Atmospheric-moisture-induced polyacrylate hydrogels for hybrid passive cooling

Area of Science:

• Materials Science
• Sustainable Energy
• Environmental Science

Background:

• Global warming intensifies heat stress, threatening human and social sustainability.
• There is a critical need for energy-efficient cooling solutions.
• Current cooling methods often rely on energy-intensive processes.

Purpose of the Study:

• To develop an efficient hybrid passive cooling material.
• To utilize low-cost, sustainable materials for cooling applications.
• To demonstrate a green manufacturing process for advanced cooling films.

Main Methods:

• Fabrication of a polyacrylate film using self-moisture-absorbing hygroscopic hydrogel.
• Characterization of the film's radiative properties: solar reflectance and mid-infrared emittance.
• Evaluation of the film's cooling performance under simulated sunlight conditions.
• Assessment of the manufacturing process's environmental impact and scalability.

Main Results:

• The polyacrylate film achieved high solar reflectance (0.93) and mid-infrared emittance (0.99).
• A surface temperature reduction of 5°C was observed under 800 W/m² solar illumination.
• The manufacturing process is entirely green, using only atmospheric moisture without additional chemicals or energy.
• The film offers both radiative and evaporative cooling, independent of sky conditions.

Conclusions:

• The developed hygroscopic hydrogel film provides an effective hybrid passive cooling solution.
• The material's low cost and green manufacturing process enable scalable production via roll-to-roll methods.
• This technology holds significant potential for reducing global carbon emissions and addressing future building and personal thermal management needs.