Dynamically adaptive window design with thermo-responsive hydrogel for energy efficiency

Jiang, Tianyue; Zhao, Xinpeng; Yin, Xiaobo; Yang, Ronggui; Tan, Guofu

doi:10.1016/j.apenergy.2021.116573

Cited by 42 publications

(26 citation statements)

References 67 publications

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“…The actuation response still survives over this time (and likely indefinitely) as PNIPAM is known to maintain its actuation over >1000 cycles. [20,85] The limiting factor currently appears to be the CNT skeletal structure, as some structures show cracking in the CNT/PNIPAM walls after repeated actuation (Figure S7, Supporting Information). This would only affect particularly severe actuation behaviors such as buckling, while others, such as transparency changes, would survive as they do not depend on contiguous CNT/PNIPAM structures.…”

Section: Light Response Of Cnt/pnipam Hydrogel μActuatorsmentioning

confidence: 99%

Light‐Actuated Anisotropic Microactuators from CNT/Hydrogel Nanocomposites

Gregg

Volder

Baumberg

2022

Advanced Optical Materials

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Over the past decades, functional hydrogels that respond to a variety of mechanical and chemical stimuli with a volume change of more than 100% have been developed. Despite this impressive behavior, practical applications of conventional hydrogels are limited by the need to transform their isotropic swelling/contraction into useful deformations, as well as their slow response times. Here, these challenges are addressed by combining poly(N‐isopropylacrylamide) (PNIPAM), a widely used temperature‐responsive polymer, with carbon nanotubes (CNTs). To ensure strong PNIPAM−CNT cohesion, the hydrogel is synthesized directly on the CNT surfaces using in situ redox polymerization. The anisotropy of vertically‐aligned CNT forests is used to transform the isotropic (de)swelling of PNIPAM into anisotropic motion. This material combination is particularly attractive because the high optical absorption and heat conductivity of carbon nanotubes converts light irradiation into PNIPAM actuation. A wide variety of CNT‐skeleton microstructures are tested to reveal a range of actuation behaviors. The authors demonstrate fast reversible movement, active switching from low to high light absorption states, lattice shape changes, and good cycling stability.

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Section: Light Response Of Cnt/pnipam Hydrogel μActuatorsmentioning

confidence: 99%

Light‐Actuated Anisotropic Microactuators from CNT/Hydrogel Nanocomposites

Gregg

Volder

Baumberg

2022

Advanced Optical Materials

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“…The hydrogel microparticles were prepared by co-polymerizing PNIPAm and AEMA via a continuous feeding solutionphase synthesis. The purpose of utilising AEMA as a co-monomer in the hydrogel synthesis is to increase the particle size so as to achieve a stronger IR transmittance modulation compared with pure PNIPAm hydrogel (Jiang et al, 2021;Li et al, 2019), as explained in Fig. 17 (a).…”

Section: Dynamic Optical Characteristics Of Thermotropic Hydrogelsmentioning

confidence: 99%

A review of advanced architectural glazing technologies for solar energy conversion and intelligent daylighting control

Liu

Wu²

2022

ARIN

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Efficient management of solar radiation through architectural glazing is a key strategy for achieving a comfortable indoor environment with minimum energy consumption. Conventional glazing consisting of a single or multiple glass pane(s) exhibits high visible light transmittance and solar heat gain coefficient, which can be a double-edged sword, i.e., it allows sufficient sunlight to enter the building interior space for passive heating and lighting; on the other hand, it can cause glare discomfort and large cooling energy consumption. Among the various advanced glazing technologies being developed, Building Integrated Photovoltaic (BIPV) glazing has a prominent position due to its ability to reduce cooling load and visual discomfort while simultaneously generating electricity from sunlight. Recent years have witnessed remarkable advances in low-concentration optics such as Dielectric based Compound Parabolic Concentrators (DiCPCs), with a growing interest in the development of Building Integrated Concentrating Photovoltaic (BICPV) glazing to improve light harvesting and electric power output. One of the challenges faced by traditional BIPV glazing systems is the lack of dynamic control over daylight and solar heat transmission to cope with variations in weather conditions and seasonal heating/cooling demands of buildings. A promising solution is to integrate an optically switchable smart material into a BIPV glazing system, which enables dynamic daylighting control in addition to solar power conversion. Thermotropic (TT) hydrogel materials such as poly(N-isopropylacrylamide) (PNIPAm) and Hydroxypropyl Cellulose (HPC) are potential candidates for hybrid BIPV smart glazing applications, due to their unique features such as high visible transparency (in the clear state), strong light-scattering capability (in the translucent state) and large solar energy modulation. This paper reviews various types of electricity-generating glazing technologies including BIPV glazing and BICPV glazing, as well as smart glazing technologies with a particular focus on TT hydrogel integrated glazing. The characteristics, benefits and limitations of hybrid BIPV smart glazing are also evaluated. Finally, the challenges and research opportunities in this emerging field are discussed.

