Novel, self-organising materials for use in gas sensor arrays: beating the humidity problem.

Clements, J.; Boden, N.; Gibson, Tim; Chandler, Rebecca; Hulbert, J.N.; Ruck-Keene, E.A.

doi:10.1016/s0925-4005(98)00005-7

Cited by 32 publications

(16 citation statements)

References 9 publications

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“…According to our previous article 18 the coherent signals observed in Ref. 33 can be identified as being due to periodic creation and destruction of space charge barriers which are created near real barriers ͑obstacles͒. This is the way timedependent self-oscillating signals can be generated in situations when the motion is purely diffusive.…”

Section: Discussionmentioning

confidence: 93%

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The effect of Coulomb interactions on the ac mobility of charges in quasi-one-dimensional systems. Example: discotic liquid crystals

Siebbeles

Movaghar

2000

The Journal of Chemical Physics

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Using Monte Carlo simulations we calculate the frequency dependence of the diffusive mobility of a group of carriers on a short one-dimensional chain. We allow the carriers to interact with each other through weakly screened long-range Coulomb potentials. We consider both doped systems with discrete immobile counterions and gated systems with constant neutralizing background. In doped systems the counterions can act as traps for the mobile charge, which results in a strong frequency-dependent conductivity. In the gated charged system, the mobility per particle decreases with particle density. The calculations show that the electron-electron interaction, in the diffusion limit, acts very much like a source of random disorder. Because the mobility depends on the number of carriers, arrays of coupled wires can exhibit current ''noise'' which is directly related to charge exchange between the wires. This noise is in principle observable in signal processing. Basing ourselves on our numerical results, we have been able to conclude that the low-frequency ac mobility measured in doped triphenylenes must be due to spatial charge inhomogeneities, and cannot be due to intrinsic charge dynamics.

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Section: Discussionmentioning

confidence: 93%

“…The way to extract these signals is to look at the current in frequency Fourier space, average out the noise, and pick up remaining well-defined resonances. 33 Generating, understanding and manipulating this type of interaction dynamics can perhaps lead to a new generation of ultra-sensitive chemical and optical sensors ͑see Ref. 33͒.…”

Section: Discussionmentioning

confidence: 99%

The effect of Coulomb interactions on the ac mobility of charges in quasi-one-dimensional systems. Example: discotic liquid crystals

Siebbeles

Movaghar

2000

The Journal of Chemical Physics

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“…Thus the columns may be described as molecular cables since the conducting aromatic cores are surrounded by insulating aliphatic chains in the columnar phase. Discotic LCs have been demonstrated as functional materials for device applications in 1D conductors, photoconductors, and gas sensors (226,227). Besides, discotic LCs have been used both as hole transporting and electron transporting materials to construct OLEDs.…”

Section: Applications Of Liquid Crystalsmentioning

confidence: 99%

Liquid Crystals

Bisoyi

2014

Kirk-Othmer Encyclopedia of Chemical Technology

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Liquid crystals (LCs) represent a state of matter which is characterized by a unique combination of order and mobility on molecular, supramolecular and macroscopic levels. This is a true thermodynamic stable state of matter and has been recognized and accepted as the fourth state of matter after solid, liquid, and gas (1-18). They have developed from a mere scientific curiosity in the beginning to one of the foundations of mobile information technology devices today (19)(20)(21)(22)(23)(24)(25). LCs are presently common topics in academic books and also in our daily life. Terms such as LCD, ie, LC display, and Kevlar have become familiar consumer products. The unusual feature which makes this state of matter unique among the others is the combination of orientational (and, sometimes, positional) order and dynamics, giving rise to materials with anisotropic physical properties that are switchable under the influence of small external stimuli. LCs have been regarded as unique functional soft materials from both scientific and technological point of view. The unique combination of counterintuitive properties, ie, order and fluidity, is not only an essential requirement for living matter, but also it is the foundation of the numerous technological applications of LC materials. Simultaneous exhibition of order and dynamics is the basic principle for self-organization and structure formation in living systems. Accordingly, LCs play a crucial role in living systems and in biology (18). For example, no life would be possible without the ordered and dynamic self-assembly of lipids into bilayers within the cell membrane. Several biological molecules such as lipids, carbohydrates, proteins, and nucleic acids have been found to exist in various liquid crystalline phases (26-34). The appearance of mesomorphism in DNAs has been related to the significant role that LCs would have played in the evolution of biological information in the pre-biotic world (35-38). LCs self-assemble into various structures with the help of many different types of molecular interactions such as van der Waals, dipolar and quadrupolar interaction, charge transfer, p-p interaction, metal coordination, and hydrogen bonding. Thus, LCs can be considered as prototype supramolecular systems which furnish well-defined self-assembled architectures using noncovalent secondary interactions (39). Scientifically, the LC field is a fertile ground to study supramolecular self-assembly of matter and soft materials. Moreover, LCs persuasively demonstrate the powerful organization principle of matter by maximizing the interaction energy and minimizing the excluded volume.Overall, LCs have developed into a fascinating and prosperous field, reaching out into different areas of science by providing basic knowledge of the fundamental rules governing self-assembly from simple to complex modes. The domains of LCs span across multiple disciplines of pure and applied science including optics, materials science, bioscience, nanoscience etc. Their science and technology are tru...

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“…Clements et al. used triphenylene‐based DLCs to detect alkane hydrocarbons 69. A relationship between the carbon chain length of normal alkane hydrocarbons and the conductivity change of the DLC has been drawn.…”

Section: Discotics As Functional Soft Materialsmentioning

confidence: 99%

Functional Discotic Liquid Crystals

Kumar

2012

Israel Journal of Chemistry

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This review article provides a bird's-eye view on discotic liquid crystals and their potential applications. Design principles, synthesis, modification of physical prop-erties and potential applications of some common discotic liquid crystals have been briefly summarized.Keywords: discotic liquid crystals · functional soft materials · liquid crystals · semiconductors · sensors Figure 1. Self-assembly and self-organization of disc-like molecules into discotic nematic and columnar mesophases. Figure 2. General template for discotic mesogens.820

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Novel, self-organising materials for use in gas sensor arrays: beating the humidity problem.

Cited by 32 publications

References 9 publications

The effect of Coulomb interactions on the ac mobility of charges in quasi-one-dimensional systems. Example: discotic liquid crystals

The effect of Coulomb interactions on the ac mobility of charges in quasi-one-dimensional systems. Example: discotic liquid crystals

Liquid Crystals

Functional Discotic Liquid Crystals

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