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A.J.J. Kragt

16 records found

Photochromic smart windows have drawn increasing attention as an approach to improve building energy efficiency and enhance indoor daylight comfort. However, existing photochromic smart windows still block sunlight from entering the room on sunny winter days, causing additional e ...
The adaptive control of sunlight through photochromic smart windows could have a huge impact on the energy efficiency and daylight comfort in buildings. However, the fabrication of inorganic nanoparticle and polymer composite photochromic films with a high contrast ratio and high ...

Programming Thermochromic Liquid Crystal Hetero-Oligomers for Near-Infrared Reflectors

Unequal Incorporation of Similar Reactive Mesogens in Thiol-ene Oligomers

Cholesteric liquid crystal oligomers are widely researched for their interesting thermochromic properties. However, structure-property relationships to program the thermochromic properties of these oligomers have been rarely reported. In this work, we use the versatile thiol-ene ...
Both temperature-responsive and patterned photonic coatings are receiving a lot of attention from a fundamental and application point of view. However, the fabrication of multicolor patterns, which are also temperature-responsive, remains challenging. The current work presents a ...
The type of glazing implemented in a building plays an important role in the heat management of a building. Solar heat entering through glazing causes overheating of interior spaces and increases building’s cooling load. In this work, the energy saving potential of window films b ...
The fabrication of reversible and robust thermochromic coatings remains challenging. In this work, a temperature-responsive photonic coating with a protective topcoat is fabricated. A cholesteric oligosiloxane liquid crystal possessing a smectic-to-cholesteric phase-transition te ...
'Smart' windows which reversibly increase their reflectivity upon heating are attracting considerable attention as devices for maintaining comfortable indoor environmental conditions. In this work, twisted nematic semi-interpenetrating liquid crystal networks which lose their ord ...
A temperature-responsive polarization converter, which reversibly changes from a full-wave to a half-wave plate upon heating, is developed. The polymer wave plate has a controlled thickness and is based on a uniaxial aligned nematic semi-interpenetrating network coating containin ...
Stimulus-responsive photonic polymer materials that change their reflection colour as function of environmental stimuli such as temperature, humidity and light, are attractive for various applications (e.g. sensors, smart windows and communication). Polymers provide low density, ...
A new principle is developed to fabricate temperature-responsive, multicolor photonic coatings that are capable of switching color. The coating is composed of a non-cross-linked liquid crystal siloxane-based elastomer that is interpenetrated through an acrylate-based liquid cryst ...
A crosslinkable cholesteric main-chain liquid crystal oligomer was prepared, and coated on glass using blade-coating. The coating showed a reflection band that varied as a function of temperature over a range of several hundreds of nanometers. This allowed patterning of the coati ...
Thermosensitive polymers show an entropy-driven transition from a well-solvated to a poorly solvated polymer chain, resulting in a more compact globular conformation. The transition at the lower critical solution temperature (LCST) is often sharp, which allows for a wide range of ...
The fabrication of stimulus-responsive coatings that change both reflectivity and topography is hampered by the lack of easy processable, patternable, and programmable elastomers. Here, an easily applied reflective coating based on a semi-interpenetrating polymer network composed ...
A temperature-responsive near-infrared reflective coating was fabricated based on a side-chain liquid crystal siloxane polymer using a simple wired-bar method. The cholesteric liquid crystalline polymer film showed a blue shift of the reflection band of 1000 nm in the IR region u ...
Control over the organization of assemblies from molecular dimensions up to the macroscopic length scale is an outstanding challenge in science, above all for materials in high dilution. Instead of inducing order by generating very long and stiff structures, an alternative approa ...
Directing the spatial organization of functional supramolecular and polymeric materials at larger length scales is essential for many biological and molecular optoelectronic applications. Although the application of electrical fields is one of the most powerful approaches to indu ...