Electrically switchable mirrors and optical components made from liquid-crystal gels

Hikmet, R. A. M.; Kemperman, H.

doi:10.1038/33110

Cited by 343 publications

(222 citation statements)

References 10 publications

Supporting

Mentioning

218

Contrasting

Unclassified

Order By: Relevance

“…On the other hand, by utilizing cholesteric gels, more complex electro-switchable devices such as mirrors or patterned optical components have been developed (Figure 14b). 245 The formation of LC gels has also been applied to the preservation of exotic LC phases such as blue phases that have intriguing photonic functions. [246][247][248][249] Remarkably, LC chemical gels also show shape variations in response to temperature and external fields.…”

Section: Functional Lc Polymers and Networkmentioning

confidence: 99%

Functional liquid-crystalline polymers and supramolecular liquid crystals

Kato

Uchida

Ichikawa

et al. 2017

Polym J

100

View full text Add to dashboard Cite

The design and functions of liquid-crystalline (LC) polymers with classifying them into conventional-, supramolecular-, dendriticand network-type LC polymers are described. LC polymers show new functions as new devices in the field of energy and environment by incorporating mesogenic moieties exhibiting photonic, electronic and ionic functions. Supramolecular LC polymers show dynamic and unique properties because the mesogenic moieties are built with non-covalent interactions. Dendritic-type LC polymers exhibit liquid crystallinity by nanosegregation of aromatic and aliphatic moieties. Dendritic fork-like mesogens have also been prepared. A variety of nonmesogeic functional building blocks including fullerene, π-conjugated moieties, catenane, rotaxane and others can be incorporated into LC phases by attaching these dendritic moieties. LC networks are constructed in situ polymerization of polymerizable nematic or nanostructured liquid crystals. The specific characteristics of the LC networks have generated new research trends to develop well-defined polymers that exhibit optical, transport and separation properties. In these materials, through suitable design of LC monomers, the preservation of smectic, columnar and bicontinuous cubic phases has been successfully used for the development of membranes with one-dimensional, two-dimensional and three-dimensional nanostructures.

show abstract

Section: Functional Lc Polymers and Networkmentioning

confidence: 99%

Functional liquid-crystalline polymers and supramolecular liquid crystals

Kato

Uchida

Ichikawa

et al. 2017

Polym J

100

View full text Add to dashboard Cite

show abstract

“…[93,94] By using a mixture of reactive chiral mesogens and non-reactive materials in the presence of a UV-absorbing dye, the reactive fraction in the LC mix begins to polymerize at the side being illuminated. This causes a diffusion of chiral reactive mesogens to the polymerized region, which in turn leads to formation of the pitch gradient throughout the thickness of the film.…”

Section: Reflection Based Technologiesmentioning

confidence: 99%

Infrared Regulating Smart Window Based on Organic Materials

Khandelwal

Schenning

Debije

2017

Advanced Energy Materials

337

220

View full text Add to dashboard Cite

(IR), here defined as light with wavelengths between 700 nm and 2500 nm, accounts for around 50% of the total energy emitted by the sun reaching Earth (Figure 1b), [3,4] and this light produces interior heating but is invisible to the unaided eye.The absorption of sunlight by building materials and passage of IR through transparent surfaces such as windows is responsible for much of the interior overheating of office rooms, automobile interiors, greenhouses, and other similar spaces. The use of artificial cooling and heating systems will only increase with the continued influence of global climate change, with energy used for cooling systems surpassing energy used for heating around the year 2070, and a 40 fold increase in air cooling energy use is expected by 2100. [5] By controlling the influx of radiant heat transfer, calculations show that more than 50% of the energy used in lighting, heating and cooling could be saved by deploying better control systems over only 18% of available window stock. [6] In areas with human inhabitants employing windows, more aspects must be considered than simply reducing the use of energy in the room: any switchable window used in, for example, a commercial office space has several other requirements that must be met before it may be installed. Among these requirement are reasonably fast switching speeds [7] (although for IR control, relatively longer times compared to visible light switching should be acceptable), good optical transparency with minimum haze, an acceptable device lifetime, [8] and functionality over a range of exterior temperatures. Controlling the excess of solar energy without compromising the visible transparency of the window is an important consideration for human health: maintaining inside/outside contact and daylighting are vital in retaining well-being and productivity, as well as providing economic and aesthetic gain by reducing the need for artificial lighting systems. [9,10] These are challenging goals for a window to realize.A number of materials have been developed over the past few decades to maintain indoor temperatures. Many of these focus on the opaque structural building elements like walls and roofing. [10][11][12][13] Other solutions target the transparent window, employing external mechanical shutters and blinds, [14] phase change materials (PCMs), [15] thermochromic materials, [16] aerogels, [17] trapped gas in fluid membranes, [18] and even phononic materials, [19] among other options. Indeed, controlling heat passage through the window in response to changing climate conditions is a great challenge; ideally, one would accomplish Windows are vital elements in the built environment that have a large impact on the energy consumption in indoor spaces, affecting heating and cooling and artificial lighting requirements. Moreover, they play an important role in sustaining human health and well-being. In this review, we discuss the next generation of smart windows based on organic materials which can change their properties by reflecting or trans...

show abstract

“…LC molecules have a positional order similarly to that of molecules in solids, but they can move freely similarly to molecules in liquids. 7) The most interesting property of LCs is their ability to respond to stimuli, such as external field, 8,9) light, 10,11) and mechanical stress. 12) Recent studies have examined electrospinning and LCs to discover potential LC applications.…”

confidence: 99%

Thermal-optical analysis of polymer–liquid crystal microfibers

Fatayati

Kusumaatmaja

Yusuf

2018

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

In this paper, the analysis of optically responsive microfibers with uniaxially ordered liquid crystal (LC) molecules at their cores is discussed. LC microfibers were electrospun from a solution of poly(vinyl pyrrolidone) (PVP) and N-(4-methoxybenzylidene)-4$-butylaniline (MBBA) using absolute alcohol as a solvent. Two parallel copper (Cu) collectors were used to obtain ordered fibers. The microfibers with oriented LC molecules were well fabricated at a voltage of 5 kV. A thermal-optical analysis revealed that the fibers were responsive to temperature. The rise of temperature from nematic to isotropic phase of LC decreased the LC intensity under a polarized optical microscope (POM).

show abstract

Electrically switchable mirrors and optical components made from liquid-crystal gels

Cited by 343 publications

References 10 publications

Functional liquid-crystalline polymers and supramolecular liquid crystals

Functional liquid-crystalline polymers and supramolecular liquid crystals

Infrared Regulating Smart Window Based on Organic Materials

Thermal-optical analysis of polymer–liquid crystal microfibers

Contact Info

Product

Resources

About