Cavitation dispersion of carbon nanotubes and modification of cement systems

Abstract

The most common research areas in construction material science deals with the development of new efficient methods to increase strength properties of materials. One of such methods is modification of composite matrices with carbon nanotubes. The characteristics of nanomodified concretes to a great extent depend on selected method of introduction of carbon nanotubes into material. The predispersion of CNT in mixing water with plasticizing additive through ultrasound impact on the environment with colloid and other types of particles including nanoparticles is the most frequently used scientific method which provides even distribution of nanoparticles in cement. In some works the separation of agglomerated CNT in suspension was conducted by means of ultrasound treatment. The further analysis showed that the main drawbacks of ultrasound dispersion are high energy output and low performance. That causes inconvenience for application of them in manufacturing process. The methods of cavitation dispersion which were developed in the late 90ies in the XXI century today are becoming commonly used in practice. The work presents the results of dispersion of multi-layer nanotubes performed on the hydrodynamic cavitation equipment. It was determined that the use of such equipment makes it possible to produce stable and even carbon dispersions and to introduce and distribute them uniformly in concrete in the same way as in the case when ultrasound treatment is performed. The advantages of this technology are considerable decrease of energy consumption and possibility to treat enormous amounts of liquids which are necessary for modification of concrete in real production process.