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“…For example, the transparent and conductive hydrogel can be fabricated as a screen and a smart window incorporated with sensing function. [ 17–19 ]…”

Section: Introductionmentioning

confidence: 99%

Ion‐Conductive Hydrogel‐Based Stretchable, Self‐Healing, and Transparent NO₂ Sensor with High Sensitivity and Selectivity at Room Temperature

Rong

Yang

et al. 2021

Small

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Here stretchable, self‐healable, and transparent gas sensors based on salt‐infiltrated hydrogels for high‐performance NO2 sensing in both anaerobic environment and air at room temperature, are reported. The salt‐infiltrated hydrogel displays high sensitivity to NO2 (119.9%/ppm), short response and recovery time (29.8 and 41.0 s, respectively), good linearity, low theoretical limit of detection (LOD) of 86 ppt, high selectivity, stability, and conductivity. A new gas sensing mechanism based on redox reactions occurring at the electrode–hydrogel interface is proposed to understand the sensing behaviors. The gas sensing performance of hydrogel is greatly improved by incorporating calcium chloride (CaCl2) in the hydrogel via a facile salt‐infiltration strategy, leading to a higher sensitivity (2.32 times) and much lower LOD (0.06 times). Notably, both the gas sensing ability, conductivity, and mechanical deformability of hydrogels are readily self‐healable after cutting off and reconnection. Such large deformations as 100% strain do not deprive the gas sensing capability, but rather shorten the response and recovery time significantly. The CaCl2‐infiltrated hydrogel shows excellent selectivity of NO2, with good immunity to the interference gases. These results indicate that the salt‐infiltrated hydrogel has great potential for wearable electronics equipped with gas sensing capability in both anaerobic and aerobic environments.

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Dynamically adaptive window design with thermo-responsive hydrogel for energy efficiency

Cited by 42 publications

References 67 publications

Light‐Actuated Anisotropic Microactuators from CNT/Hydrogel Nanocomposites

Light‐Actuated Anisotropic Microactuators from CNT/Hydrogel Nanocomposites

A review of advanced architectural glazing technologies for solar energy conversion and intelligent daylighting control

Ion‐Conductive Hydrogel‐Based Stretchable, Self‐Healing, and Transparent NO₂ Sensor with High Sensitivity and Selectivity at Room Temperature

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Dynamically adaptive window design with thermo-responsive hydrogel for energy efficiency

Cited by 42 publications

References 67 publications

Light‐Actuated Anisotropic Microactuators from CNT/Hydrogel Nanocomposites

Light‐Actuated Anisotropic Microactuators from CNT/Hydrogel Nanocomposites

A review of advanced architectural glazing technologies for solar energy conversion and intelligent daylighting control

Ion‐Conductive Hydrogel‐Based Stretchable, Self‐Healing, and Transparent NO2 Sensor with High Sensitivity and Selectivity at Room Temperature

Contact Info

Product

Resources

About

Ion‐Conductive Hydrogel‐Based Stretchable, Self‐Healing, and Transparent NO₂ Sensor with High Sensitivity and Selectivity at Room Temperature