Photoresponsive behaviors of smectic liquid crystals tuned by an azobenzene chromophore

Wang, Guojie; Zhang, Mingzhi; Zhang, Tingting; Guan, Jingjing; Yang, Huai

doi:10.1039/c1ra00615k

Cited by 32 publications

(22 citation statements)

References 54 publications

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“…The phase transitions starting from the smectic phase were also observed in several doped systems [57][58][59][60]. The smectic LC host 8CB, doped with chiral molecules and azobenzene compounds, showed the phase transition from smectic to cholesteric due to the photo-induced isomerization of azobenzene molecules, and the prolonged irradiation drove the phase transition further to the isotropic phase.…”

Section: Smectic (Sm)-cholesteric (N * ) Phase Transitionmentioning

confidence: 79%

Photoresponsive Cholesteric Liquid Crystals

Li¹,

Li²

2013

Intelligent Stimuli‐Responsive Materials

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Section: Smectic (Sm)-cholesteric (N * ) Phase Transitionmentioning

confidence: 79%

Photoresponsive Cholesteric Liquid Crystals

Li¹,

Li²

2013

Intelligent Stimuli‐Responsive Materials

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“…[ 1a,b ] However, high cost and volatile supply of V 2 O 5 raw material lead to high system capital cost and thus limit wide implementation of the vanadium ARFBs. [ 2 ] Current capital cost for V-ARFB is ≈$450/kWh according to a cost analysis [ 3 ] while DOE target cost is below $150/kWh. Therefore, there are increasing efforts to identify new fl ow battery systems with affordable material cost and high electrochemical performance to replace vanadium ARFBs.…”

mentioning

confidence: 99%

A Total Organic Aqueous Redox Flow Battery Employing a Low Cost and Sustainable Methyl Viologen Anolyte and 4‐HO‐TEMPO Catholyte

Liu

Wei

Nie

et al. 2015

Advanced Energy Materials

557

667

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exceptional design fl exibility, excellent scalability and modularity, and high energy effi ciency. These technical merits underline RFBs a well-suitable choice to stabilize the power grid and overcome the intermittency of renewable energy sources (e.g., solar, and wind).Aqueous redox fl ow batteries (ARFBs), because of safety operation and high power density, have attracted both governmental and industrial investments for technical development and applications. Currently, vanadium (V) based ARFBs are the most populated systems and have been commercialized by numerous companies. [ 1a,b ] However, high cost and volatile supply of V 2 O 5 raw material lead to high system capital cost and thus limit wide implementation of the vanadium ARFBs. [ 2 ] Current capital cost for V-ARFB is ≈$450/kWh according to a cost analysis [ 3 ] while DOE target cost is below $150/kWh. Therefore, there are increasing efforts to identify new fl ow battery systems with affordable material cost and high electrochemical performance to replace vanadium ARFBs. Hybrid nonaqueous redox fl ow batteries (NRFBS) using Li metal as solid-state anode [ 4 ] and various solution catholytes (e.g., anthraquinone, [ 5 ] ferrocene, [ 6 ] TEMPO, [ 7 ] ployhalides, [ 8 ] and polysulfi des [ 9 ] have emerged. Fullly organic NRFBs were also reported. [ 10 ] These NRFBs, albeit potential high energy densities, encounter a number of challenges for practical applications: safety issues associated the use of highly reactive Li metal and fl ammable organic solvents, low current density due to Li dendrite formation, and limited cycling life.To overcome the cost and sustainable issues and retain safety features and high power density of vanadium ARFBs, redox active quinonoid molecules have been employed in several acidic ARFBs in the last few years. In 2009, Xu et al. fi rst reported the concept of the organic ARFB by adopting 1,2-dihydrobenzoquinone-3,5-disulfonic acid (BQDS) or 1,4-dihydrobenzoquinone-2-sulfonic acid (BQS) as cathode and conventional PbSO 4 as anolyte in an acid ARFB. In 2014, Aziz and co-workers reported an ARFB study using anthraquinon-2,7-disulfonic acid (AQDS) as anolyte and bromine as catholyte. [ 12 ] The AQDS/Br 2 ARFB can be operated at impressively high current densities (>0.5 A cm −2 ), highlighting the possibility of using organic redox active materials to generate high power output. However, the use of Br 2 is concerned with Increasing worldwide energy demands and rising CO 2 emissions have motivated a search for new technologies to take advantage of renewables such as solar and wind energies. Redox fl ow batteries (RFBs) with their high power density, high energy effi ciency, scalability (up to MW and MWh), and safety features are one suitable option for integrating such energy sources and overcoming their intermittency. However, resource limitation and high system costs of current RFB technologies impede wide implementation. Here, a total organic aqueous redox fl ow battery (OARFB) is reported, using low-cost and sustainable met...

