Aerogel‐Functionalized Thermoplastic Polyurethane as Waterproof, Breathable Freestanding Films and Coatings for Passive Daytime Radiative Cooling

Advanced Science, Год журнала: 2022, Номер 9(20)

Опубликована: Апрель 27, 2022

Passive daytime radiative cooling (PDRC) is an emerging sustainable technology that can spontaneously radiate heat to outer space through atmospheric transparency window achieve self-cooling. PDRC has attracted considerable attention and shows great potential for personal thermal management (PTM). However, polymers are limited polyethylene, polyvinylidene fluoride, their derivatives. In this study, a series of polymer films based on thermoplastic polyurethane (TPU) composite with silica aerogels (aerogel-functionalized TPU (AFTPU)) prepared using simple scalable non-solvent-phase-separation strategy. The AFTPU freestanding, mechanically strong, show high solar reflection up 94%, emit strongly in the window, thereby achieving subambient 10.0 7.7 °C hot summer day film (10 wt%), respectively. be used as waterproof moisture permeable coatings traditional textiles, such cotton, polyester, nylon, highest temperature drop 17.6 achieved respect pristine nylon fabric, which both performance properties highly desirable PTM applications. This study opens promising route designing common efficient PDRC.

Язык: Английский

---

Recent Advances in Thermoregulatory Clothing: Materials, Mechanisms, and Perspectives

ACS Nano, Год журнала: 2023, Номер 17(3), С. 1803 - 1830

Опубликована: Фев. 2, 2023

Personal thermal management (PTM) is a promising approach for maintaining the comfort zone of human body while minimizing energy consumption indoor buildings. Recent studies have reported development numerous advanced textiles that enable PTM systems to regulate temperature and are comfortable wear. Herein, recent advancements in thermoregulatory clothing discussed. These advances focused on enhancing control heat dissipation between skin localized environment. We primarily summarize research controls pathways body, such as radiation- conductance-controlled clothing. Furthermore, adaptive dual-mode textiles, which can microclimate well responsive address both performance (warming and/or cooling) wearability Finally, we include discussion significant challenges perspectives this field, including large-scale production, smart bioinspired clothing, AI-assisted This comprehensive review aims further sustainably manufactured with superior outstanding practical applications.

Язык: Английский

---

Micro‐Nano Porous Structure for Efficient Daytime Radiative Sky Cooling

Advanced Functional Materials, Год журнала: 2022, Номер 32(44)

Опубликована: Авг. 19, 2022

Abstract With the aggravation of global warming and extreme weather, cooling demand has witnessed a continuous increase is expected to tenfold by 2050. Radiative sky (RSC) without any pollution energy consumption drawn worldwide attention in past few years. Large‐scale scalable porous materials have greatly advanced progress this technology. Herein, critical review on with goal advancing their commercial applications presented. The detailed design principles daytime radiative are first discussed clarify factors structures for great performance. What follows discussions from pore‐forming methods. Subsequently, recent promising particle‐embedding structures, mainly including white colorful coolers various applications, outlined. Additionally, some special highlighted further broaden RSC Last but not least, remaining open challenges insights presented advance commercialization progress.

Язык: Английский

---

A Trimode Thermoregulatory Flexible Fibrous Membrane Designed with Hierarchical Core–Sheath Fiber Structure for Wearable Personal Thermal Management

ACS Nano, Год журнала: 2022, Номер 16(8), С. 12801 - 12812

Опубликована: Авг. 10, 2022

Advanced textiles designed for personal thermal management contribute to thermoregulation in an individual and energy-saving manner. Textiles incorporated with phase changing materials (PCMs) are capable of bridging the supply demand energy by absorbing releasing latent heat. The integration solar heating Joule function supplies multidriving resources, facilitates charging storage, expands service time application scenarios. Herein, we report a fibrous membrane-based textile that was developed designing hierarchical core–sheath fiber structure trimode management. Especially, coaxial electrospinning allows effective encapsulation PCMs, high heat enthalpy density (106.9 J/g), enabling membrane buffer drastic temperature changes clothing microclimate. favorable photothermal conversion performance renders saturated 70.5 °C (1 sun), benefiting from synergistic effect multiple light harvesters. Moreover, conductive coating endows composite admirable electrothermal performance, reaching 73.8 (4.2 V). flexible membranes integrated reversible change, multi-source-driven heating, storage present great advantages all-day, energy-saving, wearable applications.

Язык: Английский

---

Hyperelastic Kevlar Nanofiber Aerogels as Robust Thermal Switches for Smart Thermal Management

Advanced Materials, Год журнала: 2022, Номер 35(3)

Опубликована: Окт. 22, 2022

Aerogels, the lightest artificial solid materials characterized by low density and thermal conductivity, high porosity, large specific surface area, have attracted increasing interest. Aerogels exhibit single-mode insulation properties regardless of surrounding temperature. In this study, hyperelastic Kevlar nanofiber aerogels (HEKAs) are designed fabricated a slow-proton-release-modulating gelation thermoinduced crosslinking strategy. The method does not use agents endows ultralow-density (4.7 mg cm-3 ) HEKAs with conductivity (0.029 W m-1 K-1 ), porosity (99.75%), stability (550 °C), increased compression resilience (80%) fatigue resistance. Proofs concept acting as on-off switches demonstrated through experiments simulations. rapid response speed 0.73 °C s-1 , heat flux 2044 J m-2 switching ratio 7.5. Heat dissipation can be reversibly switched on/off more than fifty times owing to hyperelasticity resistance HEKAs. This study suggests route fulfill highly porous tailor on-demand.

