A team from the Hong Kong Polytechnic University has developed a structured aerogel made of carbon nanotubes and cellulose nanofibers capable of converting saltwater into drinkable water using only solar radiation.
The device, lightweight, scalable, and low-cost, aims to address one of the critical challenges of the 21st century: universal access to safe water in contexts of climate crisis and energy limitations.
Structure and Operation: Vertical Porosity and Constant Efficiency
Unlike softer hydrogels, the aerogel is manufactured in layers on a frozen surface, consolidating a matrix with vertical pores of 20 micrometers that run through the entire volume of the material. This geometry promotes efficient and uniform evaporation, even in larger pieces.
In real tests, the system was placed in a cup of seawater and covered with a transparent plastic dome. After six hours of solar exposure, it managed to evaporate and condense up to 45 milliliters of drinkable water, which was collected in an internal funnel.
Technical Advantages and Potential Applications
Among the most outstanding attributes:
- Passive process without the need for electricity
- Scalability without loss of performance
- Manufactured with abundant and recyclable materials
- Portability and adaptability to various geographical environments
The design functions as autonomous units that can be quickly installed in rural areas, arid regions, or coastal communities with limited energy infrastructure.
A Tangible Advance in the Face of the Water Crisis
In a scenario where freshwater scarcity is exacerbated by the effects of climate change and overexploitation, technologies like this allow:
- Decentralizing access to drinkable water
- Reducing carbon emissions associated with conventional desalination plants
- Minimizing environmental impacts by avoiding the use of chemicals or large infrastructures
Furthermore, being made of cellulose and carbon, its production has a low ecological impact, favoring its incorporation into water adaptation strategies for vulnerable populations.
