About one and a half million people die every year in the world due to a lack of clean water suitable for consumption. This is due to the fact that more than 80% of all water resources are spent on watering soils in the desert regions of our planet. Scientists from a company developing hydrophobic materials have invented a coating for sand to reduce its need for water and irrigation. African countries, as well as the Middle East, are most affected by the lack of fresh drinking water, which is why in the United Arab Emirates, however, with the support of German experts, hydrophobic sand was invented.
To understand its nature, it is necessary to study the definition of hydrophobicity.
What is hydrophobicity and what is its difference from hydrophilicity?
These two interrelated concepts apply to any substances and materials. They are responsible for how easily or not much they come in contact with water. On materials with a hydrophilic surface, a drop of water spreads completely and is absorbed. Such bodies include carbonates, silicates, sulfates, clays and silicate glasses. The hydrophobic surface repels a drop of water and prevents it from penetrating inside. This property is possessed by all metals, paraffins, fats, waxes and some types of plastics. Hydrophobicity is a low degree of hydrophilicity. In the textile industry, fabrics are hydrophilized to better dye, and their hydrophobization contributes to waterproofing.
How to suppress hydrophilic properties in sand?
Even without delving deeply into the physics of substances, it is clear that sand perfectly passes and absorbs water. But thanks to modern nanotechnology, scientists work wonders by changing the initial properties of materials. To get hydrophobic sand, they had to treat each grain of sand with a special solution, the secrets of which were not disclosed. Such sand retains its properties for 30 years. So far, these events are being held at the experimental level, but the company is ready to work in industrial volumes. It takes about 40 seconds to process one grain of sand, but manufacturers have the resources to release 3000 tons of hydrophobic sand daily.
How will sand reduce global water consumption?
Scientists propose using hydrophobic sand as a waterproof separation layer between the fertile soil in which plants are grown and all other soil strata. This layer will reduce the number of waterings per day from 5 times to one, because the water will not go to the depth, but will nourish the roots. Scientists even decided on a bold experiment to grow rice in arid areas, but there are no concrete results yet.
Sand with hydrophobic properties will find great application in construction during the construction of foundations, in particular in regions with high groundwater levels.
How to make hydrophobic sand yourself?
In order to put a handful of sand in the water, and then remove it from there dry, it is necessary to carry out preliminary processing, as a rule, with the help of organosilicon polymers. Most curious minds are haunted by the question: is it possible to make hydrophobic sand at home? Of course, it is possible, but not of such high quality and retaining its properties for a long time. There is one way that some people show the public as a trick. It is necessary to put clean sand in a red-hot oven, let it warm up and dry thoroughly there. Then get it and treat it with water-repellent sprays for clothes. You can purchase those at any sporting goods store. After these manipulations, it is possible to repeatedly place and remove sand from the tank with water completely dry.