A Phase‐Changing Polymer Film for Broadband Smart Window Applications

Xie, Yongchun; Guan, Fangyi; Li, Zhou; Meng, Yuan; Cheng, Jiang; Li, Lü; Pei, Qibing

doi:10.1002/marc.202000290

Cited by 14 publications

(19 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[149] We added a poly(ethylene oxide) oligomer to crosslink with poly(SA), leading to microsized surface patterns in the resulting s-SVP and an increase of opacity at ambient temperature (Figure 10b). [138] The refractive indices of the crystalline poly(SA) domain and the polyethylene oxide domain are mismatched. When the poly(SA) domain melts, its amorphous state matches the polyethylene oxide domain in the refractive index.…”

Section: Materials and Applications For Optical Modulationmentioning

confidence: 99%

See 1 more Smart Citation

Stiffness Variable Polymers Comprising Phase‐Changing Side‐Chains: Material Syntheses and Application Explorations

et al. 2022

Self Cite

View full text Add to dashboard Cite

lack the adaptability biological muscles have for variable working environments. Emerging opportunities in airborne and submarine vehicles, agricultural manipulations, biomedical devices, and wearable electronics require materials with variable rigidity to respond to dynamically changing conditions. [3][4][5][6] The mechanical impedance of such materials can be altered or fine-tuned to allow the system to adapt without a sophisticated control algorithm. For example, when grasping a fragile object such as an egg using a gripper, a stiffness variable material provides an adaptive contact force to optimally complete the task. Similarly, bio-inspired robots and wearable exoskeletons require stiffness variable materials capable of a large stiffness change to provide structural load-bearing and mechanical work output. In the softened state, the material can deform to locomote, maneuver, and absorb the energy arising from a collision or when interfacing with the human body. Some applications, such as medical endoscope designs, involve "move-and-hold" operations. This is where a variable-stiffness structure that holds a particular orientation in space or rigidly supports a load is able to become deformable on demand to change shape or reposition. [7] Other potential applications that can benefit from variable stiffness materials include biomechanically compatible sensor insertions for neural implants, vibration, and noise control in aerospace structures, and conformal shape morphing robotic systems. Requirements of Stiffness Variable MaterialsTo impart the perceived smart and adaptive systems with versatile and advantageous functionalities matching or surpassing those of natural systems, the stiffness variable materials should possess the following important features:1. Wide modulus variation: A range of modulus variation greater than 100 or even 1000-fold is required. A high modulus is desired for load-bearing and supporting freestanding structures, while a low modulus provides conformation, shape transformation, energy absorption, and dissipation. 2. Mild stimulus: A mild stimulus to trigger the stiffness variable operation, such as a narrow temperature span in Stiffness variable materials have been applied in a variety of engineering fields that require adaptation, automatic modulation, and morphing because of their unique property to switch between a rigid, load-bearing state and a soft, compliant state. Stiffness variable polymers comprising phase-changing side-chains (s-SVPs) have densely grafted, highly crystallizable long alkyl sidechains in a crosslinked network. Such a bottlebrush network-like structure gives rise to rigidity modulation as a result of the reversible crystallization and melting of the side chains. The corresponding modulus changes can be more than 1000-fold within a narrow temperature span, from ≈10 2 MPa to ≈10 2 kPa or lower. Other important properties of the s-SVP, such as stretchability, optical transmittance, and adhesion, can also be altered. This work reviews the underlying molecular mech...

show abstract

Section: Materials and Applications For Optical Modulationmentioning

confidence: 99%

“…b) A polymer film of the poly(stearyl acrylate) crosslinked with a poly(ethylene oxide) oligomer is synthesized, which demonstrates tunable opacity to regulate solar irradiation and privacy protection. Reproduced with permission [138]. Copyright 2020, Wiley-VCH.…”

mentioning

confidence: 99%

Stiffness Variable Polymers Comprising Phase‐Changing Side‐Chains: Material Syntheses and Application Explorations

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…PCP and its copolymers have been investigated in drug release, actuator, and thermal energy storage . We recently introduced a thermoresponsive solid-state phase-changing polymer film for smart windows . This system has the benefits of promising transmittance modulation and cycle stability; however, its regulation law is contrary to the common smart window regulation as it is opaque at room temperature and transparent at elevated temperatures.…”