Язык: Английский

---

Ultraflexible, cost-effective and scalable polymer-based phase change composites via chemical cross-linking for wearable thermal management

Nature Communications, Год журнала: 2023, Номер 14(1)

Опубликована: Дек. 5, 2023

Phase change materials (PCMs) offer great potential for realizing zero-energy thermal management due to superior storage and stable phase-change temperatures. However, liquid leakage solid rigidity of PCMs are long-standing challenges PCM-based wearable regulation. Here, we report a facile cost-effective chemical cross-linking strategy develop ultraflexible polymer-based phase composites with dual 3D crosslinked network olefin block copolymers (OBC) styrene-ethylene-butylene-styrene (SEBS) in paraffin wax (PW). The C-C bond-enhanced OBC-SEBS networks synergistically improve the mechanical, thermal, leakage-proof properties PW@OBC-SEBS. Notably, proposed peroxide-initiated method overcomes limitations conventional physical blending methods thus can be applicable across diverse polymer matrices. We further demonstrate portable flexible PW@OBC-SEBS module that maintains comfortable temperature range 39-42 °C personal thermotherapy. Our work provides promising route fabricate scalable composite management.

Язык: Английский

---

A Hierarchically Nanofibrous Self-Cleaning Textile for Efficient Personal Thermal Management in Severe Hot and Cold Environments

ACS Nano, Год журнала: 2023, Номер 17(18), С. 18308 - 18317

Опубликована: Сен. 13, 2023

Climate change has recently caused more and severe temperatures, inducing a growing demand for personal thermal management at outdoors. However, designing textiles that can achieve thermoregulation without energy consumption in severely hot cold environments remains huge challenge. Herein, hierarchically nanofibrous (HNF) textile with improved insulation radiative functions is fabricated efficient temperatures. The consists of cooling layer, an intermediate heating wherein the porous lignocellulose aerogel membrane (LCAM) as layer low conductivity (0.0366 W·m-1·K-1), ensuring less heat loss weather blocking external weather. introduction polydimethylsiloxane (PDMS) increases emissivity (90.4%) atmospheric window also endows it perfect self-cleaning performance. Solar absorptivity (80.1%) dramatically increased by adding only 0.05 wt% carbon nanotubes (CNTs) into polyacrylonitrile. An outdoor test demonstrates HNF temperature drop 7.2 °C compared white cotton environment be high 12.2 warmer than black environment. In addition, possesses excellent moisture permeability, breathability, directional perspiration performances, making promising environments.

Язык: Английский

---

Nature‐Inspired Solar‐Thermal Gradient Reduced Graphene Oxide Aerogel‐based Bilayer Phase Change Composites for Self‐Adaptive Personal Thermal Management

Advanced Functional Materials, Год журнала: 2023, Номер 33(15)

Опубликована: Янв. 24, 2023

Abstract Although personal thermal management (PTM) materials for daily routine environments are widely investigated, the exploration of multifunctional PTM with excellent feasibility in complex and outdoor scenarios is still its infancy. Herein, inspired by temperature regulation effect atmosphere, a novel design fabricating solar‐thermal gradient reduced graphene oxide (RGO) aerogel‐based bilayer phase change composite (GRGC) featuring “energy regulation” inverse compensation” proposed self‐adaptive applications. By integrating energy conversion ability RGO, heat aerogel/octadecane structure unique RGO framework inside, latent‐heat compensation octadecane, GRGC can serve as an efficient device to mitigate drastic changes human skin harsh environments. This not only keep warm surface microclimate frigid environment −5 °C via synergistic conversion, aerogel insulation, phase‐change latent release, but also provide buffering prevent hyperthermia hot through behavior insulation. opens new avenue devices applications

Язык: Английский

---

Optical Design of Silica Aerogels for On‐Demand Thermal Management

Advanced Functional Materials, Год журнала: 2023, Номер 33(32)

Опубликована: Май 4, 2023

Abstract Silica aerogels, a type of porous material featuring extra low density and thermal conductivity, have drawn increasing interest from both academia industry owing to their excellent insulation performance. However, is always the single consideration when silica aerogels are used for management. In this study, on‐demand management (ODTM) aerogel with either passive insulation, heating, or cooling in different environments revealed. The ODTM behavior can be simply fulfilled through optical property variations such as solar light transparency infrared emissivity, which controllable via microstructures building blocks surface composition design. Robust heating 25 °C higher than ambient daytime sub‐ambient 7 at night achieved traditional transparent aerogel. Interestingly, 5 warmer state on cold nights by modifying its transmittance emissivity. This study guides comprehensive understanding leads applications tailoring conductivity properties.

Язык: Английский

---

Robust and Flame‐Retardant Zylon Aerogel Fibers for Wearable Thermal Insulation and Sensing in Harsh Environment

Advanced Materials, Год журнала: 2023, Номер 36(6)

Опубликована: Ноя. 29, 2023

Abstract The exceptional lightweight, highly porous, and insulating properties of aerogel fibers make them ideal for thermal insulation. However, current face limitations due to their low resistance harsh environments a lack intelligent responses. Herein, universal strategy creating polymer using crosslinked nanofiber building blocks is proposed. This approach combines controlled proton absorption gelation spinning with heat‐induced crosslinking process. As proof‐of‐concept, Zylon that exhibited robust stability (up 650 °C), high flame retardancy (limiting oxygen index 54.2%), extreme chemical are designed synthesized. These possess porosity (98.6%), breaking strength (8.6 MPa), conductivity (0.036 W m −1 K ). can be knotted or woven into textiles, utilized in (−196–400 demonstrate sensitive self‐powered sensing capabilities. method developing expands the applications high‐performance holds great potential future wearable smart protective fabrics.

Язык: Английский

---