is fixed.
Mentions: To further investigate the influence of 5CB concentration on the birefringence of ferronematic samples, the birefringence of samples MF-5CB, MF-5CB(2), MF-5CB(3), and MF-5CB(4) is also measured, and the experimental results are shown in Figure 3. Table 3 shows that all the ferronematic samples have the same volume fraction of magnetic particles (0.50%) but have different 5CB volume fractions. The Δn-B curves for different samples in Figure 3 almost overlap with each other, which mean that only the magnetic particle concentration is crucial to the birefringence of the samples, and 5CB concentration has no influence on the birefringence of the samples.

Bottom Line: The figure of merit of optical properties weighs the birefringence and extinction of the materials and is more appropriate to evaluate their optical properties.In addition, the enhancement of Q value increases monotonously with the magnetic field and becomes remarkable when the applied magnetic field is beyond 50 mT.The maximum relative enhanced value of QR exceeds 6.8% in our experiments.

View Article: PubMed Central - HTML - PubMed

Affiliation: College of Science, University of Shanghai for Science and Technology, Shanghai, 200093, China. shenglipu@gmail.com.

ABSTRACT
Ferronematic materials composed of 4-cyano-4'-pentylbiphenyl nematic liquid crystal and oil-based Fe3O4 magnetic fluid were prepared using ultrasonic agitation. The birefringence (Δn) and figure of merit of optical properties (Q = Δn/α, where α is the extinction coefficient) of pure magnetic fluids and the as-prepared ferronematic materials were examined and compared. The figure of merit of optical properties weighs the birefringence and extinction of the materials and is more appropriate to evaluate their optical properties. Similar magnetic-field- and magnetic-particle-concentration-dependent properties of birefringence and figure of merit of optical properties were obtained for the pure magnetic fluids and the ferronematic materials. For the ferronematic materials, the values of Q increase with the volume fractions of nematic liquid crystal under certain fixed field strength and are larger than those of their corresponding pure magnetic fluids at high field region. In addition, the enhancement of Q value increases monotonously with the magnetic field and becomes remarkable when the applied magnetic field is beyond 50 mT. The maximum relative enhanced value of QR exceeds 6.8% in our experiments. The results of this work may conduce to extend the pragmatic applications of nanostructured magnetic fluids in optical field.

No MeSH data available.


Related in: MedlinePlus