Special materials contribute greatly to the development of new materials for seawater desalination

2024-02-29

Water is the source of life, and 71% of the Earth's surface is covered by water. However, this does not mean that humans do not lack water. In fact, the freshwater resources available for direct use by people are very limited, accounting for only about 2.53% of the total water on Earth. For this reason, there are two directions of research on the utilization of water resources: how to effectively utilize limited freshwater resources and ensure their sustainable development; How to convert resource rich seawater or saline water resources into usable freshwater resources.

Regarding the sustainable development of freshwater resources, the knowledge involved is not as complex as imagined, and most of it revolves around water resource protection. And regarding seawater desalination, it is a very profound knowledge.

Recently, Monash University in Australia released a new research result, which mentioned that researchers and colleagues at the university have collaborated to develop a new type of saline water desalination technology. This technology relies on a special metal organic framework material containing poly (spiropyran acrylate) added to pores, which can quickly convert seawater into drinking water. After being exposed to sunlight, this material can quickly release adsorbed salt particles and other particles, To achieve the purpose of reuse.

Obviously, this technology provides a good direction for subsequent desalination of saltwater, but it is not the first time that humans have solved the problem of seawater desalination through scientific research technology. In fact, the history of seawater desalination can be traced back to the 16th century, and there are many technologies involved in its development today. Some technologies are even very familiar to everyone, such as distillation.

Distillation, as one of the many experimental operations, is something that many students have been exposed to since middle school. However, the application of distillation in the field of seawater desalination is no different from what everyone knows in terms of principle. By utilizing the different boiling points of different substances, saltwater is heated to the boiling point of water (which may vary in boiling temperature due to different air pressures). At this point, the water in the saltwater will vaporize into steam and rise. At this point, the water vapor is introduced into the condenser tube, and they will condense again into small water droplets. Collecting these water droplets can obtain distilled water that is basically free of impurities, and distilled water itself is a type of fresh water.

However, distillation has also made many developments in the field of seawater desalination, such as the emergence and addition of steam compression technology, as well as the optimization design of equipment, and so on. But no matter how it develops, the distillation method still faces a problem, which is cost. Distillation purification requires too much manpower, resources, and time for seawater desalination. Although the resulting fresh water can be directly used, its cost-effectiveness is too low. More intuitively, distillation is unable to undertake large-scale seawater desalination work with current technology.

At this time, the development of materials science provided a new approach for seawater desalination - the emergence of reverse osmosis membranes made large-scale seawater desalination possible.

On the one hand, reverse osmosis has an efficient desalination rate at high flow rates and can function at lower operating pressures; On the other hand, its manufacturing cost is relatively low, and it is not easily affected by temperature and pH, is not easy to corrode, and has a strong mechanical lifespan. Objectively speaking, reverse osmosis technology did provide a new idea for seawater desalination at that time, and its appropriate combination with distillation method also had good results in desalination effect. On the other hand, in terms of equipment processing, the reverse osmosis membrane method is very cumbersome. And this special material has solved both the limitations of the equipment and the efficiency and difficulty of dilution, undoubtedly marking another breakthrough in materials science.

Although it is currently unclear whether this material can become a barometer on the path of seawater desalination, it at least proves that the development of new materials has extraordinary significance for seawater desalination.

Reference sources for this article: Science and Technology Daily, Baidu Baike, Baidu Academic

A New Surface Acoustic Wave Temperature Sensor Device Designed by the Institute of Acoustics