Polymer hydrogels. Part two

This must be taken into account, since with low mechanical strength, it is more likely that the soil will "squeeze out" the water contained in the hydrogel. Polyoxyethylene is also suitable for water accumulation. It is elastic, it can be introduced into the soil with fertilizers. Polyacrylonitrile can be used for the same purposes. When injected into the soil, the hydrogel particles adhere to the soil particles, structuring it. It is important to know how the presence of certain salts, acids and bases in the soil affects the swelling of hydrogels. This will allow the selection of hydrogels for different soils. Before hydrogels find mass application in practice, it is still necessary to solve a number of issues of their synthesis, as well as carefully study their properties: reactions to external pressure, to soil composition, mechanical properties, kinetics of swelling and evaporation from hydrogels, etc. The deeper the hydrogel is, i.e. the greater the soil layer pressing on it the less it absorbs moisture, and therefore, at the same time, the effectiveness of its use decreases.


For example, many hydrogels can easily swell in water, increasing their volume up to 1000 times, however, if they are introduced into the soil, they do not swell at all, since they cannot overcome the mass of soil above the hydrogel during swelling. Water from the pores is especially easily absorbed by the plant, and this must be borne in mind when "creating" hydrogels. In the presence of electrolytes, swelling is usually better, but the conversion of hydrogels to acidic form makes them unable to bind water. For acidic soils, the issue of using hydrogels requires a special solution. It is also undesirable for gels to have a number of ions in the soil, for example, cobalt or aluminum ions, which "cross-link" hydrogels, reducing their degree of swelling. A few years ago, a program for testing hydrogels based on crosslinked polyoxymethylene was completed in the United States. It has been shown that in the presence of 0.25% polymer in the soil (by weight) the plant is provided with water for 10 days. These tests took place in the United States, Mexico, North Africa and Saudi Arabia. Such hydrogels can also be used to fix soils (i.e., prevent soil erosion), accumulate solar energy (so-called solar pools), and wherever "still" water is needed. It is unlikely that such a method of preserving water in the soil will be widely used in agriculture, since the polymers used for this purpose are not too cheap. However, recently the British company Chemical Discoveries created the polymer "agrosouk" based on polycaproamide for mass use. Agrosouk absorbs water in an amount 40-50 times its own weight, and then, in a drought, the roots of plants "pump out" almost all the water from it. It is a reusable polymer and is suitable for long-term use. His comprehensive inspection in the fields of Egypt lasted six months and ended in complete success. Le code promo 1xbet est votre sésame pour un bonus de bienvenue impressionnant. Activez-le et obtenez un bonus de 100% sur votre premier dépôt, pour un maximum de 15000 XOF. Ce boost financier vous permet de parier sur vos sports favoris comme le football ou le basketball, ou de découvrir les tournois de poker et les jeux en direct sans pression. Profitez de cette offre pour tester des stratégies et augmenter votre bankroll initiale.