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“…This greatly diminishes the impact of physical crossover, implying perhaps that SRFBs could make good use of simple porous separators that allow some limited crossover but are very low in cost. 26 It is further possible, in principle, to operate a SRFB system using a parent electroactive molecule exhibiting more than three stable redox states. Figures 3a, 3b show simulated equilibrium cell potentials as a function of state-of-charge for SRFBs employing electrolytes with four and five stable redox states, which can facilitate the transfer of 1.5 and 2 mole equivalents of electrons per mole of the electroactive parent molecule, respectively.…”

Section: Definition Properties and Advantages Of The Srfbmentioning

confidence: 99%

On the Benefits of a Symmetric Redox Flow Battery

Potash

McKone

Conte

et al. 2015

J. Electrochem. Soc.

167

177

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Redox flow batteries (RFBs) are of interest for large-scale energy storage, but implementation has been challenged by their low energy density, high complexity, high cost, and insufficient lifetime due to several types of irreversible losses in the electrolyte. To address the issue of system complexity and irreversible losses, we have undertaken a detailed analysis of the concept of the symmetric redox flow battery, or SRFB, which relies on a single parent molecule as the charge storage species in both the positive and negative electrode reactions. Herein we elaborate on the operating principles and advantages of a SRFB and report the salient electrochemical properties of a class of organic molecules, diaminoanthraquinones (DAAQs) as promising candidates for use in SRFB redox electrolytes. Modeling of various modes of operation for SRFBs are presented along with an example of an operational, lab-scale SRFB based on a DAAQ system. © The Author Renewable energy sources are rapidly growing in both implementation and research interest due to rising fossil fuel prices and concerns over pollution and climate change.1 However, a major challenge for implementing renewables, such as wind and solar, on a large scale, is their inherent temporal intermittency. For continued growth of renewables, while maintaining the expected level of stability/reliability in the energy grid, significant advances are needed in the area of large-scale energy storage. 2-7Electrochemical energy storage (EES) systems have been broadly identified as promising for short-term grid leveling and long-term energy storage.8 Of the available technologies, redox flow batteries (RFBs) are gaining increasing levels of attention as a viable approach for grid-scale EES.9-13 RFBs differ from conventional batteries in that charge is stored in a pair of liquid-phase redox couples with disparate electrochemical potentials, unlike the solid-phase anodes and cathodes used in conventional batteries (e.g. Li ion, Ni-Cd, and Pb-acid).14 Thus, these liquid species can be stored in tanks of arbitrary size and flowed through separate electrode stacks to store and recover electrical energy. These properties lend well to modular, flexible designs that decouple energy density and power. RFBs also enjoy comparatively high stability due to the lack of phase changes upon cycling.Most of the existing RFB technologies rely on aqueous transition metal redox couples. [9][10][11][12][13] The most common systems use transition metal cations in various oxidation states such as the Fe-Cr system 15 or the extensively studied aqueous vanadium flow battery (VFB). 16Hybrid systems have also been developed that make use of a solidliquid phase change at one electrode, such as the Zn-bromide flow cell.12 Implementations of RFBs are still in their early stages, and several significant research challenges have precluded their scalable implementation. Some of the major challenges include (1) low energy density, (2) high system cost and (3) limited lifetime. 9,13,17 The VFB is the most widely ...

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Photoresponsive behaviors of smectic liquid crystals tuned by an azobenzene chromophore

Cited by 32 publications

References 54 publications

Photoresponsive Cholesteric Liquid Crystals

Photoresponsive Cholesteric Liquid Crystals

A Total Organic Aqueous Redox Flow Battery Employing a Low Cost and Sustainable Methyl Viologen Anolyte and 4‐HO‐TEMPO Catholyte

On the Benefits of a Symmetric Redox Flow Battery

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