Gravity-induced asymmetric gradient PVA-based films with superior radiative cooling and flame retardancy for energy-saving building

IF 8.1 2区化学 Q1 POLYMER SCIENCE

Polymer Degradation and Stability Pub Date : 2026-04-01 Epub Date: 2026-01-28 DOI:10.1016/j.polymdegradstab.2026.111964

Lian Yin , Yuanyuan Zhang , Yizhi Liu , Sheng Zhang , Keqing Zhou

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引用次数: 0

Abstract

Polymer-based radiative cooling materials show great promise for green building and carbon neutrality by offering passive cooling. However, their effectiveness is limited by absorption of ambient heat radiation, and inherent flammability, which poses a serious challenge to meeting building safety regulations. Hence, this study modified TiO₂ surfaces using KH-550 and phytic acid to prepare silicon/phosphorus co-modified TiO₂ nanohybrids (KH-TiO₂-PA), which were incorporated into a polyvinyl alcohol (PVA) matrix. Through gravity-induced self-assembly, an asymmetrically gradient multifunctional composite film was formed, exhibiting effective radiative cooling, flame retardancy, and enhanced mechanical strength. Owing to its unique gravity-induced asymmetric gradient structure and the vibrational characteristics of C-C, Ti-O-Ti, Si-O-Si, P-O, and P=O bonds, the PVA/37.5%KH-TiO₂-PA composite film achieved a solar reflectivity of 84.7% and an infrared emissivity of 91.1%. Furthermore, the film demonstrated remarkable cooling performance, reducing temperature by up to 10.4°C in outdoor tests, with daytime and nighttime cooling power values of 61.1 W·m⁻² and 98.1 W·m⁻², respectively. According to EnergyPlus simulations, deploying the film on buildings significantly reduced energy consumption (up to 88.24% savings) and cut CO₂ emissions (up to 2.69 tons and $ 486.97 per year). Meanwhile, the incorporation of KH-TiO₂-PA facilitated gas-phase radical quenching and condensed-phase barrier effects, leading to a 40.5% reduction in peak heat release rate and a 58.6% suppression of peak CO₂ production, which substantially enhanced fire safety. Notley, when reinforced with the nanoparticles, the PVA/12.5%KH-TiO₂-PA composite achieved a tensile strength of 113.28 MPa and a Young’s modulus of 4.82 GPa, demonstrating 39.9% and 56.5% enhancements, respectively. This study offers a viable strategy for addressing climate challenges and supporting safe green building development, thereby promoting the application of multifunctional materials in energy-efficient buildings.

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节能建筑用重力致不对称梯度聚乙烯醇基辐射冷却阻燃膜

聚合物基辐射冷却材料通过提供被动冷却，在绿色建筑和碳中和方面显示出巨大的前景。然而，它们的有效性受到环境热辐射的吸收和固有的可燃性的限制，这对满足建筑安全法规提出了严重的挑战。因此，本研究利用KH-550和植酸对TiO2表面进行改性，制备了硅/磷共改性TiO2纳米杂化物（KH-TiO2-PA），并将其掺入聚乙烯醇（PVA）基体中。通过重力诱导的自组装，形成了一种不对称梯度的多功能复合膜，具有有效的辐射冷却、阻燃和增强的机械强度。由于其独特的重力诱导不对称梯度结构和C-C、Ti-O-Ti、Si-O-Si、P-O和P=O键的振动特性，PVA/37.5%KH-TiO2-PA复合膜的太阳反射率为84.7%，红外发射率为91.1%。此外，该薄膜表现出显著的冷却性能，在室外测试中降低温度高达10.4°C，白天和夜间冷却功率分别为61.1 W·m−2和98.1 W·m−2。根据EnergyPlus的模拟，在建筑物上部署该薄膜可显着降低能耗（节省高达88.24%）并减少二氧化碳排放（每年高达2.69吨和486.97美元）。同时，h - tio2 - pa的掺入促进了气相自由基猝灭和凝聚相势垒效应，峰值放热率降低40.5%，峰值CO2产量降低58.6%，大大提高了防火安全性。结果表明，PVA/12.5%KH-TiO2-PA复合材料的抗拉强度为113.28 MPa，杨氏模量为4.82 GPa，分别提高了39.9%和56.5%。本研究为应对气候挑战和支持安全绿色建筑发展提供了可行的策略，从而促进多功能材料在节能建筑中的应用。

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来源期刊

Polymer Degradation and Stability 化学-高分子科学

CiteScore

10.10

自引率

10.20%

发文量

325

审稿时长

23 days

期刊介绍： Polymer Degradation and Stability deals with the degradation reactions and their control which are a major preoccupation of practitioners of the many and diverse aspects of modern polymer technology. Deteriorative reactions occur during processing, when polymers are subjected to heat, oxygen and mechanical stress, and during the useful life of the materials when oxygen and sunlight are the most important degradative agencies. In more specialised applications, degradation may be induced by high energy radiation, ozone, atmospheric pollutants, mechanical stress, biological action, hydrolysis and many other influences. The mechanisms of these reactions and stabilisation processes must be understood if the technology and application of polymers are to continue to advance. The reporting of investigations of this kind is therefore a major function of this journal. However there are also new developments in polymer technology in which degradation processes find positive applications. For example, photodegradable plastics are now available, the recycling of polymeric products will become increasingly important, degradation and combustion studies are involved in the definition of the fire hazards which are associated with polymeric materials and the microelectronics industry is vitally dependent upon polymer degradation in the manufacture of its circuitry. Polymer properties may also be improved by processes like curing and grafting, the chemistry of which can be closely related to that which causes physical deterioration in other circumstances.