Section: Introductionmentioning

confidence: 99%

Automatically Modulated Thermoresponsive Film Based on a Phase-Changing Copolymer

et al. 2021

Self Cite

View full text Add to dashboard Cite

Thermoresponsive materials, in particular those exhibiting switchable optical transmittance via temperature change, have been widely used in different applications. If the required temperature change is within seasonal temperature changes, the transmittance change would consume low energy or be autonomous. Here, a solid-state thermoresponsive phase-changing copolymer (TPCC) film has been demonstrated, with a large transmittance modulation between room and hot temperatures (>28 °C). The polymer film comprises a hydrophilic poly(hydroxyethyl acrylate) (HEA) cross-linked with a hydrophobic phase-changing poly(hexadecyl acrylate-co-tetradecyl acrylate) (HDA-TA). The TPCC was designed such that the HEA and HDA-TA moieties produce micrometer-scale phase separation, the HDA-TA moiety undergoes reversible crystalline-to-amorphous transition at 28–32 °C, and the refractive indices of the hydrophilic and hydrophobic phases are matched at ambient temperature but are mismatched when the temperature is above the transition. The TPCC film showed high modulations of transmittance in the visible (390–780 nm), solar (300–2500 nm), and infrared (780–2500 nm) spectrum of 68.8, 62.7, and 55.8%, respectively. The opacity switching was reversible without any decay after 1000 heating–cooling cycles. The TPCC film was investigated for autonomous and climate-adaptable solar modulation window application.

show abstract

“…Dynamically regulating solar light illumination according to ambient temperatures by using the transparency or color switchable property of chromogenic materials is considered to be one of the promising technologies to reduce energy consumption as well as environment pollution. − Typically, thermochromic materials that can show optical switching property by external temperature stimuli have been widely studied to realize tunable modulation of solar light. − Among various thermochromic materials, thermoresponsive polymers with lower critical solution temperature (LCST) have attracted increasing attention due to their good availability and easiness of producing various geometries. ,− Such polymers are completely hydrated and transparent below LCST, but show phase separation above LCST due to hydrophobic interactions between polymer chains thus become opaque . However, the LCST of thermoresponsive polymers are generally higher than the environmental temperature and can not switch their transparency or color in response to ambient temperature stimuli.…”

Section: Introductionmentioning

confidence: 99%

“…So far, much effort has been made to lower the LCST. An attractive way is to design the composition and chain structure of polymers, ,, another one is to introduce thermal collector materials into polymer matrix, ,, such as plasmonic nanoparticles and graphene oxide . Nevertheless, the former will complicate the preparation process and might bring side effects.…”

Section: Introductionmentioning

confidence: 99%

Hydroxypropylmethyl Cellulose Modified with Carbon Dots Exhibits Light-Responsive and Reversible Optical Switching

Chang

Shen

Guo

et al. 2021

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

A light-responsive optical switching material is reported, which was obtained by incorporating carbon dots (CDs) into thermochromic hydroxypropylmethyl cellulose (HPMC). The ultrasmall size of CDs guarantees the considerable transparency of CDs/HPMC. Under illumination, CDs/HPMC shows rapid and reversible optical switching between transparent and opaque states due to the remarkable photothermal effect of CDs. Moreover, the interaction between CDs and HPMC enhances the light absorption and boosts the nonradiative recombination of photoexcited charge carriers that further promote the photothermal conversion of CDs, and also ensures the structural stability of the composite. The obtained CDs/HPMC with good reversibility and high sensitivity which can dynamically switch their transparency in response to weather conditions exhibits excellent solar modulation ability.

show abstract

A Phase‐Changing Polymer Film for Broadband Smart Window Applications

Cited by 14 publications

References 43 publications

Stiffness Variable Polymers Comprising Phase‐Changing Side‐Chains: Material Syntheses and Application Explorations

Stiffness Variable Polymers Comprising Phase‐Changing Side‐Chains: Material Syntheses and Application Explorations

Automatically Modulated Thermoresponsive Film Based on a Phase-Changing Copolymer

Hydroxypropylmethyl Cellulose Modified with Carbon Dots Exhibits Light-Responsive and Reversible Optical Switching

Contact Info

Product

Resources

About