Scientific duo of carbon nanotubes and nematic liquid crystals

Rahman, Muklesur; Lee, Wei

doi:10.1088/0022-3727/42/6/063001

Cited by 140 publications

(81 citation statements)

References 91 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…There have also been observations of positive effects of carbon nanotubes on the liquid crystal [71e74, 80,101,107,108], even including the function of carbon nanotubes as chiral dopants [109,110], but as the liquid crystal in these cases plays a passive role we do not further discuss these issues in this review. Almost all work has been done with nematic hosts of rod-like mesogens, primarily due to the difficulties in dispersing nanotubes in more ordered and thus much more viscous liquid crystal phases.…”

Section: Colloidal Particles Organized By Liquid Crystals and Liquid mentioning

confidence: 99%

A new era for liquid crystal research: Applications of liquid crystals in soft matter nano-, bio- and microtechnology

Lagerwall

Scalia

2012

Current Applied Physics

664

351

View full text Add to dashboard Cite

a b s t r a c tLiquid crystals constitute a fascinating class of soft condensed matter characterized by the counterintuitive combination of fluidity and long-range order. Today they are best known for their exceptionally successful application in flat panel displays, but they actually exhibit a plethora of unique and attractive properties that offer tremendous potential for fundamental science as well as innovative applications well beyond the realm of displays. Today this full breadth of the liquid crystalline state of matter is becoming increasingly recognized and numerous new and exciting lines of research are being opened up. We review this exciting development, focusing primarily on the physics aspects of the new research thrusts, in which liquid crystals e thermotropic as well as lyotropic e often meet other types of soft matter, such as polymers and colloidal nano-or microparticle dispersions. Because the field is of large interest also for researchers without a liquid crystal background we begin with a concise introduction to the liquid crystalline state of matter and the key concepts of the research field. We then discuss a selection of promising new directions, starting with liquid crystals for organic electronics, followed by nanotemplating and nanoparticle organization using liquid crystals, liquid crystal colloids (where the liquid crystal can constitute either the continuous phase or the disperse phase, as droplets or shells) and their potential in e.g. photonics and metamaterials, liquid crystal-functionalized polymer fibers, liquid crystal elastomer actuators, ending with a brief overview of activities focusing on liquid crystals in biology, food science and pharmacology.

show abstract

Section: Colloidal Particles Organized By Liquid Crystals and Liquid mentioning

confidence: 99%

A new era for liquid crystal research: Applications of liquid crystals in soft matter nano-, bio- and microtechnology

Lagerwall

Scalia

2012

Current Applied Physics

664

351

View full text Add to dashboard Cite

show abstract

“…The most relevant conclusion is that the weak anchoring limit leads to negligible deformations while the rigid anchoring may induce topological defects. Carbon nanotubes are particularly interesting within this topic, since their reorientation with external fields [15][16][17][18] arises the possibility of preparing simple devices whose electrical conductivity can be externally controlled [7,[17][18][19]. CNTs are anisotropic NPs formed by one or several rolledup graphene sheets.…”

Section: Introductionmentioning

confidence: 99%

The peculiar electrical response of liquid crystal-carbon nanotube systems as seen by impedance spectroscopy

García-García¹,

Vergaz²,

Algorri³

et al. 2015

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

Conductive nanoparticles, especially elongated ones such as carbon nanotubes, dramatically modify the electrical behavior of liquid crystal cells. These nanoparticles are known to reorient with liquid crystals in electric fields, causing significant variations of conductivity at minute concentrations of tens or hundreds ppm. The above notwithstanding, impedance spectroscopy of doped cells in the frequency range customarily employed by liquid crystal devices, 100 Hz-10kHz, shows a relatively simple resistor/capacitor response where the components of the cell can be univocally assigned to single components of the electrical equivalent circuit. However, widening the frequency range up to 1 MHz or beyond reveals a complex behavior that cannot be explained with the same simple EEC. Moreover, the system impedance varies with the application of electric fields, their effect remaining after removing the field. Carbon nanotubes are reoriented together with liquid crystal reorientation when applying voltage, but barely reoriented back upon liquid crystal relaxation once the voltage is removed. Results demonstrate a remarkable variation in the impedance of the dielectric blend formed by liquid crystal and carbon nanotubes, the irreversible orientation of the carbon nanotubes and possible permanent contacts between electrodes.

show abstract

“…Multitude of 5CB molecules is dismembered to three groups according their optical properties [6]: (i) molecules disposed far enough from nanotubes clusters forming LC host, (ii) molecules of clusters micro scale cladding (interfacial LC layer) around them, (iii) hidden molecules inside clusters, not observable by optical methods. Fraction of these parts depends crucially from nanotubes concentrations: isolated CNT clusters at their low concentrations and the percolation structure when neighbor clusters touch, LC host is broken on isolated 'lakes', and length of clusters boundaries enlarges drastically.…”

Section: Polarization Singular Optics Of 5cb Carbon Nanocompositesmentioning

confidence: 99%

Fine topological structure of coherent complex light created by carbon nanocomposites in LC

Ponevchinsky¹,

Goncharuk

Minenko

et al. 2012

SPIE Proceedings

View full text Add to dashboard Cite

Fine complex light structure, optical singularities and electroconductivty of nematic 5CB doped by multi-walled carbon nanotubes (MWCNTs) were investigated. MWCNTs gather spontaneously to system of micro scale clusters with random fractal borders at small enough concentration. They are surrounded by the striped micro scale cladding which creates optical singularities in propagating laser beam. Applied transverse electric field above the Freedericksz initiates homeotropic arrangement of 5CB and the striped inversion walls between nanotubes clusters what diminishes free energy of a composite. Theory of their appearance and properties was built. Simultaneously the striped cladding disappears what can be treated as new mechanism of structure orientation nonlinearity in nonlinear photonics. Polarization singularities (circular C points) were measured firstly. Percolation of clusters enhances strongly electrical conductivity of the system and creates inversion walls even without applied field. Carbon nanotubes composites in LC form bridge between nano dopants and micro/macro system and are promising for applications. Elaborated protocol of singular optics inspection and characterization of LC nanocomposites is promising tool for applications in modern nanosience and technique.

show abstract

Scientific duo of carbon nanotubes and nematic liquid crystals

Cited by 140 publications

References 91 publications

A new era for liquid crystal research: Applications of liquid crystals in soft matter nano-, bio- and microtechnology

A new era for liquid crystal research: Applications of liquid crystals in soft matter nano-, bio- and microtechnology

The peculiar electrical response of liquid crystal-carbon nanotube systems as seen by impedance spectroscopy

Fine topological structure of coherent complex light created by carbon nanocomposites in LC

Contact Info

Product

Resources

About